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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
00:25be 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 45kmph on the track, on a single speed prototype during part of its load testing phase.
01:26If this drivetrain ever does hit the market, in the first instance, it will undoubtedly be incredibly
01:33expensive. But of course, that's the same for any brand new and truly revolutionary tech. It always takes
01:39a bit of time for it to trickle down to those lower echelots. If CeramicSpeed really are successful
01:46in creating a drivetrain that is 99% efficient, it will of course attract the attention of those chasing
01:52every single one. Drivetrains like this could find a home on top-end TT and triathlon bikes, maybe even
02:01aero bikes optimised for flat races that will end in a sprint. The drivetrain efficiency is one thing,
02:08but the other benefits that come along with a setup like this is that there's no chain to come off.
02:13The system 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 on the bike
02:31and carry on. Snapped mech hangers will become a thing of the past, although SRAM's direct mount rear
02:37derailleur 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 Honbike. They have done away with convention and constructed a pretty
02:57sturdy and utilitarian version of a similar concept. In Honbike's case, they have also made the housing for
03:05the driveshaft integral to the frame and it doubles as the chainstay which holds the rear wheel in place.
03:12Honbike 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,
03:22it's not impossible. 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 is the Humboldt belt drive.
03:51Commonly found on urban and commuter bikes, the belt drive is just that. A belt very similar to the one
03:57that you might find in your car, but also has humps or teeth that engage with a similarly shaped front
04:04chainring and rear sprocket. Unsurprisingly, the belt itself can't be shifted, so to work
04:10around that limitation, belt drive bikes are often ones that instead incorporate a hub gear.
04:16For 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
04:27cannot rust. The hub gear is completely sealed from the elements and often only ever need servicing
04:33once every few thousand miles and even then it's just a case of topping up any oil that might have
04:39escaped. Hub shifting is notoriously smooth, it's very much a fit and forget type of system.
04:47Perhaps it's down to a lack of awareness or education, but I think that this tech on a flat bar hybrid
04:54is quite possibly the best option out there. There are minimal downsides for the intended user,
05:00but 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 onto
05:13road bikes. Let's not forget that Shimano Di2 was first found on an e-bike nearly five years before it
05:19showed up as an option for road bikes. So I think it's prudent to keep a keen eye on the latest
05:26innovations that pop up in that sphere as one day it would not be a surprise to see it become the new
05:31normal for road bikes. One innovation that has come from the behemoth that is Shimano is their
05:38automatic stepless shifting. You may be thinking, what does it do? Well, quite what it says on the tin.
05:46You start pedalling and when you do, you'll be in a nice easy gear to get you going. Then,
05:51as you build up speed and work up to a faster cadence, the auto box will move up the gears to
05:57allow you to increase 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 audible
06:10click quickly followed by a change of cadence. Perhaps this could be a great option for those who
06:16just 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
06:30terms of the next best alternative to the conventional drivetrain. Perhaps this is because
06:36it's not too far removed from what we already have. As the brand seeks to ditch the front derailleur
06:42and replace it with a wireless two-speed hub gear, we're still left with a conventional chain
06:47and rear derailleur setup. But the new tech does mean that front shifts can be conducted under extreme
06:53load without the risk of misshifting or dropping a chain. And chain lines can be optimised for an even
07:00more efficient setup. The last hurdle that the brand has to overcome is the integration with the shifters
07:07themselves. At the moment the hub is operated by a wireless button that mounts to your handlebars,
07:15but hopefully one day in the future the tech can be integrated into the OEM shifters without voiding
07:22any warranties. My 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
07:38PowerTap 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
07:59possibility. Let me know, what do you think the future is for the Humble drivetrain? Do you think
08:06it will ever develop beyond the conventional two derailleur system we already have? Do you think
08:11Classified or CeramicSpeed have the answer? If you enjoyed the video then please do drop it a like,
08:17subscribe to the channel for more content and I will see you again very soon.
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