Friday, November 7, 2014

Racks are the most important part!

I could not find a heavy duty rack that went around the disc brake and still left room for B.O.B. trailer axle mounts, and put most of the weight directly onto the axles (bolts bend). So I had to build it my self, using stainless steel because I did not want to have to take a long bus ride to have it powder coated with baked on enamel. I could have saved a lot of effort if I had built the rear rack right on to the frame when I was building the bike.

I had to buy an extra long axle to rest the legs of the rack, on. 158mm $28! That's one reason I hate the bicycle industry! A solid axle would be cheaper, but I can't use my BOB trailer with a solid axle.

I used stainless steel crimp-end lock-nuts, I do not trust the cheaper nylon lockers to not vibrate loose. And I had to go back and make adjustments after using it for a while. Like bolting the feet onto the drop-outs so that the legs would not spread apart and make it incredibly hard to replace the wheel every time I had to remove it.

316 stainless steel work hardens, so I burned out and broke several cobalt drill bits and even broke off a threading tap. 'Turbomax' bits are the best for any kind of steel, but it really pays to use a slow drill and don't even try it with out a drill press. At least I did not have to cut it with a hand saw, that would be impossible.

The best thing to use is airplane steel; 4130 chromium-mallibdinum. If you can find it in flat bar stock. I should have used two eighth inch flat bars for the leg, rather than the quarter inch.

If your obsessed with doing it the lightest way possible, extra thick air plane aluminum (6061-T6) could be ok for less weight than I wanted to carry. But make sure that it will not flex.

This rack could hold a full sized adult, but the wheel would brake spokes like the last time I tried that little feat. Now I will have to build a stronger rear wheel,and think about stronger bearings

This one maybe made of 3/32" thick flat bar for the top platform.

mild steel support arm for aluminum rack to go around disc brake

an add-on front frame rack to build 

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