Hey is there any way to look at a primary chain still in place and tell if it should be replaced? I'm putting on a new Rotor/Stater & cleaning my clutch plates so I'm right there but I don't really feel like pulling the gear/clutch basket. My chain "looks" good, the adjuster is not anywhere near even the 1/2 way mark through it's travel. No visable wear that I can see. Has any one had one break or is this something I can do when the hub bearing eventualy needs replacing? Thanks.

I think it would be very helpful if you would state approximately how many miles you think are on your chain.

I know that before I switched to a belt primary, my chain was replaced at around 15,000 miles and I remember it
showing little metal pieces of the rollers gathering in the bottom of the primary upon periodic inspection.

gtsun wrote:Hey is there any way to look at a primary chain still in place and tell if it should be replaced? I'm putting on a new Rotor/Stater & cleaning my clutch plates so I'm right there but I don't really feel like pulling the gear/clutch basket. My chain "looks" good, the adjuster is not anywhere near even the 1/2 way mark through it's travel. No visable wear that I can see. Has any one had one break or is this something I can do when the hub bearing eventualy needs replacing? Thanks.

Stretched or broken is how you tell. They will last a long time.

Those triplex chains can run just fine with a few missing links.

Sorry 1up3down, If I knew I would have stated the age. I bought this bike from a well known Norton fanatic & he was selling it for the 1st owner who lives in Asia now. The bike had close to 65,000 on the clock & has allways shown that it was maintained well. Top end was new when I got it and it pulls like a train, I'm sure this is the second or third chain on this bike & for all I know it could have been fairly new when I got it. The bike had been well gone through. I'm just wondering for those who have had failures, were they near the end of the adjustment leangth? This one clearly is not according to how much room for adjustment it has.

Chain wear is best checked by trying to lift links out valleys on back side of sprockets. New chain will not lift out its valley and as much as used one does - that's where the teeth are baring the wear loads. Chain tension has NO Effect on this measure. I feel guilty when chain lifts ~1/3 up teeth. Primary sprocket teeth are many and tough so can take a lot of chain slack till chain link innards crack up.
If in doubt spend more time and money, again.

I found a split roller or two in the bottom of the primary chancase at about 33K miles on the original Renold chain. I rode it like that to finish out the summer and then I replaced it with one of the CZ chains from Andover Norton.

when ever i buy a bike, unless its new or i have very accurate records, i always replace the primary chain - always- they are fairly cheap and easy to do. Having one break and shattering the primary (and i have this occur before this practice) or the engine case (!) from trying to get a few more miles out of it is not my idea of "stretching" a few bucks