My wife’s hybrid came with a compact chainset, but I’m a compulsive bike fettler and thought a triple might be an idea. We had a spair triple chainset (tiagra), so put it on.

Why won’t the front mech shift onto the granny ring?

(Yes, I’ve tried setting the limit screws, but it won’t adjust far enough)

(9spd stuff fwiw)

Sorry. Stupid comment. Didn’t read your post properly.
Deleted.

did you reclamp the cable? – if cable is too tight irrespective of limit settings won’t drop to granny

I’d also try turning the mech slightly but chain rub is a danger

depends a bit on the front mech – just did a quick google and Shimano generally warn against it though I’m surprised doesn’t work at all

“For Installation to the Bicycle, and Maintenance:
• A triple front derailleur cannot be used for a double crankset because the shifting points do not match. A double front
derailleur cannot also be used for a triple crankset.
Double: FD-M675, M676, 3500, A070
Triple: FD-M670, M671, T670, T671, 3503″

from http://si.shimano.com/php/download.php?file=pdf/dm/DM-FD0001-00-ENG.pdf

sure a pro’ fettler will be along shortly but a bump

It depends on the chain line sometimes. Some mech and chainset combo’s will not work due to the rings sitting too close to the frame. You could try a spacer on the BB to push the chain line out.

Might be a dumb question, but are you trying to use a double shifter with a triple crank set?

Best check your rear mech has enough capacity for a triple too.

Might be a dumb question, but are you trying to use a double shifter with a triple crank set?

i’ve disconnected the cable for now while I try to get the mech set up. I was hoping that we’d be up and running with only a bit of tinkering (ok, running without use of the big ring). But it seems we may need a new front mech and (maybe?) shifter…

Time for a coffee, that’ll help!

You definitely need a new shifter.