Sparfuchs
1 kW
- Joined
- Nov 22, 2020
- Messages
- 305
Hello EV Friends,
I'd like to covert a downhill bike into a e-dirtbike hybrid with all the normal bicycle components (cranks, gears ect.) but with a dirtbike seat, a 24 inch rear wheel and a powerful mid motor to do burnout drift, powerwheelies and fast acceleration or hill climbing. I don't need it to be faster than 70 kph/45 mph.
I don't really need it to be super light but as I think the power is anyway limited by the stability of the bike chain, the swingarm and the spokes I won't benefit from a motor with more than 10,5kg/23lbs like the cyclone 18kw (also has way more power than I could use without damaging or bending parts I guess). A DHB is quite robust but still not a dirtbike.
First I was thinking of a cyclone 3kw (nylon gears) used with way more power and optimized cooling and temp control and a gear ratio (aside the gearbox) of 13t freewheel to 53t chainring, then 32 chainring to a 11t-52t cassette. That would give me a ratio of up to 6,65 right. So with the gearbox I'd get at 52t gear a torque of 864 Nm (130 nM x 6,65) at a speed of 135 rpm (900 rpm / 6,65). Am I right so far ? So that a lot of torque (maybe more than the bike or the nylon gears can handle ) but I'm more worried that the acceleration might be bad because of the reduced speed ? In case I use the mentioned set up: First I thought of a 16s battery because I don't need to much top speed, but do you think I'd need a 20s because of the big speed reduction ?
As I could do a speed reduction of up to 6,65 I thought that a more powerful motor without a gearbox would give me better results ? So what motor do you know that could do the job ? A criterion that must be considered is that the motor can't be wider than the cyclone (171,5mm) because of the cranks. The only option I found was the cyclone 18kw with 178mm and 10,5kg... but less power and weight would be better. The most interesting wold be the motor Kuberg uses (8 to 15kw), or of the bykstar dirtbike (also 8 to 15kw), or maybe one of the lightning rod motors ? But I wasn't able to find any details to these motor or where to buy them.
So what do you thing I should use ? I also appreciate solutions I didn't think of yet but please no motors that cost more than 1000 €.
Thanks a lot for your help
Best regards Sparfuchs
I'd like to covert a downhill bike into a e-dirtbike hybrid with all the normal bicycle components (cranks, gears ect.) but with a dirtbike seat, a 24 inch rear wheel and a powerful mid motor to do burnout drift, powerwheelies and fast acceleration or hill climbing. I don't need it to be faster than 70 kph/45 mph.
I don't really need it to be super light but as I think the power is anyway limited by the stability of the bike chain, the swingarm and the spokes I won't benefit from a motor with more than 10,5kg/23lbs like the cyclone 18kw (also has way more power than I could use without damaging or bending parts I guess). A DHB is quite robust but still not a dirtbike.
First I was thinking of a cyclone 3kw (nylon gears) used with way more power and optimized cooling and temp control and a gear ratio (aside the gearbox) of 13t freewheel to 53t chainring, then 32 chainring to a 11t-52t cassette. That would give me a ratio of up to 6,65 right. So with the gearbox I'd get at 52t gear a torque of 864 Nm (130 nM x 6,65) at a speed of 135 rpm (900 rpm / 6,65). Am I right so far ? So that a lot of torque (maybe more than the bike or the nylon gears can handle ) but I'm more worried that the acceleration might be bad because of the reduced speed ? In case I use the mentioned set up: First I thought of a 16s battery because I don't need to much top speed, but do you think I'd need a 20s because of the big speed reduction ?
As I could do a speed reduction of up to 6,65 I thought that a more powerful motor without a gearbox would give me better results ? So what motor do you know that could do the job ? A criterion that must be considered is that the motor can't be wider than the cyclone (171,5mm) because of the cranks. The only option I found was the cyclone 18kw with 178mm and 10,5kg... but less power and weight would be better. The most interesting wold be the motor Kuberg uses (8 to 15kw), or of the bykstar dirtbike (also 8 to 15kw), or maybe one of the lightning rod motors ? But I wasn't able to find any details to these motor or where to buy them.
So what do you thing I should use ? I also appreciate solutions I didn't think of yet but please no motors that cost more than 1000 €.
Thanks a lot for your help
Best regards Sparfuchs