jur

On several of the bikes in my family, the rear derailer's performance in shifting into the highest gears are less than perfect... it hesitates a bit, despite all cleaning of cables, guides, hinges etc etc. I have come under the impression that the derailer return spring is not quite up to the job, just a mite too weak in some gear combos.

I'm not sure if this would make a difference over a long time, but I have taken to the habit of putting away all my bikes with the RD set to the most relaxed setting, ie to the highest (smallest) gear. I imagine the return spring will stretch less and last a bit longer.

HillRider

Springs lose tension from being cycled, not from static loads. Every time you shift you move the spring and use up some of its useful life (which is, in reality, measured in decades). Leaving the spring under tension but static does nothing to weaken it or shorten its life.

Svr

The last loop of shift housing going from the frame to the rear derailleur wears out faster than the rest. Replacing this section of housing restores shifting performance. On some frames, the Avid Rollamajig works well too.

supcom

I've had 30 year old bikes with original derailleurs that work perfectly. There is no technical reason to relax a derailleur spring for storage. It's a myth.

If your derailleur is not performing as in the past after all your maintenance, then either the pivots are worn or, more likely, your rear housing loop needs replaced. Old housings take a set and cause higher friction that impedes letting out cable when shifting to higher gears.

alancw3

for the last thirty plus years i have done the EXACT same thing. the last thing i do when returning from a ride is relax the gears. i have never had a rear derailller problem. even with a 35 year nuovo record.

Brian

Jur, check the tip for proper alignement as well. Between that and the last loop of cable, you may solve your problem.

John E

I always used to store my bikes with the chain on the small cogs, but since the springs' elastic limits are not being exceeded, I am coming around to concur that it probably doesn't matter. In fact, if you happen to come home in low gear, shifting to high for storage and then back to low to start out the next day would probably INCREASE spring wear by cycling the tension.

Al1943

I would also suspect shift cable housings, especially the small one at the rear derailleur. This seems to be a common problem with STI.

Al

ivan_yulaev

Deralleurs wear MUCH slower than most other components on the bike. By the time you have to replace your deralleur, you'll be lucky to be riding the same frame.

jur

One bike did it since the day it was bought brand new, between 5th and 6th on an 8 speed cassette. I will check the cable guide tips.

capwater

Maybe if you were going to store the bike for an extended period of time, but from one ride to the next (day or two) it doesn't matter.

HillRider

Interesting but meaningless. Your derailleur would have lasted just as well without "relaxing the gears".

It doesn't matter how long the bike will be stored, the springs don't benefit. As noted, you wear out the springs by shifting them, not be leaving them under tension but static.

capwater

Good comments, bottom line is the RD isn't going to wear out. Reminds me of the ever lasting debate on whether to rotate loaded pistol magazines to avoid spring fatigue.

HillRider

Exactly. I've been involved in that one too.

juicemouse

My Nuovo Record-equipped bike shifts perfectly too, although I haven't paid any attention to the position of the derailleurs when stored.

mcoine

+1

mcoine

Just curious, do you jack up your car when it is parked to relieve spring tension, car springs are way more expensive than a rd?

capwater

I take the springs off each night and bring them into the warm house!

Good point.

ppc

Uh? since when? A cared-for steel frame will outlast many derailleurs, and supposedly for lighter riders than me, good alu frames will last a long time too. Derailleurs don't last nearly as long.

jur

OK, thanks for the feedback, I wasn't sure about this one, just curious why several of my older derailers plus one brand new one won't shift up well? I have made absolutely sure everything in the entire mech from shifter to RD is completely clean and lubed, with no appreciable improvement. Hence my conclusion about a dodgy spring. But I will go after that last bit of cable guide again.

mcoine

what kind of shifter and der. are you talking about. Shimano rd's have a week spring because they want you to use their spring loaded shifters to help it.

SanDiegoSteve

A more likely culpret is chain stretch. Do you cross-shift a lot?

I did hear something like this yeas ago and asked in these forums about 2 years ago. Maye search for posts on what gear when not riding.

juicemouse

Since cables only act in tension (pulling force) the only spring that affects upshifting is the one in the derailleur.

thomson

Jur
The first step I would do is detach the cable and see if it shift to the high gear. If it does, something is wrong with your housings/cables/guides somewhere. If is still doesn't shift to the high gear, try adjusting it.

HillRider

What wears out in derailleurs are the pivots and the jockey/idler wheels. The pivots develop play and the wheels have their teeth worn down. The springs last forever.