Mini bike gear ratio

Clark125

Member
Messages
116
Reaction score
0
What’s the recommended gear ratio for a mini bike? Also, does the clutch have to be installed backwards from how a go kart will be?
 

mckutzy

Active member
Messages
8,323
Reaction score
15
Location
bc, canada
Define backwards from a kart????
Typically most cent clutches can be run inboard or outboard, in respects to the drive sprocket to the motor.

Depends on the tire size... but a 6:1 is typically a good start.
 

Clark125

Member
Messages
116
Reaction score
0
Gear facing inward towards the engine not outward or away from it.

I should be good then, will have 6:1 ratio on it when everything is installed
 

bob58o

The Independent Variable
Messages
7,600
Reaction score
11
Location
Chicago-town USA
Position the clutch either way so the sprocket lines up with the rear sprocket (or the jackshaft sprocket).
A baja style minibike with 18 or 19" tires comes stock with 10:1 gear ratio with your typical 5-6HP engine.

Every minibike I've put together used a torque converter and wheelied dangerously (how i like it). So my opinion may not be best for what you like.

Tire size, Engine size, and total weight of bike plus engine plus rider... These will be needed to get a personalized recommendation for gear ratio. Plus where do you ride? Streets? Offroad? Do you start and stop often? Or do you take long cruises on country roads? Do you like to cruise at slow speeds?

If somebody asked me what size shoes are good for guys, I'd say around 10.5. That will work for some, but obviously not the right question to ask if shopping for your own shoes.
 
Last edited:

Colemanman

Member
Messages
31
Reaction score
4
If your running tires like a warrior or coleman ct200u with 19 inch tires i wouldnt go under a 5 to 1 ratio. It'll go about 56 mph wide open stock motor governor removed. 5 to 1 is pretty rough on a clutches because it wont lock up until 20mph to 25mph and it will start to smoke/destroy it if you ride under full clutch lock up. Youll be limited to street riding. 10 to 1 as stated above is stock for the Warriors and Colemans, which is perfect if you ride in trails everyday or offroad. Id reccomend for a balance between torque and speed to be either 6 to 1 or 7 to 1. If your minibike has a jackshaft you can finer tune your ratios and even more so with different size clucth sprockets. You get more ratio options with 35 chain by the way. With small tires you can use much taller sprocket ratios but have it offset by the tire size. Must centrifugal clutches can be run both ways, inboard and outboard. If you want torque, speed and versatility get a converter. But remeber a clutch geared properly for its application is just as capable as a converter.
 
Top