Hovering chain, ready to throw the chain away....
 

On two different bikes I have tried a low priced chain. Both times it has shifted okay sometimes, and others it hovers on the tips of the teeth and slips. Is it just the junk chain I guess? I've never had this happen before except the other budget chain. It's a black KMC, and their stuff is usually okay right?,,,,BD

You'd try cheap ones too, every other shop in town wants $16 and up for any brand of multispeed chain....

what set-up are you usuing? A chain that is HG compatable may do this on UG or other old freewheels.

Well, no clue what HG and UG is? It's a "multispeed" pkg'd by bell, but is a KMC brand. It seems narrow enough, as it will sit down in the gears without touching either gear beside it. The bike is an 85 Peugeot with a Helico matic. I didnotice it mainly only happens during upshifting, but not going little to big. The very
edge of the chain side plate rides on top of the gear teeth.,,,,BD

Guess I'm going to buy a chain. I have to ride it to work tomorrow.....

Okay, now there's a $20 SRAM on it, and it's doing the same, just not quite as bad? What exactly is going on with this thing? All the equipment seems to be functioning. All cleaned and relubed, etc. It wasn't doing it with the chain that was on it, and it was dried up and crusty. Guess I will throw that on back on there, and save the SRAM for a bike that can appreciate it, lol.,,,,BD

It also shifting to smaller gears while back pedaling. Is this a related issue??

Your freewheel is likely worn out. It worked fine with the old chain because the old, worn-out chain and the worn-out freewheel cogs matched each other. The new chain doesn't match, so it's acting crazy.

Whenever I replace my chain, it has to "break in" for 100 mi. or so. It will skip on the smaller freewheel cogs. My LBM says it's normal and low and behold the skipping stops after 100 or so miles.

Your freewheel or cassette cogs are worn out, too. The new chain is simply taking a hundred miles or so to wear to the point that it will mesh with the worn-out cogs..............The truth is, if you really, really don't want to replace the rear cluster until the chainrings wear out, too, just ride the old chain until the whole drivetrain wears out together (rear cogs, chainrings, chain). There have been folks here who have reported 15-20,000 miles without replacing the chain. When the whole drivetrain is completely shot, it's all replaced together. The whole point of chain replacement is preserving the other, more expensive parts. And keep in mind, chainrings will last much longer than the rear cogs if you replace the chain at the prescribed intervals-

This makes me think that maybe your RD is ever-so-slightly out of adjustment--or wait, is this a friction setup? If it's indexed, check the adjustment to make sure it's spot-on.

BTW, UG = Uniglide (twist tooth design) and HG = Hyperglide (scultped, pretty much like all cogs are now).

me too.

to the OP. I have had similiar problems and have fixed them with slight derrailer adjustment of the top limit screw

That would only make sense if it only hovered on the smallest or largest cog. "Hovering" is usually caused by improper cable tension. Assuming this is a normal derailleur, and not "low normal", if it hovers on a upshift (i.e. moving from a larger to smaller cog), the cable is too tight so loosen it by turning the barrel adjuster *clockwise* a small amount. Keep playing with it until it shifts smoothly. If it hovers on an downshift, the cable is too loose so tighten it by turning the barrel adjuster *counterclockwise*.

But more likely, it's just the wrong chain for the drivetrain.

12 years+. i dread to think how many miles.

I'm thinking about putting the old chain, crank and rear block onto my new build until my new parts arrive :D

back on topic though. sounds like the cassette is worn and/or is incompatible with your new chain

Sounds like an RD adjustment issue to me. Because worn-chain issues only show up as skipping once the chain has dropped into the cogs and engaged. Until the chain engages, it doesn't matter one bit if it or the cogs are worn. A chain riding on top of the cogs means it hasn't been moved into the correct lateral position.

Well, whatever the problem is, Bikedued, I've seen the bike you're talking about on the C and V forum since this thread started, and you've done a great job with it. I really like those handlebars. The reason I went for the worn-out freewheel diagnosis is that you said everything works fine with the old chain on it. And since I assume it's friction shifting ('85 Peugeot, right?), it seems that the cable tension would have to have been loosened more than just a "tweak" when you installed the new chain to cause it to act as crazy as you say it's acting. Maybe it's the wrong chain after all-

So can I replace a helico matic freewheel? Sounds like it may be new hub time if not. It wobbles some, although it does not look all that worn. The bike was not ridden all that much over it's life, mostly just bad storage. I might try throwing the old chain back on it for the mean time. It's a daily rider, so it has to be at least ridable, slipping and jumping through gears won't work.

For what it's worth, all cables on the bike are new too. Only thing not new is the front and rear gears..
I find the cable tension thing puzzling. It either lines up or it doesn't, right? Does that mean there's so much tension that it jumps too far at too small of a lever adjustment?,,,,BD

WHAT!?!?!

Helicomatic complete six freewheel $150? If my whole freewheel is wobbling side to side, I can't get away with replacing the cogs can I? Well, I could but it would fail, and I would need the body for $95....I think a new hub and freewheel would be cheaper, even with lacing.,,,,BD

Or I could swap wheels with my PH 10, and worry about it later, lol....

I didnt' pick up on the Helicomatic hub part. That's kind of the hub from hell, I think; I've seen them on the C and V forum, usually with lots of cuss words attached. And actually, I just checked on Sheldon's site, it's not a freewheel but an early cassette hub. Other than that, I know nothing about them, but I suspect you'll be better off, if your old chain works fine with it, to just ride it with the old chain until it's completely toast. Either that or look for a replacement hub or wheel. Here's a link to Sheldon's site and the helicomatic: http://sheldonbrown.com/gloss_ha-i.html#helicomatic

Since I don't exactly have a ton of cash to blow on a freewheel alone(or a fresh build), I think I'll swap cassettes for now.The other one works perfectly fine with a new chain.,,,,BD

There is a balance between the derailleur's return spring force trying to pull it back to a rest position and the amount of tension on the cable resisting the spring. Ideally, once balanced, the rear derailleur guide pully is centered over one of the rear cogs. Once you have that, each click of the shift lever will apply just enough tension, or release just enough tension, for the derailleur to move precisely to and be centered over the next cog. You have to get that initial balance set *first* before anything else works correctly and it's done mostly by trial and error, shifting and tweaking the cable tension, until the shifts are precise. Over time, cables will stretch and you'll have to tweak it again to get it back in balance.

Put your bike in a repair stand and play with the cable tension. You'll see that very tiny twists of the barrel adjuster will cause the shifting to get sloppy as you throw the system out of balance.

Hmm, you saying clicks makes me think you're talking about indexed? This is a mid eighties friction bike.,,,,BD

Then good luck :-) I'm guessing your rear cogs are just worn out.

Not to mention the the freewheeling mechanism itself. It rocks pretty good.,,,,BD

Or would that be bad?

The freewheel wobble has nothing to do with cog wear. It screws directly onto the hub. It wobbles if the mounting turret is non-axial, which is not uncommon. When was the last time the wheel was trued? Have you pulled the axle? It might be bent (which would cause the whole wheel to wobble).

I suspect you have the wrong chain width. An old bike like that probably requires a 1/2 x 3/32 chain. Nowadays they are called "8 speed" chains and are getting hard to find. You probably have replaced it with a 9-speed chain which is narrower. The narrow chain will seat, but doesn't want to shift right.

Well, I told the guy 5/6 speed, and he is a pretty much knew what my wheel came off of by seeing it 5 feet away. A helico matic slides onto a slightly curved set of splines on the
hub, and then tightens down with a serrated lockring. It's tight. Wheel is lazer straight, and it's a skewer type axle. No bends in it that I could see. I guess it's new hub and/or wheel time. $150 for a full cassette
is too much in my book. I can get a wheel, freewheel, high dollar tire, thorn proof tube, a velox rim
strip, and still put a lot of change in my pocket;),,,,BD

I think I will do that, when my next paycheck hits. I will try the other chain though, because it still skips after swapping the wheel out from the PH10.

Most Helicomatic cassettes (and most European freewheels of the day) didn't have much taper in each teeth. Your cogs probably have vertical sides and a shallow groove along the top of each tooth. Have a look at http://chuck.kichline.com/bikes/bits/helicomatic.jpg to see what I mean. That shallow groove can 'catch' the sideplates of your chain, allowing it to 'hover'. Older chains had deeper, wider sideplates and were less prone to the problem.