Originally Posted by
texasdiver
I'm not sure bolting a second tray on top of the first one would accomplish that much because the trays have a channel on the bottom where the bolts slide in. So they don't actually nestle together tightly and two trays isn't going to provide any additional torsional rigidity. Although it will make it more rigid from downwards flex.
It's the downward flex that I was concerned about. You want to be able to cinch the tie-downs sufficiently. Not like you were compressing the suspension to strap down a motorcycle, mind you, but enough to make the bike feel like part of the vehicle. If that rear tray is too weak, it may bend. But you're the one looking at the setup, and you have to make that call.
If you're not comfortable with the single tray by itself, get a 4' strip of flat iron from the hardware store, paint it black and bolt it to the bottom of that section. Or replace the whole deal with a piece of heavier channel aluminum. Or figure out how to shift the mounting of the whole rack forward, etc.
Paraphrasing what TandemGeek said, the price of under-engineering your homemade rack is FAR greater than over-engineering it.
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BICYCLE - [[I]bahy-si-kuhl] - Noun :> A medical device used to correct the common geriatric condition of OFS, (Old, Fat & Slow), in a manner that does not induce brain-decaying boredom like walking or running.
2005 Trek T2000 tandem, Giant TCR, Eddie Merckx Majestic Ti, Fuji Team, Giant Revel 29er, Windsor Clockwork (Orange) fixie, and a BikTrix Juggernaut Ultra 1000 fat tire eBike
Last edited by Onegun; 05-11-13 at 05:48 AM.