Do I have a defective front shifter?

TomYoung said:

Hi all:

I'm struggling - once again - to fix the shifting on the front
chainring of my daughter's 2004 Fuji Absolute and I'm wondering if a
defective front shifter might be part of the problem.

Here's the setup on the bike: 52-42-30 crank/Shimano Tiagra FD-443
front derailer/Shimano Rapid Fire SL-R440 8-speed shifters.

And here's the problem: I lose the trim adjustment when shifting from
the big ring down to the second ring.

Shifting from small to large chainrings there's 3 distinctive "clicks"
at the lever, with the 1st and 2nd clicks being very close together
(i.e., very small movement of the lever) and the last click requiring
a *huge* lever throw. So, the 1st click moves the chain from the
small ring to the middle one. The 2nd click moves the front
derailleur a small amount for trim adjustment. And the 3rd click
moves the chain to the big ring.

However, when shifting from large to small chaining there's only three
"clicks" at the lever. The first click will (just barely) knock the
chain from the big ring to the middle ring, with the derailleur
resting at the "high side middle ring" trim level. The next click,
which should move the derailleur to the "low side middle ring" trim
position, instead knocks the chain down to the small ring with the
derailleur resting against the low-side stop. No amount of finessing
of the movement of the shift lever will produce that lower middle ring
trim level.

Does this sound like a defective front shifter, or some kind of mis-
adjustment?

TIA.

Tom Young

Shimano STIs don't have a trim-down technique for trim-equipped shifters...
you have to shift down then trim up. I'm not sure about the flat bar
shifters.

--
Phil

TomYoung said:

Hi all:

I'm struggling - once again - to fix the shifting on the front
chainring of my daughter's 2004 Fuji Absolute and I'm wondering if a
defective front shifter might be part of the problem.

Here's the setup on the bike: 52-42-30 crank/Shimano Tiagra FD-443
front derailer/Shimano Rapid Fire SL-R440 8-speed shifters.

And here's the problem: I lose the trim adjustment when shifting from
the big ring down to the second ring.

Shifting from small to large chainrings there's 3 distinctive "clicks"
at the lever, with the 1st and 2nd clicks being very close together
(i.e., very small movement of the lever) and the last click requiring
a *huge* lever throw. So, the 1st click moves the chain from the
small ring to the middle one. The 2nd click moves the front
derailleur a small amount for trim adjustment. And the 3rd click
moves the chain to the big ring.

However, when shifting from large to small chaining there's only three
"clicks" at the lever. The first click will (just barely) knock the
chain from the big ring to the middle ring, with the derailleur
resting at the "high side middle ring" trim level. The next click,
which should move the derailleur to the "low side middle ring" trim
position, instead knocks the chain down to the small ring with the
derailleur resting against the low-side stop. No amount of finessing
of the movement of the shift lever will produce that lower middle ring
trim level.

Does this sound like a defective front shifter, or some kind of mis-
adjustment?

That's the way it is supposed to work. It's a 'feature'!

Any 2000 to 2006 Campagnolo left Ergo shifter, or a 2007 Chorus or
Record Ergo, will not only give you a continuum of small steps both ways
but riders with small hands generally prefer the shape and the smaller
'reach' on that middle->high shift.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971