Circlip pliers. There are internal and external types.

Don't change a front sprocket without changing the chain and rear sprocket with it.

Rob

 

i have to buy a a back sprocket to if i just need the front sprocket??

 

Yep.

You rear sprocket and chain will be worn. They''ll wear out your your new front sprocket.

You can get away with replacing a chain on its own if the sprockets are OK, but with a worn sprocket you need to replace the full set.

Rob

 

Agree with William^. (Circlip/split ring; same thing to me.)
ALWAYS use your free hand to slightly "shield" your face when using circlip/split ring pliers. (Hold your hand near the assembly so if/when the clip goes flying, it doesn't get lost or injure you.)

 

With 13,000 miles on my bike, I'm still on the original 13 tooth sprocket, and on the second one (45) changed early on. If you ride serious and over the edge motocross then yes you should change out the sprockets as a set. But after all of these miles on my bike, none of the sprockets even showed wear or curl. Waste of money in my opinion to buy both when only one is needed. Even when I installed a new o-ring chain last year I left the sprockets alone. They mesh absolutely fine and have shown no wear whatsoever. JMO

 

wow, you got the frickin energizer bunny set then deej. I get one year on the putt putts. dirt bikes right at 1yr as well. Anything over 1 yr wear for me and it is time for a full set.