Broken chain link – why???

[KLizotte]

Yesterday I suddenly heard a squeaking sound from the drive train while pedaling up a hill; didn’t sound serious, just very annoying. Since I was very close to Spokes in Belle Haven I rode over to the service dept to have it checked out. I’d recently had a squeaky jockey wheel and I thought it might be related (the jockey wheel was oiled and has been quiet ever since).

The service tech said my chain merely needed some oil. He then proceeded to oil and clean the chain while we had a nice chat. I left slightly mortified that my chain cleaning skills were sub-par though somewhat mystified since the chain had been cleaned only 283 miles ago during a tune-up. My 30 mile ride then proceeded smoothly.

On my commute home tonight I suddenly hear a grinding noise then my chain started changing gear on its own in the cogs with every few rotations. I stop and fiddled with the barrel adjuster but to no avail. I then carefully rode home. I stopped in at HTO cause its in my neighborhood and the “bike enthusiast” behind the counter (he admitted he wasn’t a tech) couldn’t find a problem with the shifting but noticed a broken link (part of the rivet has broken and fallen out).

The chain is a CHAIN 10SP SHIMANO 6701 110 LINKS I purchased on Nashbar and has 1,400 miles on it.

So my question is this: why did my rivet break? Could yesterday’s squeaking noise have been the warning signal? Could the squeaky jockey wheel be somehow implicated?

I know this is an easy/cheap fix but wish to prevent it from reoccurring. Many thanks for any insights.

Now I’m peeved I can’t ride in tomorrow. Why aren’t there any 24 hr bike shops around here?!

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Topic

[jabberwocky]

It can be a few things. Shifting under load (especially on the front chainrings) can put a lot of sideways stress on a chain and pop a link open. Hamfisted shifting in general is hard on a chain. Sometimes a piece of debris gets kicked into the chain or cogs and causes it. Sometimes the chain is just faulty.

Its not a difficult fix. I personally just pop the broken links off and put a quick link on. I carry a few quick links in my MTB kit, but don’t bother on the road bike.

[PotomacCyclist]

While HTO seems to be an OK store in general, check your quick release skewers after getting work done there. After some maintenance/parts replacement work on my MTB, on my first ride, one of the tires just popped off! I discovered that they hadn’t secured the wheel correctly. Good thing I was just riding slowly in a parking lot and not on the street or on a steep downhill.

(But I can’t complain too much, since I got a very good deal on that bike a few years ago, thanks to a coupon I had won elsewhere and a season-end discount. I honestly paid more for the pedals than for the bike, which is a solid Fuji MTB. Not super high-end, but not bargain basement either.)

[Tim Kelley]

@PotomacCyclist 67175 wrote:

While HTO seems to be an OK store in general, check your quick release skewers after getting work done there.

This is a good reminder to do an ABC Quick Check before any ride, including if you were the last one on your bike!

[paulg]

Its not a difficult fix. I personally just pop the broken links off and put a quick link on. I carry a few quick links in my MTB kit, but don’t bother on the road bike.

I agree. The SRAM quick links are a good quick fix.

On possible reason for the chain break: The shimano chains require a special pin to be used when joining the chain, this special pin drives out the old pin and has tapered sections to help through the hole in the side plate, without stressing the side plate. If one of these pins wasn’t used to connect up the chain, the pin won’t make a good fit with the side plate and can lead to something like you have in your picture.

[KLizotte]

@PotomacCyclist 67175 wrote:

While HTO seems to be an OK store in general, check your quick release skewers after getting work done there. After some maintenance/parts replacement work on my MTB, on my first ride, one of the tires just popped off! I discovered that they hadn’t secured the wheel correctly. Good thing I was just riding slowly in a parking lot and not on the street or on a steep downhill.

Because I live spitting distance to HTO I use them for easy quick fixes. I’ve determined that some of the mechanics do know their stuff but they don’t work full time and the HTO model requires mechanics to be salespeople too which means they are constantly being interrupted to set up bikes for people to test ride, answer basic questions about shoes/clothing, etc. Therefore, they let a lot of stuff slip through the cracks because of the constant interruptions; I have seen some real sloppiness as a result. On the other hand, they have always been happy to answer any questions I have and do basic repairs for free even though I’ve never bought a large bike item there.

I usually go to Spokes in Belle Haven because the mechanics there are so friendly and accomodating.

[PotomacCyclist]

@Tim Kelley 67176 wrote:

This is a good reminder to do an ABC Quick Check before any ride, including if you were the last one on your bike!

I always do that now, before every single ride. (I always pump up the tires on the tri bike before every ride. For the MTB, I just do a manual check of tire pressure, and pump up the tires about once a week.) Even back then, I did the basic checks (air, handlebars, brakes, seat, chain) but not the skewers. The last time I got my bike back from HTO, I did check the tires and wheels before riding. Fool me once…

[Author]

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