What has he done

StillGoing

I've had two dealings with someone's bike with 10 speed Campagnolo Veloce.

On the first occasion, he has dropped the chain between the cassette and the hub turning the chain into a buzz saw cutting through 7 spokes and bending the derailleur cage. Replaced his spokes, straightened the cage and new chain. I'm assuming he had excessive movement in his low limit screw that allowed him to try taking a gear that wasn't there and dropped the chain over the cassette.

Second occasion, he has snapped the rear hanger, twisted the chain, bent the rear derailleur cage again, dragged it around the derailleur body burring off the stop and cut through another spoke. My thinking this time is that he has been cross chaining using inner and the smallest sprocket and tried putting lots of load in the pedals.

noodleman

Wouldn't imagine cross chaining would cause such damage. If the limit screws are properly adjusted this sort of thing shouldn't be possible.

fenix

Take the bike off him - its too much for him to cope with.

sheffsimon

philthy3 wrote:

I've had two dealings with someone's bike with 10 speed Campagnolo Veloce.

On the first occasion, he has dropped the chain between the cassette and the hub turning the chain into a buzz saw cutting through 7 spokes and bending the derailleur cage. Replaced his spokes, straightened the cage and new chain. I'm assuming he had excessive movement in his low limit screw that allowed him to try taking a gear that wasn't there and dropped the chain over the cassette.

Second occasion, he has snapped the rear hanger, twisted the chain, bent the rear derailleur cage again, dragged it around the derailleur body burring off the stop and cut through another spoke. My thinking this time is that he has been cross chaining using inner and the smallest sprocket and tried putting lots of load in the pedals.

You fixed the bike after the first occasion, therefore you are entirely to blame for the second occasion.

You should apologize profusely, give yourself a talking to, and get your wallet out.

mercia_man

This could be due to ham-fisted gear changing, poor maintenance/adjustment or bad luck.

I doubt whether cross-chaining would do this. But starting off from standstill in a high gear or suddenly trying to change gear under load when you hit an unexpected hill can both be a cause of snapped hangers.

Wrongly adjusted RD limit screws can cause the chain to jam against chainstay or wheel and the hanger to snap. A wrongly adjusted front mech or using non-standard sized chainrings can also cause a chain jam.

I have heard of Shimano and Campag advising against use of quicklinks because they protrude slightly more than the standard joining pins with the risk of interference with pick-up pins and RD cages. Leaving a bit of standard joining pin sticking out could also cause a problem. Cutting your chain too short can cause jams in big ring and biggish sprockets. Non-standard cranks with different pick-up pins might also be an issue.

Or it might just be that a stone or twig has got caught up in the chain or mech and caused a jam.

Here's a decent article from Ribble:

http://www.ribblecycles.co.uk/blog/gear-hangers-break/

dee4life2005

What about the freehub? Is it possible that a knackered, or dodgy freehub, suddenly jamming and becoming like a fixie could cause this?

Only reason I say that is because I was on a sportive a couple of weeks ago and a guy was riding a new set of expensive Campag wheels for the first time and he had a problem with the pawl springs jamming up the freehub and all sorts of nastiness resulted - though not a knackered rear derailleur thankfully for him.

Anonymous

Is the cage long enough for the cassette size in use. If the cage is too short the chain can effectively get trapped between the jockey wheel and the cassette on the lowest gears.

Semantik

I have often seen so-called experienced cyclists place their bikes down on the ground on the right hand side when stopping for a pee/fag break on rides. One I know used to do it frequently and I learned that one day his chain just 'overshifted' when changing down on a climb sending the mech into the spokes and writing off the dropout and chainstay on his carbon frame. Funny that..

thebadgerboy1982

id suggest a chain that is too short. Too much stress through the rear derailleur causing the hanger to bend and snap

StillGoing

Both occasions his chain length was fine. He does have a habit of chucking his bike into the back of his car with the derailleur downmost. His hanger had twisted before snapping so I'm wondering if his chain somehow got snarled up in the mechanism (stiff SRAM split link) and that has caused the problem.

crankycrank

philthy3 wrote:

He does have a habit of chucking his bike into the back of his car with the derailleur downmost.

Oh, that's cycling blasphemy. You can almost guarantee that this will bend the mech hanger which can cause the mech to get caught in the spokes or something else.

mugensi

philthy3 wrote:

I've had two dealings with someone's bike with 10 speed Campagnolo Veloce.

On the first occasion, he has dropped the chain between the cassette and the hub turning the chain into a buzz saw cutting through 7 spokes and bending the derailleur cage. Replaced his spokes, straightened the cage and new chain. I'm assuming he had excessive movement in his low limit screw that allowed him to try taking a gear that wasn't there and dropped the chain over the cassette.

Second occasion, he has snapped the rear hanger, twisted the chain, bent the rear derailleur cage again, dragged it around the derailleur body burring off the stop and cut through another spoke. My thinking this time is that he has been cross chaining using inner and the smallest sprocket and tried putting lots of load in the pedals.

It could be that the second incident is as a result of straightening something that should have been binned and replaced.

StillGoing

MugenSi wrote:

philthy3 wrote:

I've had two dealings with someone's bike with 10 speed Campagnolo Veloce.

On the first occasion, he has dropped the chain between the cassette and the hub turning the chain into a buzz saw cutting through 7 spokes and bending the derailleur cage. Replaced his spokes, straightened the cage and new chain. I'm assuming he had excessive movement in his low limit screw that allowed him to try taking a gear that wasn't there and dropped the chain over the cassette.

Second occasion, he has snapped the rear hanger, twisted the chain, bent the rear derailleur cage again, dragged it around the derailleur body burring off the stop and cut through another spoke. My thinking this time is that he has been cross chaining using inner and the smallest sprocket and tried putting lots of load in the pedals.

It could be that the second incident is as a result of straightening something that should have been binned and replaced.

I doubt it. The cage was straightened using a flat surface and was shifting faultlessly afterwards. He completed his first sportive on it without incident.

I can only assume, that it is due to a combination of maybe hitting the derailleur when he lays it down in his car, poor maintenance of the chain allowing it to get gunged up, the sticking SRAM split link and poor technique.