Is this just me? Tiagra 10sp issue

[Harborne Blue]

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]

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

 

[Tim Hall]

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

Good call. But if the bike's only 6 months old, if it ain't a bent mech hanger, surely it's a warranty issue.

 

[I like Skol]

I thought this was a resurrection of an old thread when I first spotted it as it sounded familiar but it seems maybe Cube have an INHERRENT PROBLEM with the cable routing on these frames?

 

[maltloaf]

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]

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.

 

[Harborne Blue]

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?

 

[maltloaf]

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]

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

 

[adscrim]

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.

 

[tincaman]

The mech hanger only has to be slightly out to cause issues, definitely get that checked first, the LBS mechanic will have a tool for it

 

[Harborne Blue]

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]

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]

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

 

[400bhp]

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.