Hello all. i am looking into changing my gearing to 15/43 to help on fuel economy. if i use that combo will i be able to use the stock chain still? I am halfway on the axle adjustment range. bike only has 1,000 miles so chain wear shouldn't be an issue yet. I'm not worried about loss of acceleration for the 250. I'm not riding it for the performance anyway. it will never be a speed demon so i might as well exploit its strong points. Thanks for any advice on this subject.

.............Thanks for any advice on this subject.

http://www.rbracing-rsr.com/chainlength.html

You are welcome :)

I am thinking the stock chain should be just fine.

Thanks for the link. yes that combo is almost exactly the same length. problem solved !!

My software says to adjust the sprocket 5mm more backward, with the FI-Model you have to go 4mm more forward.

I can work with 5mm's. thanks for the support. best 250 forum around. by far the most lively too!

Thanks for the link. yes that combo is almost exactly the same length. problem solved !! ............
I can work with 5mm's. thanks for the support. best 250 forum around. by far the most lively too!

You are welcome.............. and thanks, there is great group here trying !!!

:thumbup: :thumbup: :thumbup:

Do you think this could be "too much" gear for the engine to efficiently operate?

Do you think this could be "too much" gear for the engine to efficiently operate?

It should be OK if your engine has good torque.

Check this old thread, where 15/41 is discussed:
http://www.ninjette.org/forums/showthread.php?t=64112

This is a leverage exercise, you gain some final speed but lose some torque, which is more noticeable at start ups, up-hill, counter-wind, etc.

08 ninjette here, ran 15-45 for a few years and recently swapped to 15-43. The stock 106 link chain works fine, with room to adjust on the swingarm. Dropping to 4th to pass at freeway speeds (70-80 mph) is fine, and 6th will cruise at a cool 9k at 80 indicated. I did 1000 miles in a single sitting and having the revs lower definitely helps with that. Two up is a bit more difficult, the bike likes higher revs and lower gears however for acceleration. Went from averaging 55mpg to 65mpg with the changeover. Fill ups don't need to happen until 215 miles on the tank anymore. Positive change, do it!

stock length is good don't cut it please like the guy did that I bought my bike from.

08 ninjette here, ran 15-45 for a few years and recently swapped to 15-43. The stock 106 link chain works fine, with room to adjust on the swingarm. Dropping to 4th to pass at freeway speeds (70-80 mph) is fine, and 6th will cruise at a cool 9k at 80 indicated. I did 1000 miles in a single sitting and having the revs lower definitely helps with that. Two up is a bit more difficult, the bike likes higher revs and lower gears however for acceleration. Went from averaging 55mpg to 65mpg with the changeover. Fill ups don't need to happen until 215 miles on the tank anymore. Positive change, do it!

Thanks. i was hoping to hear some personal experience too. I think i will be happy with the swap. thanks a lot.

stock length is good don't cut it please like the guy did that I bought my bike from.

Whatcha mean? He cut the stock chain?

Thanks. i was hoping to hear some personal experience too. I think i will be happy with the swap. thanks a lot.

I RACED on 15/42 with the stock chain. The only thing that sucks is steep hills while 2up.

Things you will notice right away;
Less buzzy at highway speeds
The bike feels more relaxed at highway speeds
You will shift LESS on a normal street ride but have to shift MORE on the track

It feels like 15/43 or 15/44 should have been stock gearing lol