new chain and sprocket bedding in time..

[Timmy_Biker]

This might be helpful to know for anyone about to change their chain and sprockets.
I changed mine out for some JT sprockets and a DID gold chain, all standard toothing and 525.

I did an initial 10 miles after fitting, and that made the chain slack, and in need of adjustment. Which is understandable.
I then set out on a 700 mile journey.
About 200miles in i checked the chain tension to find it very slack. So i took it easy for another 150 miles until i could get it tensioned again at a mates house.
On my return journey it slackened again after 180 miles of very spirited riding on the Welsh roads.
Eventually when i returned home, and a further 200 miles, it needed another slight adjustment and seems to have settled down now.. 
I was not aware of the amount of initial stretch and shakedown fitting new chain and sprockets would present.
So note to self;
If intending to set out on a long journey don't fit a new chain and sprockets set! At least not a few hundred miles afterwards anyhow..

[burty]

I have not used JT sprockets but it shouldn't go slack liker that at all.  I've never needed any kind of bedding in for a C&S set.  Rather obviously check your chain adjustment is properly torqued up.  Otherwise I would be suspicious of the chain.  There used to be a lot of fake DID chains about, did you buy from a reputable dealer?

[mdr1970]

I run JT front and back and have  for a few years now without any issues.
Certainly never noted anything like that requiring multiple adjustments so soon

It can't be any of the hardware wearing so quickly (teeth of sprockets, or rollers on the chain) so it must be down to pinch bolts and the like...

[Timmy_Biker]

Thanks for the replies.
I agree, first of all i would think that the eccentric cam was slipping because of the pinch bolts not being torqued up to correct tightness. I tightened to 60Nm.
I know its supposed to be 64Nm but i feel that is a little tight for the size of the bolt going into an alloy swinging arm. I have never had issues from that amount of torque before.

But i did keep an eye on the indicator marks, and they didn't move in between re-tighenings.
I did have a chap ( much more experienced in mechanics then me) check the chain real closely, link by link, on my second go at it. He thought the chain was healthy and genuine.
One point that may have exacerbated the whole thing is the tendency for the cam to move back a little (slacken), when the pinch bolts are done up.  A little like three steps forward and one back, if you get my meaning!
Back at home, with more familiar tooling, i was able to hold the cam still while torquing the pinch bolts up.
Seems to have settled now.