What Are Drivetrains On Road Bikes?

The drivetrain as we know it, with two derailleurs and a chain, has been the favoured method of

converting spinning legs into speed for nearly 100 years. As we all know, over this time we have

seen countless improvements to the system, which has landed us with where we're at today

which by all accounts is a pretty refined and efficient system. However, as we reach what may

be a plateau of innovation in this space, suggesting we may actually have the best version

of the system, it's only natural to wonder what the next generation of drivetrains will be

While the current system serves the masses really well, for some, there are some potentially huge

gains to be had in other technologies. CeramicSpeed debuted its wacky looking system back in 2018

much to the intrigue of anybody who set eyes on it. It works by using sculpted plates rather than

chain rings and sprockets with an electronically controlled drive shaft which can shift between

different diameters of the plate to engage a different gear. As yet it's still very much in

the testing and development phase however CeramicSpeed claims that it was able to achieve

a speed of 45 kilometers per hour on the track on a single speed prototype during part of its

low testing phase. If this drivetrain ever does hit the market in the first instance it will

undoubtedly be incredibly expensive but of course that's the same for any brand new and truly

revolutionary tech. It always takes a bit of time for it to trickle down to those lower echelots

If CeramicSpeed really are successful in creating a drivetrain that is 99% efficient

it will of course attract the attention of those chasing every single want

Drivetrains like this could find a home on top-end TT and triathlon bikes

maybe even aero bikes optimized for flat races that will end in a sprint The drivetrain efficiency is one thing but the other benefits that come along with a setup like

this is that there's no chain to come off. The system is more compact and therefore more aero

CeramicSpeed are claiming that they have recorded an advantage in specialized wind tunnel

But finally, since there are no delicate components hanging off of the frame

if a rider is to have a crash, they should just be able to jump on the bike and carry on

Snapped mech hangers will become a thing of the past, although SRAM's direct mount rear derailleur also seems to be doing a pretty good job of this

From one direct drive system to another, but one is actually in existence and is available to

purchase, is the Driveshaft Tech from Honbike. They have done away with convention and constructed

a pretty sturdy and utilitarian version of a similar concept. In Honbike's case, they have

also made the housing for the driveshaft integral to the frame, and it doubles as the chainstay

which holds the rear wheel in place. Honbike has offered the system within their e-bike range

and given the system weight, it's unlikely something similar would make it over to the

world of road bikes. However, it's not impossible. There are a lot of engineers in the world

all of whom are much smarter than me. So perhaps there could be a middle ground between what

Honda Bike has created and what CeramicSpeed are working on, and perhaps that's where we'll

see more of an affordable direct drive system emerge from. One of my favourite drivetrains, and one which I feel is often overlooked

is the Humboldt Belt Drive. Commonly found on urban and commuter bikes, the Belt Drive is just

that, a belt very similar to the one that you might find in your car, but also has humps or teeth

that engage with a similarly shaped front chainring and rear sprocket Unsurprisingly the belt itself can be shifted So to work around that limitation belt drive bikes are often ones that instead incorporate a hub gear For riders who demand bomb simplicity I don think you can get much better than this

There's no oily chain to make your legs or clothes dirty, it doesn't need lubing

and it cannot rust. The hub gear is completely sealed from the elements and often

only ever need servicing once every few thousand miles. And even then, it's just a case of topping

up any oil that might have escaped. Hub shifting is notoriously smooth. It's very much a fit and

forget type of system. Perhaps it's down to a lack of awareness or education, but I think that this

tech on a flat bar hybrid is quite possibly the best option out there. There are minimal downsides

for the intended user, but there is so much to be gained. E-bikes have actually played host to

quite a few innovations years before they've made their way onto road bikes. Let's not forget that

Shimano Di2 was first found on an e-bike nearly five years before it showed up as an option for

road bikes. So I think it's prudent to keep a keen eye on the latest innovations that pop up

in that sphere as one day it would not be a surprise to see it become the new normal

for road bikes. One innovation that has come from the behemoth that is Shimano

is their automatic stepless shifting. You may be thinking what does it do? Well quite what it says

on the tin. You start pedaling and when you do you'll be in a nice easy gear to get you going

Then as you build up speed and work up to a faster cadence the auto box will move up the gears to

allow you to increase your speed while keeping you at a comfortable cadence. But the really

remarkable part about this is the ease at which it changes gear. You barely feel a change, it's

more of an audible click quickly followed by a change of cadence Perhaps this could be a great option for those who just want to focus on riding and let the bike take care of the rest Lastly and potentially most importantly

Classified seems to be leading the charge in terms of the next best alternative

to the conventional drivetrain. Perhaps this is because it's not too far removed from what we

already have. As the brand seeks to ditch the front derailleur and replace it with a wireless

two-speed hub gear, we're still left with a conventional chain and rear derailleur setup

But the new tech does mean that front shifts can be conducted under extreme load without the risk

of misshifting or dropping a chain. And chain lines can be optimized for an even more efficient

setup. The last hurdle that the brand has to overcome is the integration with the shifters

themselves. At the moment, the hub is operated by a wireless button that mounts to your handlebars

but hopefully one day in the future, the tech can be integrated into the OEM shifters without

voiding any warranties. My hope is that SRAM decide to acquire classified and then build it

into their entire ecosystem. Imagine this, a pair of zip wheels with a classified hub that also makes

use of the brand's ownership of PowerTap to create a Zip classified PowerTap set of wheels

and then perfectly integrates with SRAM's already wireless group sets. What a dream that would be

One for the future I'm sure and perhaps I'm being a little optimistic that such a thing could ever

exist but it's not outside the realms of possibility. Let me know what do you think the future is for

the humble drivetrain? Do you think it will ever develop beyond the conventional two derailleur

system we already have? Do you think classified or ceramic speed have the answer? If you enjoyed

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and I will see you again very soon