Is this just me? Tiagra 10sp issue

Harborne Blue

New Member
My mechanic and I are at our wits end...

I have a Cube Peloton Pro 2014 model with a Shimano STI / Tiagra 10 speed set which will not change gear cleanly; Here's what happens:

Change down - have to double click the shifter to move one gear, then click one back up
Change up - after the above, it's one click to shift however I cannot get into top gear.
  • We've put the rear wheel from a Giant Defy on the back (also with a 10sp cassette): still the same.
  • We've swapped out the rear derailleur for another identical unit: still the same
  • Changed all the cables: still the same. Ditto with the high/low adjusters.
Then took the cable out of the shifter and, with a tug, the gears seemed to changed, once per tug.

So what the <fruit> is wrong? We're stumped and I don't want to splash out on a new pair of shifters if that's not where the fault is (but I cannot fathom another reason).

Help!! The bike is only 6m old and is used as my daily commuter but hasn't done any serious miles yet.
 

themosquitoking

Veteran
Location
Spain
Sounds like the mech hanger then i reckon, i just want to say it before anyone else.
 

maltloaf

Senior Member
Location
Gloucester
If you disconnect the cable entirely does it sit in the smallest cog OK? If so then it's not the hanger or derailleur or frame and is a cable pull issue.

If it's jumping out of the smallest cog with the cable disconnected then it's either the limit screw, a bent or misaligned mech or hanger or bent frame.
 

Drago

Flouncing Nobber
Location
Poshshire
There's something not right. The current Tiagra should be smoother than Terry Thomas soaked in WD 40.

If it should turn out to be a bent mech hanger then good luck trying to prove you didn't bend it.
 
OP
Harborne Blue

Harborne Blue

New Member
TBH I'd just like it sorted, never mind the cost, especially as I don't want to take it back to where I bought it from.

Is there anyway to check the mech hanger before I go back into my mechanic?
 
Last edited by a moderator:

maltloaf

Senior Member
Location
Gloucester
Have you done what I said? if it won't go into the smallest cog with the cable disconnected and the limit screw adjusted then it's an alignment / geometry problem
 

jack smith

Über Member
Location
Durham
Sounds like the mechanic dosent know what he is doing tbh lol, my betting is poor adjustment of the rear mech(s)
 

adscrim

Veteran
Location
Perth
try replacing the piece cable housing at the rear mech. a LBS should be able to provide you with a piece of outer for pennies and it will, if nothing else, eliminate another possible issue.
 
OP
Harborne Blue

Harborne Blue

New Member
Thanks guys - it's too dark here to work on the bike in the evening so I'll get it on the stand at the weekend and check the hanger and alignment.
 

Tim Hall

Guest
Location
Crawley
Thanks guys - it's too dark here to work on the bike in the evening so I'll get it on the stand at the weekend and check the hanger and alignment.
If you've got a spare back wheel you can screw the axle into the mech mounting hole (having removed the mech first, obvs.). Measure the distance between the two wheels at 12, 3, 6 and 9 oclock positions. If the mech is straight it should be the same. It'll need to be a Shimano axle (M10 x 1)
 

screenman

Legendary Member
Any mechanic who does not check rear mech alignment before making any adjustments to my rear mech would not touch the bike again.
 

400bhp

Guru
Even worse is the mechanic that cannot spot it when there's difficulty with the shifting.

I got a free spot check a while ago whilst getting a free i-d tag for the bike. The mechanic noted that my rear mech was slightly bent. And he's right, as I have shifting issues not dissimilar to the OP.

It's a winter bike and I CBA to change the derailleur as it's good enough.
 
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