[corksil]

Hello. I have been through three chains in a hurry with this bike. Between 5k and 27k miles, averaging 7k miles per chain. Sprocket wear doesn't seem too excessive.

Just about to put on new chain and front/rear sprockets.

Each chain installation had me thinking "the front and rear sprockets look slightly out of alignment" after inspection.

Always assumed it was "normal" for such a mass production bike, just something to deal with and not fuss about.

Now I'm about to put on new chain and sprockets and upon closer inspection, the rear sprocket seems offset slightly front the bolt holes.

Closer closer inspection has me thinking that my last rear sprocket was flipped incorrectly in terms of vertical axis.

It would explain why I wore through chains in such a hurry -- each rapidly developing tight spots. I had to adjust one chain so loose to account for the tight spot that it actually popped off the rear sprocket in the middle of a turn.

Another chain actually snapped the masterlink (clip) and under full acceleration power -- was ejected from the rear of the bike leaving me with a 5 mile hike home.

Please take a look at your ninja 250r, and tell me which way your sprocket is oriented.