Right – I’ve set them up before, but I can’t get this one right, can anyone help?

It’s a Sram Rival 1×11 and the symptoms are:

• If indexing is set to go up the block (towards low gears) correctly, it is slow to respond coming down the block again.
• This gets worse as you go up the block – tapping to go to a smaller cog from one of the 3 biggest ones often results in nothing happening at all. Towards the smaller cogged end of the block, it’s not as bad. It will move, but in its own time. Occasionally it will ghost-shift into a smaller cog.

• With the bike upside down and me spinning the pedals, same thing happens. If I pull the derailleur myself, it will shift.

• High- and low-limit set correctly (to my eye at least); B-tensioner adjusted per instructions.

Any ideas? It’s as if there’s friction in the system – but could this also be a bent mech/hanger symptom? (Bike fell over and hit the patio hard a few weeks ago, and that’s in the back of my mind. It *looks* straight to me, but sometimes not…)

Thanks : \

Easiest solution is fitting a spare mech hanger… i’ve had hangers that look straight but when you take them off are clearly not.

Have you seen the mech hanger alignment tools, not used one myself but they’re pretty cool if you ask me.

I’m hoping/assuming your shifter and mech are compatible ?

SRAM 1x rear mech are super sensitive to B tension.
I bet less tension will solve this for you.

Why wouldn’t it be friction?

Hanger is straight if it looks straight.

The only thing with friction is, I can’t work out where in the system it would be.

I’ve lubed it all up, except for the bit of cable that goes from the levers up under the bar tape, come to think of it …

How old are the cables?

I’ll try to get some oil up there and have another play with my angle of dangle, then.

scot – it’s all new – bought bike last august, only started riding it in anger this year

If you don’t have full cable outers can you move the mech up and down smoothly by pulling on the inner?

^^ I will check this when I get back tonight. But, I think I can.

I generally test without the cable attached in these situations. Push against the spring to change gear and then let go and see if it changes back automatically as expected. If so, you have issues in the cabling/shifter and the mech is all good.

I generally test without the cable attached in these situations. Push against the spring to change gear and then let go and see if it changes back automatically as expected. If so, you have issues in the cabling/shifter and the mech is all good.

Hmmm, good point.

With the cable attached, if I push it from the small cog up to big cog, without touching the lever, the mech comes back smoothly across the block to the small cog again.

So I guess that does prove there’s something out at the shifter end… what could that be?

It’s shifter or cable in that case. If you leave the cable loose and move the shifter you’ll see if the shifter has friction. This is unlikely though, much more probable that you’ve done something to the cable either poor routing or wear/kinks. There’s no great advice to find this unfortunately, just looking closely and ripping the whole thing apart to look see

Yep – went for a ride at lunchtime today. Clicked to move down from big cog to little cogs, nothing happens. Reached down and gave the exposed cable a tug, and the mech dropped smoothly onto correct cog.

So, something at the lever then.

At least I didn’t build that bit myself, but I might have to un-tape my bars now to get to it. :/

Thanks for talking me through it.

… yeah, cable end had become unseated from the ratchet, causing irregular malfunction. My hamfisted attempts at fixing it caused it to become wedged in the wrong place; now I’ve to get in there to rescue and re-seat it somehow. At least I know what the problem was, though.

cable end had become unseated from the ratchet

This might have happened because of a stiff cable – the derailleur spring needs to be able to keep tension on the cable end to keep it seated.

So to keep this thread updated – after stripping and rebuilding to no avail – cable end still pops itself out of its housing in the shifter – bike is now with LBS for the opinion of people who actually know what they’re doing.

(First time I’ve admitted defeat and taken a bike to a shop for repair in about 30 years. I feel small, but relieved. It’s been really bugging me.)

Any ideas?

Remove groupset, place in bin, replace with Shimano.

That’s what I did with my SRAM road drivetrain. Hateful stuff.

Remove groupset, place in bin, replace with Shimano.

Yup – that’s the line I’m trying to stop myself going down.

In fact: sell bike; replace with Shand+Rohloff+Gates.

shifter mechanism a bit knackered if the cable end has come a bit loose?

… or just a bit shit.

Verdict from shop, just for the record:

• Friction: rear cable run at too tight an angle
• Bent mech hanger: slightly

Very sensitive to friction, apparently, so I was right all along, just incompetent (apart from straightening the hanger, which is beyond me and my toolbox).

So I retract my ‘maybe a bit shit’ comment, until or unless it goes wrong again.

For the record, IME checking the hanger as straight should be the first not the last thing.

Wiggle do the tool for £20 worth buying if youre a regular fettler.

yup 🙄