Originally Posted by
waddo
It seems that Specilized do not publish geometry numbers! It means I would have to measure myself. Looking at the Surly chart the reach and stack are measured from an unidentified point above the "head tube." What is the point?
"Those 3 measurements will give you a level set between a sloping tube bike and a level top tube bike."
I can't quite understand what these number will give me!
I googled and instantly found
geometry figures for Specialized Sirrus Comp at the top of the list. You may have to work harder to find geometry info on older bike.
Disregard stack and reach. Compare effective top tube (ETT) length between your wife's drop bar bike and LHT. If you intend to build LHT with flat bar, then you will need ~50-70mm more reach (ETT+stem length) for comparable fit. On a LHT this will likely result in an undesirably high standover height (SH). Bear in mind that 26" LHT SH is based on ~1.37"/35mm tires (628mm diameter), so if you fit larger tires than this the SH will be even greater. Refer to diagram to measure ETT:
https://www.bikecad.ca/effective_top_tube_length