Thoughts, musings, and frustrations in the pursuit of perfection. In short, complicating simplicity.

Saturday, August 14, 2010

on hard tails and mounts

Jig and Axle plates
   I decided to start making my own hardtails this year, since the quality of off the shelf stuff seems to have gone down, and building my own meant complete control over the way the hardtail would sit. The hardtails I want on my bikes use tubing 1 1/4" diameter, 1/8 walled to match the rest of the frame; solid axle plates 3/8" or 1/2" thick; and have my idea of optimal stretch and drop. In order to get frame geometry correct, we built a jig, measured our angles; and used a decent amount of CAD, both cardboard aided design and computer aided design. For our axle plates, that means drawing files to be sent to the water jetters. Simple, but it means drawingwith illustrator, cutting out mockups (preferably with mat board), cursing, and redoing until it works right.

Square is good.
  There is nothing better than having a relatively local and extremely friendly water jetter. We use DaVia Water Jet, and waterjetting gives us the ability to cold cut parts that are either important structurally(no worries about hot cutting and grinding which may make the part brittle), and to cut parts that would highly irritating to spend hours fabricating from scratch for each build (ie, headlight mounts, license plate mounts, motor mounts, etc). And while the initial drawing aspect is irritating and can be longer then it would take to fabricate a single part, the time saved next time I need one is worth it, and once I have a template, I can make subtle changes for different applications.
 Then comes mounting the axle plates onto the jig, and bending the tubes, lining things up, and spot welding things together.  This process involves measuring, swearing, measuring, and then replicating on the other side.
   Since the motorcycle fairy has yet to gift me with a TIG welder, I  asked my friend Keith to do the structural welding on the frame, and well he does a better and prettier job than I ever could, since he spends ridiculous amounts of time doing extremely precise welding on aluminum rims as owner of AZ true wheel. His welding makes me want to do a stainless steel frame, so I don't have to powdercoat over his welds.  

 Final Product: One awesome OIF hardtail. Next step: fabricating mounts.

No comments:

Post a Comment