bing181

In my case, Campy chorus. Curious because my dealer is telling me it needs replacing, but it was new 10 months ago, and has done around 10 000 km. Any tips for prolonging life?

seely

I am curious why you think it needs replacing? I have derailleurs that are 15+ years old and still work perfectly. I find it VERY rare a rear derailleur needs replacing. Maybe new pullies, but rarely a replacement.

SSenorPedro

Yes...And the fact that it is a Campy will allow you to rebuild any part that is malfunctioning. The beauty of Campagnolo as opposed to other folks....

I ditto the old derailluer comment as well, but most of mine do not have 10,000+ Km on them.

531Aussie

There was a thread a while ago that said it's preferable to park your
bike with the chain on the small chain-ring, and on one of the smaller rear cogs.

This is meant to reduce the tension on the derailleur, but at the time I thought it was a gag(??)

Bobthe....

Yes, This is good practise. It leaves the derailleur springs with less tension, leaves the cables and levers relaxed, and allows lube to creep under the surfaces that might be to tightly locked up when things are under tension.

Bobthe....

powers2b

Derailers only need replacement after a crash that has severely bent or damaged it.
If you have not crashed and there is no history of misuse your campy probably just needs some TLC.
Your LBS is full of BS.
I'm curious, why was the bike in the shop?

sydney

How long is a rope?

sydney

Well actually the pivots do wear out. some slop isn't a deal killer on a friction system but it is on a 10 speed index one.

MichaelW

On my all-weather commuter bike, a midrange Shimano mech lasts about 2 years/10,000miles.
I dont clean it very much and lube it abut once/month. I do re-grease the pully wheels once or twice/year.
When mine wears out it is because the pivots become sloppy , not because the springs go weak.

phantomcow2

Definantly believable, my fathers roadie from 1970's has the same derailleur and it wors flawlessly, of course its only 5 speed but still it works great. If you take care of your derailleur it will last

supcom

Nonsense. The tension on the springs does no damage to them and if your pivots are not already lubricated, the oil is not going to suddenly appear and 'creep' into them.

sydney

Yeah, isn't friction wonderful? Makes ya wonder why people are so in love with that new fangled index stuff.

SAB

As long as there is no crash-related damage (ie: bent cages, etc...) a derailleur will last a VERY long time, provided you can replace the pullies, bearings, and pivot joint when they were out after a few years and tens-of-thousands of miles.

supcom

Most (all?) deraillers have simple pivots that are not repairable. Once the derailler body wears against the pin, repair would require drilling out the holes and installing an oversize pin. The pin itself is unlikely to wear significantly - especially with an aluminum derailler. There are no replaceable bearings that I can think of. Pulley wheels can be replaced.

However, deraillers are generally inexpensive considering the long service life you get from them.

Bobthe....

You're entitled to your view, but...........

I've had derraileurs that lose spring tension over years.
Allowing the system to sit with tension on it will extrude lube from the points of contact. If you allow the surfaces to part slightly the film of lube will creep back and fill microscopic roughness in the surface. Using light oil on high contact pressure pivots is very temporary. Most cyclists don't lube until everything looks dry. The points of contact went dry months before and have been wearing ever since. Its better to use a heavier oil (motor gear oil, or chainsaw bar oil) and to relax the system between uses.
This is also for the cables, guides and levers.

Bobthe....

super-douper

I don't know how many miles, but the one on my beater is 10yrs old and works fine still. This is a mountain bike too, so it saw a lot of abuse in the early years. I've got well over 1,000 miles on the bike this year (don't know exactly since my computer died this summer).

Oh, and I've never been too good about lubricating the chain or deraileur. But you and/or your LBS might have different opions about the meaning of "works good" than me. On my bike, if I hit the shifter, and it shifts it works good. I don't have to apply extra tension to the cable to make it shift. That "works good" as far as I'm concerned.

Avalanche325

I agree. It is a gag. The springs are not stretched to a point that it damages them.

bing181

Thanks for all the replies ...

The problem is that there's a lot of sideways play with the derailleur, apparently. Tension etc. from the chain etc. is enough to displace it it seems. To be honest, I'm not particularly technical, but for example, I'm not able to set the derailleur up so that on the middle rear sprocket it can freewheel or I can pedal backwards .. if I do so, the chain starts wrapping itself around the pulleys. When I asked my LBS to look at it, he did and said to me that it was too worn and couldn't be adjusted with precision.

The bike was in the shop because the campy chorus seat post mounting wasn't holding the seat firmly. After every hour, I was finding that the seat started slipping (up/down, not on the rails i.e. forwards/backwards). He has greased the mounting and locking bolt .. we shall see.

All this on a semi-pro team bike that I recently bought at the end of the season at a knock-down price. In theory, it has been very well maintained, which is why I'm a bit thrown by this.

miamijim

supcom, sydney, I agree with your comments.


Derailleurs do in fact wear out due to use. Plain and simple. Once slop develops in the pivots theres nothing that can be done other than replacing it. The amount of slop developed is directly proportional to the number of shifts, how much pressure is on the drivetrain while you shift and how well its maintained. It always good to slightly back oof on pedal pressure while shifting. If you do you'll find your shifts to much quicker more precise and crisper.

10K Km is very believable to me.

Leaving a spring under tension WILL NOT prematurely fatigue it. I'm not a mechanical engineer but if you find one I'm sure he/she would support that staement.

MYTH BUSTED.....

If you cant pedal backwards something is bent. The derailleur itself or the hanger.

miamijim

About as long as a Shimano Altus derailleur.

sydney

That backpedaling issue could be nothing more than a sticky cruddy chain or sticky pulleys,and has nothing to do with the derailer being worn. If it shifts right it's ok. If poor shifting connot be corrected by addressing a host of other issues,then it's time to suspect the derailer if it's old and has had lots of use. Quality RD are expensive.The other fixes to cure shifting issues are damm inexpensive.alot of LBS like to sell expensive stuff.