Hi all. My gf came home from work and on her commute the rear shifter suddenly stopped switching to a smaller cog. I’m thinking a cable issue but it feels like a faulty shifter. The bike is a Kona Rove with Sora shifting and it’s only a few months old. It has also been maintained properly at out LBS. The bike was purchased from out of town so I’m asking for your help before shipping this thing back.
What is wrong with my gf’s bike? A fault in the rear shifter
byu/sivaltaja666 inbikewrench
by sivaltaja666
17 Comments
shift cable might have come unhooked in the shifter.
edit: to check, roll the hoods forward and remove the [“Unit Cover”](https://si.shimano.com/en/pdfs/ev/ST-R3000-3975/EV-ST-R3000-3975.pdf) (Part 11) to see inside the shifter. if the head is where it’s supposed to be then you can also check for other debris and also relube the mechanism.
edit2: and if the cable came unhooked inside the shifter then the cable/housing is likely worn/corroded/frayed or bent and should be replaced.
Cable seems like it might be stuck in the shifter? I’d try to replace that and see if it resolves the issue. Does it shift if you pedal the bike? I would typically avoid shifting a bike when it’s not being pedaled.
Those shifters often develop sticky mechanisms with age. Some silicone spray should loosen up the old grease which may have degraded over the years. Flip the bike upside down, spray a little, work the shifter back and forth. Repeat.
Might be either a binding shift cable or a loose cable. With the amount of dirt on that bike, it will probably work again if you give it a good cleaning and re-lube of the cable.
It could also be too much friction in the shift cable. If so, the solution is to replace the shifter cable and housing.
Pull the hood back and check the cable. Since it’s the rear side, the cables are prone to snapping and will stick the mechanism. This will be a reason some others have said “it’s stuck in the high gear”, this makes sense because the mechanism is jammed by the broken cable.
The cable can be made up of 10 smaller wires and maybe 5 or 6 have snapped due to friction.
Take to your LBS to sort.
Edit: deleted because my brain isn’t working. Carry on.
I’ve been meaning to ask my own similar question but I have two bikes with Campy groups and both of them do this since I put new rubber hoods on them. I know it’s the hoods because if I take them off then they shift just fine.
Does your bike shift ok if you pull back or remove the rubbers?
So if it’s not shifting up I imagine something is binding up in the shifter, pull the hood back and post a photo, could just be dried grease, could be something eise
I’ve got that in my 10yo DuraAce shifter right now – if I push it forward as well as sideways it sort of works. I’m pretty sure it’s a sticky cable through the outers between shifter and rear mech. But it’s internally routed so it’s a pain to take it all out and clean/lube it.
Don’t theses gears on work on the move
The dork disc is to blame 💥
Pull back the hood and have a look at the cable head. If it’s seated correctly, pull on the cable itself (somewhere) and try to shift it with increased tension. Then pull the head out and inspect. The shifter is not likely faulty, it’s usually something else.
Needs a shifter flush
If it’s not a stick or seized cable then it’s likely a gummed up shifting mechanism. Verify the cable itself is moving freely in the housing and if it is, give the inner shifter mechanism some blasts with wd-40 or something similar and work it into the mechanism by moving the levers back and forth.
How to say it? There is a gearlike mechanism inside, which moves the gear and locks it (= the wire is pulled and fixed in a position). Sometimes little pastic teeth break off, check it. You need to dissassemble and look inside.
If one of the teeth is broken, iirc you need to replace the whole STI
Gummed up over time. Happens all the time. Use WD-40. Works like a charm. Spray the shit out of the innards with WD-40. It will break down the gummed up build up in the shifter and allow for movement.. within minutes. Trust this.