Rear derailleur setup

mitchgixer6

Hi all

Just finished building up a new winter frame (Dolan Preffisio). I'm having a slight issue with the rear derailleur. It's a shimano 105 11s, 5800.

Gears are shifting up and down the block no problem, but when in the lowest gear (biggest cog) it's wanting to jump down to the next gear. I've tried moving the limit screw. Even until its virtually all the way out, but still have the same result.

I've also tried moving the 'b' screw in and out but that's doesn't seem to help either.

Any ideas?

cooldad

Needs more tension in the cable? Or limit screw needs adjusting.

Vino'sGhost

sounds like the limit screw needs adjusting but you say youve already done that. I'm not trying to be rude but are you sure you've adjusted the right one?

it doesnt sound lke a hanger alignment thing but worth checking if youre running out of ideas

mitchgixer6

Cheers folks

Definitely adjusted the limit screw, and it's definitely the correct one. Will try changing the cable tightness again

Matthewfalle

cable should just be snug - as tight as you would hug a freshly laundered lab coat if you didn't want tocrease it. no need to mash it.

jgsi

New frame so I wouldnt expect anything to be out of kilter.
You do have 11 speed shifters?
B screw is just a red herring.
I'm saying this because a 10 speed Tiagra rear mech was NOT compatible with 105 10 shifters and I had to go and buy a 105 mech. Go figure Shimano logic on that 1.
Just check if all your components are compatible.

mitchgixer6

Thanks again for the help folks.

I gave the cable tension a small tweak and that seems to have done the trick. Cable must have stretched a bit after the first few rides.

Cheers

cooldad

Just for interest, cables don't stretch. It's actually the outers settling into the cable ends and mech. Just takes a bit of a mm.