I need chain size help

[fidel rambo]

I was putting together my bike yesterday and threw on single speed KMC chain I had lying around, I think it's 1/2" x 1/8".....obviously it doesn't look like the right size chain. This is on a Columbia Superb repro frame....I don't think this is a skip tooth sprocket...?? Or do I need a chain with a longer pitch?

Bigger pic of the bike can be found here:
http://www.ratrodbikes.com/forum/viewtopic.php?f=37&t=21366

 

[deorman]

If the sprocket isn't worn down from a bad chain, it may be one of those oddball 10mm jobs. Good luck finding that. I would say that if it fits at the wheel, use a different sprocket. Too bad, it's pretty.

 

[rms37]

10mm Pitch chain is much smaller. I believe the problem is the chain width is too narrow to allow it to drop onto the sprocket. if you have 1/2"x1/8" chain you need the wider 1/2"x3/16" chain which was used by some companies before WW2 and also in BMX applications.

 

[fidel rambo]

yeah, the width looks to be the problem, thanks guys.

 

[Wildcat]

The length of the links is different also. Follow the alignment of them and you see they are closer together than the teeth on the sprocket. Do you have an old chain to compare?

 

[deorman]

It looked that way to me as well. That sometimes happens to sprockets that are run with a worn chain. However, it's hard to be sure from a photo if that's because it's not seating on the sprocket. It does look similar to trying to put a 3/32" chain on a 1/8" sprocket, so RMS37 is probably correct. My idea about 10mm was just a guess about something I've heard of, but never seen. In retrospect, it would be smaller, since 1/2" is about 13mm.

 

[fidel rambo]

well, I'm a little confused now, but I think it still comes down to getting a wider chain.....I took some measurements -- the tooth-to-tooth gap on the pictured sprocket above measured the same as the rear brake sprocket (which the chain fits on fine), and that rear sprocket is a few mm thinner too. two other cruiser bikes I have had the same gap measurements. all were 1/2", which is pretty much the only pitch size available right?

so it has to be the width, but I don't have any spares to test fit. guess I gotta make some calls to the local LBS's tomorrow...

 

[deorman]

All current bike chains that I know of use 1/2" pitch.

 

[Dr. Sizzle]

Measure the tip of a tooth the the tip of the next tooth and you have your pitch measurement. Then do the same with you chain. once you have your measurements search for both a chain ring and chain and replace which every you find first or cheaper. you should also measure your pitch on the rear wheel sprocket as well so everything matches.