Tiagra Eront mech

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johnt
Posts: 62
Joined: 30 Apr 2011, 1:57pm

Tiagra Eront mech

Postby johnt » 8 Mar 2012, 5:49pm

I have recently fitted a Tiagra triple front mech and Dura Ace bar end shifters. It is so stiff that it actually hurts my hand to change. Is just stiff and needs to "wear in", or have I fitted something wrongly? Any ideas?

Brucey
Posts: 39498
Joined: 4 Jan 2012, 6:25pm

Re: Tiagra Eront mech

Postby Brucey » 8 Mar 2012, 7:11pm

are the cables OK? No binding anywhere? Good quality lined inners?

(I know some folk say not to, but I grease my cables with Finish Line grease and I've had no trouble)

Maybe a teflon-impregnated cable might help?

Also how have you got the cable anchored on the front mech? If the arm is nearly vertical the mechanical advantage will be slight.

BTW Does the lever/cable move easily without the F.mech attached?

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

PW
Posts: 4519
Joined: 23 Jan 2007, 10:50am
Location: N. Derbys.

Re: Tiagra Eront mech

Postby PW » 8 Mar 2012, 7:54pm

I'd have said the same. It's usually cables, if it isn't then the cable may be attached to the wrong side of the bolt on the lever arm. Just rarely it may be the mech pivots but that's not been common in my experience and some type of squirty oil in large quantities usually cures it.
If at first you don't succeed - cheat!!

reohn2
Posts: 39427
Joined: 26 Jun 2009, 8:21pm

Re: Tiagra Eront mech

Postby reohn2 » 8 Mar 2012, 9:50pm

Brucey wrote:are the cables OK? No binding anywhere? Good quality lined inners?

(I know some folk say not to, but I grease my cables with Finish Line grease and I've had no trouble)

Maybe a teflon-impregnated cable might help?

Also how have you got the cable anchored on the front mech? If the arm is nearly vertical the mechanical advantage will be slight.

BTW Does the lever/cable move easily without the F.mech attached?

cheers


spot on!
Execpt for the telon cables,I've had the teflon come off and bung up the inside of the outer.I much prefere pre stretched stainless steel ones.
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I cycle therefore I am.

JohnW
Posts: 6376
Joined: 6 Jan 2007, 9:12pm
Location: Yorkshire

Re: Tiagra Eront mech

Postby JohnW » 9 Mar 2012, 4:43pm

Undo the cable binder bolt on the mech, and see whether you can move the cage back and forth easily - that could give you a clue. With the cable binder bolt loosened, try to push the inner cable backwards and forwards in the sheathing, and see how much resistance you meet with.

With the cable bolt tightened again -when you move the lever against the spring in the mec (i.e. changing up), obviously from what you say, you are meeting with resistance. But when you push the lever back (i.e. changing down from big ring to smaller ring), are you still meeting with the same resistance? If yes, then I suggest the lever needs a course of thinking about. Next, check the cable when you've pushed it to the limit to change down - has the inner cable gone slack?, then I'd have a look at the mechanism. If, when you change down, nothing happens, then I'd suggest that the return spring on the mech isn't strong enough to overcome the resistance in the system, and indeed I'd say that the cable is stiff in the sheathing.

If everything is new and if all has been fitted correctly, then the cable shouldn't be stiff. If, however, the ensemble has been in place for some time, and the stiffness has developed gradually, again, it would seem stiffness in the cable - between the cable and the sheathing.

Before the days of stainless steel cables, and/or sheathed inner cables, it was general to take the cable out and grease it every six months or so.

Brucey
Posts: 39498
Joined: 4 Jan 2012, 6:25pm

Re: Tiagra Eront mech

Postby Brucey » 9 Mar 2012, 5:45pm

reohn2 wrote: Execpt for the telon cables,I've had the teflon come off and bung up the inside of the outer.I much prefere pre stretched stainless steel ones.


ooh er...! I've not found I need to use them much myself (likewise gravitating towards the stainless ones too), but others have reported improvements on tight/awkward cable runs; I hadn't realised that the stuff could come off wholesale.... was there any other lube present, sharp edges that scraped, or did it come off all by itself?

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

johnt
Posts: 62
Joined: 30 Apr 2011, 1:57pm

Re: Tiagra Eront mech

Postby johnt » 16 Mar 2012, 6:01pm

Thanks for all the suggestions guys! It turned out to be that the inner wires that make up the inside of the outer casing were pulling through the plastic ferrule on the end slightly and jamming the inner cable. Cleaned it up with a file and seems fine now. I think metal ferrules would stop this happening, but can't seem to get them in gear cable size. Cheers!

Brucey
Posts: 39498
Joined: 4 Jan 2012, 6:25pm

Re: Tiagra Eront mech

Postby Brucey » 16 Mar 2012, 6:10pm

ah, that makes sense.... I think you can get metal ferrules for gear cable but not every LBS stocks them.

If you can dress the ends of the outer cable square when the outer cable is held (bent) roughly in its final orientation this will make it much less likely that odd strands will poke through in the way you describe. I use an angle grinder to dress the cable ends smooth like this BTW.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

JohnW
Posts: 6376
Joined: 6 Jan 2007, 9:12pm
Location: Yorkshire

Re: Tiagra Eront mech

Postby JohnW » 17 Mar 2012, 1:07am

Brucey wrote:.............. I think you can get metal ferrules for gear cable but not every LBS stocks them.........


Mine do!