Bearonabike

The chain on my old S-10-S skips and I can't figure out why. I rebuilt the bike myself and have done some work to fix the problem. First, a new freewheel thinking that the skipping came from a worn out old one. That was accompanied by a new chain as the old one was fairly close to worn out.

Result: Skip skip skip.

Checked rear drop outs and wheel alignment. No problem with the drop outs, but the wheel was not as "true" as it could have been when tightened down, fixed that.

Result: Skip Skip Skip.

As the bike is friction shift, all I can think is that the LBS may have pulled a chain for a bike with more than a 6 speed freewheel, leaving me tolerances that are too close. I plan to check out that possibility with the LBS on Monday.

Any other ideas? I really want to beat this as the bike is a sweet ride otherwise.

FBinNY 

Saying old S-10s is kind of redundant. (For the youngsters out there this is a 10 speed as in 2x5)
nice to see someone still riding one.

Anyway, since you've replaced both the chain and freewheel, I think we can rule out chain stretch.

Please try to analyze the skipping and give us more specific info.

skipping as in climbing out of and disengaging the cog under load?
skipping as in doesn't settle, in or disengages the freewheel sprocket regardless of load
skipping as in changes gear on it's own?
are you sure it's skipping of the rear sprocket and not possibly doing so off worn chainrings?
is the skip of a specific frequency, and possibly caused by a stiff or damaged link?

With a bit more info, I'm sure I or someone else can help you pinpoint and fix the problem.

X-LinkedRider

Doesn't mean that it is the correct size chain. Also just your derailleur. RD could be slightly off kilter or have a broke tooth.

Bearonabike

skipping as in doesn't settle, in or disengages the freewheel sprocket regardless of load

The LBS and I both agree that the chain rings are in very good condition, that possibility has been ruled out. I can't find any "regularity" to the pattern but it seems to happen more in higher gears than lower and more on the inner chain ring than the outer.

Bearonabike

RD has no broken teeth and is in fine shape. I replaced the worn parts with Suntour NOS chromed steel at the refurb. What do you mean by "off kilter" with respect to the RD?

X-LinkedRider

The hanger, if there is one for the RD. If it is not properly verticle it could be pulling incorrectly and snapping back. Also look into possibility of shifters disengaging under pressure.

Bearonabike

Okay, 2 things to check for sure, thanks.

X-LinkedRider

Good luck. I am assuming you have lever shifters (friction) or are they index shifters. If old style (friction) check to see if the tensioning screw/spring part is tightened but not TOO tight.

MikeWinVA

Is it a possiblity that the bike is ghost shifting? If the cables are routed under the BB, lube the area with some dry slide lube or graphite.

If you are "getting on it" and are big and strong enough, you could be flexing/twisting the frame and causing this.

Bearonabike

While I am a Clydesdale, I have been making an effort not to "get on it". I will lube the area under the BB

Bearonabike

Already checked that, but thanks.

operator

Check for

1) stiff link
2) Twisted link

Backpedal and carefully watch the rear derailleur for a "jump". Look *carefully* for a twisted link. Since it's a new chain it's not unlikely that someone created a stiff link when joining it.

operator

You can't rule that possibility out by visual inspection. Define "higher" gears. Bigger rear cogs? Smaller? Is the chain the correct length?

Panthers007

Assuming they measured it properly ^^^.

Kimmo

If it isn't a stiff link, I can only imagine it being a question of derailleur alignment, whether the hanger's bent, or the derailleur's simply worn and sloppy, or something.

The Clydesdale-induced ghost shifting is an interesting possibility, but I think it's safe to rule out on a five speed cluster.

I'd say check the straightness of the hanger (on steel frames you can carefully bend it straight with a large shifter, with a rag for the paint), and try another derailleur.

DArthurBrown

I had a similar problem on a 12 speed friction shift road bike. We never really figured out what was causing the problem but managed to stop the skipping. (I actually faceplanted while trying to diagnose the skip.)

A visual inspection can't rule out the chainrings, but in my experience, a skip on a chainring is pretty obvious, and the chain usually flies off because the RD can't take up the slack fast enough.

Since you've checked the chain, freewheel, and chainrings, look at the rear derailleur and alignment of wheel, cogs, and the chainline of the crank. If you use a new chain, new freewheel, the chainline is proper, and the wheel and rear axle are straight and true, the problem must be in the rear derailleur. My theory is that your vintage rear derailleur doesn't wrap far enough around the freewheel to secure the chain. That was my issue. That, combined with the modern, ramped teeth allows for the chain to slip under load. I solved my problem by installing a cheap Shimano Tourney rear derailleur which was actually far superior to the vintage Campy derailleur on the bike.

griftereck

I had suntour vx rear mechs on my Carlton and bob jackson bikes. they were old and worn on the pivot pins. so could jump out of gear sometimes. I changed the gear mechs to get away from the fear of crashing or getting hit by a car, when the gears jump.

Any mech I see I grab it by the jockey cage and the end of the body. If I can twist it and it feels gritty. Im not keen on it. Mechs can twist a little bit even when new. But a lot means it'll ghost shift

Bearonabike

Thanks to everyone. I hope to have a day or two to work on my bikes real soon. I have this problem to solve, then I have 3 to do a complete clean and re-lube, one to change out seat, adjust FD, and raise the stem, and 2 (Suteki and Franken-MTB) to rebuild to sell. ONLY THEN can I get to the rebuild of 2 for my wife and I to keep. We're doing a frame-up with matching paint schemes.

X-LinkedRider

Could have done at least half of that stuff in the time that it takes to type up all these messages. GL

BCRider

You mentioned about perhaps having the wrong chain and I don't see where anyone followed up on that. A proper fitting chain should have a little bit of side play when it's on the teeth of the cogs or front rings. Not much though. About as much play side to side where the teeth fit up into the spaces as a business card or a hair less. Certainly if there is no play at all then any grit or misalignment at all and the chain may not sit down into the gullets of the cogs and rings correctly.

operator

How the hell is it possible to have the wrong chain on a 5 speed FW? All chains will work on that. If it's 1/8 teeth won't even engage. The I.D fo 6/7/8/9/10 speed chains are still 3/32.

vredstein

Get ahold of another rear derailleur you can install, just to eliminate or positively identify the old unit as the culprit. Could you use a rear derailleur from any of the other three bikes?

DArthurBrown

That's right. Having too wide of a chain can lead to slipping, since the wider chain can catch on the teeth and jump, but having too narrow of a chain could only lead to poor shifting (I've run narrow chains on 5-speeds without issue many times). There's no plausible way to have too wide a chain on a 5-speed.

Bearonabike

I'm thinking too narrow a chain. Given the post above about the tolerance I am looking for, the chain is correctly sized for a 5 speed friction freewheel.

FBinNY 

In all likelihood you won't find a chain marketed as a 5s, but you might find one marked 6s which will be the same width. Otherwise any chain marked 7s or 8s will only be slightly narrower and should run fine. I use a 8s chain on my 6s freewheel (same spacing as 5s) with absolutely no problems.