Originally Posted by
jon_norstog
Hello Isaac!
You are asking the BIG QUESTION in frame design. one that I have been doing my best to answer for 20-some years. My approach is to go for lateral stiffness and a reasonable measure of vertical compliance. The heart of the frame is the seat tube and chainstay - that's where you need stiffness the most. For a person your size and strength I would build a 1.25" butted seat tube, and look for very stiff chainstays. The old Reynolds track chainstays are nice but hard to find; mostly I bend my own out of 3/4 x .035" aircraft grade tubing. The next most important tube for lateral stiffness is the DT - the TT and seatstays aren't really in the picture that much.
The culprit in your Salsa's wimpy ride may be the chainstays - give them the squeeze test in your hand.
For the main triangle I use an OS (28.6/31.7) tubeset and have had good luck with a .7-.4-.7/8.-.5-.8 TT/DT combo. That gives me a bike that I can ride all day without getting beat up too badly. For a little more stiffness you could bump it up to .8-.5-.8/.9-.6-.9 or go up to 31.7/35 and use the lighter butt profile.
Be careful of "short butt" tube sets!
Good luck
jn
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