How do I replace the chain?

Hi All,

I've got a '73 850 Commando. The chain was broken when I got it (link is missing). Is there some sort of magical way to replace the chain without having to remove the primary chain case, clutch and alternator? I can easily get it around the rear sprocket, but trying to get it on the front sprocket is driving me crazy! Any advice would be appreciated.

(For those who helped me in previous threads, I'm happy to report the bike is now starting very easily and running smoothly with excellent idle)

Dave

If you remove the chainguard then you should be able to feed the chain over the gearbox sprocket.

@L.A.B. the only chain guard I know of is the chain chain over the rear sprocket. I don't see a chain guard in the front. The chain is covered by an overhang on the rear cover of the primary chain case.

DaveinCanada said:

the only chain guard I know of is the chain chain over the rear sprocket.

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Yes, well that's about your only choice if you don't want to remove the primary drive case. Or you could try hooking it over with a piece of wire. The best option is to connect the new chain to the old chain then pull it through but I guess that wasn't possible in this case if the chain was broken.

You can feed it over the front sprocket and as Les has said can feed a wire through and pull the chain through that way no need to remove the primary case at all, with the new chain will have to be broken down to size and a retaining clip to join but if the old chain is still on easier to connect to the old chain but as you say its broken so less chance its still on the front sprocket, the connected wire trick will work and you be able to turn the front sprocket from under the primary case, done this a few times when my Norton threw a chain and spat it out on the road.

I used wire method a couple times , a bit of faff but very doable

A long screwdriver usually solves the problem.

How I do it- buy a new chain. Hopefully the broken chain is still in place. I believe you said the problem was the master link was missing. If that is all that is wrong, use the master link from the new chain to connect the new chain to the old chain. You don't need to add the second side of the master link, just carefully feed it through and new chain is on the bike. If old chain is NOT on the bike, I would use the wire method. Good luck!