105 shifting issues

[thunderlips76]

Hi there,
So I have a Cannondale caad12 with 105 group set. The issue I’ve been having is that after a long climb in the small chain ring I can’t shift back into the big ring without getting off the bike and shifting. This is not an issue after shorter punchy climbs, on flat road or not under load. Just after longish climbs. Not sure what the issue is but does anyone have any suggestions?

 

[DCLane]

My guess is that your front derailleur needs adjusting; there are two screws for high and low limit.

Have a look at this or similar:
View: https://www.youtube.com/watch?v=Ea03ChN-7Vg&vl=en

 

[Sharky]

Probably adjustment as said above, but when you change up, which sprocket are you in at the rear? If you are still on the inside sprockets, the angle of the chain could be just enough to stop it being picked up by the front changer. If you move up at the rear first, before changing to the big ring, does this work better?

 

[raleighnut]

My guess is that your front derailleur needs adjusting; there are two screws for high and low limit.

Have a look at this or similar:
View: https://www.youtube.com/watch?v=Ea03ChN-7Vg&vl=en

Doubtful it's the limit screws, the cable adjuster may need a tweak to shorten it slightly would be my first guess.

 

[thunderlips76]

Probably adjustment as said above, but when you change up, which sprocket are you in at the rear? If you are still on the inside sprockets, the angle of the chain could be just enough to stop it being picked up by the front changer. If you move up at the rear first, before changing to the big ring, does this work better?

 

[thunderlips76]

Yeah it makes a difference but not all the time

 

[boydj]

It should be easier as you get down to the smaller cogs at the back. I'd try backing off the outer limit screw, just a touch, and check that the cable is reasonably tight when on the small chainring.