- 19 hours ago
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How have we gotten in wrong with rear-suspension designs? In so many ways! Kevin and Mark take a tour through rear suspension systems that didn't work and never beat the simplicity of the conventional swingarm, plus they get into all kinds of other elements of the chassis.
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How have we gotten in wrong with rear-suspension designs? In so many ways! Kevin and Mark take a tour through rear suspension systems that didn't work and never beat the simplicity of the conventional swingarm, plus they get into all kinds of other elements of the chassis.
Find us on Patreon! https://www.patreon.com/cw/CycleWorldPodcast
Become a Channel Partner: https://octanemedia.co/home/become-an-advertiser/
Listen on Spotify: https://open.spotify.com/show/6CLI74xvMBFLDOC1tQaCOQ
Read more from Cycle World: https://www.cycleworld.com/
Buy Cycle World Merch: https://teespring.com/stores/cycleworld
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SportsTranscript
00:00:00Hello, everyone, and welcome back to the Cycle World podcast. I'm Mark Hoyer. I'm with Kevin Cameron. If you've never
00:00:04joined us, thanks for joining us. If you have joined us, like I said, welcome back.
00:00:13So we recently did a podcast about rear suspension, principally the swing arm. Had a few little chit chats in
00:00:20there, but we're going to talk about failures of rear suspension, things that we possibly pondered and looked at the
00:00:28sky and thought,
00:00:28what if the wheelbase never changed? What if? What if? What if? Constant steering geometry. Imagine perfection.
00:00:43Exactly. Imagine perfection and then imagine getting into the dyno cell and putting a connecting rod in the roof, for
00:00:51example.
00:00:52Yes.
00:00:54But yeah, we're going to talk about suspension, the failures of different types of rear suspensions and all the implications
00:01:01of what we're working on motorcycles here.
00:01:05Very quickly, if you haven't found us on Patreon, go find us on Patreon.
00:01:09You can get every episode that we've ever done commercial free, plus extra content that Kevin and I are working
00:01:15on every week and posting every week on Patreon.
00:01:17Stuff that's exclusive to subscribers. It's five bucks, you know, not too bad.
00:01:24And, you know, YouTube's great too. Join us here if you want. Just know you're paying YouTube a lot more
00:01:28than you're paying us.
00:01:30Oh no, did I say that?
00:01:33Anyway, thanks for joining us. Let's get right into rear suspension, Kevin.
00:01:37Okay. Front suspension came first because if you hit a bump and it's tall enough, it acts as it tries
00:01:54to wrestle the steering out of your hands.
00:01:56Well, I think there's more natural padding on the other end, too, compared to your hands.
00:02:01Well, that's true. Yes, that's true. Except for my maternal grandmother.
00:02:08But front end needed suspension because otherwise bad things happened right away.
00:02:17So people learned to ride with front suspension only, so-called rigid frame.
00:02:24But there were efforts made to add suspension to the rear, most notably Indian in 1912, who made an effort
00:02:35in that direction, was an option, wasn't a popular one.
00:02:40And there were a number of attempted swingarm revolutions which failed because, well, I should say, giving rise to the
00:02:53wisdom of the ages, which was nothing steers like a rigid.
00:02:57Now, the reason for that is a rigid allows the rider a monopoly of control.
00:03:06You turn the bars, causes the machine to flop over right or left at your choice.
00:03:14So, but if you have a swingarm bike with a weak swingarm, then there's a second opinion on steering.
00:03:25Is the throttle pulling, causing the chain to pull strongly on the swingarm?
00:03:32Are you hitting bumps?
00:03:34Is the frame flexing?
00:03:35So, what was the good compromise in that period from the creation to 1935 was the large section tire.
00:03:51That was rear suspension, in effect.
00:03:54The same revolution had occurred in automobile tires.
00:03:58They had learned the comfort-producing qualities of not blowing the tires up to 100 PSI.
00:04:07And they began to build thinner-walled, larger section tires operating at lower inflation pressure.
00:04:15I'm a big fan of bringing back the more sidewall.
00:04:19We need tall tires.
00:04:20None of this 30-series, 20-40-series, low-profile, oh, man, sidewall.
00:04:27That's where it's at.
00:04:28Yeah, well, near the end of Goodyear's participation in road racing in 1984, and right at the end of the
00:04:40two-stroke era,
00:04:42there was created, and Dunlop did it too, tall sidewall tires.
00:04:48Because it was believed that if you added some lateral flexibility, that the motorcycle would be more stable.
00:04:58There would be an opportunity for the flexing rubber to provide damping force.
00:05:03But that diverts us from our subject, which is rear suspension.
00:05:08Then came 1935, and two big things happened.
00:05:15One, Phil Vincent, in 1929, had bought the name and a few bags of frame lugs from Howard Davies,
00:05:31who had made his own motorcycle and won the TT on it.
00:05:36He won the TT on a bike he'd built himself.
00:05:39So Phil Vincent buys it.
00:05:41Phil Vincent, as a schoolboy, was drawing pictures of motorcycle frames.
00:05:46And what he built was a rear suspension that was triangulated, so that the two beams of the suspension were
00:05:58more resistant to this motion,
00:05:59which would cause the rear tire to tilt from side to side.
00:06:06One of those bikes finished 7th in the 1935 TT.
00:06:10And remember, Vincent was never really a factory.
00:06:14It was more like two creative guys with a lot of helpers.
00:06:21And the other creative guy, of course, was Phil Irving.
00:06:26So here's this bike in 7th with nothing but factory Nortons and a couple of factory NSUs, which were just
00:06:33German Nortons, some would say, ahead of it.
00:06:39Distinguished finish.
00:06:43Well, aside from the first place, which was Stanley Woods on the factory 120-degree V-twin Moto Guzzi with
00:06:58a triangulated swing arm.
00:07:02And this was a shock because nothing steers like a rigid.
00:07:06People don't like to find that, you know, thou shalt not kill.
00:07:11Well, actually, it's okay if the right people tell you to.
00:07:14You know what I mean?
00:07:17People like to nail down these home truths.
00:07:25So no less an authority on everything motorcycle-wise than Joe Craig, Norton's long-serving racing manager.
00:07:36In a 1942 magazine article, he proclaimed that Stanley Woods could not have achieved his stunning last lap in the
00:07:461935 TT on a rigid frame.
00:07:49Suddenly, everybody's got to have rear suspension.
00:07:52Rear suspension is hot.
00:07:53It won the TT.
00:07:56Well, how can we do this on the cheap?
00:07:58How can we, you know, like make it look like rear suspension or something like that?
00:08:04And this gave birth to things like sliding pillar.
00:08:10Here comes the two members, triangulated members of the rear suspension, the hard tail, down to the axle holders.
00:08:24And instead of just putting the wheel into the axle holders, you make room, weld on some brackets, and put
00:08:32the sliding pillars there and attach the rear axle to them.
00:08:36Presto, suspension.
00:08:38Not much of it.
00:08:39It's there.
00:08:40And I got to say, my experience with those types of frames is, you know, it's possibly more comfortable, but
00:08:46perhaps also more unsettling.
00:08:49Yeah, yeah.
00:08:52Well, of course, one of the things is I noticed that detective dramas on television tend to be better put
00:09:03together because so many people are working on them.
00:09:06And then along comes a family comedy and it's, I think I'll go get a sandwich.
00:09:13So the fact that large numbers of people were working on these concepts eventually made them workable.
00:09:24There was a thing in 1919 called Coulson B.
00:09:29Coulson B, instead of attaching stick-slip-prone sliding pillars, had little dinky vestigial swing arms at the ends of
00:09:43the hard tail.
00:09:44And the axle, I think, was supposed to somehow prevent this whole thing from flopping to side to side.
00:09:51Footnote to history, Coulson B.
00:09:55It went nowhere.
00:10:02So this was pretty much the state of affairs from 1935 onward, although Velocet enthusiastically adopted rear suspension in the
00:10:13form of three pieces of pipe, not welded together, but mechanically fastened.
00:10:18Make those joints good and tight, and you might have less of this.
00:10:27Never having ridden a Velocet, I will have to defer to Mark, who has not only ridden them, but to
00:10:34an extreme.
00:10:36Well, the ridges were, I had a 37 KSS with a girder fork, and it was a pleasure to ride
00:10:43on a winding road.
00:10:44And you can see, it was, for me, it was the education that took me from, I'd already owned the
00:10:48KSS, or the MSS, which is the pushrod 500 single.
00:10:53It was the first swinging arm 500.
00:10:55I had the 19th bike off the line, in fact, for swinging arm bikes.
00:11:01And it's a pretty good handling bike.
00:11:04Of the early 50s, mid-50s British bikes that I've ridden, much better than a sprung hub that Triumph was
00:11:12doing.
00:11:12We'll get to that.
00:11:13That's quite a contraption.
00:11:16But, um, Velocet swinging arm was pretty good, and as Kevin was talking about earlier, getting some of the action,
00:11:23you know, not rigidly connecting the steering head to the axle.
00:11:30Nothing steers like a rigid.
00:11:31They're connected, and that means they're not having a twist, which Kevin's talking about, introducing rear steering.
00:11:37Whether you're braking hard, or accelerating, or hitting bumps in the corner, and starting to get cycles going, where you
00:11:44just, I rode a Norton 500 twin that was a Model 7, and it was, uh, it was, yeah, it
00:11:55was exciting.
00:11:55It was, it was, uh, it was not bad, but, I mean, the Velocet for the Euro works pretty well.
00:12:02Although, getting back to it, the single, it had a vestigial seat post in the middle of the frame.
00:12:08Oh, yeah, didn't it, though?
00:12:10Which is what?
00:12:11Came up between the gearbox and the engine?
00:12:13Yeah, and there's, and there's a lug for the, uh, swing arm pivot, which is a pipe through a lug
00:12:19that's about this wide.
00:12:20And then you clamp on the swing arm arms.
00:12:24They have little pinch clamps on them.
00:12:26Um, so you have to pinch them, get them lined up, you know, so that they're not out of a
00:12:32skew.
00:12:33So there's some setup there, and then you clamp them on.
00:12:37And it can't have any play in it, and I've, you know, it's, sometimes you gotta sleeve them, and then
00:12:41you clamp the thing.
00:12:42I don't know, there's like a kit.
00:12:44Norton's having them.
00:12:45Articipatory motorcycling.
00:12:47Yeah, you gotta really work at it.
00:12:48I mean, that's, that's why we're here, you know?
00:12:51Yeah.
00:12:52There's plenty of stuff you can buy.
00:12:53You never think about the swing arm pivot for the life of the motorcycle.
00:12:56In any case, they worked okay.
00:12:59Velocet's worked pretty, the swing arm Velocet's worked pretty darn good.
00:13:02It was a step.
00:13:04And it was, um, it took some courage, I'm sure.
00:13:08Well, the, I want to give also one more little bit of credit to Velocet was that you could adjust
00:13:14the position of the upper shock mount.
00:13:17They had an arc in the frame.
00:13:19We'll, we'll throw a, an image up.
00:13:21That famous arc, yes.
00:13:22Um, and what you can do is basically change how compliant the suspension is by tipping them forward or making
00:13:30them more vertical.
00:13:31And it would change that physical ratio.
00:13:34And it's, uh, it's useful.
00:13:38I mean, look at the size of me.
00:13:42It, uh, it improves the bike.
00:13:43And it was a, uh, a method of adjustment that no one else had at the time.
00:13:47Around 1950, Edward Turner did something very characteristic of Edward Turner.
00:13:54He was the man who, when he designed a parallel twin for Triumph, made sure that it would slip into
00:14:03the frames that were made for the single.
00:14:08Now, this is not lavish manufacturing, uh, backed by the courage of an enormous market.
00:14:15This is, uh, mind the pennies and the pounds will take care of themselves.
00:14:21So what did he do?
00:14:22He designed the rear suspension into the wheel hub.
00:14:27So that it could simply be slipped into the, uh, axle carriers of the stock frame.
00:14:35No modifications, no extra costs.
00:14:41Now, this has been, the spring hub has been referred to as a jack in the, jack in the box.
00:14:48Because if it happens accidentally to open, something will spring out, namely the springs.
00:14:56Well, I was very much told by my friend, the Bill Getty, who's run JRC engineering.
00:15:01He's, he's a incredible British bike mechanic in his historical knowledge.
00:15:05He's worked on everything.
00:15:06He used to run a shop, uh, for a long time.
00:15:08And now it's aftermarket parts for, uh, British motorcycles.
00:15:12But, uh, he said, you know, Mark, if you ever own a spring hub Triumph, don't open it.
00:15:18So, as Kevin points out, there can be explosive.
00:15:23The big, the other big development in 1950 was, of course, the Norton Featherbed frame, which was developed by Rex
00:15:35and Chromie McCandless in Northern Ireland as a result of actual testing.
00:15:41And, uh, rather than, uh, armchair platonic theorizing, such as we want a constant wheelbase, we must have constant steering
00:15:53head angle, we must have purity in all things and perfection.
00:15:59So, Norton were so impressed with this thing, they contracted with, uh, the McCandless's to build the frames for the
00:16:081950 TT bikes for Norton, the factory Nortons.
00:16:12And, uh, and they won the TT.
00:16:16And not only that, they gave the Italian four-cylinder bikes, uh, a terrible scare because they could get on
00:16:26the gas earlier in a corner.
00:16:29They were stable, they braked well, and, uh, in Norton's testing, the Featherbed version could be ridden around the outside
00:16:44of their previous bike, the so-called, uh, garden gate frame, which was a single-plane frame, similar to that
00:16:53of a bicycle.
00:16:55Uh, the Featherbed frame had twin loops, and the swing arm was placed between them at the aft end so
00:17:04that it had a broad base for, uh, stiff mounting, not a lot of flopping and flexing.
00:17:15And Jeff Duke would have won the world championship on that bike first time out, except for tire failures, chunking
00:17:23at high speed.
00:17:25So, and then in 1951, he did win the world championship, the last one that Norton would win in 500
00:17:32or other classes.
00:17:35The, the singles were not finished, but almost.
00:17:42However, the terror felt by the Italians resulted in a widespread Nortonizing campaign.
00:17:50What is it about this bike that makes it so?
00:17:54Uh, Abel, we'd like to have some of that.
00:17:59And, of course, uh, the, the great ambition of English riders was to be summoned to Italy and be well
00:18:07-paid to arrive and to ride the frightening fourth.
00:18:13And they would bring with them in their suitcases, British-made, uh, telescopic coilover, uh, rear suspension dampers inspired by
00:18:25those made by hand by the McCandless brothers, which included remote reservoirs, not to be seen again for 20 odd
00:18:36years.
00:18:36So, this was, this was, this was a movement of goalposts.
00:18:43Uh, this set the scene for 20 years of convention in which if you wanted a good handling motorcycle, you
00:18:55would buy one of these Nortons with the feather bed, uh, chassis.
00:18:59And you would try to, and you would try to understand it.
00:19:02And, of course, it wasn't so mysterious.
00:19:06McCandless moved the rider and the engine forward almost three inches.
00:19:12Big change.
00:19:14And, uh, I've spoken to you before about the, uh, JSME article, which, in which they ran motorcycles stationary on
00:19:27a moving belt highway.
00:19:30And they tested them for stability and they found out that loading the front tire rather than the European practice
00:19:38of backing the engine up against the rear tire produced stability and steering that did what you expected.
00:19:50So, this was the new standard and it would rule the world until the coming of Antonio Cobas and his,
00:20:00uh, inventions in the early 1980s, which culminated in the twin aluminum beam, um, establishment of the present moment.
00:20:11Uh, not to, uh, uh, not to, uh, overlook the significance of so-called trellis frames as practiced by Ducati,
00:20:23um, KTM also, uh, wasn't adherent of multi-tube space frames.
00:20:32So, one of the very important things that Norton added was supple, smooth acting hydraulic dampers front and rear.
00:20:41Telescopic fork in the front, twin shocks in the rear.
00:20:45No more stick slip from scissors type dry friction dampers, which had been the world standard for, since there was
00:20:55rear suspension.
00:20:57Sort of like a clutch.
00:20:58And before that, it was used on, on girder forks.
00:21:01Yeah, you sort of, sort of like a clutch, except it had two arms on it that were attached to
00:21:05different elements.
00:21:06And that was your, you know, attached to the front wheel, attached to a fixed area.
00:21:09And then, in some of them, there was a big wing nut by which you had adjustable damping.
00:21:15Steering dampers were, were like that, uh, for a time you had a big knob.
00:21:20You could turn on your steering head and the rod went through to it.
00:21:22Right into the 60s.
00:21:23Yep.
00:21:24Uh, to a, essentially the same friction pack underneath the, uh, steering pivot, so.
00:21:32Well, in 1973, uh, there was an explosion of rear suspension innovation from motocross.
00:21:41And this is where, uh, suspension is so badly needed.
00:21:46So, it's not a surprise that innovation, uh, should come, should well up out of the dirt, so to speak.
00:21:58And what had been the norm for many years was the three to three and a half inches of travel
00:22:04of a pair of trusty old black curling shocks with a variety of springs that you could get at your
00:22:12nearby stockists.
00:22:15Stockists.
00:22:17I've always liked that.
00:22:19I'm not going to say it again.
00:22:20Don't worry.
00:22:22Uh, riders rode as hard as they could with those short travel units.
00:22:29When they began to extend the travel, they found they could go much faster.
00:22:35Now, one reason is that the energy absorption ability of a suspension is proportional to travel squared.
00:22:47Double the travel, you can absorb four times the, uh, energy of the shorter travel unit.
00:22:57And the other thing was that, as pointed out by former Honda, American Honda racing manager, Gary Mathers,
00:23:07riders push as hard as they can, but they are stopped by what they call harshness.
00:23:16And whether that means that your brain is being jarred into foolishness or that your muscles are unable to go
00:23:25any further in the direction they're going or your peripheral circulation shuts down.
00:23:31I don't know what it is.
00:23:33I'm sure that, um, sports physiologists could tell you what harshness is.
00:23:39But what happened was that as they extended travel, at first, everyone enjoyed the softer suspension and the ability to
00:23:49magically travel at great speed over rough terrain.
00:23:56But, as usual, people rode to their limit, the harshness limit.
00:24:04So, Mathers noted, they ended up with the same spring rate with 12 inches of travel that they had had
00:24:11with three and a half inches.
00:24:15And I find that fascinating.
00:24:18Well, racers, you know, the good, the good racers, what do they do?
00:24:21They, or any tester, you ride the bike until it does something wrong.
00:24:26You push it harder and harder until it does something wrong.
00:24:29That's actually the job.
00:24:31Because most things are good.
00:24:32It's 70%, 80%.
00:24:35Most things are pretty darn good.
00:24:36But it's when you start asking more.
00:24:40Well, long travel, um, hit road racing, too.
00:24:47And, um, one rider told me that with his long travel Honda with suspension, uh, that had the latest in
00:24:58low, um, rigidity compression damping.
00:25:05Traditional compression damping was just a hole through which oil was pumped by the moving piston in the damper.
00:25:14What a suspension damper does is it converts bump energy into the velocity of oil rushing through a limited area,
00:25:26in this case, a drilled hole.
00:25:28And the resistance to that flow goes up as the square of the flow, which means at some level, the
00:25:38resistance becomes essentially rigidity.
00:25:43And there's, there's all kinds of wonderful stories about riders throwing, uh, shocks into, into lakes or abusing them in
00:25:55other ways.
00:25:56But what this led to was a new type of compression valve that was progressive and that whose resistance was
00:26:06more nearly proportional to shock rod velocity, uh, than to the square.
00:26:15And so, uh, uh, this made it possible for the rider I'm talking about to hit the banking at what
00:26:22used to be turn five out of the Daytona infield up onto the banking without timing it to coincide with
00:26:29an upshift.
00:26:30He could just ride through there on the power with this innovation.
00:26:36So this is not engineers playing with pencils and papers.
00:26:42This is, let's try this.
00:26:47Be sure to wind your stopwatch.
00:26:49Okay, here we go.
00:26:51Oh, that's much better.
00:26:53Let's talk to the rider and so on.
00:26:55Um, this is how it actually goes.
00:26:58We are not sitting in Plato's cave looking at mere shadows of reality.
00:27:06We're getting in there and messing with it.
00:27:10So we get results this way.
00:27:15Now there are some, uh, exceptions.
00:27:19The atomic bomb worked perfectly the first time.
00:27:23Um, although there have been some fizzles since then.
00:27:26Well, the atmosphere didn't even catch on fire either.
00:27:29That was one theory, right?
00:27:31No, the nitrogen and oxygen failed to rush into each other's arms.
00:27:35Yeah.
00:27:36But it was a sort of nagging itch until they actually saw the fireball through their smoked goggles.
00:27:47So when long travel hit, um, road racing and street bikes, of course, what people noticed was these bikes have
00:27:59powerful brakes and pavement has more grip than dirt, which means you break and the bike noses over rather radically.
00:28:11And for each inch that the front suspension compresses, you lose roughly one degree of your steering head angle.
00:28:18Now this is, uh, there are people who say that this can be a terrifying thing and then there are
00:28:24others who, uh, dismiss it.
00:28:27But I've not risen to those heights in my own modest motorcycling.
00:28:35So people began to say, let's put a stop to this, um, extreme attitude change.
00:28:43We don't want to go back to short travel.
00:28:45Let's put anti-dive onto the front end.
00:28:49And hydraulic, mechanical, there was a wide variety of, of devices.
00:28:58You may have seen, um, the Kawasaki ones that had all these levers, which used the, uh, effort of the
00:29:09brake caliper to follow the brake disc to generate a force that lifted the front of the machine.
00:29:17Now, uh, Udo Giedel has commented that it could brake nicely or on a rough surface, it could stutter horribly.
00:29:28Then in the end, um, once again, reality prevailed because it was found, wait a minute, these guys over at
00:29:38Yamaha are out braking our guys and they don't have any anti-dive on their bike.
00:29:43What do they know that we don't?
00:29:46Well, what they knew was that when the front of the bike sinks dramatically, it takes the center of gravity
00:29:55down with it.
00:29:56And that makes the lever, the height of the center of gravity over the pavement, by which front brake torque
00:30:05can lift the rear wheel into a stoppie, makes the lever shorter.
00:30:10So you can brake harder, so you can brake harder and not lift the rear wheel.
00:30:16And so, overnight, anti-dive just disappeared, went off the street bikes, it was all gone.
00:30:23Oh, so embarrassing.
00:30:27And this is how things go.
00:30:29Oh, uh, there was initial resistance to monoplanes.
00:30:35I mean, where are the bracing wire?
00:30:37Well, they're inside the wing, so to speak.
00:30:40Yeah, but I don't, I don't really trust that.
00:30:43I mean, the biplane, it's built like a box kite, you know, you can trust it.
00:30:49They didn't like a canopy over the pilot because he couldn't feel the slide slip on his cheeks and judge
00:30:59how the turning was going.
00:31:01Well, I mean, imagine a Cessna 195 in the late 40s with no wing braces, no, it just, it just
00:31:08was a straight wing sticking out and there was no, nothing visibly holding it.
00:31:16Well, uh, anti-dive disappeared.
00:31:21Okay.
00:31:21Uh, there were various strange anomaly, uh, anomalous, um, suspension proposals from like 1970s onward.
00:31:40And U.S. Kawasaki played with what they called the FUBAR rear suspension.
00:31:47There were, uh, two swing arms going up and down together.
00:31:53Their aft ends joined by an upright that was perforated for the rear axle.
00:32:02When they described this to me, it sounded like someone slightly familiar with the A-arm geometry of race cars
00:32:11had fallen in love with the idea of the virtual pivot.
00:32:17That, that is far away in space.
00:32:21And so what was hoped for initially from this design was that it would absolutely prevent wheelies, allowing you to
00:32:29just scoot out of corners and disappear.
00:32:33But in practical sense, I think they discovered anti-squat and they actually put this on Yvonne de Hamel's race
00:32:44bikes, air-cooled and liquid-cooled from 73 to maybe 77.
00:32:51And then it disappeared.
00:32:54And then it disappeared.
00:32:54They, it didn't go any further, but they put a lot of effort into it.
00:32:58Another possibility, um, which I've never seen in the aluminum and steel is the, um, Chebyshev linkage.
00:33:10Um, in 1859, um, Pafnuti Chebyshev, a Russian mathematician was trying to devise a way to change straight line motion
00:33:25into rotary motion.
00:33:26And in the process, he came up with twin swing arms that were crossed.
00:33:35This was perfect for the constant wheelbase theorists, because at last you could have the rear axle going up and
00:33:45down in a straight line.
00:33:48Zero wheelbase change.
00:33:52Perfection is at hand.
00:33:55I don't even know if any prototype of this kind was built, but there was the idea.
00:34:04So.
00:34:06What a lot of these ideas for rear suspension were trying to do can be broken down into three areas.
00:34:17One is people were beginning to be aware as engines grew more powerful.
00:34:23Remember the two strokes came to Daytona with a hundred horsepower in 1972.
00:34:28That got people thinking.
00:34:31Um, chain force had an effect on rear suspension.
00:34:36It might either cause it to rise up or to squat down.
00:34:40And so people were trying to negate this force so that it would be neutral.
00:34:46So Hasek's rear suspension, he wanted the swing arm, center plane of the swing arm to be horizontal.
00:34:53He wanted the chain above it to be horizontal and parallel with the pavement.
00:35:00Um, ATK came out with a similar idea.
00:35:05They placed two sprockets clamped one above the other to the chain side swing arm beam.
00:35:15And they were arranged at such a height that the upper chain run and the lower chain run,
00:35:22when either of them was under tension, would be parallel with the swing arm.
00:35:27So there would not be this tangent force tending to cause the swing arm to extend.
00:35:34The thing that I loved about ATK was that they made a demonstration toy was fascinating to play with.
00:35:42You could, you could change the variables, uh, so that it was bad, normal thing where the rear suspension extends,
00:35:50or it would be super modern, um, with no net force, no effect from the chain tension on rear swing
00:36:02arm height,
00:36:03you know, suspension height.
00:36:05Then the, the second idea was, no, rather than setting the swing arm free from chain pull,
00:36:13let's use the chain pull on these powerful motorcycles, which otherwise will squat down in the rear when they accelerate.
00:36:22Let's use it to generate the lift force just to the point that it cancels the squat.
00:36:32So that here you are in the turn trying to accelerate.
00:36:37And as you twist the throttle and the rear end squats down, weight comes off the front tire and goes
00:36:44on to the rear tire.
00:36:45And the front tire pushes you head for the outside.
00:36:50This is squat and push.
00:36:55And I remember seeing, uh,
00:37:00one of the South American lads who made it big in GP racing,
00:37:05come in to his, uh,
00:37:08crew and make the universal sign for push,
00:37:13push, which is,
00:37:15you know,
00:37:16Mars crossing.
00:37:17Yes.
00:37:17Yes.
00:37:19And which is now called, uh, something else.
00:37:22They call it, um, closing, closing the front end.
00:37:27And then the third, um,
00:37:31possibility was to,
00:37:34uh,
00:37:37completely ignore all of the above and focus only on constant chain slack.
00:37:44Because.
00:37:46There are some peculiar motorcycles out there.
00:37:49Yamaha's TZ 500.
00:37:52Um,
00:37:53you had to be careful adjusting the rear chain slack because there was a place in the arc of the
00:37:59rear suspension where it got real tight.
00:38:02And that's where you had to adjust it.
00:38:05And.
00:38:07So these guys were going to,
00:38:09to nail down constant chain tension by making the swing arm pivot concentric with the output sprocket center line.
00:38:21Famous Spondin chassis got that.
00:38:23And then BMW was playing with that on their,
00:38:25uh,
00:38:25dirt bike,
00:38:26which didn't work out too well for them.
00:38:29On the dirt bike.
00:38:30It didn't work out too well for anyone.
00:38:32Anyone.
00:38:33Because it completely ignores the chain pull effect on rear suspension height.
00:38:40And,
00:38:41but it's invented several times each year and it probably will be as long as the motorcycle exists.
00:38:47Hey,
00:38:48here's a good idea.
00:38:50Why don't they do this?
00:38:52But it's not a good idea.
00:38:55It works.
00:38:56It achieves its purpose,
00:38:57but it ignores effects that cannot be ignored on powerful motorcycles.
00:39:07So.
00:39:09All these,
00:39:11uh,
00:39:12well,
00:39:12then,
00:39:13then there's Hasek.
00:39:15Hasek was involved in the formula one,
00:39:19um,
00:39:21development.
00:39:22And at one point they had a chassis bolted to the wall and they had a,
00:39:27a great big bar through the,
00:39:29the projecting end.
00:39:31And they were going to test that the twist resistance in pounds per degree.
00:39:38And this is good.
00:39:39This is,
00:39:40this is finding out stuff you want to know by lashing up something that doesn't cost a million and a
00:39:46half dollars and has to come from a German high precision.
00:39:50Outfit.
00:39:52Um,
00:39:53bathroom scale and the drill press,
00:39:55uh,
00:39:55you got it.
00:39:56Test your spring rights.
00:39:57There's a famous picture of Dan.
00:39:58And then there's a suspension springs.
00:40:00You got it.
00:40:02So,
00:40:03um,
00:40:11I once,
00:40:12uh,
00:40:13stood just off of,
00:40:14um,
00:40:15what used to be turn nine at Laguna,
00:40:17the left hairpin and watch the TZ seven fifties upshift off of that corner.
00:40:25As soon as the clutch went home,
00:40:28clunk,
00:40:28the bike,
00:40:28bike rose up and hit the upstop.
00:40:31They had plenty of anti squat.
00:40:34This is why,
00:40:36um,
00:40:37in the early nineties,
00:40:41adjustable swing arm pivots began to be seen.
00:40:45Adjustable height,
00:40:47usually in the form of a rectangular opening on either side of the frame into which plugged a plate with,
00:40:54a hole for the swing arm pivot at a particular height.
00:40:59And you had a fitted case of these like fine cigars.
00:41:04And you could select the ones that had the height change that you thought would put an end to all
00:41:11your problems and shut your rider up with all his complaining.
00:41:16Whiners.
00:41:18So,
00:41:20uh,
00:41:20that was,
00:41:23that was that.
00:41:24When it came to FUBAR,
00:41:27uh,
00:41:28nothing is going to change the fact that the thrust accelerating the motorcycle is at ground level.
00:41:35Whereas the center of mass is maybe 20,
00:41:4022 inches above that.
00:41:42What that means is the thrust is tending through this lever arm to exert a torque on the chassis and
00:41:52lift the front wheel off.
00:41:53So,
00:41:54what you need to prevent this is either a chaparral like,
00:42:01um,
00:42:02big suction fan up front that is pulling the front end down onto the pavement or winglets or a tiny
00:42:10rocket motor that fires only when you accelerate.
00:42:14Nothing else is going to stop wheeling.
00:42:16No complexity of linkage gears,
00:42:19cams and linkages.
00:42:20Forget that.
00:42:21Now,
00:42:23here come the elf alternative motorcycles.
00:42:28At first,
00:42:29André de Corton's,
00:42:31a Frenchman,
00:42:32uh,
00:42:32with Formula One experience,
00:42:34reasoned very reasonably,
00:42:36there must be,
00:42:38with all the research done in Formula One,
00:42:42concepts that are immediately applicable to the motorcycle,
00:42:45that poor primitive creation,
00:42:47which will greatly improve it.
00:42:50And I will be a star.
00:42:55Well,
00:42:56one of their improvements was,
00:42:59everyone knows that a motorcycle handles better if it has a low center of gravity.
00:43:04Right?
00:43:04Wrong.
00:43:05Wrong.
00:43:07Look.
00:43:09At modern motorcycles,
00:43:10you will see that the rider is way up in the air above the rear tire.
00:43:14It used to be that the seat back,
00:43:17the underside of it was arranged to be barely greater than the suspension travel.
00:43:25And many a motorcycle had tire burns on the underside of the seat pan.
00:43:32They found that that didn't work well.
00:43:35Well,
00:43:36Honda bought into Elf because they wanted to be,
00:43:40uh,
00:43:41in a position of advantage.
00:43:43And this looked like it.
00:43:44In 1984,
00:43:45they brought their,
00:43:47uh,
00:43:50NSR 500,
00:43:53their new four-cylinder bike to Daytona with the fuel carried under the engine
00:43:58and with the exhaust pipes rooted over the top,
00:44:02protecting the rider by means of an insulated dummy tank.
00:44:08And it was found out,
00:44:09they added,
00:44:10they used this concept on their,
00:44:12uh,
00:44:14500 GP bike.
00:44:17Um,
00:44:19as their main,
00:44:22they,
00:44:22they placed all their bets on this.
00:44:24And Freddie Spencer said,
00:44:27I can't change direction as quickly on the bike with the fuel on the bottom
00:44:33as I can on my old three-cylinder.
00:44:37And a test was arranged.
00:44:40Orange cones created a slalom.
00:44:42The three-cylinder was sent through the slalom until Freddie said,
00:44:47that's about all I can do.
00:44:49And a click,
00:44:50they had a measure.
00:44:53They sent the NSR 500 into the slalom at Freddie's entry speed and knocked all the cones down.
00:45:04Actual physical testing,
00:45:06not just sitting by at fireside in a comfortable armchair,
00:45:12reading Plato.
00:45:14Actual testing.
00:45:17Revolutionary.
00:45:19So that was the end of that.
00:45:22It was also the end of the court's house.
00:45:24They brought in two other fellows instead.
00:45:27Instead.
00:45:29And this is an excellent story because it shows.
00:45:36Persistence,
00:45:37willingness to spend money.
00:45:40And ultimately acceptance of the fact that it added up to nothing.
00:45:47But that's something learned.
00:45:50So what went on there was that,
00:45:54uh,
00:45:55the radical bike,
00:45:59didn't go as well as some bikes modified to be somewhat less radical.
00:46:06And so they went in that direction.
00:46:09And all the hub center business with gears,
00:46:13cams and linkages gave way to a simple,
00:46:16almost like a McPherson strut.
00:46:21and,
00:46:21uh,
00:46:23the poor guy on the bike,
00:46:26um,
00:46:28is trying to give good feedback and get good finishes.
00:46:34And he was,
00:46:36uh,
00:46:36fifth or third,
00:46:37or he had some good finish positions in the championship in the middle eighties.
00:46:43Um,
00:46:45so it can't be,
00:46:47it was Ron Haslam.
00:46:51Very earnest,
00:46:52a corner speed rider.
00:46:54The bike's wheelbase kept getting longer and longer.
00:46:56They started at 53 inches and they ended up at 57 plus.
00:47:02And when,
00:47:04uh,
00:47:05what was it?
00:47:05Scott Redding.
00:47:06I'm not sure which rider it was.
00:47:08Told me about the difference,
00:47:09the physical difference in the motorcycle from a corner speed bike to a point and shoot bike.
00:47:15He said,
00:47:15the corner speed bike is long and low.
00:47:19And that's what Honda built for Ron Haslam.
00:47:24And of course,
00:47:25as the bike became more conventional,
00:47:28people had heard of McPherson strut and a lot of people were driving cars with it.
00:47:35The extremists squeaked and moaned because it wasn't radical enough.
00:47:42It was not true to the original concept of changing everything.
00:47:46Wait a minute.
00:47:48What are we trying to accomplish here?
00:47:51To annoy people or to win races?
00:47:56So,
00:47:57uh,
00:47:58that
00:48:00just
00:48:01didn't work.
00:48:03At one point,
00:48:03um,
00:48:05a quote on,
00:48:07from a rider was,
00:48:08directional stability,
00:48:09a problem at almost any speed.
00:48:11That's for Elf 2A.
00:48:13For Elf 2C,
00:48:15uh,
00:48:17front patter of terrifying proportions.
00:48:19But braking was exceptionally good.
00:48:23Because you know that a telescopic fork,
00:48:27side-loaded by braking force,
00:48:31operating on a long leverage,
00:48:34tends to bind,
00:48:36tends to cause stiction
00:48:38that prevents the front end from following the pavement surface during hard braking.
00:48:43But with a pivoted front end,
00:48:45no stiction.
00:48:48Excellent grip.
00:48:50Shortest braking distances.
00:48:52And when Harley built their,
00:48:54uh,
00:48:57retro leading link suspension,
00:49:01I went to interview the engineer who had done the project,
00:49:05and he was sort of apologetic.
00:49:07And I said,
00:49:08well,
00:49:08I want you to tell me,
00:49:09there's got to be some point of superiority here,
00:49:12and I want you to tell me about it.
00:49:14Well,
00:49:15he said,
00:49:15um,
00:49:17it does have the shortest braking distance of any bike we make.
00:49:25And this is what you would expect from a pivoted front suspension.
00:49:30So,
00:49:32there was a point of,
00:49:34um,
00:49:35advantage,
00:49:36but it wasn't enough to win races.
00:49:40And Honda pulled out of the Elf Honda thing,
00:49:43and no more was heard about it.
00:49:48So,
00:49:50tough one.
00:49:55then we have,
00:49:57uh,
00:50:01leading link,
00:50:03uh,
00:50:04BMW made long leading link Earl's forks for their,
00:50:08uh,
00:50:09flat twins in the early post war years.
00:50:14And for a number of years during that period.
00:50:17Uh,
00:50:18and the thing about leading link is that instead of going up and back,
00:50:23the way,
00:50:25uh,
00:50:25the wheel does with the telescopic fork,
00:50:27it goes nearly up and down with very little wheel base change.
00:50:35Now,
00:50:36how you can stiffen this assembly of two little leading links,
00:50:43it's kind of like Coulson B so that the wheel doesn't cock from side to side
00:50:49as you go through a turn with bumps in it.
00:50:53I don't know,
00:50:54but Cootsie managed to win the three 50 world championship five times in a row,
00:51:001953 through 57.
00:51:03And then they pulled out of racing and that was that BMW,
00:51:09uh,
00:51:10kind of like the emperor has no clothes,
00:51:13they finally realized marketing realized that the graceful waving of the front end
00:51:22on those leading link BMWs is kind of like hand typesetting in an era of laser printing.
00:51:32So that came to an end.
00:51:34It's an historical footnote.
00:51:36It was an era was an attempt to find a better way to do it.
00:51:44So.
00:51:45Then there was the Bimota Tasey,
00:51:51early 90,
00:51:531990.
00:51:53I think it was shown Cologne and it has a hub center front end on it.
00:52:00If you're not familiar with a hub center,
00:52:03imagine a drum like open at the ends,
00:52:09a ring that is spoked into a rim.
00:52:13Then imagine two large bearings inside that empty drum with another drum pushed through it.
00:52:22And the drum that's pushed through it has a kingpin.
00:52:28And grasping the bearings from one or both sides by reaching in through the open ends of the drum
00:52:35is a front swing arm.
00:52:39Now,
00:52:39the only thing that steers is the wheel,
00:52:42the discs and the brake calipers.
00:52:44There are no ponderous fork tubes
00:52:48swaying from side to side with the wheel.
00:52:52And this is potentially a strong point of this hub steering because it is more resistant to wobble.
00:53:01Wobble is rapid oscillation of the front wheel,
00:53:05which generally times out at about 40 or 45 miles an hour.
00:53:10Or if you put your hands back on the bars,
00:53:12if you have on certain motorcycles decided to do the snaps on your gloves.
00:53:19Oh,
00:53:20yes.
00:53:23I won't do that again.
00:53:28Life's little travails.
00:53:31So the,
00:53:32the Tasey,
00:53:33I wanted it to succeed because it looked right.
00:53:38We all did.
00:53:39And the frame,
00:53:40the frame is just a,
00:53:41a thing that went from the frame was the engine.
00:53:45It went from the front swing arm pivot to the rear swing arm pivot.
00:53:48There was no steering head up in the air with long poles going down to the front axle.
00:53:53Just little arms,
00:53:54delicate little steering arms to get down there.
00:53:57Of course,
00:53:58the,
00:53:58the front swing arm had to have elbows to provide clearance for the front tire.
00:54:04And this was a problem for Ron Haslam at one point on the number three Elf Honda bike,
00:54:12because going through,
00:54:14I think a left-hander,
00:54:17and he used a lot of lean angle.
00:54:19He was a corner speed stylist.
00:54:21He dragged the swing arm on the pavement.
00:54:26And not many can make this claim.
00:54:31So,
00:54:34this stuff
00:54:38came to an end.
00:54:40Tasey,
00:54:42I encountered a man who liked the Tasey that he bought so much,
00:54:47that he bought two more so that he would have one at each of his three residences.
00:54:55Hmm.
00:54:56And he was a,
00:54:57a cheerful guy who just loved his motorcycle.
00:55:02So he had three of them.
00:55:03Yeah,
00:55:03they're neat.
00:55:04They are cool.
00:55:05I,
00:55:05you know,
00:55:06I don't know if I need three,
00:55:07but they are,
00:55:08it is a charming way.
00:55:09You got a V twin?
00:55:10Yeah.
00:55:10But the thing is,
00:55:13there are a lot of ways to build a motorcycle that will chuck,
00:55:16chuck,
00:55:16chuck,
00:55:16chuck,
00:55:17chuck along the highway and get you where you're going and provide you with a
00:55:22sporty feeling.
00:55:26But with that,
00:55:28I'm sure,
00:55:28for example,
00:55:29that we could build a lovely chassis of adequate stiffness out of steamed
00:55:34plywood.
00:55:36But when you push something to its limits,
00:55:41you learn other things and racing riders on racers on TASY or similar bikes
00:55:50found the steering vague.
00:55:54They complained of lack of feedback.
00:55:59Well,
00:56:00the information,
00:56:01it was like that story about,
00:56:03um,
00:56:05owl,
00:56:05a tiny creature,
00:56:07a mouse went by owl's house and he heard a commotion.
00:56:10And he told his friend,
00:56:12owl was up in there throwing the furniture out of the windows and stomping in
00:56:18the bottoms of all his pots and pans.
00:56:21When the signal is transmitted through several repeaters,
00:56:25the signal at the end may not be the same as the signal at the beginning.
00:56:31And so they said,
00:56:33if there are gears,
00:56:34cams and linkages,
00:56:36heim joints,
00:56:36rose joints,
00:56:38uh,
00:56:39things that have to be lubricated with a grease gun,
00:56:44it's going to take the feel out of the front end.
00:56:47But like Mark says,
00:56:49it's a perfectly adequate motorcycle in other respects,
00:56:53but it failed to make a revolution.
00:56:55There was no reason to build it that way.
00:56:59Having to do with superior performance other than I'm sure it has a good
00:57:04breaking distance.
00:57:08So this is,
00:57:11uh,
00:57:12this brings us to the present moment.
00:57:14When,
00:57:14uh,
00:57:15I was in the press room at Valencia once in a,
00:57:18a gentleman came over to show me a project that,
00:57:22uh,
00:57:22he was,
00:57:23uh,
00:57:23I think a machine shop instructor and he and his lads were building a high
00:57:28tech front end for a motorcycle.
00:57:30And I said,
00:57:30well,
00:57:31now I'm puzzled because people call this high tech,
00:57:36but it has never been adopted at the highest level of motorcycling,
00:57:40which is,
00:57:41uh,
00:57:42world supers,
00:57:43motor GP,
00:57:44et cetera.
00:57:45Oh,
00:57:46he said,
00:57:46I'm,
00:57:47I'm perfectly aware of that,
00:57:48but my class want to build this.
00:57:50Oh,
00:57:51okay,
00:57:51fine.
00:57:52That's,
00:57:52that's okay.
00:57:53But this continues.
00:57:56Journalism loves to call complex things,
00:58:00high tech,
00:58:02extra parts.
00:58:04Like the NASA guy said,
00:58:06if you have a million parts and the reliability of each one is a million
00:58:13chances,
00:58:14a million times it flies and one time it fails,
00:58:16you're going to have a failure every time.
00:58:19So reduce the number of parts.
00:58:23Simplicity.
00:58:24Yeah,
00:58:24there've been,
00:58:24this was the lesson that I took from all of these complexities,
00:58:29which is that the motorcycle can't go too far from being two wheels,
00:58:36an engine,
00:58:37and a place to sit.
00:58:41And what the McCandless brothers created hydraulic damping at both ends of a strong frame with a well-founded swing
00:58:54arm,
00:58:55telescopic fork up front.
00:58:57It's still not wrong.
00:59:01So all of these excursions have been instructive,
00:59:07but they have failed to produce a revolution.
00:59:11Some of these bikes,
00:59:13what was the name of the Yamaha that was built with a strange front end?
00:59:22The GTS 1000 had the Omega frame,
00:59:25and I'm forgetting that fellow's name who put it together.
00:59:28It was his idea.
00:59:29He was a big proponent.
00:59:34My brain,
00:59:35my brain was actually recently diverted by thinking back to the Moto SIS with the,
00:59:39the variable trail inserts and the not tell the flex adjustable fork on that.
00:59:44That was an interesting time as well.
00:59:47That,
00:59:48that could be part of a podcast in and of itself.
00:59:51there,
00:59:52I,
00:59:53there are people who've,
00:59:54who've devoted years of their lives to these projects,
00:59:57and we have to respect that.
01:00:01But it does turn out sometimes like carrying the fuel under the engine.
01:00:07It just doesn't work.
01:00:09Why didn't it work?
01:00:10Because people were confusing the sense of security that they have on a heavy motorcycle.
01:00:17If it has a low center of gravity,
01:00:19like a Harley big twin,
01:00:22confusing that with a low center of gravity on some,
01:00:26a sporting motorcycle.
01:00:28Because as it turns out,
01:00:31people imagined if this is the ground plane and this is the motorcycle,
01:00:36people imagined that the motorcycle pivoted around the line of contact of the two foot tire footprints.
01:00:43It does not.
01:00:46It does not.
01:00:47Instead,
01:00:47what happens is the bottom of the motorcycle goes one way and the top of the motorcycle goes the other.
01:00:53So what does it do?
01:00:55It rotates around its own center of mass.
01:00:59When I was learning to ride faster and riding more and more hours,
01:01:05I discovered that because you would see an object in the road you wanted to avoid and you didn't steer
01:01:13around it per se.
01:01:14The center of gravity could continue in very nearly the same direction it was going,
01:01:19but you would swing.
01:01:20You would actually swing the wheels out of the way.
01:01:22It reminds me of sports.
01:01:25It's the center of the center of the center of the center of gravity of the motorcycle wants to travel
01:01:30in a relatively smooth line.
01:01:34And things are pivoting around it.
01:01:37Your wheels are going out.
01:01:38The rider is doing things to alter where that center may be,
01:01:41but you're,
01:01:42you're trying to carry the center in a nice smooth manner down the road.
01:01:46it insists.
01:01:47Yeah.
01:01:48And it does.
01:01:48And you don't want to,
01:01:49well,
01:01:49you have to.
01:01:50And like,
01:01:50how do we best control it?
01:01:52It reminds me of sports.
01:01:53If you look at,
01:01:55a surfer doing crazy things on a wave.
01:02:00If you follow the path,
01:02:01their head,
01:02:02their head is relatively stable because it's just like the squirrel.
01:02:05When the squirrel gets flung out of a tree,
01:02:07the first thing it does is it could be flailing about.
01:02:12It's sighting it's landing.
01:02:14And then it's rotating.
01:02:17it's head is everything.
01:02:19And that's just,
01:02:20that's sort of where the center of mass is.
01:02:22And in a bike,
01:02:22you swing the wheels out just as,
01:02:24as you were describing,
01:02:25you need to miss a screw.
01:02:27You see something,
01:02:28you just go,
01:02:29you turn a little bit,
01:02:30you get the bike swung and then you allow it to get the wheels around the
01:02:35outside of it and hope you don't hit what you're trying to avoid.
01:02:38But yeah.
01:02:39And return to equilibrium.
01:02:40Yeah.
01:02:41And it's what,
01:02:41what right back under his.
01:02:43Yep.
01:02:44So it's,
01:02:48it's not intuitive unless you have a little familiarity with Isaac Newton and
01:02:55his,
01:02:56his work.
01:02:58He seems to have been a peculiar fellow.
01:03:02Yeah.
01:03:03He complained once that all my friends,
01:03:05he said,
01:03:06are constantly trying to embroil me with women.
01:03:15So Newton's laws are just what we found happens most frequently.
01:03:21And we call that a law.
01:03:23It's more of an expectation.
01:03:25And so what was happening when they put the fuel on the bottom is they moved it away from
01:03:30the center of mass.
01:03:32Therefore changing what was more like a cannon,
01:03:37a 24 pound cannon ball into something that was more like a 12 foot long,
01:03:4224 pound ladder.
01:03:45You're moving masses away from the center of mass so that Freddie's efforts to change
01:03:52direction produce less result.
01:03:56So then they took the gas out and put in two quarts and they put 32 pounds of ballast up
01:04:06among
01:04:07the pipes and Freddie went sailing through the orange cones without knocking down one.
01:04:16So,
01:04:17um,
01:04:20good stuff.
01:04:23I,
01:04:24um,
01:04:25I'm pleased with that.
01:04:27Well,
01:04:27you know,
01:04:28we,
01:04:28uh,
01:04:29like in many things in life,
01:04:31mythology is very easy to,
01:04:32uh,
01:04:33say is,
01:04:34yeah,
01:04:34oh yeah,
01:04:36that's how it is.
01:04:37That's how it is.
01:04:37Just like you talk about moving the engine to the rear.
01:04:39No,
01:04:40we got to get traction.
01:04:41We got to get traction and drive,
01:04:42you know,
01:04:42all that stuff.
01:04:44And,
01:04:44um,
01:04:45McCandless brothers doing science,
01:04:47testing actual things and really just check your prejudice.
01:04:51at the door,
01:04:52forget your bias.
01:04:53Just look at what's going on and,
01:04:57you know,
01:04:58whatever it is,
01:04:59engine building,
01:04:59look at the marks on the bearings,
01:05:01look at measure the temperatures.
01:05:05I don't know.
01:05:06You just,
01:05:07you send the oil in for analysis.
01:05:10What's what,
01:05:11where particles are in there.
01:05:14Truly.
01:05:15So companies do it all the time.
01:05:17I'm a firm believer.
01:05:18I got my little black bottles and,
01:05:20uh,
01:05:22I,
01:05:22you know,
01:05:22I rebuilt the engine of my Ford four 60 and it's relatively low miles.
01:05:27And I know what the service interval is recommended.
01:05:32And I changed the oil and I've,
01:05:34uh,
01:05:34I've got a vial that I'm going to send in.
01:05:36And I did it at the interval and I'm going to see what happened,
01:05:39knowing how I drove it,
01:05:40knowing that it's relatively new,
01:05:42but I'll track it.
01:05:43And it's,
01:05:43it's relatively inexpensive,
01:05:46but it gives you actual information.
01:05:48It's not just,
01:05:49as you pointed out,
01:05:50we talked about oil change interval.
01:05:52And,
01:05:53um,
01:05:53I actually,
01:05:54I believe the first time I had this comment from you was reading your book,
01:05:57the sport bite performance handbook.
01:06:00It's a great book.
01:06:01If you can find it.
01:06:02And,
01:06:02um,
01:06:03my first try,
01:06:04Kevin,
01:06:04it's a nice book.
01:06:06It's got hand-drawn graphs,
01:06:08all kinds of neat stuff.
01:06:09That's very artisanal.
01:06:10And I like it.
01:06:13I loved it.
01:06:14Actually,
01:06:14it was a craft paper and,
01:06:15and,
01:06:16um,
01:06:16one of the things that,
01:06:17one of the things that you said in that book about oil change interval was,
01:06:23well,
01:06:24you could change your oil every 10 minutes.
01:06:26And wouldn't that be something it was along those lines about frequency of oil change.
01:06:32So it's good to know the truth.
01:06:33If you,
01:06:34um,
01:06:34if you can go to the effort and spend the money,
01:06:37you know,
01:06:38spend,
01:06:38I think it's 40 bucks or something.
01:06:39And you can send a nice big oil sample in and,
01:06:42and it gets some actual data.
01:06:43The sensor that,
01:06:45um,
01:06:47causes the change oil soon light to illuminate.
01:06:52What does it measure?
01:06:54Is it measuring oiliness?
01:06:56Oh,
01:06:57this oil is terrible.
01:07:00Does it measure viscosity?
01:07:01Maybe the viscosity improver agency agents are,
01:07:07which began life with long chains have now become little short things.
01:07:12No,
01:07:13what it measures is the presence of anti-wear because as long as there's anti-wear
01:07:18in the oil additive that has not yet been consumed in the process of protecting
01:07:26metals from each other,
01:07:28when they come very close,
01:07:31what that additive does is it produces a sacrificial solid lubricant layer,
01:07:38which is scuffed away,
01:07:41but it immediately reforms because that area is hot.
01:07:45And the additive is still in the oil says,
01:07:48Oh,
01:07:48here's my chance.
01:07:50And as long as there's anti-wear additive in the oil,
01:07:54uh,
01:07:56it is not worn out.
01:07:58Now there is another phenomenon called falling out of grade,
01:08:02which is exactly what I mentioned before.
01:08:04Namely,
01:08:05the VI improver is a long chain molecule.
01:08:12Viscosity index VI.
01:08:14Yes.
01:08:14Like,
01:08:14like,
01:08:15um,
01:08:16I think of,
01:08:17of oil as like a pot of boiling spaghetti.
01:08:23And when you want to thicken a light oil in order to have a multi-grade 5W20,
01:08:32for example,
01:08:33you start with five and you boost it to 20 by putting these long chain molecules into it.
01:08:43Now,
01:08:44if those molecules are not the high quality kind,
01:08:48and I forget which one that is,
01:08:51they can break,
01:08:52they can lose molecular length.
01:08:54And then what happens is called falling out of grade.
01:08:59It's becoming more like a 5W5 than a 5W20.
01:09:05And you don't really want to.
01:09:06I think I took that out of my pressure washer because I bought a used pressure washer and I don't
01:09:10think they ever changed the oil.
01:09:12But also I think the carburetor may have been putting fuel into the oil as well.
01:09:16So it was definitely out of grade.
01:09:20And we're,
01:09:20um,
01:09:21off the subject here,
01:09:23but I was just thinking that,
01:09:24but you know,
01:09:25we,
01:09:25we were talking about trying to know the truth and that's what we,
01:09:28uh,
01:09:29that's why we send our oil in at least once in a while and,
01:09:33uh,
01:09:33to find out what's going on,
01:09:34see what's in it.
01:09:35And,
01:09:36um,
01:09:38well,
01:09:39there were those,
01:09:39uh,
01:09:40there was that B-29 crew who were refusing to fly and a Jeep comes up and screeches to a
01:09:46halt and a red faced officer piles out.
01:09:49You will fly that airplane.
01:09:51And someone said,
01:09:53yes,
01:09:54but,
01:09:54uh,
01:09:55they gave us engines from Bendel air depot.
01:09:57I'll have,
01:09:58you know,
01:09:58that those Bendel air depot engines are just as good as the ones that come from New Jersey.
01:10:04And he's ranting and raving.
01:10:07Meanwhile,
01:10:08the pilot has said to the flight engineer,
01:10:11you want to go pull the screens on number three?
01:10:14And he's out there doing it.
01:10:17And the red face is getting redder and redder.
01:10:21Court martial is about to convene,
01:10:23at least in his imagination.
01:10:25And here comes the flight engineer with the screen with bolt heads and pieces of piston ring on it.
01:10:33And he,
01:10:37oh,
01:10:37I'll fly that.
01:10:38No,
01:10:39I won't.
01:10:40I'll fly it myself.
01:10:42Yes,
01:10:42sir.
01:10:43He was going to fly it himself.
01:10:44I know I've told that story before,
01:10:46but it's a good one.
01:10:47Well,
01:10:48and it's much like oil.
01:10:50It's a crude form of oil analysis.
01:10:53Pull the screen and see what's on it.
01:10:55Well,
01:10:55cut open your oil filter.
01:10:58Yep.
01:10:59Yeah.
01:11:00The NASCAR car,
01:11:01NASCAR guys,
01:11:01cutting the filter open.
01:11:03Oh,
01:11:03no.
01:11:04Yeah.
01:11:04I mean,
01:11:04you can,
01:11:05you can see what's on it.
01:11:06Oh yeah.
01:11:07The lab,
01:11:07the lab that,
01:11:08that does the oil analysis for the stuff that I send in,
01:11:12you can also send a filter in and they'll,
01:11:15they'll dismantle it for you,
01:11:16but you could just cut it open.
01:11:18You can get your big pipe cutter and cut your can off.
01:11:22I mean,
01:11:22I have the fortune of having so many canister filters in my life.
01:11:25I don't have to cut the can off because it just comes off and makes a mess anyway.
01:11:28Even the Toyota,
01:11:30the newer,
01:11:30the newer Toyota that we drive has a canister oil filter.
01:11:34I thought I'd never get away from it.
01:11:36And I guess I haven't,
01:11:37but it is,
01:11:41it's good to try and find the truth.
01:11:45Well,
01:11:45that's it.
01:11:46Yeah,
01:11:46that's it.
01:11:47We,
01:11:47we covered swing arms,
01:11:48both front and rear and alternative alternatives.
01:11:52We,
01:11:53we managed to skip Dr.
01:11:57John Wittner,
01:11:57a little bit of him on his slightly alternative.
01:12:00Oh yeah.
01:12:01We'll get to him.
01:12:02We'll get to him.
01:12:03I think John Wittner could be his own podcast.
01:12:05Well,
01:12:06he sure could.
01:12:07Yeah.
01:12:07There's so,
01:12:08so much going on there and the allegiance.
01:12:11His father was an aeronautical engineer and a very practical one.
01:12:14Oh good.
01:12:15See,
01:12:15that makes sense.
01:12:16Doesn't that make sense?
01:12:18Yes.
01:12:20Indeed it does.
01:12:21Hasek and there was the troll front end,
01:12:24troll engineering.
01:12:25That was kind of like a,
01:12:27oh,
01:12:28consider your tracks on your closet door.
01:12:31But for giant doors and they metal rollers and it had this blade with V's on
01:12:36either side of it.
01:12:37It had wheels that located it and there were rolling elements instead of.
01:12:41a linear bearing.
01:12:42Yeah.
01:12:42A linear bearing.
01:12:43And I rode one of those.
01:12:44It had a very rigid tubular front end and kind of like almost a miniature
01:12:49trellis.
01:12:50That was fascinating too.
01:12:52We have,
01:12:52we have podcasted about some of that stuff,
01:12:55but we'll see you soon,
01:12:58Dr.
01:12:58Wittner.
01:12:59Thank you for riding with us when you get to us.
01:13:02Thanks everybody for checking us out and we will catch you next time.
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