My bike fell off the roof of my car (I forgot to strap the wheel down). Anyway, there is a story that goes with it, but now I want to check out my alignment. Its a old R531 steel frame and it looks like the rear triangle could be off a bit and the fork is definitely off. I need some ideas for home tools. I'm trying to avoid buying the real tools or paying a shop to look at it, besides just plain wanting to do it myself. Its my beater/commuter so i need to get her back up and running so I can stop riding everyone on my roadie!!

I figure I might be able to make a fork end alignment tool using some long bolts. It looks like one of the fork blades is bent as well. Any chance on a home made straightener? For the rear triangle I'll go with Sheldon's 2x4 and string method.

Thanks for the advice!
Timbo

Tie a string to your derailleur hanger. Run it up around the head tube and down to the other rear dropout and pull it tight. Since the string creates straight lines, you can measure the distance from the frame to the string at the same point on both sides of the frame. You should have a pretty easy time determining if it is bent or not with that method.

Thanks. To expand on that suggestion, if you tie it directly to the drop out instead of the der. hanger it will be a bit more accurate.

Yeah, the hanger may be bent as well.

For straightening all you need is an exposed beam, some 2x4's and a small bottle jack and a few hand tools. It involves some creative work to make a press using the beam for your house from above, the floor below (probably concrete assuming you're doing this in the basement) and some 2x4's cut with U grooves to support the tubing and the bottle jack to provide the pressure. A pair of nailed together doubled 2x4's will provide the extendion to the beam. Use two 2x4's on edge with U's cut into them and one under the pad of the small bottle jack. Put the lower two supports about 2 inches to either side of the center of the bend or at the ends of the arc if it's a longer gentle bend and put a third short section on edge with a U in it in the middle and then place the bottle jack on top and the doubled 2x4's on top of that and jack until the extender touches the support beam and then look carefully at the leg or frame tube as you apply pressure. Go a hair beyond straight and release. Repeat as and with as much force as needed. Reposition the cauls if needed based on how it's bending. Some trial and error will be needed but don't go past and then correct. Sneak up on being truly straight and move the cauls around if it seems to need this by closing the spacing up or widening it out or shifting off center or whatever is needed to get the job done.

No need for anything more unless you're planning on making a habit of this....

Thank you very much for this advice. One problem is that I don't work in a basement (no basement) and there is not an exposed beam I can work with. I might try a variation of your system however.

Any advice on a bent fork blade?

park? made a thing like a car jack that would straighten forks pretty well by pushing off of the bottom bracket. I'd be hesitant to do too much to a 531 fork.

Actually all that stuff was intended for the fork as well as the frame if needed. You need to saddle the bent part of any tube between to resting cauls and then push down between with the needed force. To do this you need two surfaces be they walls or floor and ceiling or a big frame similar to a bearing press you can see at many automotive supply stores that specialize in tools. SOMETHING needs to contain the force you need to straighten the tubes. The floor and beam was the easiest to find.... normally...

If you insist on having at it then you can TRY making a frame to contain the pressures. Single right and left 2x6's with overlapping double 2x6's top and bottom with the verticals sandwhiched between. Glue and screw and allow to dry overnight. Make it up to be 3 feet wide by 5 feet tall. That can be your frame to contain the forces used for the straightening. A couple of more 2 to 3 foot 2x4's just screwed to the outsides will act as feet to hold it vertical. That way you can unscrew the legs and store the frame for "next time"... You'll still need scraps to form U saddles into to support the tubes while pushing on them. At NO time should you push on a tube with a flat surface or you seriously risk it kinking the tube.

By the time you get all this and put it together so that you can straighten the parts it may be easier to just write it off and shop for something used that is similar. Or take this opportunity to upgrade. We're talking about a lot of work and fussing around here with no guarantee of success coming out the other end. You may fix up a lot of this only to find something that can't be worked on.

you have a good point there. I may end up giving it a shot, but if i fail, I'll just have to get another fork. We'll see what happens. The rear triangle doesn't look that bad. The drops are a bit off parallel, but I'll be able to fix that alright. Thanks again for all your help.
Tim

It's hard to align the fork unless you have some accurate measuring tools. I make wood V-blocks to clamp the fork steerer in a vise. Then spin a 2-foot section of broomstick down to 22.2mm and stick it up the steerer from between the blades. Using a T-square, you can measure the fork blades centering relative to the broomstick. Bend as necessary. However, you'll still need to visit a shop and use the dropout alignment-tools to make sure the faces are parallel.

Great Advice Danno, Thanks! I made a dropout alignment tool from two large stainless steel eye bolts, nuts and washers. I'm begininning some volunteer work at Plan B here in New orleans soon, so maybe they have some tools I can use.

Tim