Giro 400 deraillers

in message <[email hidden]>, Jonathan Schneider

(') said:

This is my first bike of this type. It's the only Dawes with
Campagnolo and has a Xenon set with its plasticy levers. I bought it
in December (yes), still have my other bike for day-to-day use have
done oh maybe a thousand or so miles on in.

Since new the front derailler has now and again thrown the chain
inside when changing down. I believe the adjustment is right but the
problem is that the spring is quite lively and the motion inwards very
sharp.

They're meant to be sharp. You need to adjust (tighten) the low limit
screw so it doesn't move in so far. If this doesn't solve the problem,
fit a dogtooth, which will.

Quoted message said:

Could do with gunging up a bit. I've learnt that it is less
likely to happen with the throttle open just a bit. Are they all like
this ?

Quoted message said:

While testing the above I noticed something. When I put my weight
(13st) on the right pedal I can see (relatively anyway) the chain move
outwards into the outside of the derailler cage by a mm or two. I'm
not sure it can be adjusted never to touch there without then touching
on the inside when on the smaller cog. Is this a fact of life with
lightweight frames or might the bottom bracket bearings be bad ?

It's a fact of life, particularly with flimsier chainsets but frankly it
happens a bit under power even with very good kit. The better Campag
front mechs have a little replaceable resin insert in the outer side of
the cage with is designed to rub against the chain silently and with
minimal friction. You adjust the mech so this just touches the chain
when you're on the big ring, and everything is sweetness and light.
Don't know whether Xenon has this feature.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

Due to financial constraints, the light at the end of the tunnel
has been switched off.

Jonathan Schneider said:

This is my first bike of this type. It's the only Dawes with
Campagnolo and has a Xenon set with its plasticy levers. I bought it
in December (yes), still have my other bike for day-to-day use have
done oh maybe a thousand or so miles on in.

Since new the front derailler has now and again thrown the chain
inside when changing down. I believe the adjustment is right but the
problem is that the spring is quite lively and the motion inwards very
sharp. Could do with gunging up a bit. I've learnt that it is less
likely to happen with the throttle open just a bit. Are they all like
this ?

They are all sharp and tricky to adjust but the chain won't come off, with
standard chainrings, if adjustment and angle of the whole derailleur
really is just right.

It's more of a problem when using a 26 or 24t grannies, I've sorted mine
by offsetting the inner ring inwards with washers.

Quoted message said:

It did its trick earlier, caught and pulled through the clamp the
cable to the rear derailler loosing me access to the larger cogs (no
big deal in East Anglia) so I've had to set that up again but it's ok
now.

While testing the above I noticed something. When I put my weight
(13st) on the right pedal I can see (relatively anyway) the chain move
outwards into the outside of the derailler cage by a mm or two. I'm
not sure it can be adjusted never to touch there without then touching
on the inside when on the smaller cog. Is this a fact of life with
lightweight frames or might the bottom bracket bearings be bad ?

Even bogstandardweight frames will flex a bit, have to allow enough
clearance for it. Again the angle of the derailleur is relevant as well
as the limit screw.

Test BB by pushing & pulling crank sideways (I bet it's fine).

~PB