Well, its been quite a while since I posted anything, but finally got motivated to jump back in. Got out of coaching a couple of years back, just doing a little consulting with a few local teams. Anyway, on tension members in a bridge....
In archives, you'll find my previous input on the subject.
Briefly, the best solution I've found is 1/64th" paired strips. By "best", mean the lightest. By "paired strips", mean two on each of the two trusses (sides of the bridge)- one on each side of the legs, run parallel. Width and density depend on required/design loading.
On a C Division bridge I'm consulting on this year, all four together weigh 0.9 grams, for a span of a bit over 18" 3/16" wide, cut from 3"x36"x1/64" sheet weighing 7.2 grams (this falls into "heavy" density range as that term is used by Specialized Balsa). Tested one- as in a single strip) to a bit over 8kg, with the design load (i.e., the tension load on the members, on one truss at 15kg structure loading of 5.5kg. So, even at this weight, way over-engineered- massive safety factor. For comparison, typical weight for 3/32nds bass is around 1.5gr per 24", so a LOT heavier.
You need to be careful using this technique to make sure the strips are of very equal length (w/in a fraction of a millimeter), otherwise, one of the pair gets all/most of the loading, stressing it, putting a twisting load into the leg, and if lengths on the two sides/trusses aren't equal, then one side gets all/most of the loading. The other thing to take into account is that there will be some stretching/elongation at full load. Testing will get you to the answer for how much in your particular design. In the bridge noted above, we're at a bit less than a millimeter. So, when you shorten, which 'pulls the legs inwards' a bit, as the bridge loads, the legs slide out, and at full load, everything 'straightens out to design configuration.'
Last, re: the post above, on bracing off of a tension member, while it can be.... effective if you're bracing off of something like a 3/32nds bass tension member, won't work well on paired 1/64th strips.
Fort Collins, CO