DIY Decaleur?

March 16, 2010 11:10 PM

Can I make a decaleur? If not, which should I buy?

Asking for my girlfriend: I'm building a front mounted bike bag for a friend who doesn't have a front bike rack. It is quite large, by request, and needs some support. I'm thinking about a decaleur, but would rather make one, if possible, than buy one. In particular, something like this would be ideal. Has anyone had experience either making something similar, or if not, good experience with a particular model?

posted by heliostatic to Sports, Hobbies, & Recreation (1 answer total)

Best answer: You could probably do the bending to make your own part, given enough steel wire stock of the right gage, and some kind of bending jig. But most commercially made parts of that complexity of shape, are bent from soft steel wire, and then heat treated to give them good shape retention. To heat treat something like that accurately, without making it badly distorted, or overly brittle, you need to use the right wire alloy, and have a controlled heat treatment oven, plus maybe a quench process as specified by the wire alloy supplier, for the characteristics you want in the final product. You can outsource heat treating of parts in small lots, but wire parts are more expensive to do than sheet steel blanks, because of their small thermal mass. Wire parts also distort easily in heat treat, and you might find you have to make a ceramic mandrel for them to go through heat treat successfully; even then, you might have to make 3 parts, to get one that is acceptable shape after heat treat.

Once heat treated, you'd probably want to chrome or nickel plate the thing, to provide corrosion resistance. Again, something you can probably outsource, if money is not a great concern. Plating is less traumatic to the workpiece, by far, than heat treatment; you basically just have to be concerned that acid etching or pickling baths used to clean the part before plating don't eat into the part substantially, reducing its cross-section at stressed bend areas, to prevent weakening the part.
posted by paulsc at 8:04 AM on March 17, 2010