dougmc

I've got a 27 speed MTB that I convered to an Xtracycle with a Free Radical kit.

Works well, but it keeps breaking chains. The chain is pretty much new, a SRAM 951.

It's never broken at the master link -- it always breaks somewhere else. It seems to happen at random times -- it's not always when I'm going up a hill, for example.

I've had a professional mechanic take a look at it, and he says there's nothing wrong with how I've done the chain, and he checked every link (it's extra long, so I had to join two chains. I bought two new chains to join when I put the bike together.) But he suggested that the problem is that the chain is extra long, so it can flex sideways or twist and that's why it's breaking. He had no suggestion about what I could do about that.

I've got a recumbent with a similarly long chain -- but it never breaks. Of course, that's a seven speed chain, so it's thicker.

Any ideas about what I can do with the Xtracycle? I've found some complaints about this model of chain breaking, but I don't know if that means I should get another, or there's nothing wrong with this model of chain. (I need two of them, so the price is substantial, but if it fixes the problem, it would be totally worth it.)

If the problem is twisting, anything I could put to help guide the chain and prevent it from twisting?

Jeff Wills

I have SRAM chains on my recumbents (plural) and I've haven't borken a chain since I broke a Shimano one 12 or so years ago. That includes several 9-speed bikes.

I assume you're using the SRAM master links to join the chains together. We used to use chain tools to push pins back through, but I don't use that method anymore- the plates get distorted when the pins get pushed through. I only use the SRAM links to assemble an extra-long chain.

My chain jumps, flops, and twists like crazy- my pedal strokes is really lumpy and I have tattoos on my calf and frame to prove it. I still don't have issues with the chain, though.

dougmc

I've used both a master link and the chain tool. So far, the best explanation is that it's breaking where I used the chain tool -- I don't know that for sure, but it seems to make sense.

Though I wonder why I don't have such problems on my other bikes where I've also used a chain tool.

I guess the fix is to get a few master links and wait for the chain to break again, and then make sure any links I replace are held with the master links.

noglider 

I like the mechanic's theory about twisting, though before you try to address that, try an entirely different brand of chain. Please report your findings back. This is a curiosity.

joejack951

It sounds like the issue is that you are removing pins and then pressing them back in on a chain that was not designed for that kind of reassembly. Newer 6/7/8, 9, and 10 speed chains all use rivetted pins. Once the pins are pressed out, the peened end is destroyed and the pin cannot be reused. Shimano makes a special rejoining pin which is a one time use pin as well.

Since you are using an SRAM chain, you might as well use their Powerlink (or whatever it's called) to rejoin your chain. If you are using two chains, just use two links.