Clamp-on derailler

In article <[email hidden]>, Brendan Halpin
[email hidden] says...

Quoted message said:

I'm considering ordering various bike parts, but have a puzzle: if
my down-tube diameter is a measured 29mm, what do I order if the
choice of clamp-on front derailleurs is 32mm and 35mm?

Is my bike really that obsolete?

No more so than mine. I just cut a steel shim and wrapped it around the
seat tube - squirted with WD40 occasionally and hasn't gone rusty yet
(or at least it hadn't the last time I looked at it). :-)

Brendan Halpin said:

I'm considering ordering various bike parts, but have a puzzle: if
my down-tube

seat tube

Quoted message said:

diameter is a measured 29mm, what do I order if the
choice of clamp-on front derailleurs is 32mm and 35mm?

Is my bike really that obsolete?

Look for a different supllier or model. 28.6mm should be an option as well.
(Painted tubes may actually measure a bit more than this, but still a "28.6"
mech should fit).

Alternatively, bulk up the tube with a shim or tape and use a 32mm.

~PB

Brendan Halpin said:

I'm considering ordering various bike parts, but have a puzzle: if
my down-tube diameter is a measured 29mm, what do I order if the
choice of clamp-on front derailleurs is 32mm and 35mm?

Is my bike really that obsolete?

Try another supplier ?

Some Shimano front derraileurs come with shim components in the package to
fit "normal" tube sizes. If purchasing those, check the shim doesn't push
the mechanism too far out for your bike's inner ring.

I bought a Shimano unit with shims from a local bike shop on the
understanding they'd accept it back if it couldn't work on the inside ring
due to insufficient clearance. On fitting, there was just enough space on
the bike, but it was close.

(If I was totally stuck, I'd have made an eccentric shim, but not everyone
has a lathe in the shed).

- Nigel

--
Nigel Cliffe,
Webmaster at http://www.2mm.org.uk/

In article <[email hidden]>, Nigel Cliffe
[email hidden] says...

Quoted message said:

Some Shimano front derraileurs come with shim components in the package to
fit "normal" tube sizes. If purchasing those, check the shim doesn't push
the mechanism too far out for your bike's inner ring.

That shouldn't be a problem - the bottom bracket is a standard width and
the seat tube is centred on the bottom bracket.

Nigel Cliffe said:

Some Shimano front derraileurs come with shim components in the
package to fit "normal" tube sizes. If purchasing those, check the
shim doesn't push the mechanism too far out for your bike's inner
ring.
I bought a Shimano unit with shims from a local bike shop on the
understanding they'd accept it back if it couldn't work on the inside
ring due to insufficient clearance. On fitting, there was just
enough space on the bike, but it was close.

(If I was totally stuck, I'd have made an eccentric shim, but not
everyone has a lathe in the shed).

28.6 to 34.9mm eccentric shims:

www.sjscycles.co.uk/find.asp?cid=MPSUUMRLL0FS6LG22K7GJYMHJEIROYV0

~PB

in message <[email hidden]>, Brendan Halpin

(') said:

I'm considering ordering various bike parts, but have a puzzle: if
my down-tube diameter is a measured 29mm, what do I order if the
choice of clamp-on front derailleurs is 32mm and 35mm?

You should be able to find plenty of smaller ones - but if you can't, you
can always use one which is 'too big', if you shim it.

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

((DoctorWho)ChristopherEccleston).act();
uk.co.bbc.TypecastException: actor does not want to be typecast.
[adapted from autofile on /., 31/03/05]

Rob Morley said:

In article <[email hidden]>, Nigel Cliffe
[email hidden] says...

Quoted message said:

Some Shimano front derraileurs come with shim components in the package to
fit "normal" tube sizes. If purchasing those, check the shim doesn't push
the mechanism too far out for your bike's inner ring.

That shouldn't be a problem - the bottom bracket is a standard width and
the seat tube is centred on the bottom bracket.

It /shouldn't/ need an eccentric shim but some off the current [censored]*)
of shimano derailleurs (they couldn't have made them any clunkier if you
payed them) need one

*) some typo's are good enough to leave alone
--
/Marten

info(apestaartje)m-gineering(punt)nl

Brendan Halpin said:

I'm considering ordering various bike parts, but have a puzzle: if
my down-tube diameter is a measured 29mm, what do I order if the
choice of clamp-on front derailleurs is 32mm and 35mm?

Does it have be clamp-on? You could get a BB-mounted front mech.

In news:[email hidden],
POHB <[email hidden]> tweaked the Babbage-Engine to tell us:

Quoted message said:

Brendan Halpin said:

I'm considering ordering various bike parts, but have a puzzle: if
my down-tube diameter is a measured 29mm, what do I order if the
choice of clamp-on front derailleurs is 32mm and 35mm?

Does it have be clamp-on? You could get a BB-mounted front mech.

I had one once.

It was this: [censored].

Never again :-(

--
Dave Larrington
<http://www.legslarry.beerdrinkers.co.uk>
You can't have ham!