price per psi

i'm abandoning Zona in favor of True Temper tubing for the time being, probably Versus Heat Treated. Jury's still out on Reynolds, though.
these figures don't include shipping and other such costs, but even so, they're revealing.
i'm assuming 2 tubes of 28.6mm diameter and 1 of 31.7mm, all .8/.5/.8 mm thicknesses.
Zona is $54.72 from Nova, yields at 137,785 psi (950 MPa), so $0.000397 per pound per square inch.
True Temper VHT is $43.85 from Henry James, yields at 175,000 psi, so $0.000250 per pound per square inch.
True Temper OX Platinum is $81.60 from Henry James, yields at 185,000 psi, so $0.000441 per pound per square inch.

VHT is thus the best value according to my numbers, by a pretty good margin. Zona's the weakest, but not the cheapest, so what's the point?
these numbers DON'T take into account weight, but i'm not a weight freak.
if a tube suffers a big hit, nothing matters except the strength of that tube...a broken tube isn't worth anything to anybody.
i imagine the strength increase from 175k to 185k must take a lot of work, or else True Temper wouldn't charge nearly twice as much for it.

2 comments:

Anonymous said...

Huh? This price to strength thing, do you think it makes any sense?

Any strength beyond what you need is useless.

Any strength below what you need is useless.

Figure out your use and the strength you need. Then pick a set that does the job.

All this math is delaying getting your hands dirty.

BTW, the strength is primary necessary in the joint. Handled properly, any of the tubes you named will work (except as a downhill or jumping bike).

But, some of the tube sets (like the HT Versus) require a more delicate touch with the torch to maintain their properties. So, as a beginner, you might not get what you buy with them.

Finally, Joe Bringeli and Deda tubing is usually the best bargin I can find.

Anonymous said...

That is the single dopiest way I've ever seen to choose a tubeset. You're off to a great start.