Bbr 4 stroke 49cc eng limits

[Will'smotobikes19]

I think he has a bbr lock n load. Huasheng has an electronic governor built in. You shouldn't worry about rpm going up a hill because the rpms drop. If you always go downhill full throttle it could wear on the motor some but again the governor kicks in. I have a 49cc honda ruckus it will carry me 240lbs up a hill at 15-20 mph. Unlike the 2 strokes most people use the 4 stroke has a built in air cooling system instead of using the air going by as you're riding. Shouldn't overheat.

 

[Sidewinder Jerry]

I think he has a bbr lock n load. Huasheng has an electronic governor built in. Dont know if he has a 37cc or a 49cc. You shouldn't worry about rpm going up a hill because the rpms drop. If you always go downhill full throttle it could wear on the motor some but again the governor kicks in. I have a 49cc honda ruckus it will carry me 240lbs up a hill at 15-20 mph. Unlike the 2 strokes most people use the 4 stroke has a built in air cooling system instead of using the air going by as you're riding. Shouldn't overheat.

Oh but you should worry about rpm going up a hill. Max torque is at 4500 rpm on these engines and clutch engagement is around 4000 rpm. Dropping below 4500 rpm can put you near the engagement point thus potentially burning up the clutch due to slippage.

At least with a multi-speed bicycle one can choose a ratio that's more efficient in maintaining the 4500 rpm while pedal assisting.

 

[Will'smotobikes19]

Oh but you should worry about rpm going up a hill. Max torque is at 4500 rpm on these engines and clutch engagement is around 4000 rpm. Dropping below 4500 rpm can put you near the engagement point thus potentially burning up the clutch due to slippage.

At least with a multi-speed bicycle one can choose a ratio that's more efficient in maintaining the 4500 rpm while pedal assisting.

Maybe that's why some people on here have problems burning huasheng clutches. On my honda I've never done anything to the cvt except putting 5.5 gram sliders in the variator.

 

[Sidewinder Jerry]

Maybe that's why some people on here have problems burning huasheng clutches. On my honda I've never done anything to the cvt except putting 5.5 gram sliders in the variator.

That's exactly why they burn them up. The clutch on my bike is 14 years old. The reduction range on my bike is 66.79\1 to 16.25\1. It's the widest range in both forum histories. On my engine max torque rpm is at 5000 and max hp rpm is at 7000. So if at full throttle I drop below 5000 rpm I shift to a lower gear; if I go above 7000 rpm I shift to a higher gear.

 

[darwin]

And wheel size.

Disagree, I used to think wheel size mattered too with a FD. Someone on here corrected me that it doesn't. 1in roller will go a certain distance in a 1000revs, 1.25in roller will go farther in a 1000revs. 1in roller will have more torque than the 1.25in roller just like gearing, all assuming same engine rpm.

 

[Sidewinder Jerry]

Disagree, I used to think wheel size mattered too with a FD. Someone on here corrected me that it doesn't. 1in roller will go a certain distance in a 1000revs, 1.25in roller will go farther in a 1000revs. 1in roller will have more torque than the 1.25in roller just like gearing, all assuming same engine rpm.

After checking math formulas, you're right tire size doesn't matter, only roller size when it comes to determining speed. However, when determining what the reduction ratio equivalent would be, tire size does matter. Tire Size ÷ Roller Size = Reduction Equivalent using that same size tire.

 

[Sidewinder Jerry]

Disagree, I used to think wheel size mattered too with a FD. Someone on here corrected me that it doesn't. 1in roller will go a certain distance in a 1000revs, 1.25in roller will go farther in a 1000revs. 1in roller will have more torque than the 1.25in roller just like gearing, all assuming same engine rpm.

Using a 0.93" roller will only give a top speed of 19 mph. It's also like using a reduction system of 29\1 on 26" wheels. Which isn't enough reduction for large people (225+ lbs) going up steep hills (20+% grade). One needs at least a 40\1 reduction and a lot of pedal assist.

For a starting gear on level ground I use a 37\1 reduction on 26" wheels.