Can anyone give a step by step idiots guide to removing my front sprocket

I am not very technically minded, and have a history of screwing things up!

I want to change my chain and sprockets for the first time on my 2006 WR250f. I have managed to remove the old chain, the rear sprocket and fitted a new rear sprocket. Obviously I appreciate that the best idea is to change everthing as a set, but I cannot work out how to remove my front sprocket.

I see a nut which obviously will need to be loosened, but when I try to turn this the hole sprocket just moves. I am using an adjustable wrench to try this.

I cannot find any advice in my manual whatsoever in terms of removing this.

Can you help? What direction should I be trying the move the nut, and how do I stop the whole thing from turning? Does anyone have a video/photo of what needs to be done. Is there a recommended (cheap) tool better that the adjustable wrench?

Any help would be greatly appreciated.



Put your rear wheel back on with the old chain. Put the bike in gear and have someone step on the rear brake. The chain will keep the countershaft sprocket from turning while you loosen it. Righty tighty lefty loosey works on Yamaha sprockets. Make sure you straighten out the locking washer on the sprocket nut first, and remember to bend the locking washer back to help keep the sprocket nut from coming loose. Good Luck, WD

Thanks I will give that a try. Only problem is my old chain is already in the bin after removing it with a grinder! Should I fit the new chain and try this do you think?

Thanks again


yes it will work

Or you could just use an impact wrench if you have one. Then it's a one person job.

+2 on the impact gun.

+2 on the impact gun.

I want to change the front spoket bat i cant remove the back wheel. Help me please


I want to change the front spoket bat i cant remove the back wheel. Help me please


is it stuck or something, or have you just never done it?

well if youve never done it, its extremely easy. take the axle nut off and slide the axle out(you may need to give it a little tap). right before the axle is totally out, grab ahold of the rear wheel so it doesnt drop, then just take it off (if the chain is still on, just take the chain off the sprocket, or remove the master link from the chain). and vice versa for putting it back on. clean and regrease the axle at this step. before you tighten the axle nut back on, make sure the wheel is totally forward with the correct chain tension, step on the rear brake pedal hard(hold it down) and turn the wheel forward to lock the brake caliper in place. keep pressure on the brake pedal and keep holding the wheel in the forward locked position and tighten the axle nut until you're sure its snug. then you can release the brake pedal and wheel and fully tighten the nut(be sure to recheck your chain tension).

when the wheel is off, dont step on the brake pedal, or if you do then youll just have to gently pry the brake pads back apart(enough to get the disc through), then youll be fine.

if you knew all of this already and i didnt answer what you needed, then well, cool.!

and yeah, impact is the way to go for front sprocket removal. and a chisel to get to lock washer off.

I had to put my front wheel against my truck so the bike didn't move and i strapped it down. I put a pipe on the wrench for more leverage.

Also do what "Wheeldude" said.

Thanks for everyones advice. I dont have an impact wrench but just had a look on ebay and there are loads really cheap to buy so will probably get one. I notice a lot of them state 1/2" drive. Is this big enough for the nut on the front sprocket or do i need to get a bigger one?

Thanks again


!/2" drive is fine. You want one with a high ft/lb rating, highest you can afford. Only use it to remove nuts. Do not use it for tightening.

Beware though, some things are cheap for a reason.

Just buy a socket large enough and slide a piece of pipe over the ratchet for a bit more leverage. Chain on, rear brake applied. Done.

Don't use an adjustable wrench.


many thanks one and all for your help with this. I successfully replaced the front sprocket using a breaker bar and a large socket.

thanks for your help - much appreciated


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