Much appreciation for this thread. I’ve had to refer to it twice!
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Mavic have been working on a compact mid-drive with some unique features.
Cycloidal drive that will utilize 24mm axle from regular crankset. There is an attachement that will drive the chainring. Complete disengagement from drive unit to cranks with a one-way clutch.
Lightweight at a total system weight of 3.2 kg. Only 39 Newton meters of torque nominal at 250w.
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I’ve recently been speaking with FreeFlow Technologies in the UK about their new motor system. It’s a compact mid-drive in the same vein as the TQ and Mavic motors but looks really well suited to steel frames as they have an external battery option and can supply a steel motor shell. I was clear about being a hobby builder and they seemed perfectly happy to speak with me, sell me one of their systems, and offer tech support during my build if I need it. They claim the motor is fully serviceable by any bike shop - that alone is a massive difference from most other manufacturers. They’ve been working with a number of other small builders already too, according to their web site and Instagram feed, and say they’re happy to ship internationally.
To be clear, I’m in the process of ordering but no money has yet changed hands and I’ve not yet got hands on or ridden the motor but, if all goes well then I’d say they’d be a great company to deal with as a hobbyist or small-scale builder. I’ll follow up here as things progress.
There was a Road.cc video published a couple of months ago which put me onto them:
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I have a Tern GSD with a Bosch mid-drive, and I hate the way the power just abruptly cuts out at 19.8mph. @Alex – on the other end of the spectrum, how does your bike ride with the assist set to zero or turned off? On my Tern, I feel like there is a ton of drag which makes the bike literally unrideable – it feels like a brake is dragging or something, but of course the bike coasts downhill just fine. I’ve always wondered if that’s normal or not…?
Thanks!
-Jim G
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I had the same experience with the cutout on a Shimano EP8 system. My conclusion was that anyone fit enough to be pedalling a bike above the cutout speed is not going to enjoy the drop in power. And here in AU the legal limit is lower at 20km/h (15.5 mph).
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To follow up on my purchase of the Freeflow motor, the parts have arrived and I’m planning for the build in another thread.
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Picking up on this thread, and raising some points:
- You need to work with a motor company that will sell you single units, this is how we work at FreeFlow.
- You need the system to not compromise your on style of frame building, right?
- As you all make amazing frames and sell them to customers around the world you need a motor that can be serviced in any bike shop in the world, this is a key design feature of the FreeFlow System.
Finally just in summary we as a brand are here to support you on the journey of stalking into making eBikes, please do contact me to discuss your goals on ebike building.
Regards
David
Dear Jim,
I would like to add a comment to your point around “drag” The FreeFlow system has been created that when the rider goes past the regulatory cut off speed or if they run out of battery the FFT system resistance is only the BB bearings and the pedal bearings, this make our mid drive ride like a normal bike.
With a MOQ of only one system from us and we also make the steel motor bracket its very easy and fast for you to get a working bike that you and your customers can try very quickly.
Take a look at the integration file on this link for our system: FreeFlow System file
Be happy to chat more here or contact me at david@freeflowtechnologies.com
David
I just saw this message @jimg. Yeah, the older Bosch systems (gen 2) feel terrible when manually pedaled. There is a big gear reduction that you are pedaling through (to speed up chainring speed for the small cog) and that has a lot more friction than a normal IGH. I think this is better on the newer Bosch bikes that use normal size chainrings, but I haven’t ridden those enough to say.
My other e-cargo-bike uses a hub motor that has a clutch and it has essentially zero drag so it rides quite well with the motor off. Hub motors have a poor reputation but work pretty nicely in my experience.
Hi Alex, thanks for that info – ugh that makes total sense now that you mention it! My bike has the tiny front “chainring” so it must be the Bosch Gen 2 system. I always wondered why the newer Tern models started coming with normal front chainrings!
Thanks!
-Jim G
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The small chainring was a clever way to avoid a massive single stage reduction inside the motor box, but trades it off with a crank-based one. My wife has the same first generation GSD as you (and I have a R&M Packster that uses the same drive system) and can confirm that it’s gen2.
The Cyclone drive systems with an externally visible chain are doing something similar, it’s just all visible.
FFTMotors who keeps chiming in here uses a cool harmonic reduction to make this all pretty compact. I have no experience with those though. It’ll be interesting to see what these look like with a higher max torque suitable for cargo bike solutions.
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Paul Brodie has a 2-part series of building a hardtail ebike on his YouTube channel. The downtube made of sheet metal is impressive.
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I don’t know if anyone has seen this but looks like an interesting concept. It says it works with the Shimano EP8 mounting. Speaking of which, does anyone have any sort of CAD for the shimano motor cabinet? The closest I could find was a partial drawing on Ti Cycles website.
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I started modelling one from the Shimano tech manual and also from the dud motor Shimano supplied me for dummy fit ups. When I decided to can the project I didn’t modelling any further.
Thankfully someone has done it all though and in a bunch of formats. Always check against the dimensions you can get hold of though.
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Thanks!
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I would reach out to Allotec via Email. They have provided me with their CAD in the past. I have their Bosch Cabinet.
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Excellent, thank you!
I reached out to the manufacturer (intra drive) and they said these units will be available Q2 2025. Very nice staff that I corresponded with.
I got this file from Framebuilder Supply.
E55 motor cabinet.step (2.5 MB)
This is the EP8, EP6, etc shimano motor cabinet
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Thanks! That’s great.
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