Tiagra rear shifter

Mike67

Anyone got any ideas on this one?

My rear shifter is taking a double click to move down a gear (larger cog) for two or three cogs only in the middle of the cassette.
I can then click the small lever once and it still stays in the same gear.

Going up the range, ie releasing the tension it shifts with no issues.
It also shifts with no issues on the smallest 3 and largest three cogs...it's just the middle three that give this problem.

I've checked cable tension, indexing, derailleur stops etc and all seems fine.

Could it be the shifter itself...anyone had this themselves?

The bike is still rideable like this but it's driving me nuts

CarlosDSanchez

How old are the gear cables and outers? Have you ever lubed the cables? Is there much wear in the upper pulley?

Wear in the upper pulley will mess up the gear change as will sticking cables. Had a similar problem and a new set of cables sorted it out.

nmcgann

Also check the main derailleur pivot (see http://www.parktool.com/repair/readhowto.asp?id=76 and look at the pic with the big blue arrows). I had a similar problem to the one you describe recently and this was the problem - main pivot worn.

The only fix is a new derailleur.

Mike67

Thanks guys.

I forgot to mention I'd changed the inner cable and cleaned out the outers.
I don't think it's down to them sticking as they move fine when releasing the tension going up the gears. They also shift well in the upper and lower three cogs.

Just checked my mileages and the derailleur has done around 2000miles.
It does get a fair bit of use/abuse though as there are lots of big hills around that I struggle to get up, so I'm forever changing gear.
I will check for wear in the derailleur pivot and pulleys...good excuse to upgrade I think

onbike 1939

I'd check that the RD hanger is plumb as this fault is typical of a bent hanger. It should always be the first thing you do before messing with anything else.