Brucey wrote:The clearances on the roller bushings vary with chain design, and the campag measurement contains 1x roller bushing slack.
Just measured a brand new cheapo chain I bought to fit on the RSW16 I have in the shed.
132.29mm Therefore the Campag method works.
-on that chain....
Roller clearances are different on different new chains and then vary between chains as they wear. This isn't always related to the chain 'stretch', which is the more important thing.
I can't, for the life of me, understand why there is so much agonising about this. I cannot see the advantage of measuring with Vernier callipers unless you intend to measure every link and ditch the chain if one single link is out of spec. The name of the game is wear management. Wear and tear is not a precision process. Much better, surely, to make a simple measurement on a sensible sized sample (12"?) or the whole chain, that can then be compared with a similar measurement made on a new, or, perhaps more usefully, a nearly new chain. (One given a few hours use just to settle down and expel any excess factory lube). The key point, for me, is that the decision about whether the chain is scrap or not, is a rule of thumb anyway. If you get it slightly wrong, either way, it's not the end of the world. Is it?
Trying to retain enough fitness to grow old disgracefully... That hasn't changed!
Mick F wrote:....Chaincheckers are all basically the same in that they gauge the internal distance of a number of links....
except that isn't the case; some (a few) chain checkers are built such that they eliminate the roller slack from the measurement entirely. IIRC shimano's is like this, but it is one of just a few that are. On a short gauge length, roller slack can be significant.
Although it may not be vitally important when you change your chain, exactly (provided you don't leave it too long....) you could otherwise decide that Brand A chain is wonderful and Brand B is rubbish simply because one has more roller slack than the other.
When proper wear tests are carried out, they eliminate roller slack from any measurements, I believe. If you want to know how your chain really wears for some reason, then I think you should do the same thing.
Mick F wrote:Mr Tullio Campagnolo and his mates suggest this:
that is the max after which which u dump the chain? Mine I just measured with the dig vernier is 132.82. My Sram PC41 were in fact packed in sealed Campagnolo wrappers.
Elsewhere I read they say 0.03% wear but thats for 11speed chains
So are the wear-dump rates different for differnt speed chains. eg I remember reading for my park tool they do say can be used for 9/10 but have to dump before u get to the .75% and the 11 speed at .5 rather than the 1% if my memory is correct.
NA Thinks Just End 2 End Return + Bivvy - Some day Soon I hope You'll Still Find Me At The Top Of A Hill Please forgive the poor Grammar I blame it on my mobile and phat thinkers.
