During my razz around Cornwall in April 2017 I found the chain to be stretching at a most alarming rate. Finally, with 40649 miles under its rollers (!) the trusty DID VM that I fitted way back in November 2011 had stretched to the point where there was no more adjustment left on the chain adjusters and it was still slack. It was so worn that the links didn't really fit the holes in the sprockets any more, there was too much length between each one! So worn, in fact, that I could almost pull the chain around the teeth of the rear sprocket.. Something had to be done. At the same time both front and rear sprockets were hooked and the cush rubbers in the rear wheel had long since given up on the idea of being useful, while the rear wheel bearings were so stiff I could barely turn them by hand - work was required. The saga of the cush rubbers is in the post previous to this, and what a joy that was. Anyway, the first step is actually kind of fun - find the rivet link in the chain (this will hopefully be a little softer than the rest), arm yourself with an angle grinder and grind the ends off the links.
This really wasn't enough. More grinding required!
The only real test of chain wear is to bend it sideways. This shows how much the links have elongated their holes in the plates. Here is the old VM, she did me proud..
That's really very bad. For comparison here is the new chain:
Quite a difference!
I am always interested in trying new brands, and saving money, so after much deliberation I ended up buying a kit from an ebay seller based in Germany - I would get a 104 link X ring chain from XAM, who seem a popular make in Germany and Australia and are of Japanese manufacture so should be good, and sprockets from a selection of manufacturers - you get whatever they have in stock. I got lucky and unlucky in that they supplied an AFAM front sprocket (yuck) and an Esjot rear (interesting!).
Annoyingly they supplied the wrong rear sprocket, Esjot part number 50-32013-31 (JT part 279.31) which is the part for a CMX250C - I need Esjot part 50-32032-31 (JT part 272.31). The two are close, but the base thickness/offset is different. This made it really hard to fit, and I had to use an old washer underneath the new Esjot to make it sit in the correct position. No good sending it back to Germany of course, the postage would be horrendous. Bugger!
The more shallow base also made doing up the nuts harder as the peg things kept spinning round, I found it best to lever the whole lot away from the sprocket with a small screwdriver while twirling a ratchet around on the nut. I should've just bought my own bits separately of course, never trust anyone to provide the right parts if they don't specify part numbers.. Live and learn. And learn. And learn again.. This also means the peg stud things poke out quite a way from the sprocket, almost grazing the swingarm, and aren't as far in to the cush rubbers as they should be. There is nothing good about this situation at all, other than it all fits nice and snug.
Soon enough, it was all together.
The rivet link is right where the Scottoiler tubes are. Riveting a chain is quite a game and a very messy business, the sooner chains go away the better!
Ta da! I must admit I'm also dubious on the merits of painting a sprocket, such as Esjot seem to do - surely the paint will just wear away and cover everything? Never mind, I'm sure they know what they're doing..
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