teachme

It seems to be worn out. The spring does not quite spring back and my chain slips down the cog sometimes. Chain and casette have recently been replaced. Can the derailer be adjusted? I would like to get a few hundred more miles out of it, or is it time to replace it?

HillRider

It sounds like you have a chain length and/or shift cable tension adjustment problem. Unless you ride in hub deep sand all the time no derailleur will ever wear out in 2000 miles. I have 25,000 miles on a mid-line Shimano rear derailleur and it isn't close to being replaced.

teachme

Should I take a link out of the chain?

rithem

Seems to me whom ever replaced the chain and cassette could address your issue otherwise what u are describing is sorta vague.

teachme

Yes, I could bring it back to the LBS but I am trying to learn to do my own repairs...

rithem

2000 miles is low mileage go to lbs or post pix so we can see the rear d

chriskmurray

A lot of times when your bike is not shifting to the higher gears very well it is something as simple as needing to replace the cable and housing on the read derailer.

FBinNY 

+1 Derailleurs last nearly forever since they only move during a shift, and therefore there's no cause for wear.

More likely it's an adjustment as Hillrider says, but if you're referring to the spring that returns the derailleur to high gear, the issue may be cable friction. Depending on riding conditions it's fairly common for rust or dirt to cause friction inside the housings.

Start with some of the tutorials that are free on the net, and dial in the adjustments as well as possible. If it's OK but sluggish returning to high gear, especially from the 2nd to the outermost sprocket, then cable friction may be at play, and you may need to fieldstrip and clean/lube the housings or replace the cables.

HillRider

No, you should get the problem diagnosed properly. Whoever did the chain and cassette replacement should be able to readjust the shifting.

rithem

Agreed On housing Did they Chang that when they did the chain&cass?

FBinNY 

+1 Definitely have someone knowledgeable take a look. Not because it's rocket science, but because you can probably save some dough. A chain and cassette at 2000 miles seems premature (but not impossible) so it makes me suspect the person you have working on it now. A good diagnosis and proper identification of the problem can save you lots of dough. The causes can range from bad adjustments, bent hanger, cable friction, or lever issues, but chain length it way down the chart and can be eliminated immediately just by looking at the bike.

Shift to the small/small combination and look at the chain. If the chain is short enough the RD will take up the slack and the lower loop will run straight across. If it's hanging down like a possum belly then it's too long.

Homebrew01

If you want to work on it yourself, you can go here to see the steps to follow, https://www.parktool.com/blog/repair-help
then come back with specific questions.

dsbrantjr

+1 on FB's comments. When checking for cable friction issues be especially suspicious of the last loop of housing which goes into your rear derailleur. Due to its position it is likely to catch water and road gunk and start binding. Never shorten a chain in attempt to address shifting issues; it is rarely the problem and a too-short chain can damage your derailleur or even your frame.

Al1943

Yeah it sounds like you need to adjust the cable, from the rear of the bike try 1/2 counter-clockwise turn on the barrel adjuster.
2000 miles is nothing on a derailleur.

Myosmith

Realize that once you work on it, you have voided any warranty on the workmanship of the install. If you aren't confident that you can diagnose and fix the problem on your own, take it back to the shop that did the install and they should fix it under the original install agreement. Checking the rear derailleur adjustment and assuring that the chain is the proper length are normal parts of an installation. A good mechanic won't let a bike leave the shop unless everything he/she touched is in good working order.

Clean, lubed and in proper adjustment, a RD will last a long, long time. The only things that are likely to wear (usually in much more than 2,000 miles) are the two small sprockets and those are easily replaced. I've fixed up bikes that are 30+ years old, rusty and badly neglected. Almost always I've been able to use the RD after cleaning and lubing it. The only times I've replaced an RD has been for a substantial upgrade or when one has been damaged, never for wear. I'm sure there are riders who have actually worn out an RD, but it should take a lot of miles.

mechBgon

Also, inspect the cable at the shifter end. It may be starting to break strands and fray, which can result in the type of symptoms I think you're describing here. Preemptively replacing the rear shift cable and housings every 2000-3000 miles isn't a bad idea.