Can a dent in an aluminium rim be fixed?

Last weekend I damaged the rim of my Campagnolo Eurus (previous
model with steel spokes) due to a pothole. The side wall has a
little (inwards) dent that is clearly noticeable during braking. I
asked some people about repairing this and got conflicting answers:

1. Try to push it back (with pliers?): should be ok.
2. It will break if you do that (or something similar).

So what can/should I do? I really like the wheel and there doesn't
seem to be anything comparable to replace it (the new Eurus has
aluminium spokes, and the Neutron doesn't have the G3 spoke pattern).

I could continue to ride the wheel if I could be reasonably sure
that it doesn't break.

"Claus Assmann"
wrote in message ...
Last weekend I damaged the rim of my Campagnolo Eurus (previous
model with steel spokes) due to a pothole. The side wall has a
little (inwards) dent that is clearly noticeable during braking. I
asked some people about repairing this and got conflicting answers:

1. Try to push it back (with pliers?): should be ok.
2. It will break if you do that (or something similar).

So what can/should I do? I really like the wheel and there doesn't
seem to be anything comparable to replace it (the new Eurus has
aluminium spokes, and the Neutron doesn't have the G3 spoke pattern).

I could continue to ride the wheel if I could be reasonably sure
that it doesn't break.

You can try straightening it. Note that if you're watchful you won't have a
cataclysmic failure of the wheel. You might develop a crack but more likely
you won't be able to make a decent straightening so that you don't get the
pumping you presently feel through the levers.

ANY cracks mean the rim must be discarded. Remember that rims have been
cracking since they first were invented. If you just remain watchful you can
take a good try.

On Mon, 1 Dec 2008 21:10:55 +0000 (UTC), Claus Assmann
wrote:

Last weekend I damaged the rim of my Campagnolo Eurus (previous
model with steel spokes) due to a pothole. The side wall has a
little (inwards) dent that is clearly noticeable during braking. I
asked some people about repairing this and got conflicting answers:

1. Try to push it back (with pliers?): should be ok.
2. It will break if you do that (or something similar).

I've tried, using a C-clamp and some metal plates to distribute the
pressure and it's helped, but never got the rim as good as new. Got
it tolerable to rider.

I think you should try -- there is not much risk in breaking it worse
than it is if you go slowly.

On Mon, 01 Dec 2008 21:10:55 +0000, Claus Assmann wrote:

Last weekend I damaged the rim of my Campagnolo Eurus (previous model
with steel spokes) due to a pothole. The side wall has a little
(inwards) dent that is clearly noticeable during braking. I asked some
people about repairing this and got conflicting answers:

1. Try to push it back (with pliers?): should be ok. 2. It will break if
you do that (or something similar).

So what can/should I do? I really like the wheel and there doesn't seem
to be anything comparable to replace it (the new Eurus has aluminium
spokes, and the Neutron doesn't have the G3 spoke pattern).

I could continue to ride the wheel if I could be reasonably sure that it
doesn't break.

the #1 question is about dent size. small ones can sometimes be repaired,
large ones, the rim is gone. chances are though, you can still ride it if
the wheel doesn't lock while braking. rims wear out anyway, so wheel
expiration is a matter of "when", not "if".

On Dec 2, 12:07*am, jim beam wrote:
On Mon, 01 Dec 2008 21:10:55 +0000, Claus Assmann wrote:
Last weekend I damaged the rim of my Campagnolo Eurus (previous model
with steel spokes) due to a pothole. The side wall has a little
(inwards) dent that is clearly noticeable during braking. I asked some
people about repairing this and got conflicting answers:

1. Try to push it back (with pliers?): should be ok. 2. It will break if
you do that (or something similar).

So what can/should I do? I really like the wheel and there doesn't seem
to be anything comparable to replace it (the new Eurus has aluminium
spokes, and the Neutron doesn't have the G3 spoke pattern).

I could continue to ride the wheel if I could be reasonably sure that it
doesn't break.

the #1 question is about dent size. *small ones can sometimes be repaired,
large ones, the rim is gone. *chances are though, you can still ride it if
the wheel doesn't lock while braking. *rims wear out anyway, so wheel
expiration is a matter of "when", not "if".

the modulus of aluminum is like 2 or 3 percent, that is not going to
give you a lot of room to bend your rim back, in fact you will be
causing a fracture of the material and you will have to consider how
long do you want to walk back when it finally goes

jim beam wrote:

the #1 question is about dent size. small ones can sometimes be repaired,

About 15mm in length, and about 1.5mm "deep".

large ones, the rim is gone. chances are though, you can still ride it if
the wheel doesn't lock while braking. rims wear out anyway, so wheel
expiration is a matter of "when", not "if".

That reminds me that I have to buy a caliper to measure the wall
thickness. What is a "safe" thickness for this kind of rim?

wrote:
On Dec 2, 12:07 am, jim beam wrote:
On Mon, 01 Dec 2008 21:10:55 +0000, Claus Assmann wrote:
Last weekend I damaged the rim of my Campagnolo Eurus (previous model
with steel spokes) due to a pothole. The side wall has a little
(inwards) dent that is clearly noticeable during braking. I asked some
people about repairing this and got conflicting answers:
1. Try to push it back (with pliers?): should be ok. 2. It will break if
you do that (or something similar).
So what can/should I do? I really like the wheel and there doesn't seem
to be anything comparable to replace it (the new Eurus has aluminium
spokes, and the Neutron doesn't have the G3 spoke pattern).
I could continue to ride the wheel if I could be reasonably sure that it
doesn't break.
the #1 question is about dent size. small ones can sometimes be repaired,
large ones, the rim is gone. chances are though, you can still ride it if
the wheel doesn't lock while braking. rims wear out anyway, so wheel
expiration is a matter of "when", not "if".

the modulus of aluminum is like 2 or 3 percent, that is not going to
give you a lot of room to bend your rim back, in fact you will be
causing a fracture of the material and you will have to consider how
long do you want to walk back when it finally goes

6061-T6 aluminium [1] has a typical 12% elongation to fracture. Elastic
modulus is typically about 69 GPa.

[1] A common material for bicycle frames and rims.

--
Tom Sherman - 42.435731,-83.985007
LOCAL CACTUS EATS CYCLIST - datakoll

Claus Assmann wrote:

Last weekend I damaged the rim of my Campagnolo Eurus (previous
model with steel spokes) due to a pothole. The side wall has a
little (inward) dent that is clearly noticeable during braking. I
asked some people about repairing this and got conflicting answers:

1. Try to push it back (with pliers?): should be OK.
2. It will break if you do that (or something similar).

So what can/should I do? I really like the wheel and there doesn't
seem to be anything comparable to replace it (the new Eurus has
aluminium spokes, and the Neutron doesn't have the G3 spoke
pattern).

I could continue to ride the wheel if I could be reasonably sure
that it doesn't break.

From what you say, it seems only the sidewall (the bead) is bent.
This is an easy one t fix if done with care. Use a large adjustable
wrench (Crescent wrench) with which to clasp the bead and bend it back
to its normal shape as well as you can. To but a flat section into
the arch of a rim takes a hard landing on a hard tire. That is harder
to repair but can also be done. There is a rim straightener tool:

http://tinyurl.com/ozv9t

but before I got one of these I loosened the spokes in the area and
hung the wheel on a 2x4 beam and hung on it. That worked well.

Jobst Brandt

On Dec 2, 1:31*am, Claus Assmann ca+sendmail(no-copies-please)
@mine.informatik.uni-kiel.de wrote:
jim beam *wrote:
the #1 question is about dent size. *small ones can sometimes be repaired,

About 15mm in length, and about 1.5mm "deep".

large ones, the rim is gone. *chances are though, you can still ride it if
the wheel doesn't lock while braking. *rims wear out anyway, so wheel
expiration is a matter of "when", not "if".

That reminds me that I have to buy a caliper to measure the wall
thickness. What is a "safe" thickness for this kind of rim?

that's not a big bend- I'd say leave it and live with it, brake more
with your other wheel

SJM? wrote:

http://tinyurl.com/ozv9t

but before I got one of these I loosened the spokes in the area and
hung the wheel on a 2x4 beam and hung on it. That worked well.

Do you do that to alloy rims? Do they last afterwards?

I've always been reluctant to do that with alloy due to weakening
the alloy. But they aren't making any more vintage rims, so I'm
starting to consider it.

No, I only do that to aluminum rims and they last a long time... until
the sidewalls wear thin from braking on my road wheels. Of course I'm
talking about MA-2 rims, not CF or steel.

Jobst Brandt