Retro E-Bike conversion.

[Trebz]

Well it's all fitted now but not being used as the off side crank arm squashes the peddle assist sensor to a point where the crank arm barely turns by hand, way too much pressure on the sensor to take it out riding. I would swap out the bottom bracket for one with a longer axle but it's stuck in the frame. So far approx £400 spent and it's not been used onse hehe. My only idea to make it work is to take an angle grinder to the inner face of the crank arm and grind off 2mm. I'm not happy about doing this as it's a really nice original Shimano unit. The bike has been shoved to the back of the garage for now.

 

[hamster]

Which kit did you settle for finally? Just want to check before looking at one for the Mrs, who has arthritis in her hip.

 

[greencat]

Well it's all fitted now but not being used as the off side crank arm squashes the peddle assist sensor to a point where the crank arm barely turns by hand, way too much pressure on the sensor to take it out riding. I would swap out the bottom bracket for one with a longer axle but it's stuck in the frame. So far approx £400 spent and it's not been used onse hehe. My only idea to make it work is to take an angle grinder to the inner face of the crank arm and grind off 2mm. I'm not happy about doing this as it's a really nice original Shimano unit. The bike has been shoved to the back of the garage for now.

Got a pic?

Depending on the motor the pedal sensor is not absolutely necessary. Sometimes it can even remove any speed limiters as the bike's electronics believe the bike is always travelling at 0 mph

For stuck bottom brackets, I've found nothing can resist an impact wrench. I keep one just for that job now.

 

[Trebz]

Which kit did you settle for finally? Just want to check before looking at one for the Mrs, who has arthritis in her hip.

https://www.yosepower.co.uk/product...36v250w-front-motor-36v15-6ah-hl-plus-battery

 

[IceCzar]

Might start here
https://ebikes.ca/learn/power-ratings.htmlhttps://ebikes.ca/tools/simulator.html
Personally I’ve only built mid drive motor Ebikes where after brakes and placing the extra mass it’s the chain line and wheel strength that are most important.

 

[IceCzar]

Sorry those links don’t directly link, some navigation of the site would be required

Main Menu > Learn > Motor Power Ratings
Main Menu > Tools > Motor Simulator

 

[Retrorockit]

Grin technology in Canada is a good resource for hubmotor info. Actual engineers there.
https://ebikes.ca/I see links to them just above this, but I'll leave it in to 2nd the motion.
In fact I just looked there and they're overstocked on their smaller hubmotor kits because every one is buying their own all axle motor instead. So they're offering 30% off on not just the motors, but whole kits until their inventory levlels off.
https://ebikes.ca/blog/post/mini-g310-g311-kits-on-sale.htmlFWIW Avid BB7 cable discs can handle anything your likely to encounter at 250W. I started a thread here on them.
https://www.retrobike.co.uk/threads/avid-bb7s-in-the-modern-world.485595/ They'll be fine as is at that level, but upgrades can be added as you go.