I recently cold set my steel frame from 126 to 130 mm. I looked up some DIY dropout alignment tools that had been posted on various forums, and looked at the "real" tool sold by Park and others. I didn't have ready access to the real tool and didn't really feel like spending the money anyway, so I went with my own version of a DIY tool using hardware available just about anywhere, any time. It's pretty much the same in function to the other DIY and real tools.

I've attached photos of the materials I used and how it worked. I think that the differences between what I used and what I've seen used are:

I used 3/8" threaded carriage bolts because it had full-length threading and was easy to find. Most of the other bolts I found had threading that was too short, and I didn't feel like messing with threaded rod which only came in something like 3 foot lengths. I used 7 or 8" carriage bolts thinking I'd need the leverage, but I think 5" would work fine

I used fairly long "coupling nuts" to act as the alignment surface. The long threading allowed them to adjust toward each other and still stay solidly threaded on the bolts. Regular nuts would serve a similar purpose, but would be less adjustable toward and away from each other.

The only other variable is the flat washers. I just bought a few sizes, and used the largest ones that would fit flat against the dropouts to maximize the force/leverage that would keep them aligned perpendicular to the bolts.

The steps are the same as used for every DIY tool and in the Park tool instructions.

Center the rods - I threaded the coupling nuts totally on the bolts, and left a 1/2 " or so gap to begin with.

Secure the rods very tightly to the dropouts.


Adjust the coupling nuts toward each other until they almost touch.

(the extra nuts were intended to lock the coupling nuts in place. They're not really needed.)

Use the leverage of the extended bolts to move each side into alignment with the other. Follow the instructions on the Park Tool website for their tool if you're unsure how to do this. I found it totally intuitive and simple.

Use the facets of the coupling nuts to decide which way to move the dropouts. You can feel how well each facet on the coupling nuts arealigned. I think you can easily feel 1mm or less, which is a specification I read for adequate alignment.


This was pretty easy. The dropouts were very easy to align, and the 3/8" threaded bolts were more than adequate in strength to do it