Question about E type front mechs

In article <[email hidden]>

Mark said:

Hi,

My front mech has worn out and needs replacing. It's an E-type with
the mounting around the bottom bracket. If I understand things
correctly there is no height adjustment for these so they must be
matched to the front chainrings. Most front mechs of this sort seem
to expect a large chainring with 44 teeth whereas mine has only 42
teeth.

Is this close enough, or is this likely to be a problem?

I know I could swap to a conventional mount, but I believe that would
involve changing the BB. I don't want to spend too much at the moment
;-). I think I am limited to top-swing, since there is a bolt on the
seat tube close to where I would expect to mount a bottom swing mech.

Just reach down and shift the chain by hand - it's less hassle than
trying to figure out what front mech to buy these days.

Mark said:

Hi,

My front mech has worn out and needs replacing. It's an E-type with
the mounting around the bottom bracket. If I understand things
correctly there is no height adjustment for these so they must be
matched to the front chainrings. Most front mechs of this sort seem
to expect a large chainring with 44 teeth whereas mine has only 42
teeth.

Is this close enough, or is this likely to be a problem?

I think you want the mech pretty close to the teeth of the big ring in a
vertical sense, something between 1mm and 3mm, judging by the
instructions that came with my new front mech.

The difference in radius between a 44 tooth and 42 tooth chainring is
probably about 3mm, so I think you'd be pushing it a bit, but might just
get away with it.

Quoted message said:

I know I could swap to a conventional mount, but I believe that would
involve changing the BB.

I don't think you have to change the BB. I had a front mech like what I
think you're describing: it was attached to a sort of little plate that
protrudes from somewhere around the BB. I took the mech off (can't
remember the details-- just undo the obvious bolts) and the plate is
still there. The new chainrings I had were much bigger than the old
ones, completely precluding attaching any kind of mech to the plate, so
I just put on a normal front mech that clamps to the frame. Works fine.
I will have a go at removing the plate if I get around to it, and may
find it is impossible without changing the BB, but it doesn't get in the
way of anything at the moment.

I think you're right there's no height adjustment for these E-type
mechs.

Ben C said:

Mark said:

Hi,

My front mech has worn out and needs replacing. It's an E-type with
the mounting around the bottom bracket. If I understand things
correctly there is no height adjustment for these so they must be
matched to the front chainrings. Most front mechs of this sort seem
to expect a large chainring with 44 teeth whereas mine has only 42
teeth.

Is this close enough, or is this likely to be a problem?

I think you want the mech pretty close to the teeth of the big ring in a
vertical sense, something between 1mm and 3mm, judging by the
instructions that came with my new front mech.

The difference in radius between a 44 tooth and 42 tooth chainring is
probably about 3mm, so I think you'd be pushing it a bit, but might just
get away with it.

I don't want to risk it if the difference is that great. The last
mech never changed very well and I want things to be better.

Quoted message said:

Quoted message said:

I know I could swap to a conventional mount, but I believe that would
involve changing the BB.

I don't think you have to change the BB. I had a front mech like what I
think you're describing: it was attached to a sort of little plate that
protrudes from somewhere around the BB. I took the mech off (can't
remember the details-- just undo the obvious bolts) and the plate is
still there. The new chainrings I had were much bigger than the old
ones, completely precluding attaching any kind of mech to the plate, so
I just put on a normal front mech that clamps to the frame. Works fine.
I will have a go at removing the plate if I get around to it, and may
find it is impossible without changing the BB, but it doesn't get in the
way of anything at the moment.

I think you're right there's no height adjustment for these E-type
mechs.

I'll guess I'll try a conventional mount and leave the bracket there
if it does not foul on the new mech.

Thanks for the reply.
Mark