Hi all,

I have an MC21 and just got a new 520 chain as the old one was looser than a (insert maternal reference here).

Anyway the new chain is all good and tight which is good - however I have a new problem where because the chain is tight, the inside of it is rubbing against a bit of chassis near the front sprocket. Quite loud when coming off throttle. If the chain was a tiny bit more slack then it would not touch. However there is no more give in the rear wheel position to loosen it.

Anyone else ever have the problem? I'm thinking of just waiting for the chain to stretch. However its not a nice sound when you are trying to sell the bike!

When you say "tight" tell me you don't mean the chain actually is tight.
There's got to be some slack in it, it says 20-30mm up and down movement midway between the front and rear sprocket is about right.
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Sounds like the chain is too short. This is real bad! It will cause handeling problems as well as damaging the chain and sprockets.
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Argh yes its too tight! Its actually tight. Why did the guys in the shop do this? They are a dirt bike specialist.

So I don't know much about chains but what can I do? Possible to get a new link added or do i need a new chain? The rear wheel has run out of movement to make it looser. Its a 520 chain - same as my old loose one.

Thats odd dirt bike chains are often run even looser because of the long travel suspension. You may be able to run two master links and a one extra link but that will probally be too long. If you have a chain riviting tool you should be able to make it long enough. I would take it back to the shop and make them fix it. I don't know if I would want a shop that let a bike out the door like that working on my bike again though.
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Sounds about right for a NZ motorcycle mechanic. You need to fix it or it'll crush the rubber engine mounts and end up cracking the frame or breaking something.

thinking back the chain should be 520,108 links on the 21 and as fontyyy said 20-30mm up and down movement

Have you check that the adjuster isnt all the way out ? Should be in the green section if you still have the little sticker on there
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