SRAM shifting issues.

[Proto]

Having trouble with the shifting on my CX/Gravel bike. Driving me nuts.

Single ring setup, SRAM Force cranks, 38t ring, 11/36 cassette, Force 1 medium cage rear mech, Force shifters.

Shifting up through the gears all works fine, however, when on the largest cog it won't shift down. Shifter 'clicks', cable releases sightly, but mech doesn't move. Click again, and again, and maybe it will then shift down a cog, but not always. Sometimes I have to physically nudge the mech outwards. Once off the biggest cog it generally shifts fine all the way back down to the smallest cog.

The shifter looks fine, I've cleaned and lubricated (3in1 spray) as best I can. I've taken the mech off, cleaned and lubricated, can't see anything wrong with it. I've changed the gear cable, can't see anything wrong with that either. Checked the mech hanger alignment, all good. So I'm stumped.

Anyone got any suggestions?

 

[weareHKR]

Does the Mech move as it should without the cable attached?

 

[Proto]

Yes. The return spring is strong, no sticking or lumpiness. I've also got a spare Rival 1 medium cage mech I could try.

I'm going to refit everything except the chain. See what it does then.

 

[fossyant]

Points at a sticky cable to me. You've completely replaced the inner and outer ?

 

[Proto]

Points at a sticky cable to me. You've completely replaced the inner and outer ?

Yes, pretty sure you're right, although I don't think it's either the inner or outer!!

I think I now know what's going on. The nipple sits in a pocket (red plastic) in the shifter. When shifting up a gear (down the cassette) a single tap allows the red plastic part to rotate within the shifter, lengthening the cable and allowing the mech to move out. However, the cable sticks, and the nipple pops out of its housing, and if you 'tap' too many times, the red part keeps rotating and the cable ends up jamming inside the shifter.

I've replaced the inner, and it made no difference.

Very little resistance between inner and outer on the bench but as soon as you assemble with a shifter, resistance is introduced.

Examination/experiment shows the problem to be in the shifter body itself. Where the cable is introduced into the shifter, through the plastic nipple housing, 90 degree turn up to the exit of the shifter and into the outer cable - somewhere in there something is causing friction. Not sure I can fix this. I've put some oil down, and will experiment further.

 

[fossyant]

Replace both inner and outer. 10 speed upwards can be very fussy about a perfect cable. About 18 months ago my MTB started not quite shifting perfectly. Changed the cables for Jagwires again, hey presto perfect. SRAM 2 x 10. I couldn't feel any drag on the old cables.

You could have some dirt dragging just enough in the outer to stop it shifting.

 

[Proto]

I've got some new outer (both Jagwire and SRAM) so will replace anyway but pretty sure the dragging is in the shifter body. I need some of that super furry dental floss to drag through the cable channel in the shifter. Starting to go off SRAM.

 

[Trickedem]

I had loads of issues with my SRAM 1x11 on my Gravel Bike. I just couldn't get it adjusted correctly. Turned out the hanger wasn't aligned properly. Doesn't sound like your issue is this though.

 

[fossyant]

I've never had an issue with SRAM or Shimano. Both my 'teens' bikes have had SRAM X4 and X5 and it's been flawless.

My X9 shifts perfectly, unless the cable is worn, or the chain rings get too worn for a new chain. Make sure the shifter is cleaned out too. Brake cleaner is good for getting greasy crap out of tight spaces like a cable channel.

Hangar issues are another problem for 10 plus speeds as well.

 

[raleighnut]

I'd replace that short bit of cable outer between the frame exit point and the mech, notorious for causing this kind of issue.

 

[Proto]

I'd replace that short bit of cable outer between the frame exit point and the mech, notorious for causing this kind of issue.

It’s one length of outer cable from shifter to the rear mech.

 

[Proto]

I have no advice - at least not that hasn't already been given. But just to chime in with the SRAM Bashing ...

My SRAM Apex right shifter started off with the paddle refusing to return to centre and then a month or so later something inside snapped and the paddle ended up sticking out at a crazy angle. RIP shifter. It lasted about 15,000km ish /10,000 miles ish.

I hear great things about SRAM wireless kit, but I’m a Campagnolo fanboy, can’t believe anything is better than my Super Record EPS!

 

[Hacienda71]

I have very similar issues with my Sram MTB setup which is 1x12. Spinning on a 50t rear as you descend after cresting a hill is highly annoying. It does seem to be periodic and sometimes works fine. Never had aproblem with this on 2x10 sram road setups. I like the 1x drivetrain for it's simplicity, but it is a compromise and I can't quite get the indexing perfect on it either.

 

[raleighnut]

It’s one length of outer cable from shifter to the rear mech.

Replace the lot then.

 

[Proto]

Replace the lot then.

I understand Campagnolo now make a gravel groupset .............