Rebending chromo forks

meb said:

I had a bent chromo Peugoet fork that was letting the front tire
intermittently contact the downtube. Rather than risk the tire going
into the downtube and acting as a brake, I bent the fork forward by
removing the front wheel, and inserting the blades between a plate and a
concrete wall and simply pulling down on the handlebars. I had fulcral
points about 8-12 inches from the droppouts and the rebending took place
with the surprisingly small force of about 50 lbs. Given the relative
ease of the rebend, it has me wondering if this bent fork is weakended
and prone to potential failure.

Any thoughts?

Probably ok. Obviously, this bike had run into something. Was the down
tube or top tube dinged?

I had a steel Motobecane (Vitus CroMo tubing) that was in a crash with
a wrong way bike rider. LBS bent the forks back, and I never had a
problem. There was a slight "bump" in the downtube an inch or so from
the head tube lug.

Art Harris

meb said:

I had a bent chromo Peugoet fork that was letting the front tire
intermittently contact the downtube. Rather than risk the tire going
into the downtube and acting as a brake, I bent the fork forward by
removing the front wheel, and inserting the blades between a plate and a
concrete wall and simply pulling down on the handlebars. I had fulcral
points about 8-12 inches from the droppouts and the rebending took place
with the surprisingly small force of about 50 lbs. Given the relative
ease of the rebend, it has me wondering if this bent fork is weakended
and prone to potential failure.

Quoted message said:

Any thoughts?

1. In my opinion, most traditional 70's / 80's steel forks get "one
free bend-back", as long as the damage is minor (i.e. as long as
front wheel isn't touching downtube.)

2. You must have used more like 100 lbs of force. If you used only
50 lbs of force, the whole front end of the bike would likely
buckle the first time you sat on the bike after the accident (I'm
assuming you're 150+ lbs.)

3. I bent my front fork (2040 carbon steel raleigh grand prix) in
~1975, and got it bent back at a local shop. It worked fine until
a crash maybe 3 years later, when it bent again, and I replaced it
with an aftermarket tange fork.

In many cases, the fork is stronger than the frame, i.e. I was
given a 1974 raleigh international 531-throughout frame with a
very mildly bent top-tube (about 3 mm, which I had straightened to
about 1 mm), and not even any rippling in the chrome on the front
fork. That means the front fork was WAY STIFFER than the top tube
of the bike.

4. If it bends again, You can get a very nice tange fork for
$29(plain, www.novacycles.com)-$80(chromed sloping crown).

- Don Gillies
San Diego, CA

QUOTE='Donald Gillies said:

I had a bent chromo Peugoet fork that was letting the front tire
intermittently contact the downtube. Rather than risk the tire going
into the downtube and acting as a brake, I bent the fork forward by
removing the front wheel, and inserting the blades between a plate and a
concrete wall and simply pulling down on the handlebars. I had fulcral
points about 8-12 inches from the droppouts and the rebending took place
with the surprisingly small force of about 50 lbs. Given the relative
ease of the rebend, it has me wondering if this bent fork is weakended
and prone to potential failure.

Quoted message said:

Any thoughts?

1. In my opinion, most traditional 70's / 80's steel forks get "one
free bend-back", as long as the damage is minor (i.e. as long as
front wheel isn't touching downtube.)

2. You must have used more like 100 lbs of force. If you used only
50 lbs of force, the whole front end of the bike would likely
buckle the first time you sat on the bike after the accident (I'm
assuming you're 150+ lbs.)

3. I bent my front fork (2040 carbon steel raleigh grand prix) in
~1975, and got it bent back at a local shop. It worked fine until
a crash maybe 3 years later, when it bent again, and I replaced it
with an aftermarket tange fork.

In many cases, the fork is stronger than the frame, i.e. I was
given a 1974 raleigh international 531-throughout frame with a
very mildly bent top-tube (about 3 mm, which I had straightened to
about 1 mm), and not even any rippling in the chrome on the front
fork. That means the front fork was WAY STIFFER than the top tube
of the bike.

4. If it bends again, You can get a very nice tange fork for
$29(plain, www.novacycles.com)-$80(chromed sloping crown).

- Don Gillies
San Diego, CA[/QUOTE]

Are the forks a little weaker now after bending them?