Dude, I'm sorry if I offended you. @ 450 LBS, he breaks things awfully quickly...
The stock wheels on his hoss broke rather quickly, and needed frequent truing...

Your rear brake sucks more ass than it needs to because its set up like crap. Granted I am sure that you don't have much experience setting up u brakes so its not your fault but still it could be set up a lot better, I mean just look at the straddle cable. Find a shop with a mechanic who rides bmx and have them dial in your U brake. I also would drop the dollars for a 990 or a Hombre with the Fiesta pack to replace that generic looking u brake, and maybe some better pads, like Odyssey 1x4's or Kool Stops. But otherwise that is a sweet looking bike. I found a nos DX bmx cassette hub laying around the shop I work that Im going to lace to a Sun Mammoth rim also randomly hanging on the back wall, now I just need a frame.

Actually these wheels felt pretty sturdy while pedalling around. Feltup did good, as far as that ubrake, no matter how it looks, it functions how it should, the pads set equal distances from the rim and work..it's just rim brakes have never really worked all to well for me. BTW...this bike will remain mechanic free...it's a SS project and it's gonna stay that way. The whole idea is to get by as cheaply as possible :D

BTW... here's Sheldon Brown's pics of the cantilever brake family:

http://www.sheldonbrown.com/cantilever-adjustment.html

hahahhhaha

It's true...I swear I should be a product tester for the "beefiest stuff" If it's supposed to be tough, gimme and let me ride it out :D

Tell me where I went wrong on the brake. I couldn't get the straddle cable even. Both pads are the same distance from the rim and they move well. It works a lot better than I thought it would.

Alot of it has to do with the spring tension being fine tuned and the straddle cable does matter; but mostly it is in how you tension the spings. I was just offering some advice as the it was specifically stated that the brakes were not to his liking. And I understand you are trying to keep it cheap but if you are really unhappy with the u brake spend the twenty bucks for an hombre with the fiesta kit, I am a big guy and those things can lock up the wheels on my flatland bike no problem.

I bet if I tinker with those bolts we twisted and set the tensions up I might be able to set the cable more evenly, but guess what, it works, haha I don't care. I have yet to see a rim brake that will lock up with me.