Hey guys according to the Haynes manual I need to replace my chain as it has more than 25 mm sag. It's says thatboth sprockets need to be replaced. Does this mean I have to replace the smaller front sprocket as well?

Thanks.

Hi, if your wheel is as far back in adjustment and your chain still has that much sag in it then yes you should replace both front and rear sprockets. If you put a new chain on old sprockets it'll just wear the new chain out very quickly!
Happy new year

Ian

Ok thanks. Yeh the red mark on the rear wheel slider is just about pulled back till it meets the marker on the block on the inside of the swing arm, if that makes sense.

Something to try for your amusement. Can you pull the chain off the rear sprocket, at the mid wrap around point, by more than a 1-2mm . If so then chain is probably on its way out. Next put a section of new chain on the same sprocket and repeat the test. IMHO, if the new chain is a tight fit ie cannot be pulled of the sprocket, then the sprocket is probably good for another go round with a new chain.

My view is that chain pin, bush and roller wear results in pitch change that allows the chain to ride up the sprocket teeth. If this process is allowed to continue it will eventually damage the sprocket teeth, but if a new chain is tight on the "old" sprocket then it will not ride up the teeth.

Chain pin, bush and roller wear is why O ring chains are considered superior and should last longer that non O ring. The O ring traps lubricant between pin, bush and roller. Also I believe oiling O ring chains is basically pointless as it is unlikely that any lubricant is going to get to the pin, bush and roller interface unless the O rings have failed, in which case the chain is stuffed.

Oiling the chain can only provide lubricant between the roller and the sprocket teeth, and since these two components do not form a moving interface at any time, there is nothing to lubricate. Also, I find it hard to believe that the lubricant that might initially be trapped between sprocket teeth and roller is capable of keeping these components separated under the driving force of the engine.

HINT, loosen the front sprocket bolt before removing the old chain

Ok cheers I'll give it a go