I'm only getting 25mph with the 32 tooth sprocket?!?

[classicjondo]

Hi all, I've had my Huasheng 4-stroke bike for a while now, and I use the 32-tooth sprocket with it. It gave me about a 5mph boost over the stock one, but I see people on here and YouTube boasting about their 30-40mph bikes?? How does a guy go about getting that kind of speed from the 4-stroke? I looked into a shifter kit but it's just too expensive for me to justify getting it. So what do you guys recommend for aftermarket parts to get me going faster? Thanks a ton!

 

[ultralight01]

Jackshaft kit. You can upgrade parts but it won't gain you much more speed. Either custom build a 4 stroke bike with a predator that can go 40mph or stick to 30 max without a jackshaft system.

 

[classicjondo]

Ugh, that's what I thought. Is this the jackshaft kit I need? I have the 5G dual-chain gearbox: http://www.sickbikeparts.com/catalog/product_info.php?cPath=21&products_id=110

 

[ultralight01]

http://www.sickbikeparts.com/catalog/product_info.php?cPath=21&products_id=110
This is what you need, or build your own with pillow blocks and various parts. There's a member here who just lengthens the output shaft on the gearbox, which goes straight to the freewheel. However this kit should work quite well.

 

[Greg58]

What was the stock sprocket size, 44 tooth? If so you may have went too far. The little engines need to run at a higher rpm to perform at their potential. A 36-40 might be a good compromise.

 

[UtiliD]

Whats your tire size and gear reduction because if it's 26" or bigger and your using a 5to1 tranny you should be going faster. It's more than a governor holding you up your not getting the rpms this motor is supposed to have. My bone stock 26" tire bike has a 40 tooth sprocket, 5to1 reduction and 26" tire starts off from a stand still and moves my 200 lbs 33 mph on radar. Even if you weigh more the bike just might take more time to get to top speed and it should be more than 25 assuming a 26" tire & reduction mentioned actually even if you had 4to 1 I'm confident you should be going faster. I won't claim mine takes off like a bat of **** but, I don't have to pedal assist to take off at all, even at base of the weak excuses for hills we have around here.