[I Are Baboon]

Any idea what might cause me to keep breaking chains? My chain breaks a LOT more often than I get flat tires. My chain broke again Friday during my ride wth Splat. Fortunately, it broke after 3.5 hours/12 miles of riding and we were only a quarter mile from the car. This is the 4th time this year my chain has broke. The first two breaks came on a PC-69 chain, the last two on a PC-99. None of the breaks occured while I was shifting.

Oh, and I have only flatted once during that same time.

 

[Tenchiro]

Are you breaking them on the quick link? Or maybe you have a bent tooth or something prying them apart.

 

[BikeGeek]

I noticed some hard shifting on climbs. I guess that could cause some premature chain fatigue.

Can you tie the breaks to any specific activity? Any cross gearing going on, small cog/big ring or vice versa?

 

[tonyhawk]

when you install the new chain, do you have to break it first, or is it one that has a master link? if you break it first, make sure that after putting it back together the link you broke is nice and loose. last time I did this, it was pretty tight and broke 50' into the ride.

how's your chainline look while in middle/3 or 4? turn the bike upside-down and check it - should be fairly straight. maybe your bb spindle is the wrong width? ever not had this problem on this bike?

is your chain too short or too long?

 

[I Are Baboon]

Originally posted by Tenchiro
Are you breaking them on the quick link? Or maybe you have a bent tooth or something prying them apart.

By quick link, do you mean like a Powerlink? If so, then no. The Powerlinks are holing up fine. All four breaks have come in different spots.

Originally posted by BikeGeek
I noticed some hard shifting on climbs. I guess that could cause some premature chain fatigue.

Can you tie the breaks to any specific activity? Any cross gearing going on, small cog/big ring or vice versa?

Yeah, I know I am not the smoothest shifter in the world. I'm working on that. The thing is, none of the breaks came during a shift. The break that occured on the ride with you happened on a flat. The other three breaks occured on climbs (twice on fireroad climbs). I can not recall any specific ring combo that may be doing it.

 

[I Are Baboon]

Originally posted by tonyhawk
when you install the new chain, do you have to break it first, or is it one that has a master link? if you break it first, make sure that after putting it back together the link you broke is nice and loose. last time I did this, it was pretty tight and broke 50' into the ride.

how's your chainline look while in middle/3 or 4? turn the bike upside-down and check it - should be fairly straight. maybe your bb spindle is the wrong width? ever not had this problem on this bike?

is your chain too short or too long?

You have to break the SRAM chains. Actually, the link was a little tight, but still pretty loose when I installed it.

I'll check the chainline tonight. My chain breakage is a new thing for this year. I think I am leaving it the right length.

 

[DRB]

Originally posted by I Are Baboon
You have to break the SRAM chains. Actually, the link was a little tight, but still pretty loose when I installed it.

I'll check the chainline tonight. My chain breakage is a new thing for this year. I think I am leaving it the right length.

Check your cassette and chain rings for burrs or anything else that maybe hanging the chain during shifts. I had a cog that had a couple of bent teeth that were the source of 2 broken chains.