Who could rewind my outrunner?

[Metallover]

Originally Posted by johnrobholmes

I see now you are using a stoker setup. Can you run the chain from your stoke hub to the biggest ring on your cranks?

I could do that but I'd have to get a couple chain links and the pedals would spin really fast. I might do that if rewinding it proves impractical for the cost.

sabongi - That part is a freewheel and acts as a pinion. Making it bigger would make the gearing even worse.


The gear reductions are - 11/72 to the "spool", 14/32 to the crank, and 48/12 to the wheel in top gear. I want to get about 35 in top gear. The motor is 250kv at the moment and I'm running 24v. That's 6000rpm. The wheel has a 13" radius so 2pi13=81.7 inches/revolution.

I'm not quite sure on my math, but I think I get 1,584 rpm at the wheel so that's... holy sh!t - 180mph!! - Someone check my math...

I figure I will need 1,168rpm at the motor so thats... 49kv.


Is this going to work out or will I need to make some major changes to the gearing?

[whitrzac]

Originally Posted by Metallover

I could do that but I'd have to get a couple chain links and the pedals would spin really fast. I might do that if rewinding it proves impractical for the cost.

sabongi - That part is a freewheel and acts as a pinion. Making it bigger would make the gearing even worse.


The gear reductions are - 11/72 to the "spool", 14/32 to the crank, and 48/12 to the wheel in top gear. I want to get about 35 in top gear. The motor is 250kv at the moment and I'm running 24v. That's 6000rpm. The wheel has a 13" radius so 2pi13=81.7 inches/revolution.

I'm not quite sure on my math, but I think I get 1,584 rpm at the wheel so that's... holy sh!t - 180mph!! - Someone check my math...

I figure I will need 1,168rpm at the motor so thats... 49kv.


Is this going to work out or will I need to make some major changes to the gearing?

I think your best bet would be to get a 3s lipo
IDK if a flux capacitor will fit on a bike though

[crazyjr]

Originally Posted by Metallover

I could do that but I'd have to get a couple chain links and the pedals would spin really fast. I might do that if rewinding it proves impractical for the cost.

sabongi - That part is a freewheel and acts as a pinion. Making it bigger would make the gearing even worse.


The gear reductions are - 11/72 to the "spool", 14/32 to the crank, and 48/12 to the wheel in top gear. I want to get about 35 in top gear. The motor is 250kv at the moment and I'm running 24v. That's 6000rpm. The wheel has a 13" radius so 2pi13=81.7 inches/revolution.

I'm not quite sure on my math, but I think I get 1,584 rpm at the wheel so that's... holy sh!t - 180mph!! - Someone check my math...

I figure I will need 1,168rpm at the motor so thats... 49kv.


Is this going to work out or will I need to make some major changes to the gearing?

it's been a while since i was in school, but i thought it was pi X diameter, not 2pi X diameter. if you do single diameter you get 40.82. Still moot point because if everything else is right, you are still looking at 90 mph and still need further reduction or lower kv

Originally Posted by crazyjr

it's been a while since i was in school, but i thought it was pi X diameter, not 2pi X diameter. if you do single diameter you get 40.82. Still moot point because if everything else is right, you are still looking at 90 mph and still need further reduction or lower kv

metallover's right... It's 2*pi*r to get circumference or a circle

[crazyjr]

Originally Posted by Bad Karma

metallover's right... It's 2*pi*r to get circumference or a circle

My bad, didn't see the radius, I assumed diameter

[johnrobholmes]

Another 5:1 would be your best bet. Can you pedal at 35mph though? search google for top hat adapter, you could put a 36t sprocket on your disc brake side and get all the geardown you need with your stoker setup.
Just going down in KV won't help, you will loose all of your power.

[Metallover]

Originally Posted by johnrobholmes

Another 5:1 would be your best bet. Can you pedal at 35mph though? search google for top hat adapter, you could put a 36t sprocket on your disc brake side and get all the geardown you need with your stoker setup.
Just going down in KV won't help, you will loose all of your power.

YEAH!! That's awesome. Not only will it work and be easy, but it will suit all me needs and it will be more efficient. I'm going to do some more research. Feel free to show me what I would need.

I just did some math and I'll need a 14/185 pinion/spur to do it all in one shot.