Brucey wrote:one thing I would mention is that the B1 chain is made to different tolerances than typical bushingless chains are. In particular the amount of slop in the rollers appears to be quite a bit less.
It seems to me that one knock-on from this is that, on a used (and slightly worn) sprocket, a new B1 chain is liable to be noiser and less smooth-running than a new bushingless chain might be.
cheers
i've just found this to be true. i'm hoping that the chain and sprocket wear in a bit soon as it drives me nuts.
if the (usually sprocket) teeth are even slightly hooked, this is what makes most of the noise. You can 'dehook' the teeth with a bit of cunning grinding action, and this is usually reasonably successful on a SS/fixed/IGH setup, whereas it more usually isn't entirely successful with derailleur sprockets. The setup still won't be entirely silent, because the rollers will be bearing against the 'ramps' that lead into the 'hooks', so won't be 'perfect' until the chain and/or the sprocket has worn slightly.
With an IGH, once the chain and sprocket are worn, the amount of noise in the transmission varies with how slack the chain is; it needs a fair amount of slack to run silently, and I think this is so that the chain can ride outwards on the sprocket so that the pitch of the teeth (which is larger at a bigger diameter of course) better matches the pitch of the (worn) chain. Obviously this amount of chain slack less than pleasant when riding fixed, plus there is a real danger of the chain unshipping, so the net effect is that fixed gear bike chains are usually need changing well before IGH ones do.
The KMC B1 chain is not particularly hard-wearing; I usually don't mind this on a bike running an IGH, because the sprockets are cheap and I can tolerate a fair amount of chain slack. But on fixed gear and with expensive sprockets, I might well choose another chain, or expect to 'demote' the B1 chains to an IGH bike on a regular basis when they are slightly worn. If you want to preserve your sprockets and don't have a use for ~0.5% worn B1 chains, it might seem a bit wasteful.
BTW in my dreams I make a chain lube that genuinely separates the (large) bushing surfaces in 1/8" full bushed chain. In this event it doesn't matter much if the bushings are made in very hard material or not; if they are clean and well-lubed, they are not touching so they oughtn't wear. Needless to say it hasn't happened yet...
yes i've been a bit disappointed with B1 chains. i thought they'd be a lot more hard wearing. the trouble is most 1/8th chains seem to wear quickly. hey ho, not so expensive i guess. there was a sachs chain years ago that seem to last well. something like PX-1 or similar. can't find those anymore.
SRAM PC1 chain is the equivalent 1/8" chain today. However this is a bushingless chain. I've been a bit disappointed with those too TBH, but I think they do wear better than the KMC B1.
Brucey wrote:SRAM PC1 chain is the equivalent 1/8" chain today. However this is a bushingless chain. I've been a bit disappointed with those too TBH, but I think they do wear better than the KMC B1.
A couple of years ago I bought a number of KMC 710SL 1/8" chains from Planet X @ *£3 each ( *Probably 'cos they were PINK ! ) - Impressively smooth and quiet and lasted me well commuting in all weathers.
Wippermann also do a 1R8 model which is allegedly more wear resistant than the 108/100.
All these chains are fully bushed
cheers
ahh. they do the job yes just not for very long. i ran a 108 a few years ago and it lasted maybe 800 miles. cruddy conditions and everything but hmmm not so good. maybe give them another go though as most chains seem fairly disposable.
the last fully bushed wippermann chain I used was a 3/32" one, some years ago, on a derailleur system. I wasn't terribly impressed with it, and soon reverted back to my then usual diet of Sedisport/Sachs chains. But I guess I am overdue giving them another go....
All chains ae a compromise of some kind but I have a sneaking feeling that perhaps the usual manufacturing route for fully-bushed chains results in a compromise regarding the busing hardness. The bushing that joins the inner side plates is made from a piece of wrapped sheet metal; this metal must be ductile enough to be formed into the bushings, yet hard enough not to wear very fast. The pins (rivets) can be case-hardened (the wippermann ones claim to be IIRC), but I doubt very much that the bushings are ever as hard as that.
If the loads are low enough, the bushing has a large enough area and the lubricant has a high film strength, then in theory the hardness of the bushings isn't likely to be as important. However getting to (leave alone staying in) this magical condition seems to be tricky; maybe it isn't ever a realistic expectation with a fixed gear drive...?.