Hellcat Rear Sprocket mod???

[HooterScooter]

First I apologize of this has been addressed (I searched but didn’t see this specific mod addressed). I have done the 428 17t front already. Wondering if there is a mod for the rear or a different chain to squeak out a bit more on top end speed. TYIA.

[Big Bird]

Grom 428 chain conversion rear sprockets should work. I haven't seen a instance that the front sprockets 14-17t wouldn't cover though.

[HooterScooter]

Grom 428 chain conversion rear sprockets should work. I haven't seen a instance that the front sprockets 14-17t wouldn't cover though.

Just noticed my post did not save the entirety of my message. Wondering if there is a chain and/or rear sprocket swap I can do in order to squeak out any more top end on the 125cc. I’ve already done the 428 17t front mod. Thanks again

[Big Bird]

Weird I just had the same issue, I was able to go back and copy what I had written.

"With these bikes the hurdle to top speed seems to be hp vs aerodynamics. I don't think you will see more top speed than what is attainable with a 16t/17t front and 34t rear. I think you would start to lose top speed if you went any taller on gearing, at least on flat ground.

I can gain about 5mph going into a "full tuck" riding position. And I have noticed even what I wear has an effect. When I am "squiding" it. I noticed my top speed seems to be a couple mph higher than when I'm riding with my jacket.

These bikes are so hp limited that everything seems to have an effect. I'm still waiting for some of the parts in the mail but I'm going to do a high compression bbk and high lift camshaft to get me to the next level of speed out of the 125. Supposed to be good for about 12hp+. The only other option for more speed is to go the zs190 route which is 18hp?!?!"