Intra Drive's Combined Motor & Gearbox Fits Bikes Designed For Shimano EP8 [Updated on expanding into the aftermarket]
We first spotted Intra Drive at Eurobike 2022, but we now have some more details on the Scottish startup's product that's aiming to disrupt the e-bike drive unit market.
Firstly, it combines a motor and an 8-speed gearbox into a single unit, eliminating the conventional external derailleur drivetrain which can be exposed to damage, requires regular maintenance, and wears more quickly when used with a motor. Secondly, and perhaps even more intriguingly, it uses the same form factor as Shimano's popular EP8/EP801 drive unit, which means it can be fitted to the same bikes. Thirdly, the product is designed with an emphasis on sustainable construction, longevity, repairability, and recyclability. The company even has "Nature" on the board of directors.
Motor specs
The drive unit promises 600 Watts of peak power (250 W nominal) and up to 350% assistance. The torque will vary depending on which gear is selected, so this can't be directly compared to other systems, but assuming the peak power doesn't come at ridiculously high cadences, it should have enough oomph to compete in the "full power" e-bike category. The automotive-style gearbox has eight speeds with a 473% gearing range. The gaps between gears are nice and consistent at 18.4 - 20.8%. There are spur gears made of hardened steel that are changed with an electronic actuator, apparently in just 100 milliseconds. The drive unit weighs 4.5 kg, which is about 1.8 kg more than the Shimano EP801, but remember that includes a gearbox.
The system includes a bar-mounted display and remote (top left) to control the gears and power modes.
The unit can be combined with a chain or belt to transfer drive to the rear wheel. Two systems already exist which combine a motor and a gearbox into a single mid-drive unit, (Pinion and Valeo) but what makes the GD8 unique is that it fits all that into the same form factor and mounting bolt pattern as Shimano's popular drive units, meaning it can be fitted as an alternative option (like spec'ing a bike with either a Shimano or SRAM drivetrain).
It would be great to see an aftermarket option for Shimano owners keen to try a gearbox-based system, but Intra Drive are currently pursuing a Business-to-Business (B2B) model, supplying their system to bike manufacturers so they can offer different motor specs out of a single design. We love the idea of consolidating motor mounts in the eMTB space, but it’s not without issues in the aftermarket—the small chainring size especially may not play nice with some suspension designs. Shimano’s mounting system is open and available for others to use, but we have to assume it will void most frame manufacturers’ warranties to run a motor their bikes weren’t officially designed around. At least for now.
How Intra Drive sees their system fitting into the e-bike market.
The 24-tooth drive chainring is smaller than most ebike drivetrains (which typically use 32-36 teeth). On full-suspension bikes, this will affect the suspension performance by increasing the interaction between the chain tension and the suspension movement (anti-squat), which may not be ideal with some suspension designs - this is something frame manufacturers will need to bear in mind. I asked Intra Drive why they went with this smaller chainring/pulley wheel:
 | The chainring is relatively small at 24t, this is driven by some other parts in the product which constrain how large we can make the chainring. However, this doesn't impact on the gear ratios as we simply size the rear sprocket to achieve the overall ratios we need in the design. We are running a wide single-speed chain on our prototypes, with custom sprockets - this ensures long life despite the relatively small chainring. The chainring rotates at different speeds relative to the cranks, depending on which of the 8 speeds is selected. For example, in 1st gear, the sprocket rotates slower than the cranks, whilst in 8th gear it will rotate 2.4x faster than the cranks. |
Sustainability
Intra Drive claims to have "set out to achieve the lowest environmental impact possible over the lifetime of the product". They aim to achieve this in four key ways: "Longevity and repairability; long-term availability of spare parts; minimise embodied carbon emissions; power the e-mobility revolution".
Yes, the GD8 motor is not just for off-road playthings (eMTBs) but also for powering commuter bikes, e-cargo bikes and Light Electric Vehicles which could reduce the use of cars and vans, especially in cities.
Recently, Intra Drive announced that they would appoint "Nature" to the board of directors - an unusual move but one which has been done before by fellow Edinburgh-based brand Faith In Nature. I asked Intra Drive what this means in practice:
| A company’s success is dependent on having a healthy planet upon which to operate. So giving Nature a seat at the decision-making table can help a business to thrive, whilst respecting planetary boundaries. In practice, we will need to recruit a Non-Executive Director to our board, whose job will be to represent the interests of the Natural world, and who will have equal influence on strategic decisions to other board members. We are not the first to do this - we have been inspired by other forward-thinking businesses, and we hope our radical stance will motivate others to rethink the way we do business. The two links below go into more detail on this. The first article covers the rationale behind appointing Nature as a Non-Executive Director, whilst the second one provides some more practical detail on how Faith in Nature implemented this. One thing worth highlighting is that this unusual and bold move was driven by the lead investor of our current seed investment round, who requested we implement this, which myself and founder Mark fully support. |
Intra Drive is currently in the industrialisation phase, testing pre-production prototypes and building a European supply chain. They expect to see bikes on sale with the GD8 powertrain in early 2025.
For more information, head to intra-drive.com
Update on expanding into the aftermarket
| We would very much like to go down the aftermarket route in the future because it is in line with our circular economy aspirations, and because we get asked this a lot - it's clear there is demand. Our plan is to sell B2B initially, then enter the retrofit market once we're established. The reason we're not doing it just yet is because our unit sits slightly deeper into the bracket and we found that it doesn't fit every EP8/E8000 frame out there. We have a product roadmap to shrink the unit ever so slightly to make it fit more frames, but we still have the issue of chainstay clearance on full suspension bikes due to our smaller chain ring and because our unit is wider than an EP8/E8000, it won't fit carbon frames that tend to wrap around the sides of the drive unit. We stand a pretty good chance, however, of supplying hardtail, cargo and commuter bikes as an aftermarket option. It would also stand to reason that we would make a Bosch Gen2-3 compatible version as well. |
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See the drivetrain silhouette, and overalls even the Orange bike is nice this way :-).
They mention some patented gear shifting mechanism, I must study that !!!
Why? Have you spent a lot of time riding one?
Curious, is this going to have more anti-squat due to smaller chainring size?
If I could buy this, bolt it on to my Decoy and plug it in to the existing battery, I’d order one right now.
Quackity quack quack, mother duck!
I know nothing about suspension design, would that be the same for all suspension designs (4 bar, VPP, singe pivot etc.)?
You'd be off the back, or more likely, off the road.
I wonder are you of German descent and take all jokes literally?
By the way, I made it to the US nationals for 10 years straight, both road racing and time trialing. And I'll freely admit I was nowhere nationally.
Not sure what the joke you were referring to was? Oh, by the way, all the speeds you referenced are slower than the speed I mentioned, which I have topped on numerous occasions. Do I win the contest?
If someone else had picked the down selection keypoints let see.
SHIMANO massive resources massive support massive user base
Bosch massive resources massive support massive user base
Pinion SELF SUSTAINING resources support & increasing user base
Startup hoping to crowdfund and having burned through all the eu and uk grants they could get
I reckon this will belong to someone else in under a year in the current economic climate
I noticed a massive shift in their marketing as soon as pinion dropped their new drive unit.
Just to let you all know we are currently raising investment to enable us to take the product to market, and have a campaign on Crowdcube which is ending TONIGHT! The campaign closes at midnight (UK time).
For potential investors who share our vision, and are already registered on Crowdcube, please see our campaign pitch here: www.crowdcube.com/intradrive
Unfortunately if you're not already registered on Crowdcube you won't be able to invest in this round as it takes 24hrs to register. But please head to our website and sign up for email updates (don't worry, we won't send out spam, only occasional updates of significant mielstones etc). www.intra-drive.com
We'll remain open to larger (£10k+) investments after the Crowdcube round closes.
For further info, drop us a line: investment@intra-drive.com
If the limiter was removed, now we’re talking. Just need a battery with a bit more capacity to offset the extra drag
The pitch of gates belt is slightly shorter than a bike chain, so the outside diameter of a 24t belt sprocket is just over 82mm, while a 24t chainring is 104mm.
I was surprised by this when I got a belt drive -- my 46t sprocket is similar to a 38t chainring.
www.gatescarbondrive.com/~/media/files/gcd/gates-tech-manual-en.pdf
www.wolftoothcomponents.com/pages/chainring-diameter-by-tooth-count
I mean, a belt + sprocket is larger diameter than the sprocket alone (5-10mm at a guess?)
But a chain + chainring is bascially the same diameter as the chainring alone
What could possibly go wrong with this^?
The truth seems to be even more weird.
In light of this, I would recommend avoiding this sort organizational structure or public statements. Doing so doesn’t prevent you in any way from achieving your environmental objectives. So, by all means, please be environmentally responsible with how you operate your business, just remember that these kinds of statements can actually get in the way of accomplishing your environmental aims by inviting criticism as well as unneeded scrutiny and the potential for the spread of misinformation about your environmental work and the motivations behind it.
Frames with the ep8 motor have kinematics and tubes that are designed around a much bigger chainring so if it's not an Orange then the chainstay will probably be in the way meaning you cant fit the Intradrive, and if it doesn't get in the way then the pivots will be in the wrong place for optimal suspension performance, either way frames would need a redesign around the chainring, rendering the whole USP of interchangable mounting without a frame change useless, you may as well redesign the mounting points at the same time and fit the more proven/supported pinion box.
I'm rooting for the startup to disrupt the market but the reality is without the same chainring size the interchangability that makes it stand out, doesn't exist.
And the reapairability/Shimano mount standard for s music to the ears of mtbers sick of incompatible standards
A bigger chainring could see it really take off (or if its good enough bikes designed around it)
Be very interesting to see if this became a settled standard whether regular bikes would go gearbox too
Bummer in a way, as I have made Shimano EP8 frames, and, think they would not have problems with the 'deeper / higher' top section of the Intra Drive that Mark from ID mentions above.
One problem I see with the Intra Drive, is how the RH side case 'wraps' further back around / over the Chainwheel. That Will limit it's fitment on quite a few frames, especially many with a high / forward pivot frames, with an Idler wheel. My frames are like that - well, not that high, but well forward. So, an extra Idler would have to be placed to have the chain go 'back' then forward / up to the original idler.
I can of course make a different frame design, but that problem, that Intra Drive have not given thought to, and the (my assumed) aftermarket (and hence, small frame making businesses like mine) availability being near the same as the Pinion, well, my interest in the Intra Drive has lessened, Considerably. But, we'll see how it all pans out, I guess.
www.effigear.com/fr/content/24-valeo-cyclee
Let's compare them in reality. That would be interesting...
Is it as efficient as a Rohloff for example?
I asked, because if you don't desresctrict the bike, pushing an ebike after 25km/h you push more watts into those pedals than on a bike.
Unfortenatly I can't share actual numbers, since I;don't have a power meter, but for the same effort (feeling):
Ebike: you'll cycle around 32/33km/h
Bike: you'll be close to 40km/h
And air resistance increase with square to the speed (assuming same area).
Drivetrain efficiency, also will have effect on the battery range, so it's not that simple.
Even if it's only 2...3% difference.
And Rohloff when new, is really PITA on this
Anyway I see what you're saying and that does have some importance that I had not thought of.
The rohloff works much better.
In this direction I think combining shifting and motor like pinion, valeo or intradrive will work best.
I'm quite happy with the effigear gearbox. There is drag, but having the chain straight without an idler is super nice in the mud. Chain stays clean and smooth. Instead, I'm running lighter tires which compenstes a little bit for the drag. Getting used to it anyways.
Currently I would never ever combine a motor with a chain shifter in the back. Thats just... nope. The shimano gear hub (nexus 5 speed) is no alternative either
I'm too cynical to believe in "you notice the difference" statements, even if they were perfect apples to apples tests (which they almost never are), confirmation bias is a reality.
Thank you for sharing.
But just some food for though...
Drivetrains markeyt is presently owned by Shimano and Sram.
Neither have internal gearbox, and both, will maintain the wheel rooling, until some real radical company starts to sell internal gearbox like hot cakes.
I don't forsee that for at least some years from now.
Ebikes have a BIG problem regarding reability.
There are all kind of problems, much associated with new tech...
Also, ebikes are still ubber expensive!
To make it less expensive, manufacturers will have to work on ramping up production, sorting all problems. This will automatically lead to lower prices, due to mass production and quality cost reduction
Then, we have the Batteries. And against what people predicted, prices are stable, and power/weight is also stable.
We need lower cost batteries, and higher energy with less weight (like all electrical things with battery!).
Manufacturers such as Shimano and Sram, will work towards this problems, gaining much more market, as prices goes down.
Who wouldn't have an ebike (a good one), if it cost ±800euros more than the equivalent bike?
Internal gears may appear at the very high end, but it will be so few, that it's easier to find the golden pot at the end of the rainbow
Please try and experiment, then you may enter and discuss.
Until then.... LOL
Btw, whether you have a 100% efficient drivetrain orone that is 50% efficient, that e-bike motor resistance won't change (because why would it).
Bless you and all the ground you smash with your holly tires
Most people couldn't accurately gage their power output or speed within 10% (that's why even tour de france riders use headunits and powermeters) without data, to then go and notice much smaller efficiency variations is insane.
But bless you if you somehow have a god like awareness of your body, that is a real superpower.
I'm not saying it's 4%, 3%, or even 10% efficiency difference.
What I've stated since the begining, is that it's a noticeable difference with this:
- pushing an ebike beyond the speed limit - you will feel the motor drag
- pushing any hub gear bike, with similar tyres and weight - rohloff/sturney/shimano (never tried sram/sachs).
It's like the iddler pulley drag.
Some swear that they notice the drag, others will say it's BS.
Take care... carefull with those step climbs, pedalling standup!
Chains have a limit
Maybe this type of product development from a small brand will influence other major brands to build their own version and release it to mainstream faster so it's not so proprietary.
If this thing is truly modular and motor parts can be replaced easily, that would be awesome for sustainability, and to reduce the worry about stuff going expensively sideways after warranty expires.
What I'd really love to see would be an industry wide standard for mounts, both motor and battery. Unlikely in an industry that can't even agree on sticking with BSA73 BBs, but hey, one can dream.
Think about this more as the gearbox and motor on your car; it's nice likely to break over the life of the vehicle and if it does, you'll need to take it to a specialist anyways.
Car manufacturers like to argue safety or privacy (with all the stupidly integrates electronics), but you can easily wreck yourself with a car just changing a tire or many things that are "allowed"; the privacy bullshit is attempting security through obscurity which any security expert will tell you is literally useless.
Bike electronics manufacturers are trying the same bullshit, and we're trying to call them out before it gets entrenched as "the way".
It should be the opposite, actively encouraging people to take on repairs and overhauls themselves, but in doing so and making products modular manfacturers open themselves up to their competition catching up plus cutting off their future revenue by not having that planned obsolescence when a product is updated and parts are mysteriously no longer available. Or, as Shimano are hideously guilty of, not having spares available at all and you're forced to buy a complete assembly anyway.
This product seems like a good starting leap, making it plug into an existing motor envelope. Plus if it is truly more environmentally sound for the product lifecyle then all power to them. Unfortunately corporate greed is completely at odds with with environment but this shows there is still, maybe, some hope left...
That said, I totally agree with you that normal 12 speed bike maintenance isn’t exactly rocket science, nor is it very time consuming.
How? There is no dirt coming in and unlike chains gears don't stretch, so they don't wear out.
IF something goes wrong it's much harder, but the key point really is that you can design a gearbox to work with virtually no wear parts. Just make the gears as thick as they need to be and they will work happily forever. On a derailleur where space and shifting performance constraints mean that you have to accept cassetes and chains wearing out.
Belt vs. Chain is another debate, I think if belts turn out to really be bad, single speed chains and sprockets are an option and don't need nearly as frequent replacement as chains that work with a derailleur.
This bs virtue signalling makes me sick....
If e-bikes are still bothering you, perhaps skipping the articles will alleviate some of your concern?