Conundrum of a gear issue thats baffling me
Discussion
I have a gear shifting conundrum for you!
On my Ribble with Tiagra gears, they work fine until I've done about 30ish miles then they start mis-shifting down the cassette. It sounds like the derailleur hasn't moved far enough to move the chain so have to do a double press down then up 1 to get the gear I want.
From cold they shift fine, and if you leave it for 30 mins or so after the problem starts they work fine. Its always in the same direction too, up the cassette (grabbing a larger cog), down works faultlessly, and always after I've got some miles on a ride too, never at the start.
Cables are Shimano and 3 months old, and haven't covered many miles.
On my Ribble with Tiagra gears, they work fine until I've done about 30ish miles then they start mis-shifting down the cassette. It sounds like the derailleur hasn't moved far enough to move the chain so have to do a double press down then up 1 to get the gear I want.
From cold they shift fine, and if you leave it for 30 mins or so after the problem starts they work fine. Its always in the same direction too, up the cassette (grabbing a larger cog), down works faultlessly, and always after I've got some miles on a ride too, never at the start.
Cables are Shimano and 3 months old, and haven't covered many miles.
Celtic Dragon said:
From cold they shift fine, and if you leave it for 30 mins or so after the problem starts they work fine. Its always in the same direction too, up the cassette (grabbing a larger cog), down works faultlessly, and always after I've got some miles on a ride too, never at the start.
Mine are doing that. 10sp Tiagra. But it's all the time at the moment, not after half an hour. It all seems to be around the 4th and 5th cogs on the cassette. Going from the 5th to 4th, as you say I usally end up going 5th to 3rd then back down to 4th.
I was wondering if it was somethting to do with the spacing/ratchet or whatever in the shifter as for most of the other changes it's OK. FWIW I was trying to sort it out before with the barrel adjusters but the cable snapped. Once the new cable has stretched out I'll be having a proper look at it.
upsidedownmark said:
Have you tried the obvious solution of adding 1/4 to half a turn more cable tension? Maybe that you're overthinking the symptoms and the cable has just settled in a bit and needs a tweak.
^ This. Sounds classically like a moderate re-indexing is needed, and at 3 months, the cause is likely to be cable stretch (cables are supposed to be pre-stretched these days. Supposed to be). upsidedownmark said:
Have you tried the obvious solution of adding 1/4 to half a turn more cable tension? Maybe that you're overthinking the symptoms and the cable has just settled in a bit and needs a tweak.
If it's changing to a bigger cog then surely the cable is too tight and a quarter less turn is required?Towards a bigger sprocket = pulling the cable. Way OP writes it, I understand double shift to get it on, then one back towards the small end to settle it inline, and going down to smaller sprockets no problem, therefore cable is too slack.
... plus cables rarely shrink all of their own accord
... plus cables rarely shrink all of their own accord
Greg66 said:
upsidedownmark said:
Have you tried the obvious solution of adding 1/4 to half a turn more cable tension? Maybe that you're overthinking the symptoms and the cable has just settled in a bit and needs a tweak.
^ This. Sounds classically like a moderate re-indexing is needed, and at 3 months, the cause is likely to be cable stretch (cables are supposed to be pre-stretched these days. Supposed to be). Gassing Station | Pedal Powered | Top of Page | What's New | My Stuff