sticky STI

[Cappi]

hi, im sitting with a little problem. my left STI requires lots of effort to change from small to the big blade. I have loosen the cable and the front derailleur moves fine. the sti also clicks nicely with finger tip movement(no load on cable). but once the cable is connected it struggles to shift? it has a 105 group set 6700 I think with cables under tape.it also has the little adjuster barrels just after the outer cable housing comes out from the tape. any help/suggestions please?

 

regards

[GaryvdM]

Check that the cable has not started the fray in the sti, i.e. remove the cable and do a visual inspection on it.

[David Marshall]

I would replace the cable and housing before looking at the STI. Dirt, wear and even a kink in the cable can introduce a lot of drag.

[Cappi]

Check that the cable has not started the fray in the sti, i.e. remove the cable and do a visual inspection on it.

hi, guys the bike has less than 500km on it. it was bought 2nd hand. funny thing is that if I release cable at derailleur it pulls nice and easy up when shifting ?? that's what confuses me.

 

thanks for the pointers. gonna do the cheapest thing first and change the cable then the housing and take it from there.

[DJR]

hi, im sitting with a little problem. my left STI requires lots of effort to change from small to the big blade. (1) I have loosen the cable and the front derailleur moves fine. ( 2) the sti also clicks nicely with finger tip movement(no load on cable). (3) but once the cable is connected it struggles to shift? it has a 105 group set 6700 I think with cables under tape.it also has the little adjuster barrels just after the outer cable housing comes out from the tape. any help/suggestions please?

 

regards

hi, guys the bike has less than 500km on it. it was bought 2nd hand. funny thing is that if I release cable at derailleur it pulls nice and easy up when shifting ?? that's what confuses me.

 

thanks for the pointers. gonna do the cheapest thing first and change the cable then the housing and take it from there.

 

Lets see.....

 

1) Does the front derailleur move easily and correctly when you move it by hand while the cable is off? Then the derailleur should be fine.

 

2) Does the sti click nicely and easily and pull cable through while cable is disconnected at the derailleur end? Then the sti seems fine.

 

3) That leaves the cable and its outer as the main suspects.

 

What to do?

 

1) If you know how things work or you can Google and follow instructions, remove the cable and the outer. Check the cable for kinks and frayed parts. If anything is amiss, replace both.

 

2) If the cable seems fine, then oil it lightly. Blow something like Q20 through the outer to clean it and then reassemble.

 

3) Oil derailleur joints, pivots, springs with a light oil

 

4) oil moving parts of sti with a light oil

 

If it doesn't help?

 

1) get help from a reputable mechanic

 

PS I assume your cable line is correct and that the cable makes a nice slack curve from the bars backwards. Too sharp a corner and it may cause difficult movement.

 

Hope this helps