Life span of a mech?

EX DH

How long should a front mech last?

Ive had the bike in the shop for a general overhaul(new cassette, chain, rings, cables) and i got a call yesterday saying the front mech was broken and i need a new one. On closer inspection the bolt that holds the cable in place has broken. The part of the mech body that takes the bolt has gone soft and split when the mechanic tried to nip it up. Ive seen it and looks like there was already a crack in the body and the weather has finished it off.

Never known of it happening before but does it happen? or should i sent it back and try it on?

Oh its a campag centaur 2010, dprob done 10/15000 miles.

Yossie

Mechanically I've never had a front mech break, but hey, its a component - if its plastic where the bolt goes in there is a likelihood that it's going to break at some point - wear, tear, exposure to the elements, being done up too tight at some point in its life leading to a stress failure, that sort of jazz.

Take it off, chuck it in next door's garden, fit a Super Record one. Job jobbed.

unixnerd

My Sora front mech broke it's spring after 9 years, I think corrosion killed it (winter bike).

If only the bolt has snapped on yours I'd not replace the mech. Just get another bolt.

ugo.santalucia

I have a Campagnolo Gran Sport rear mech, class 1958, it still works perfectly... I also have a front derailleur Valentino, I think it's mid 60s and it works fine. A century seems a pretty reasonable time for a derailleur to last

Yossie

unixnerd wrote:

My Sora front mech broke it's spring after 9 years, I think corrosion killed it (winter bike).

If only the bolt has snapped on yours I'd not replace the mech. Just get another bolt.

I think he means where the bolt bolts into the mech so the bolt housing itself - do up the bolt and the split in the housing just expands, doesn't tighten up and eventually the bolt pops out of the side.

Some mechs have a plastic housing that the nut sits in (holds it captive) - the bolt bolts into this - I think this is what is jazzed.

Alternatively, some have a threaded boss as part of the mech so this may have split as well leading to fucktardo mechio, as they say in the trade.

EX DH

Its the bit where the bolt goes into the mech(metal). Only had it 2 years. Got a new one going on tomorrow, just wanted to know if its a common fail? or do you think its a manufacturing defect?

Yossie

ugo.santalucia wrote:

I have a Campagnolo Gran Sport rear mech, class 1958, it still works perfectly... I also have a front derailleur Valentino, I think it's mid 60s and it works fine. A century seems a pretty reasonable time for a derailleur to last

Exactomondo. The mech itself is extremely simple and will last forever, its when you start having plastic housings and that sort of jazz that they end up breaking.

ugo.santalucia

Yossie wrote:

ugo.santalucia wrote:

I have a Campagnolo Gran Sport rear mech, class 1958, it still works perfectly... I also have a front derailleur Valentino, I think it's mid 60s and it works fine. A century seems a pretty reasonable time for a derailleur to last

Exactomondo. The mech itself is extremely simple and will last forever, its when you start having plastic housings and that sort of jazz that they end up breaking.

The Gran Sport is a beauty... even the jockey wheels are made of steel and they have ball and cone little bearings... shame the chrome has pretty much gone and I have to keep the rust under control. Full steel construction, yet only 300 grams... don't allow me, or I will talk all day about that thing!

EX DH

Yossie wrote:

unixnerd wrote:

My Sora front mech broke it's spring after 9 years, I think corrosion killed it (winter bike).

If only the bolt has snapped on yours I'd not replace the mech. Just get another bolt.

I think he means where the bolt bolts into the mech so the bolt housing itself - do up the bolt and the split in the housing just expands, doesn't tighten up and eventually the bolt pops out of the side.

Some mechs have a plastic housing that the nut sits in (holds it captive) - the bolt bolts into this - I think this is what is jazzed.

Alternatively, some have a threaded boss as part of the mech so this may have split as well leading to fucktardo mechio, as they say in the trade.

Thats the one! it has an expander insied that has slpit the housing. Common?

Yossie

Useless answer here: not sure about it being common on Campy mechs, but have seen it a lot in mechs that have been overtightened in the past - plastic expands to accommodate overtightened nut, weather hardens/cools the material, material splits, constant pressure of over tightened nut causes constant splitting leading to failure.

Seen quite a bit on bits of m/bike as well - generally caused by people not taking enough care to tighten just enough plus and smidge and just going to FT on the monkey wrench.

Twostage

The front DR on my first road bike (now my commuter) lasted 7 years, first few years it had no care and attention (at all).