Stumped - Sticky SRAM

Discuss light weight issues concerning road bikes & parts.
Post Reply
User avatar
itsacarr
Posts: 724
Joined: Fri Nov 14, 2008 4:55 am
Contact:

by itsacarr

SRAM Red 2013.

Perfect downshift - Crisp

Upshift - gets tighter and more difficult the further up the cassette I go. I can shift through all gears but it is significantly more tight that my other 2013 red gruppo.

Replaced all cable and housing, length good as well ... when un tightened at the pinch bolt the shifter shifts freely and happily. No stress. Cable guide under the bottom bracket is clean and oiled.

This leaves me to believe that maybe ... this is a rear derailleur issue over shifter pod.

Anyway - im all ears and im stumped .... thoughts?

by Weenie


Privateer
Posts: 383
Joined: Thu Feb 03, 2011 2:28 pm

by Privateer

When you push the derailleur by hand across its range of motion does the resistance increase?

If it does, your issue is a function of the rear derailleur spring getting tighter as it is extended (and is probably normal, though you could check by comparing to another example- at a shop or on a friend's bike, if you don't have another bike with Sram Red).

sungod
Posts: 1415
Joined: Fri Dec 24, 2010 9:37 pm
Location: it's raining, it must be uk

by sungod

it'll be a hassle, but if you can't find the cause, swap the rd with the one on the bike that's ok and see if the issue moves with the rd or not

sigismond0
Posts: 236
Joined: Tue Feb 05, 2013 8:29 pm

by sigismond0

Are you sure your B-screw is adjusted properly?

blantonator
Posts: 115
Joined: Sat Oct 23, 2010 8:36 pm

by blantonator

try lubing your cables with the shimano cable lube. I had the same problem as you when i switched away from gore ride-on.

User avatar
prendrefeu
Posts: 8586
Joined: Wed Oct 31, 2007 10:32 pm
Location: Los Feliz, Los Angeles, California
Contact:

by prendrefeu

RD cable tensioned too tightly to start with?
Exp001 || Other projects in the works.

Cosmo
Posts: 83
Joined: Sun Feb 25, 2007 5:05 pm
Location: Netherlands

by Cosmo

Be sure the cable is routed correctly inside the shifter. It's possible to install the cable so the wire does not go into the small hole in the spool but under the spool outside the guide, will exit the shifter in the right place so you don't notice it. If this happens the shifter "works" as the head catches and pulls "correctly" but as the wire is not guided along the spool the friction is very high.

We see a few DIY cable installs come into the shop this way. Typically the person said they fought to install but then suddenly went in easy.

Of course the obvious-RD movement by hand, no odd bends, if internal downtube routing cables no wrapped around each other.
after 2 drinks I'm a loser, after 3 a star

NovemberDave
Posts: 164
Joined: Sat Oct 09, 2010 11:42 am
Contact:

by NovemberDave

I'm with sigismond0, the B screw seems a likely culprit.

I'd also check what Cosmo said - getting the cable started off in the shifter can be a pain in the butt, especially if you aren't using SRAM cables which are ever so slightly thinner than others.

Last, is your chain really short?

thisisatest
Shop Owner
Posts: 1980
Joined: Sat Jun 13, 2009 4:02 am
Location: NoVA/DC

by thisisatest

Does the frame have internal cable routing? Cables crossed inside the down tube?

Rush
Posts: 347
Joined: Thu Mar 01, 2012 2:10 am

by Rush

Cosmo wrote:Be sure the cable is routed correctly inside the shifter. It's possible to install the cable so the wire does not go into the small hole in the spool but under the spool outside the guide, will exit the shifter in the right place so you don't notice it. If this happens the shifter "works" as the head catches and pulls "correctly" but as the wire is not guided along the spool the friction is very high.

We see a few DIY cable installs come into the shop this way. Typically the person said they fought to install but then suddenly went in easy.

Cosmo - I just removed the original cables in my SRAM Force shifters and replaced them with Yokozuna cables. I've found that the cable head sometimes comes loose from the spool. I have given the cable a good firm pull (as per the instructions) to ensure the head is seated correctly in the spool. But if I run up and down the ratchet, sometimes the cable head comes loose.

Note I haven't tightened the cable to the rear derailleur yet, it's still hanging free once it leaves the housing.

Will this still be a problem once the cable has more tension when it is attached to the derailleur? I'm a bit bemused by the problem as even thought the Yokozuna cable is slightly thicker than the original SRAM cable, the cable heads seem to be identical in size.

sigismond0
Posts: 236
Joined: Tue Feb 05, 2013 8:29 pm

by sigismond0

Once it's under tension, it will he held in the ratchet. Fiddling with it while it is loose doesn't really tel you anything because there's no force pulling on it to keep it in place.

Sram brand cables are 0.1mm narrower than standard shift cables, but regular ones will work just fine.

Cosmo
Posts: 83
Joined: Sun Feb 25, 2007 5:05 pm
Location: Netherlands

by Cosmo

[/quote]
Note I haven't tightened the cable to the rear derailleur yet, it's still hanging free once it leaves the housing.
[/quote]

Any shifter, regardless of brand, should not be "dry" shifted with an unloaded cable. As in shifted without being tensioned. While not likely to cause any real damage what you describe is a typical outcome, cable head comes out of where it should be and could end up stuck in an odd place which can then become a mess. As sigismond noted once under tension all good but whenever a bike is dry shifted it's a good idea to make sure things are back where they should be especially if something feels stuck. As long as you make sure things are reseated correctly then unlikely any harm done.

By very fuzzy memory Campy had a warning sticker on the shifter regarding this many years ago. And if you really want to piss off a shop wrench randomly shift bikes on display, does basically the same thing. I remember digging a stuck cable head out of a then "new" Ultegra 9 speed-first and only STI shifter I will ever take apart.
after 2 drinks I'm a loser, after 3 a star

Rush
Posts: 347
Joined: Thu Mar 01, 2012 2:10 am

by Rush

Cosmo wrote:Any shifter, regardless of brand, should not be "dry" shifted with an unloaded cable. As in shifted without being tensioned. While not likely to cause any real damage what you describe is a typical outcome, cable head comes out of where it should be and could end up stuck in an odd place which can then become a mess. As sigismond noted once under tension all good but whenever a bike is dry shifted it's a good idea to make sure things are back where they should be especially if something feels stuck. As long as you make sure things are reseated correctly then unlikely any harm done.

By very fuzzy memory Campy had a warning sticker on the shifter regarding this many years ago. And if you really want to piss off a shop wrench randomly shift bikes on display, does basically the same thing. I remember digging a stuck cable head out of a then "new" Ultegra 9 speed-first and only STI shifter I will ever take apart.

Funny you should mention that, as I had to dig the original SRAM cable head out of an inside corner shifter body before putting the Yokozuna cable in. This required taking the faceplate off.

Isn't it nice that SRAM shifter bodies are so easily serviced?

by Weenie


mariocippollini
Posts: 36
Joined: Sun Mar 02, 2003 9:58 pm

by mariocippollini

I had a similar problem with a second hand pair of levers I bought, I stripped them down (much easier than Campag and next to impossible with Shimano) and I realised a couple of the circlips were missing on the gear lever mechanism. Sourced some new ones very easily and cheaply (just a standard sized circlip), cleaned all the parts and put back together and its as crisp as when new. The double tap shifters can be stripped and rebuilt in less than 20 mins per lever once you've got the hang of it, also parts such as springs are easily available from Sram. A big plus over the other manufacturers in my mind (although Campag aren't too bad).

Post Reply
  • Similar Topics
    Replies
    Views
    Last post