Framebuilders are metals and materials experts, so I'm sure that you guys will know this...
I want to build a bike tray for my existing Yakima roof rack for for my Canondale tandem. I'm too cheap to pay $350+ for a Yakima, Thule, etc., tray, so I thought I'd build one. My plan is to imitate the design of a RockyMounts bike tray for tandem
With this system, you leave the back wheel on the ground while you attach the front fork (because the fork attachment point swivels), then pivot the tandem up and attach the the rear wheel.
Here's my material's list:
* 1.75" x 1.75" x 0.125" wall 6063 Aluminum Square Tube or 2" x 2" x 0.1875" wall 6061 Aluminum Square Tube
for the primary longitudinal member (about 78" long) and for a short (~10") piece that will attached to the main member by a 3/8" bolt as a pivot point and to which will be attached a fork skewer like this:
Note: an 8' piece of the 6063 sq. tube is $57 at Metalsdepot
, but the 6061 is $91.
* 1.25" X 1.25" X 0.125" 6063-T52 Aluminum Arch. Channel (Sharp Corner)
for the wheeltray. I'll buy a 2' piece of this ($10.00) and attach about 10" of it to the main member as a place for the rear wheel to rest. Since I buy positive/negative velcro straps in continuous 1000' rolls for general purpose stuff, so I'll just use about a 12" piece of same and use it to keep the rear wheel secured in the tray.
Since I don't weld (not aluminum, anyway), I'll hire a pro to tack-weld the forkblock to a piece of 0.25" aluminum plate, and then tack-weld that plate to the swivel piece. I'll also have him tack-weld the main longitudinal member too two 4" x 4" x 0.25" plates at the same spacing as the "cross-bars" of my existing Yakima roof rack system. I'll attach those plates to the cross-bars using u-bolts (hopefully, with some sort of tamper-resistant nuts). A 12" x 12" x 0.25" plate is $31.00.
What do you think of my materials selection?
Would you suggest something else?
Or is there a smarter way to tackle this problem?