From Concept to Prototype: Ultra-Light Ebike Kit for Road Bikes Now in Development!

[Katrina92]

Hi everyone,
The enthusiasm from our previous discussions about a lightweight road bike-compatible hub motor (targeting bikes like my Scott Addict) inspired my engineer partner and me to take the leap — we’ve built a functional prototype!

Why This Matters:

• There are few ultra-light e-bike conversion kits on the market for thru-axle riders. Although systems like the Mahle X20 meet the lightweight requirement, they're only available on complete bikes. So, it seems that riders like me, who don’t want to buy a whole e-bike, have few options left.
• Our goal is to create an ultra-light, super-compact hub motor, which can assist climbing without being a burden, only helping when needed, while preserving the essence of the cycling experience.

Here is my previous post:
https://forums.electricbikereview.c...-the-idea-in-my-head.57724/page-3#post-681391

What We’re Sharing:

• A design sketch

• Prototype structure components

Welcome to leave your comments. Any thoughts will be appreciated

 

[Base]

kindernay like hub-shell would be great to be able to service the motor and easy-er building wheels. Also how are you going to include a torque arm/ non turn washer like thing to the hub? Build in rotation sensor or pressure sensor?

 

[mschwett]

Hi everyone,
The enthusiasm from our previous discussions about a lightweight road bike-compatible hub motor (targeting bikes like my Scott Addict) inspired my engineer partner and me to take the leap — we’ve built a functional prototype!

Why This Matters:

• There are few ultra-light e-bike conversion kits on the market for thru-axle riders. Although systems like the Mahle X20 meet the lightweight requirement, they're only available on complete bikes. So, it seems that riders like me, who don’t want to buy a whole e-bike, have few options left.
• Our goal is to create an ultra-light, super-compact hub motor, which can assist climbing without being a burden, only helping when needed, while preserving the essence of the cycling experience.

Here is my previous post:
https://forums.electricbikereview.c...-the-idea-in-my-head.57724/page-3#post-681391

What We’re Sharing:

• A design sketch

View attachment 194018

• Prototype structure components

Welcome to leave your comments. Any thoughts will be appreciated

how is the reaction force against the frame handled? there’s a reason lightweight carbon road eBikes have much heavier rear dropouts than their acoustic cousins - to house the non-rotating nut and transmit those forces into steel pieces embedded into heavier carbon members.

i would guess the chainstay is where you’ll need to do this, with some kind of external arm. seat stays are too thin and of more variable geometry. power wires also have the potential to be super messy, are you going to get them through a custom through axle?

 

[Rás Cnoic]

Thought there was something fishy in your previous messages. Something about the tone was a head scratcher. I even began to suspect this was AI.

It didn't quite add up that you were just looking for help in finding a lightweight motor.

I feel used...

 

[PedalUma]

From experience, lightweight road bikes are already pushing limits without margins of redundancy for strength. You will kill the bike, not enhance it.

 

[Stefan Mikes]

Good luck Katrina. I'm waiting for your future report. I still wonder where you intend to house the battery and what battery. Hopefully, the bike frame would not crack at the most unfortunate moment, so you'd be able to report!

There were thousands of bike inventions that now pave the Hell.

 

[EMGX]

Thought there was something fishy in your previous messages. Something about the tone was a head scratcher. I even began to suspect this was AI.

It didn't quite add up that you were just looking for help in finding a lightweight motor.

So, in 2 weeks posts go from discussing with an engineer friend to a prototype (image no longer visible on my browser), right. What's next a crowdfunding announcement?
No one was "used" since anyone is free to post despite whatever their true intentions are and forum members are free to respond or ignore but I agree that the multiple threads and posts didn't seem to fully align with the OP stated intentions - and now this.

 

[Gionnirocket]

The factory has already started trimming weight off the unnecessary. . .

 

[PedalUma]

But it could work if rolling backwards. First an aside: I was working as an inside sales support advisor for a large bike company. Someone called in. Their bike rolls forward in their apartment but does not roll backwards. The answer was KICKSTAND! When rolling forward the freewheel coasts. It only engages when rolling backwards. So according to the drawing it could work going backwards, but not forwards. It would not engage but only spin without moving the gears in the forward setting.

 

[harryS]

Hope you succeed, . Seems like you'll be using a lot of gears in there to push a bike..

 

[EMGX]

But it could work if rolling backwards. First an aside: I was working as an inside sales support advisor for a large bike company. Someone called in. Their bike rolls forward in their apartment but does not roll backwards. The answer was KICKSTAND! When rolling forward the freewheel coasts. It only engages when rolling backwards. So according to the drawing it could work going backwards, but not forwards. It would not engage but only spin without moving the gears in the forward setting.

The sketch looks similar to how the Keyde thru axle compatible hub motor works. It isn't a true thru axle which just passes thru the hub but the motor axle is integral to the motor itself with cap screws/bolts screw into the axle part to fix it. The Keyde axle is horseshoe shaped to fit into the "dropout" indentations. Since this type motor doesn't use any torque arm it appears that it would depend on being fixed by compression between the dropouts while axle rotation would also be secured by the U shaped indentations At least that is how it looks to me, I'm not an engineer and don't have a carbon thru axle bike (I have an aluminum framed one).

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