Gears are sensitive?

Miss Pootle

Had a few problems with my gears. First time I put it down to minor adjustments required after new purchase and transportation. I made some adjustments myself to front derailleur but took it to the shop to do it properly (I nearly managed it apparently). Now I have a more serious problem - it won't shift down at all! I took it to the shop and apparently the set-up is sensitive... There haven't been any major knocks that I can remember, so am I going to have to expect this every time my bike feels sensitive? Can I tell it to man up? Surely there must be an answer... Spec below...

Front Mech: Shimano 105 FD-5703BL triple, clamp 34.9mm

Rear Mech: Shimano Ultegra RD 6700GS

Shifters Shimano Ultegra ST-67003 10-speed

Chainset: Shimano 105 FC-5703 2-Piece 50x39x30T

Bottom Bracket: Integrated BB

Cassette: Shimano 105 CS-5700 11-28T, 10-speed

Chain: Shimano 105 CN-5700 108 links

earthvspace4XTuUWcX

"Sensitive" I've really no idea what your shop mean by that. If it doesn't shift down at all (do you mean the front mech or rear mech by the way) this would suggest a more serious problem then simply the set up requiring minor adjustment.

turnerjohn

front mechs can be a told a*se to set up at times...other one shot deal !
if you tinkered with with it that was probably the issue ! If the mech isn't tight to the frame it can slip and this effects the tension and thus the shift. Check your cables are ok...no frayed ends sticking in the shifter (I had that once) check the mech isn't gunked up either.

Yossie

I run D/A on one bike and Red on the other and they are both very sensitive: you call one a kant or or a communter or similar insult and they will sulk for days.

Seriously guys, you don't know what forces you could be messing with next time you blame your slowness on your bike and not your fat lard arsse.

Miss Pootle

Front mech same as before. I didn't tinker this time. I also suspect disconnected cable or gunk but too scared to look inside when I don't 100 per cent know what I'm doing. I don't think my original tinkering has caused this - that was a while ago.

skyd0g

Front derailleurs can be particularly sensitive, triples more than doubles. If speaking to a family friend or an Auntie confidentially doesn't help them with their issues, you can try this link from Park Tools which will guide you through their set-up.
http://www.parktool.com/blog/repair-help/front-derailleur-adjustments

...if you get stuck, or this doesn't solve things 100% come back here for further help.

slowbike

Miss Pootle wrote:

Front mech same as before. I didn't tinker this time. I also suspect disconnected cable or gunk but too scared to look inside when I don't 100 per cent know what I'm doing. I don't think my original tinkering has caused this - that was a while ago.

Quite simply - when you release the cable tension with the STI then the front mech should move inwards - it uses a spring to do this.
It's not sensitive at all - although getting it to stop in the right place is a little more "sensitive" ...

If your front mech isn't shifting at all when you're releasing the cable tension then something is stopping it moving - possibly either the end-stop screw is too tight (set up issue) or there is too much gunk in there - last resort could be that the mech has corroded too much for the spring to overcome or the spring itself is broken.

Assuming the cable tension is releasing, it's not the end-stop screw and the front mech isn't moving inwards from the middle or outer ring then I'd disconnect the mech, remove it from the bike, soak it in WD40 or GT85, get a tooth brush or similar and give it a thorough cleanout before refitting and trying again.

If it's just a case of it's stopping in the wrong place then that's down to setup ...