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  • 22 hours ago
Road bike drivetrain technology is under the constant scrutiny of the entire cycling industry.

There are some very promising options out there so Cycling Weekly's Sam Gupta runs through what he believes could be the tech of future for road bike drivetrains.
Transcript
00:00The drivetrain as we know it, with two derailleurs and a chain, has been the favoured method of
00:05converting spinning legs into speed for nearly 100 years. As we all know, over this time we have
00:12seen countless improvements to the system, which has landed us with where we're at today,
00:18which by all accounts is a pretty refined and efficient system. However, as we reach what may
00:24be a plateau of innovation in this space, suggesting we may actually have the best version
00:29of the system, it's only natural to wonder what the next generation of drivetrains will be.
00:35While the current system serves the masses really well, for some, there are some potentially huge
00:41gains to be had in other technologies. CeramicSpeed debuted its wacky looking system back in 2018,
00:53much to the intrigue of anybody who set eyes on it. It works by using sculpted plates rather than
01:00chain rings and sprockets with an electronically controlled driveshaft which can shift between
01:05different diameters of the plate to engage a different gear. As yet, it's still very much
01:12in the testing and development phase. However, CeramicSpeed claims that it was able to achieve
01:16a speed of 45 kilometers per hour on the track, on a single speed prototype during part of its low
01:24testing phase. If this drivetrain ever does hit the market, in the first instance, it will undoubtedly be
01:32incredibly expensive. But of course, that's the same for any brand new and truly revolutionary tech.
01:39It always takes a bit of time for it to trickle down to those lower echelons.
01:43If CeramicSpeed really are successful in creating a drivetrain that is 99% efficient,
01:50it will of course attract the attention of those chasing every single watt.
01:55Drivetrains like this could find a home on top-end TT and triathlon bikes, maybe even aero bikes
02:02optimised for flat races that will end in a sprint. The drivetrain efficiency is one thing, but the
02:09other benefits that come along with a setup like this is that there's no chain to come off. The
02:14system is more compact and therefore more aero. CeramicSpeed are claiming that they have recorded
02:20an advantage in specialised wind tunnel. But finally, since there are no delicate components
02:26hanging off of the frame, if a rider is to have a crash, they should just be able to jump
02:30on the bike
02:31and carry on. Snapped mech hangers will become a thing of the past. Although,
02:36SRAM's direct mount rear derailleur also seems to be doing a pretty good job of this.
02:45From one direct drive system to another, but one is actually in existence and is available to purchase,
02:52is the driveshaft tech from Honda. They have done away with convention and constructed a pretty sturdy
02:58and utilitarian version of a similar concept. In Honbike's case, they have also made the housing
03:05for the driveshaft integral to the frame and it doubles as the chainstay which holds the rear wheel
03:11in place. Honbike has offered the system within their e-bike range and given the system weight,
03:17it's unlikely something similar would make it over to the world of road bikes. However, it's not
03:23impossible. There are a lot of engineers in the world, all of whom are much smarter than me,
03:28so perhaps there could be a middle ground between what Honbike has created and what Ceramic Speed
03:33are working on, and perhaps that's where we'll see more of an affordable direct drive system emerge from.
03:45One of my favourite drivetrains, and one which I feel is often overlooked,
03:49is the humble belt drive. Commonly found on urban and commuter bikes, the belt drive is just that,
03:56a belt very similar to the one that you might find in your car, but also has humps or teeth
04:02that engage
04:02with a similarly shaped front chainring and rear sprocket. Unsurprisingly, the belt itself can't be
04:09shifted, so to work around that limitation, belt drive bikes are often ones that instead incorporate a hub
04:15gear. For riders who demand bomb-proof simplicity, I don't think you can get much better than this.
04:21There's no oily chain to make your legs or clothes dirty, it doesn't need lubing and it cannot rust.
04:28The hub gear is completely sealed from the elements and often only ever need servicing once every few
04:34thousand miles, and even then it's just a case of topping up any oil that might have escaped. Hub
04:44is too much a fit and forget type of system. Perhaps it's down to a lack of awareness or education,
04:51but I think that this tech on a flat bar hybrid is quite possibly the best option out there. There
04:57are
04:58minimal downsides for the intended user, but there is so much to be gained.
05:07E-bikes have actually played host to quite a few innovations years before they've made their way
05:12onto road bikes. Let's not forget that Shimano Di2 was first found on an e-bike nearly five years
05:19before it showed up as an option for road bikes. So I think it's prudent to keep a keen eye
05:24on the
05:25latest innovations that pop up in that sphere, as one day it would not be a surprise to see it
05:31become the
05:31new normal for road bikes. One innovation that has come from the behemoth that is Shimano is their
05:37automatic stepless shifting. You may be thinking, what does it do? Well, quite what it says on the
05:46tin. You start pedalling and when you do, you'll be in a nice easy gear to get you going. Then,
05:51as you
05:52build up speed and work up to a faster cadence, the auto box will move up the gears to allow
05:57you to
05:57increase your speed while keeping you at a comfortable cadence. But the really remarkable
06:03part about this is the ease at which it changes gear. You barely feel a change, it's more of an
06:10audible click quickly followed by a change of cadence. Perhaps this could be a great option for
06:16those who just want to focus on riding and let the bike take care of the rest.
06:25Lastly, and potentially most importantly, Classified seems to be leading the charge in terms of the
06:30next best alternative to the conventional drivetrain. Perhaps this is because it's not too far removed
06:37from what we already have. As the brand seeks to ditch the front derailleur and replace it with a
06:43wireless two-speed hub gear, we're still left with a conventional chain and rear derailleur setup.
06:49But the new tech does mean that front shifts can be conducted under extreme load without the risk
06:55of misshifting or dropping a chain. And chain lines can be optimised for an even more efficient setup.
07:02The last hurdle that the brand has to overcome is the integration with the shifters themselves.
07:09At the moment, the hub is operated by a wireless button that mounts to your handlebars. But hopefully,
07:15one day in the future, the tech can be integrated into the OEM shifters without voiding any warranties.
07:23My hope is that SRAM decide to acquire Classified and then build it into their entire ecosystem.
07:30Imagine this, a pair of zip wheels with a classified hub that also makes use of the brand's ownership of
07:37PowerTap to create a zip classified PowerTap set of wheels and then perfectly integrates with SRAM's
07:46already wireless group sets. What a dream that would be. One for the future, I'm sure. And perhaps
07:53I'm being a little optimistic that such a thing could ever exist. But it's not outside the realms of possibility.
08:01Let me know, what do you think the future is for the Humble drivetrain? Do you think it will ever
08:06develop beyond the conventional two derailleur system we already have? Do you think Classified or Ceramic Speed have the answer?
08:14If you enjoyed the video, then please do drop it a like, subscribe to the channel for more content, and
08:19I will see you again very soon.
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