Bicycle TutorBicycle Tutor

Show off your bike!

Related video tutorials:
How to Adjust Your Front Derailleur How to Adjust Your Front Derailleur
* Now with 3D interactive instructions
DL rear derailleur
#1
my 15 year old Specialized Ground Control no longer shifts nice and snappy in the back. The derailleur loses uuumph pulling the chain to the 7th, 8th, and 9th gears. I've already replaced the rear cable and I always keep my cables oiled up so it's not that. I'm thinking the spring has lost tension by now. Otherwise the derailleur is in too good shape to replace . Can't I just swap out the spring? Or is there a way to remove the spring and then bend it back in order to increase the tension? Thanks for listening.
Reply
#2
Did you replace the housing also? 15 year old oil can get gummy
There are two kinds of people in the world, "Those who help themselves to people, and those who help people!"
Reply
#3
I second both the housing idea and the diagnosis of the weak / worn spring. Taking apart a rear dérailleur (and reassembling) is not that easy (well, depends on type / brand, check tutorials here and on park tools homepage), lots of springs under tension etc. A new mid-range RD is not that expensive (I guess below 40 USD if you shop around and are willing to accept last year's model). Considering the time it might (will) take to source the replacement (if still available) I'd just get a new(ish) RD.
Reply
#4
(09-02-2011, 03:13 AM)painkiller Wrote:  Did you replace the housing also? 15 year old oil can get gummy

I take my housing off and run Tri-flow through it to flush out any old lube.
Reply
#5
(09-03-2011, 12:08 AM)ssteichen Wrote:  
(09-02-2011, 03:13 AM)painkiller Wrote:  Did you replace the housing also? 15 year old oil can get gummy

I take my housing off and run Tri-flow through it to flush out any old lube.
Your housing probably has a teflon liner that is worn out?
Wheelies don't pop themselves. (from a QBP fortune cookie)
Reply
#6
(09-03-2011, 12:27 AM)RobAR Wrote:  
(09-03-2011, 12:08 AM)ssteichen Wrote:  
(09-02-2011, 03:13 AM)painkiller Wrote:  Did you replace the housing also? 15 year old oil can get gummy

I take my housing off and run Tri-flow through it to flush out any old lube.
Your housing probably has a teflon liner that is worn out?
After seeing how car springs flatten over time my thoughts are that the mainspring of the derailleur has flattened to the point where it can't overcome the resistance of the cable in the last 3 gears. 7,8,and 9 are the gears your derailleur has to pull to as the spring is losing tension. These are the last gears it pulls to. And these would be the first gears to go out if spring tension went down. Thanks again.
Reply
#7
unless it is a really cheap rd i doubt it is the spring. unless by now you have jacked with it.
like a car they have cables and housing and after awhile they get old and do not function like they did when new.
I would replace my housing first. cheaper,less hassle than replacing a rd and just might take care of the problem.
All your spring does is nudge it in the right direction your shifter, chain and cogs do the rest. So unless your spring is limp and hanging loose that is probably not the problem
your welcome, again
There are two kinds of people in the world, "Those who help themselves to people, and those who help people!"
Reply
#8
I have experienced bad shifting due to weak springs on many bikes (ok, anecdotal evidence, but still). The spring is essential for the shifting, if it is too weak the dérailleur will be difficult (impossible) to set up correctly. New cables and housing are - of course - as important. I would guess that after 15 years the spring may be worn. The spring does not "only nudge" the RD in the right direction, it has to overcome the friction in the cable (the shifter just lets the cable slack a well defined amount), and the stiffness in the chain that has to be forced to move to a different sprocket.
Reply


Possibly Related Threads...
Thread Author Replies Views Last Post
  SRAM rear derailleur arm length jacke 0 1,593 06-28-2017, 04:52 AM
Last Post: jacke
  Road Bike Rear Derailleur Problem Lighttower 5 2,740 05-19-2017, 01:01 AM
Last Post: painkiller
  Rear derailleur rolling chain off It's your boy 0 4,137 06-05-2016, 04:36 PM
Last Post: It's your boy
  What would you use to replace a Suntour alpha 3000 rear derailleur? eab 5 4,949 08-09-2015, 04:33 PM
Last Post: nfmisso
  Replacing old rear derailleur eab 3 8,612 05-14-2015, 09:55 PM
Last Post: DaveM
  What if your new rear Dérailleur nordog 3 3,763 05-08-2015, 12:30 AM
Last Post: nfmisso
  Rear Derailleur Suicide Into Spokes. fribbles 5 5,320 04-25-2015, 05:22 AM
Last Post: nfmisso
  what Rear Derailleur hanger do i need pastaman06 0 4,432 04-24-2015, 08:36 AM
Last Post: pastaman06
  Rear Derailleur.. I have no idea what I'm doing jjc5 4 5,023 04-13-2015, 03:38 PM
Last Post: elmore leonard
  SRAM X9 - Rear Derailleur Pulley - Wobbles columkelly@yahoo.com 2 5,054 03-24-2015, 03:07 AM
Last Post: fredbyte

Forum Jump:



ISSN 1918-3445 © Copyright 2007-2010 Bicycle Tutor / Privacy Policy / Created by Alex Ramon

feed