weird mechanical incident

[redrhodie]

I was about to climb a hill, but was still on the flat when it happened. As I shifted from big to little chain ring (compact double), my rear wheel suddenly locked. I was in the middle of my cassette. I got off, and I could pedal backward, but not forward at all. The chain was not off, and I couldn't figure out where it was jammed. I released the rear wheel quick release, and it unjammed.

Any ideas what that could have been?

[beccaB]

I was about to climb a hill, but was still on the flat when it happened. As I shifted from big to little chain ring (compact double), my rear wheel suddenly locked. I was in the middle of my cassette. I got off, and I could pedal backward, but not forward at all. The chain was not off, and I couldn't figure out where it was jammed. I released the rear wheel quick release, and it unjammed.

Any ideas what that could have been?

I'm not particularly mechanical, but I had sort of the same problem and the bike store technician loosened my cable some. It had nearly thrown me off my bike when it happened.

[DebW]

The only thing that comes to my mind (and this probably isn't it or you would have noticed) is that the wheel slipped in the dropouts and jammed against the frame. But that could only happen if you have horizontal dropouts. Otherwise I can't imagine what would make a rear wheel lock - I assume the wheel wouldn't turn in either direction, but the cassette was still free to go in reverse. I'd pull the rear wheel off the bike and see if anything seems amiss, eg. broken axle, disintegrated bearings, stick jammed in the hub. What kind of hub and how old is it?

[Pedal Wench]

The only thing that comes to my mind (and this probably isn't it or you would have noticed) is that the wheel slipped in the dropouts and jammed against the frame. But that could only happen if you have horizontal dropouts. Otherwise I can't imagine what would make a rear wheel lock - I assume the wheel wouldn't turn in either direction, but the cassette was still free to go in reverse. I'd pull the rear wheel off the bike and see if anything seems amiss, eg. broken axle, disintegrated bearings, stick jammed in the hub. What kind of hub and how old is it?

I was thinking the same thing. I have an older Ti Colnago that has horizontal dropouts and once when I stood up to climb, it slipped and jammed up into the frame. I'm thinking about putting in a regular skewer back there instead of a quick release so I can really clamp it in there.

[lph]

I have jammed the chain (and boy, how!) between the frame and the cassette a couple of times, but my spatial sense fails me tonight - could that lock the wheel?

[Biciclista]

yes, it could. I've done that and had to jump off the bike!

[GLC1968]

Ditto, Deb W - what kind of hub is it and how old is it?

My husband had a similiar problem with the front hub on his Trek 520 (he'd bought it off some guy and it was fairly old and well-used). The hub bearings were old and they totally locked up. The wheel came to a sharp halt. No budging it. Luckily, he was just starting out from a stop when it happened or he could have gone over the bars! He took it apart and regreased the hubs and it solved the problem. They were almost dry!

I would think that if the same thing happened to a rear wheel, the cassette would still be able to rotate in reverse even though the wheel wouldn't move.

Just a guess though...

[redrhodie]

The only thing that comes to my mind (and this probably isn't it or you would have noticed) is that the wheel slipped in the dropouts and jammed against the frame. But that could only happen if you have horizontal dropouts. Otherwise I can't imagine what would make a rear wheel lock - I assume the wheel wouldn't turn in either direction, but the cassette was still free to go in reverse. I'd pull the rear wheel off the bike and see if anything seems amiss, eg. broken axle, disintegrated bearings, stick jammed in the hub. What kind of hub and how old is it?

I think I have horizontal dropouts. It's a 1980s Eddy Merckx. I had just had it locked up at a bike rack, so that could have caused slipping. The wheel and hub were stock from my '05 Dolce. I'll have the shop check it over.

[redrhodie]

I just read Sheldon Brown's glossary on horizontal dropouts, and I'm 99% sure now that's what it was. Thanks, Deb. I guess I didn't tighten the quick release enough changing my last rear flat.

[myjas]

I had this happen once. A tiny little stone was stuck in my chain between the rollers. I could peddle it back because I was not peddling it enough that the stone hit the chainring. Took me atleast 10 minutes till I figured it out.

[DebW]

I just read Sheldon Brown's glossary on horizontal dropouts, and I'm 99% sure now that's what it was. Thanks, Deb. I guess I didn't tighten the quick release enough changing my last rear flat.

That used to be a trick that cyclist used when they needed to leave their bike but didn't have a lock. Just open the rear QR skewer, and if someone jumps on and tries to ride off, the rear wheel slides slideways and stops them. At least slows them down so you might catch them if you're watching the bike from a distance.

[redrhodie]

That used to be a trick that cyclist used when they needed to leave their bike but didn't have a lock. Just open the rear QR skewer, and if someone jumps on and tries to ride off, the rear wheel slides slideways and stops them. At least slows them down so you might catch them if you're watching the bike from a distance.

That's great! I'll do that next time I ride to the beach.