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jstark47 wrote:Larger (more teeth) front sprocket.

That would likely require a longer (i.e. new) chain, whereas dropping a few teeth on the rear sprocket would allow him to shorten and reuse the chain he has. Plus, going larger in the front will sometimes cause clearance issues and will most certainly spell disaster if the chain breaks.

MakeCarsStandSTill wrote:I was wondering if anyone could help me or tell me how to change gear ratios? does anyone know?

Pull the clutch lever in and pull up on the gear-shift lever..... I'm just here to help out with the obvious

As a point of reference, on my XS650 YAM, the stock sprockets are 17 front, 34 rear. A drop in one tooth on the rear produced a 300 RPM drop at 60 mph, and two teeth down produced a 500 RPM drop at 60 mph. Going up to an 18 tooth sprocket on the front with the stock 34 tooth rear produced a 500 RPM drop at 60 mph. I never tried an 18 tooth front and 32 tooth rear combination for fear of stressing the clutch, but the combinations that I tried produced no loss of roll on speed at 60 mph with one up rider. XS

thanks for you help guys!

with the exception of high side!! LMAO

roscowgo wrote:Let us know how the sprock-swap goes on that 250. I'm pretty curious.

I got home last night to find a package waiting for me... two sprockets and a pair of boots. Since I ride the bike to work I decided to stage the change and only install the front sprocket... the rear sprocket will be replaced this weekend.

The front sprocket was $13.99 from Dennis Kirk, and since I was also ordering some boots (jumping the total over $100) shipping was free. The change probably took 30-45 minutes, much of that spent readjusting the chain tension.

I went for a ride last night, and then commuted to work this morning... about 75 miles total since the change... not a huge difference, but the bike is a lot more pleasant. Around town and on tighter twistier roads dropping into 1st before a turn is no longer a mistake...you can accelerate all the way through an intersection without having to shift now, and on the interstate the bike is just a little bit calmer (approx. 500RPM drop at 60MPH) without much loss of performance.

All told, I'd say it's the best $14 you can spend on a Ninja 250.

I'll drop the 42t rear sprocket in the rear this weekend, but I'm not sure if it'll be too much of of a change.... we'll see.

ZooTech wrote:

jstark47 wrote:Larger (more teeth) front sprocket.

That would likely require a longer (i.e. new) chain, whereas dropping a few teeth on the rear sprocket would allow him to shorten and reuse the chain he has. Plus, going larger in the front will sometimes cause clearance issues and will most certainly spell disaster if the chain breaks.

Not necessarily. Routine practice in the Bonneville world (bike I'm most familiar with.) Bonnevilles come with 17 tooth fronts standard, can go up to 19 tooth with no chain problems. Chain adjusters have enough play to make up the difference. Can cause a little clearance issue with the chain guard, but that's easy enough to fix. No particular reason for the chain to break with the 19 tooth front any more than the 17 tooth.

Yep... don't always need a new chain... I went from 14t to 15t without any problems. Chain is basically new, too (3600 miles) so not stretched out and saggin.