Fixing bent fork?
 

The fork on my 25 year old Lotus got bent.

It looks like the fork is bent at the bottom of the head tube so that the blades are shifted (pointed) to the right side. It's not that far off (it's a bit hard to tell).

Any ideas of how I might get it back to a more normal state?



Here's a picture (1.5mb)

http://www.ramaposkiclub.org/images/IMG_1617.jpg

Pictures might help.

+1

A 'quick search' has yielded...

http://www.bikeforums.net/showthread...ork+straighten

No, I'm pretty sure that taking pictures do not return forks to their normal state. ;)

I just love this photo of Ernest Csuka bending this frame with a bar.
Could be you may have to clamp that fork down and bend it true.
http://www.framebuilders.toucansurf.com/SingerCS.htm

Thing is, he's not going very far. You could do that with 531 or Columbus SL, but nowadays you have to be careful.

Bending a fork back from undergoing significant bending may result in localized thinning of material that will result in a very weak fork. There will probably be significant micro-cracking. Depending on if the steel was closer to gas pipe or high alloy steel, this may or may not result in problems.

unterhausen,
I am sure you are right about the forks.
It looks like Ernest has quite far to go if he is bending the frame in the photo to meet the pointer on the surface gage!

parallax makes it tough, but it looks like he's actually past the pointer. Because of springback, you have to bend it past where you want to go. I just did this to get 130mm wheels in a vintage frame, it's a good time.

Here's a picture (1.5mb):

http://www.ramaposkiclub.org/images/IMG_1617.jpg

if i could, id replace it. a bend in the forks can ruin their integrity and safety of the bike. besides, back in the day when i tried to rebend bent forks, the bike never seemed to be the same again.

I used an aluminum multi-ladder to straighten my fork. It was bent front-to-back, not side-to-side, but I just put the ends between two rungs and leaned real hard on the tube. In fact, to get enough leverage I attached it to the rest of the bike to do the unbending.

Take it to an old school LBS or a frame builder. There is a tool that will help give the proper alignment in all directions and cold setting a fork is no problem. A good mechanic who can use this tool can usually "feel" when the fork is beyond help and the cold set has affected the metal negatively. I bent a cross fork back using the tool of a local frame builder/mechanic and it was much worse that your pic. Look on Park for an example of the tool.

Good luck

The owner of the local bike shop here in lancaster pa is a frame builder and could put that right in about 2 minutes. His minimum charge is $5.

I've messed up a few forks working on the street and I've found a few options. Have an LBS straighten it (cheap, effective). Get a new fork, a crowned 4130 model is $16 from Babac, a nicer molded crown version in better tubing is about $35. I've also seen/had done for me a ghetto a** process that involves taking the wheel off and pushing the blades against a curb. Though the last option was a short term fix for a wasted fork that was bent at the crown and therefore unsalvageable

It's not that much bent and could be straightened IMO. Be sure to check that the dropouts are paralell afterwards, though.