Need help with gears on chainsaw bike

With China girl engines they which are actually 66cc they generally run a total reduction between 11:1 to 14:1. The engines that run a reduction under 5:1 are the 212cc.

As for gear ratios a 9t is around the smallest you'll find that'd be practical to use. I recommend this engine to jack shaft 10:40; jack shaft to rear wheel 10:40 for a total reduction of 16:1.

Here's your speed formula:

RPM÷(1056× total reduction)×wheel diameter × ⚻

6000÷(1056×16)×27.5×⚻=30.7 mph.

That's a very realistic build for a first time DIY build. I also suggest for the small sprockets to use 410. This way you can use 410 chains.
 
Ok wat would u suggest for gearing for a result of 45mph im looking for something to go fairly long distances so I need to have it go a little bit faster
 
Mrgoodcat said:
Ok wat would u suggest for gearing for a result of 45mph im looking for something to go fairly long distances so I need to have it go a little bit faster
Click to expand...
Your engine is too small to realistically expect to do 45 mph. At best you might could get up to 35 mph provided you aren't a very large person and you don't have any really steep hills to contend with.
 
Last edited:
O it did!!!
 

Attachments

  • 20210803_045330.jpg
    20210803_045330.jpg
    72.7 KB · Views: 182
  • 20210803_045259.jpg
    20210803_045259.jpg
    69.5 KB · Views: 195
iv got everything set up right,,, i think ,, and it wont start ? i checked the wiring, plug and fuel everything seems to be in order ,, wats up?
 
You must log in or register to reply here.
Back
Top