hi everyone i have a mongoose supergoose 2008 that i am converting to a motor bike i have a stihl fs 36 cc 2stroke motor i was wondering for max speed and acceleration and hill climbing ability what gearing should i use ? i also have a centrifugal clutch built into the motor with no sprocket attached and the bike is stock
gear sizing
- Thread starter cox24711
- Start date
Sidewinder Jerry
Well-Known Member
Depending on how much you weigh and how steep the hills are, you may need a shift kit for an engine that small.
I'm 250 lbs. Where I live lots of 20%+ grade hills. The bike weighs 100 lbs uses 26 inch tires. The engine is a Robin Subaru 35. 4 stroke, 33 cc, 1.6 HP at 7000 rpm, 1.2 ft/lbs torque at 5000 rpm and 8000 max rpm. The 7 speed reduction range is 49.21-18.82:1.
Max climbing torque is 59 ft/lbs. I have to lightly pedal assist on 25% grades had heavily assist on 30% grades. From an old setup I used to use a 55:1 reduction I lightly assist at 30% grades. That would give me 66 ft/lbs.
The level ground speed is 28.8 mph at 7000 rpm. The downhill assist is 32.9 mph at 8000 rpm.
I hope this helps some. Knowing the rpm range will really help. You can order a tach fairly cheap on eBay.
I'm 250 lbs. Where I live lots of 20%+ grade hills. The bike weighs 100 lbs uses 26 inch tires. The engine is a Robin Subaru 35. 4 stroke, 33 cc, 1.6 HP at 7000 rpm, 1.2 ft/lbs torque at 5000 rpm and 8000 max rpm. The 7 speed reduction range is 49.21-18.82:1.
Max climbing torque is 59 ft/lbs. I have to lightly pedal assist on 25% grades had heavily assist on 30% grades. From an old setup I used to use a 55:1 reduction I lightly assist at 30% grades. That would give me 66 ft/lbs.
The level ground speed is 28.8 mph at 7000 rpm. The downhill assist is 32.9 mph at 8000 rpm.
I hope this helps some. Knowing the rpm range will really help. You can order a tach fairly cheap on eBay.
Last edited:
cox24711
New Member
hi i weigh 40 kgs and the bikes wheels are 20 inch
The_Aleman
Well-Known Member
You're not going to get "max speed and acceleration and hill climbing ability" with one gear. You can get max speed or you can get acceleration/hill climbing ability.
With one gear, you'll always have to compromise somewhere.
With one gear, you'll always have to compromise somewhere.
cox24711
New Member
then what gearing should i use? for max speed
The_Aleman
Well-Known Member
I don't have near enough information to answer that question. I don't know anything about your engine or what kind of drive system you plan on using.
Even if I knew that stuff, I wouldn't be able to recommend a gear ratio. You'll have to play around with a gear ratio calculator and do some testing to find a middle ground.
Even if I knew that stuff, I wouldn't be able to recommend a gear ratio. You'll have to play around with a gear ratio calculator and do some testing to find a middle ground.
Similar threads
