Help me diagnose some bad 9 speed shifting (Sora 9 Speed Road Groupset)

[wonderloaf]

I feel your pain as I've just been through very similar. Like you I changed gear cable inners and outers and even tried a new cassette and chain to no avail, I just couldn't get the chain up onto large sprocket (32T) unless I really ramped up the tension, but then of course the downshift was affected, which seem to suggest to me a friction problem. I checked friction at each point along the cable run and it didn't seem excessive. However if I gave the RD the slightest nudge (literally less than a millimetre) the chain jumped up onto the large sprocket.

In the end it seems it came down to worn jockey wheels, the bearings were very worn causing the wheels to wobble excessively from side to side and I guess not aligning the chain properly to the sprockets. Luckily I had a newer spare RD and as soon as swapped the jockey wheels over shifting was much improved, so a new pair of wheels have been fitted and normal service has been resumed! Phew!

I'm not saying this your problem but it might be worth checking, problem being is that I understand the jockey wheels are designed to 'float' so checking could be difficult, but I guess too much float is a bad thing! For reference my wheels had done about 12,000 miles, don't know if that's a lot, it seems some people do 10's of thousands without problems but there you go.

 

[Boopop]

I feel your pain as I've just been through very similar.

Thanks for the suggestion. It seems unlikely as I only replaced the previous mech in October, but I'll have a nosey tomorrow 👍

 

[richardfm]

Not entirely sure what you mean here but I'll take a look.

Cheers!

A photo of the cable clamped on the rd will help @Smokin Joe explain

 

[Boopop]

A photo of the cable clamped on the rd will help @Smokin Joe explain

Yeah, I'll take a couple tomorrow.

 

[Ajax Bay]

Not entirely sure what you mean

https://si.shimano.com/en/pdfs/dm/GN0001/DM-GN0001-27-ENG.pdf#DM-GN0001-27-ENG.indd:.71402:7130
(Page 30) It's possible (but wrong) to clamp on the side of the bolt further away from the wheel.

 

[Big John]

Where I work (a bike charity) we have an endless supply of used rear mechs. I've had problems, similar to yours, and the boss has told me to just swap the mech for another one and see what happens. This is similar, in a way, to what Wonderloaf did although he just changed the jockey wheels. If you have another mech knocking about (and we all have spares knocking about or is it just me? Lol) it wouldn't take you long to swap it over and just see what happens. It's not guaranteed but it might just work. You just have to keep trying.

 

[fossyant]

New cables front to back (SP41 or Jagwire etc) and degrease the mech and thoroughly clean it. I've seen the state of bikes on here too many times. Even good gear cables aren't up to it beyond a year or so with 10 speed plus - Shimano or Jagwire cables - you can't half replace stuff. Lots of crap can get in near the 'brifter' too, so bar tape off and replace. Just done the same to fix slow shifts on a 10 speed 105.. new cables 12 months ago (complete rebuild) - but sloppy changes more recently. New SP41 cables for £14.99 sorted it. Re-wrapped the bar tape. Bike wasn't heavily used.

 

[Aristotle Kristatos]

I agree @fossyant . As for me this seems like an outer cable issue.
I have found they release easy but when put under load they do run into old wear grooves and stick a bit.
Gear cable outers have the metal run lengthways unlike brake outer so flexing them is not usually successful.
So yep bartape off and refit.

 

[Ming the Merciless]

Okay, so we are waiting for you to answer Ian’s questions at the moment.

 

[Boopop]

Okay, so we are waiting for you to answer Ian’s questions at the moment.

Oh, in reply to his questions - yes, yes and yes.

You lucky people, I've recorded you all a video!


This was recorded after starting off with the chain and shifter in the highest gear, and then adjusting the barrel adjuster until it would shift to the biggest cog. When I upshift the cable moves each time, but the 2nd or 3rd shift doesn't move the cable enough. This is after now having loosened both limit screws, replacing the inner and all outer cable, and checking the derailleur hanger for alignment yesterday. It doesn't shift to the smallest cog. If I rotate the barrel adjuster until it does, it'll no longer go in to the biggest cog, again, like when I first clamped the cable. When one of the upshifts happens (and subsequently fails), you can see that the derailleur does actually move, it just doesn't have any effect.

This is how the cable is connected.

I know it's not clean but I don't think that's the issue, I'm sure this is where most of you will disagree! The chain was cleaned a day or two ago and I don't usually have issues shifting with the drivetrain in this condition.

I don't want to spend £70+ on a shifter I want to replace by the end of the year, so it looks like I'll be spending some money with aliexpress soon.

 

[fossyant]

Start be giving the mech and jockey's a good clean - if you can manually align the mech/jockey's with the top and bottom sprockets, you've either got a mucky mech, mucky shifter or you need new cables, or all three.

STI's are fussy buggers. When did you change the cable outer under the bar tape ?

 

[Boopop]

Start be giving the mech and jockey's a good clean - if you can manually align the mech/jockey's with the top and bottom sprockets, you've either got a mucky mech, mucky shifter or you need new cables, or all three.

STI's are fussy buggers. When did you change the cable outer under the bar tape ?

All outer cables have been replaced, the inner cable is brand new. Yes the rear mech is dirty but it's less than 6 months old.

 

[Ming the Merciless]

For a start, it’s not clamped properly. Did you also align the jockey wheels under lowest cog before clamping?

 

[Boopop]

How is it not clamped properly? It looks the same as the image from the manual Ajax Bay helpfully posted from the manual to me.

As I said in my post with the video, "This was recorded after starting off with the chain and shifter in the highest gear", so in answer to your question, yes.

 

[fossyant]

The 'tab' on the clamping washer should be over the cable.

I'm still going with cables. I put decent Decathlon PTFE lined stainless shift cables on my CX bike with 105. Worked fine at first but shifting got 'lazy'. Swapped to SP41 and the difference is massive. Inners come in 1.2 and 1.1mm and the 1.1mm stuff runs much better (SP41). £14.99 for a set - this will save you time.

Remove the cable from rear mech, clean up, GT85 it and if it will manually move over the top/bottom sprockets by hand, it's a cable issue.