Sprocket upgrade tips
 

Hey guys, wondering what's the best way to upgrade your sprockets for more torque on the coolster 3150-dx2 150cc. What size and how many teeth for the rear as well as front? Is it a simple mod? Where do you get the sprockets from? Upgrade the chain as well? Thanks guys.

Hey there Zack!
Check this thread, http://www.chinariders.net/showthrea...=215343&page=6
The procedure etc. should be the same, or very close.

Regards,
Dak

Hey Zack first you need to find out what size chain your Coolster has.

Second is find out what the bolt pattern and spacing is for the rear sprocket. Take note of the center hole diameter too.

For the front sprocket you will want to pay attention to the splines. I'm not sure though what sort of shaft you have coming out of that CVT though.

I think yours is similar to the TaoTao 150's .. I believe there are some better choices in gears front and rear for that style ATV if its 520 chain.

My Rhino is a 530 chain setup.. not sure what yours is. I stuck with that size chain for the added stress of the very heavy loads I am hauling. This link may help you figure that one out for sure... http://www.gizmology.net/sprockets.htm

To figure out the largest sprocket you can fit in the rear without having to hack the sprocket guard and re-weld it use this link. https://www.rbracing-rsr.com/calcsprocketdiam.html

I think I used the McMaster Carr websites 530 sprocket page for dimensions of the different amount of teeth at the time.

Keep in mind if you do go bigger then the rear sprocket guard can handle you will lose ground clearance.

I'm not a big fan of buy and try .... and not knowing if what I bought will fit. A lot of these Chinese ATV parts dealers will sell you parts they state will work, but wont work, wont fit so be careful if you don't see specs and dimensions listed. Those grainy pictures can be deceptive. I paid a little more from a dealer I could trust but got it right the first time. Do your homework.

I think a lot of us on here are a bit frugal so don't think I'm alone on this. :)

The guys on here are a great help... if you get stuck... ask

One last note. Steel sprockets will last much longer then aluminum. Only a concern if you are racking up a lot of miles.

All that and I forgot to answer the question... I ramble sometimes. :doh:

You want less teeth in the front sprocket and more teeth in the rear for torque. It works the same on bicycles, minibikes, gokarts and any other geared contraption you can think of.

For an automatic CVT setup you would change the sprocket that goes from the CVT unit to the rear sprocket. Changing both sprockets makes a big difference with them. It did on my minibike. My minibikes torque converter (Tav2 Clone) did have a spring in the rear pulley that could be set for more torque or more speed along with a middle setting.

That adjusted the tension on the spring to change the rate the pulley opened and closed (shifted) Not sure if the CVT has that option on yours. Might be possible to get a heavier rated spring though possibly.

You will lose top speed if you go this route. If you don't go full open throttle and keep it there its not much concern. You will still have plenty of top end speed to get around.

Another thought on what you’re looking to do. The CVT setup on your Coolster is adjustable for more low end grunt or higher speeds. There are springs and weight that change the belts movement that will give you what you need. I would start there before changing teeth.

http://www.chinariders.net/showthread.php?t=17928

Both pages have some great info on tuning the CVT on these quads.

Thanks guys. And swampy you're right. I'm probably gonna start off upgrading the springs or maybe just the whole clutch to 1500 pound springs. I read that it holds you in first gear longer which is what I'm looking for to get up hills and stuff. Definitely replace belt with a Kevlar one. You can even put heavier roller weights in the front varistor. Has to do with physics and spinning at high rpm. That's why it's called a centrifugal clutch. Definitely gonna look into stiffer springs before I start changing chains and sprockets. Thanks again guys.

If the spring is anything like the one on my Tav2 torque converter be prepared for a workout when you preload the spring.

If they offer any special tools to do the swap ... buy em.

Yea a spring compressor might be needed. And I'm guessing a flywheel remover tool? I've removed flywheels on a 50cc gy6 before and didn't need that tool they sell. Maybe the 150cc is different.