Managed to find time to fit the new 428 sprockets with the 428 chain today...

Managed to find time to fit the new 428 sprockets with the 428 chain today, rushed like mad but wondering if I could of messed up I doubt it, bike just seems to be a lot more quite (like 7k Rpm sounds like what 2-3k used to) and I have lowered the ratio a little bit (+1 tooth front and back) but it dosent seem to have kick in any gears, and reached a lower top speed too, going off the same gps speedo as before.

All iv done since last ride was, Change oil, new 428 chain and sprockets and adjusted my chain as it seemed loose. Anything I could of missed?

Good parts from Ben, quality stuff.

  • What a weird gearing change. you made the gearing slightly taller, which is dumb to do on a stock motor, you'll probably lose both acceleration and top speed. Also the chain is heavier so it'll slightly (maybe not even noticeable) decrease acceleration.

  • Yeah thinking that, my thing is long roads to work. So the potential top speed was worth the chance all I can think is chain is too tight. Rest all seems right.

  • They need like 3cm of play or something like that. Seems excessive but it tightens up heaps with weight on it. So it'll seem loose with nobody sitting on it. You're correct in assuming the top speed will be potentially increased but groms barely have the power to pull redline in fourth gear with standard gearing

  • So it's 16/35 now, which is higher ratio might get a 14t to get 14/35 which will be an interesting one much in the other direction to choose what I need or which I prefer

  • Chain has 3cm exactly, but I'm a big lad so might need more haha slow speeds does feel like it's got a tight spot but has less than 10miles on the chain

  • Better to be loose on the safe side than too tight

  • I know your slowdown isn't because of extra weight or friction in the chain. Ive been running 428 for a while now without any slowdown. It has to be the higher gearing you went with. I went with 15/36, gearing it lower allowed me to reach a higher top speed compared to the stock 15/34.

  • Yeah gunna get a 14t front then so I can go 14/36 and 16/36 so I have each end of the spectrum just gotta wait payday again haha see if I get used to it by then or see if it changes

  • Yeah I'll stick it over to 4cm

  • Yeah going to get a 14t front as well swing is far the other way see which I prefer 52mph was my max coming home from work on new sprockets was 56 before on stock

  • You added a tooth to the front. That's where you went wrong. Unless you're bike has oodles of power never go up on the front.

  • Depending on where your rear axle is adjusted to now you might find the chain is to slack with a 14t fitted.

  • It's almost as far forward as it will go just slightly back. If it dosent fit I'll I'll shorten it abit

  • You do know that going 1 tooth bigger on the front is the same as loosing 3 on the back so that would theoretically give you a higher top speed if the engine can still rev out in top . If you then also went 1 bigger rear then you're still running higher gearing assuming you're saying you went 1 tooth up from stock

  • Yeah I know I was still going to a higher gearing just added one on the back to make it abit more subtle, just lowered everything haha gunna get a 14 front flip the other way