I have a 1989 Kawasaki ZX750 H1 and I just got it from the shop and started riding it. I was just wondering if anyone could help me. When Im doing about 65 mph im in 6th gear at about 6000rpm, that just seems way too high to me, it seems like I should be in 4th or maybe 5th, but not 6th. My redline is 12rpm and my speedo goes up to 170, at this setting it seems like I would top out at 120 or sumtin. Everything seems to be fine on the bike other than that, it shifts fine and everything. Im not sure if I need a bigger sprocket or what, but even stock seems like it should be better than that. Anyway, Im new to riding crotch rockets so if anyone could help or give advice, please post.

 

What tooth number of sprockets are on the ride right now?

edit: I went up 2 on the rear on my '90 and 5th gear is 156mph radared at 11k rpm. I need to double check on the full sprockets since I play with gearing at certain track conditions.

 

I just counted 46 on the rear.. and as far as I know its stock.

 

ok, had to go look on what is on it now. 16/46

 

So is that right for those size sprockets??

 

Do you think that if I were to upgrade to a 48 on the rear then that would drastically improve my top end?

 

No, it would lower your top end. Stunters use larger sprockets in the rear, smaller in front - changes the groundspeed for the torque curve. You want to go the other way - BUT - you will lose some of your take-off if you do. 1 tooth in the front is equal to 3 teeth in the rear.

 

So your saying that if I want to improve my top end and do 150 in 5th gear than I need to add teeth to the front and reduce them in the back? I always thought you could just get more teeth in the rear. More teeth does mean a larger sprocket right? And larger sprockets should increase the top end.

 

Think back to your old 10 or 21 speed bicycle. Big gear in back = go slow but more low end torque. Small gear in back = go fast, but require lots of power at low speeds.

To be honest - the 7 should easily hit 150 with stock gearing... if it doesn't, then you have something else happening. Remember it is also a 6 speed, not a 5 - you mentioned "top end" "150" and "5th gear" all in the same sentence.

If you do decide to mess with the gearing... I would lose a tooth or two from the rear, and not mess with the front, but that's me. I have never honestly found the need to alter from stock gearing on any of my Ninjas. The ZX9 cruises at 72mph at 5000, and I believe my ZX7 would cruise at 64 at 5000 - but that was a 93.
$.02

 

Ohh!! Okay I understand, so going with something like a 44 on the rear would help out a lot. One more thing though, is it a big deal if im only getting about a 1000 to 3000 rpm drop when shifting up?