Daily Archives: 03-May-14

Rear Mech Hanger Snapped

I had a fairly spectacular mechanical failure during the week. It all started towards the start of the week when my commuter started to slip gear on the cassette occasionally. I put it down to the fact that I’ve just upgraded the entire groupset and the cables had probably stretched slightly, meaning that I needed a small tweak on the barrel adjusters. However, over the next couple of days, it got progressively worse.

By the time I was heading home on Thursday, it was so bad I kept on having to get off my bike to tweak the barrel adjuster randomly in the hope it would stop skipping gears. It was all over the place – up and down, and my cranks were slipping constantly, really irritating. So when I was about 2 miles from home, I came to a sudden halt.

The noise, when your rear mech becomes detached and launches into your wheel is not one you can mistake. I knew instantly what had happened, and nearly went over my handlebars, but thankfully managed to recover before going all the way over.

IMG_3955I got off my bike and went to have a look to see what had happened. The rear mech was complete detached and had buried itself into my cassette and wheel, with the jockey wheels lodged nicely in the cassette. My rear wheel had become entirely detached from the dropouts and was now hanging precariously with only the chain keeping it anywhere near where it was meant to be.

At first, I thought my frame and wheel would likely be goners. However, what I’ve learnt is that the rear mech attaches to a detachable part called a hanger, and it’s actually meant to brake, to save your frame from breaking. And this is what happened. Also, because I was going slowly when it happened (I was going up a steep hill), and because I’m fairly light, I think this saved my wheel. I can’t see any damage to the wheel at all, and indeed managed to push the bike for a mile before the wife came to collect me, as I managed to reattach it to the dropouts after removing the cassette.

It took quite some effort to get the broken part of the hanger off the cassette, but I got there eventually. I think the rear mech has survived, which is more than can be said for my chain which has a link that’s been completely mashed. However, only one link, so the rest is looking ok. If I get a replacement chain of the same type, then I figure I can make 2 chains out of one, by shortening the new one to the same length as the old one, and adding a link from the new one to the old one to make them the same length.

So it’s off to the shops to try to find a rear mech hanger. Apparently all frames come with their own version of a hanger, but my commuter is a Specialized, so fairly common and therefore I’m hopeful that somewhere will have something…