Most common mechanical failures?

[citoyen]

I have seen photographs of cunning 'splint' type arrangements which have been deployed when framesets and carriers have failed. Never had to do one myself, but a key ingredient often appears to be a cheap flat spanner, lashings of string, and hose clips/araldite.

Beer can shim and zip ties for the legendary Mr Berwick.

[mattc]

It is true that bicycles hold an outsized fascination for engineers. A steel road bike is an object lesson in many facets of engineering, and yet it is within the grasp of an able individual to understand it all to a deep level. Maybe that’s the appeal? The hope, strictly false as it is, that you can understand everything there is to know about the whole machine. A jumbo jet will always have simplifying black boxes for any one individual.

See also: https://en.wikipedia.org/wiki/Wright_Cycle_Company

[andrew_s]

Years ago, I had a freewheel that undid its lockring, on a long climb in Norway.  I'd heard of this happening to a chum of mine, whilst touring abroad. Turned  out ( I found out later) it was the same climb....

I wondered if it was trolls....

Coincidences are always interesting.

One year I was doing the Brevet Cymru 400k, when I had a puncture going down the hill on the north side of Grosmont, so I pulled into a driveway, and started mending it, waving at a clubmate as he went past a little later.
The following year, the same happened again - the same driveway, the same wheel, and at the same stage in the repair process when the same clubmate went past.

[Samuel D]

One year I was doing the Brevet Cymru 400k, when I had a puncture going down the hill on the north side of Grosmont, so I pulled into a driveway, and started mending it, waving at a clubmate as he went past a little later.
The following year, the same happened again - the same driveway, the same wheel, and at the same stage in the repair process when the same clubmate went past.

As hallucinations go, that beats a “twelve foot high white rabbit”!

[quixoticgeek]

During yesterdays Paris Roubaix event I came off one sector of pavé, and the guy in front of me said something to me in french. I had no idea what he was saying, so smiled and continued. Then he said Derailure. I now realised what he was saying, and stopped to look at my rear derailure... Turns out if you ride the gutter on the pavé you have a substantial risk of picking up vegetation that makes a right mess of your running gear... who would have thought it!





Spent about 10 minutes with a leatherman picking vegetation out of the running gear. Glad I caught it early enough, was a enough of a sod to get it all out as it was, without adding any more km to it.

Dunno if this counts as a common mechanical tho...

J

[The Family Cyclist]

Reading this reminds me I need to put a spanner in mybtool kits as both the kids bikes have solid axles secured with nuts where as I've had quick release for so long I wouldn't think to carry one.

[citoyen]

Just been thinking through some of the mechanical failures I've experienced over the years. Mercifully not that many, really...

Broken spokes - I've had a couple over the years, but not a problem that affects me as much as some others, it seems. Probably down to dumb luck.

Derailleurs - had a Di2 rear mech overshift into the wheel, not sure why. Cage got bent but luckily the hanger snapped before anything more catastrophic broke. Last derailleur problem before that was when one that fell apart mid-ride, requiring me to shorten the chain and ride home single-speed. That was probably down to a poor maintenance/cleaning regime. It was some years ago.

Chain - I've only ever once had a chain snap on me mid-ride. That too was probably down to a poor maintenance/cleaning regime, or maybe just cack-handed shifting. I felt it going before it actually went. Stopped to inspect the cause of the strange skipping and found one of the outer plates almost at right angles to the rest of the chain.

Cranks - had a Brompton LH crank snap on me while pulling away from the lights, sending me tumbling into the road. Inspection of the crank revealed that the crack must have been developing for some time, so maybe I should have caught that before it happened. I also once had the RH crank separate from the chainring, also while pulling away from the lights. That was on the old style Brompton chainset, which was made of cottage cheese.

Cables - on my LEJOG in 2016, I was about 30 miles from JOG when I noticed that the gears were no longer shifting properly. Initial inspection suggested the cable had come loose, so I retensioned and tightened it and carried on. But the problem recurred soon after, so I stopped and investigated further. I discovered that a grommet was missing where the cable exited the chainstay, so the outer was slipping inside the frame, effectively slackening the cable. I have no idea why it waited until almost the very end of the ride to start making itself noticed but shifting had been fine up to that point.

Shifters - had a 105 5700 LH shifter catastrophically fail when a pawl inside the shifter snapped. No idea if there's anything I could have done to prevent that, I suspect it's a design flaw as I've heard of similar failures for other people. It's also a part that you can't buy as a spare, so the whole shifter was scrap. Replaced it with a second-hand Ultegra 6700 shifter that is still going strong.

[Kim]

Spent about 10 minutes with a leatherman picking vegetation out of the running gear. Glad I caught it early enough, was a enough of a sod to get it all out as it was, without adding any more km to it.

Dunno if this counts as a common mechanical tho...

It does if you've got a small rear wheel, derailleur gears (particularly with a MTB rear mech) and you ride it over recently cut grass (as is commonly found on campsites).

Bonus points if there are chain tubes to clog as well as sprockets and jockey wheels.

Standard mitigation for short stretches of the stuff is to select a small:small gear combination in order to raise the derailleur cage away from the grass (trikes), or to get off and push so it doesn't ingest the cuttings (bikes).

[Nuncio]

Vorsprung's observations as LEL 2013 volunteer mechanic:https://audaxing.wordpress.com/2013/08/01/common-mechanical-problems-on-london-edinburgh-london/

[rogerzilla]

In the early 90s it was de rigeur to fit road mechs to MTBs for this reason.  They're also lighter and shift better.  The downside is that you're limited to 28T and big-big is well out, but only a drongo would select big-big.