Thread: ORGS build up
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Old 02-12-2011, 11:18 PM   #132
x3300 OP
geoff
 
Joined: Mar 2005
Location: San Jose, CA
Oddometer: 170
Rear Rack

I needed the tube bender to finish up my subframe and make a rear rack. Here's where I left off with just a single fender mount and no rear cross member.

http://stuff.gotdns.org/bike/orgs-build-up/40-rear-rack/with-fender.jpg

I used my bender to put two equal bends in a piece of 3/4" tube. This photo was from early in the fitting process. The final angles were close to 90 degrees.

http://stuff.gotdns.org/bike/orgs-build-up/40-rear-rack/loop-bending.jpg

Once I got the cross tube fitted I used this piece of aluminum plate to hold it in position for welding. Having the two straight down tubes welded to a cross tube worked out OK, but I think a better solution would be to just use a single long tube and put two bends in it.

http://stuff.gotdns.org/bike/orgs-build-up/40-rear-rack/loop-holding.jpg

I had planned to have a detachable rear rack to save some weight when not in use, but decided simplify my design and have a small rack integral to the subframe. I bent these two 1/2" rails with my bender then ground the ends on a bench grinder so they would mate with the 3/4" subframe tubes.

http://stuff.gotdns.org/bike/orgs-build-up/40-rear-rack/rails.jpg

Here's how they fit onto the subframe. I left some space in front between the rack and the seat to allow access to a seat lock.

http://stuff.gotdns.org/bike/orgs-build-up/40-rear-rack/rails-welded.jpg

To finish the rack I added a front cross member and a center rail.

http://stuff.gotdns.org/bike/orgs-build-up/40-rear-rack/rack-done.jpg

In my design the fender hangs down below the rear cross tube. I made up this paper template for a small bracket then transfered that to a piece of 16 gauge steel.

http://stuff.gotdns.org/bike/orgs-build-up/40-rear-rack/bracket.jpg

I thought the rear cross tube will naturally be used to lift the bike up when it gets stuck in the sand or whatever, so I put a nice friendly radius on the bracket to allow fingers to slide in.

http://stuff.gotdns.org/bike/orgs-build-up/40-rear-rack/bracket-welded.jpg

Here's the subframe just about finished except for brackets to mount the side racks, tool tray, seat, etc.

http://stuff.gotdns.org/bike/orgs-build-up/40-rear-rack/sub-frame.jpg

And a mock-up with my old seat pan and a load.

http://stuff.gotdns.org/bike/orgs-build-up/40-rear-rack/loaded.jpg

I very happy with my little rack. Its just the right size to carry a small pack and doesn't add much weight.

-x3300
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