I sprang for a new wheel set (Zipp 606) and put the Zipp-recommended 21 mm tubulars on. They roll beautifully, but they got the gear geek in me wondering what the forum thinks about the various tradeoffs among tyre width, pressure, weight savings, handling, etc.

For instance, it looks like switching from a 21 mm to a 19 or 20 mm tyre can result in a weight savings of 100 g, or thereabouts. However, I remember also reading somewhere that someone said s/he would never ride on a tyre narrower that 21mm, presumably because of loss of handling ability. I would imagine that the narrower, lighter tyre also has less rubber, and therefore less puncture resistance.

I imagine that puncture resistance is also influenced by pressure. Are narrower tyres also capable of taking a higher pressure? For instance, some of tufo's lightest, narrowest tyres appear to have the highest psi ratings, on the order of 175 psi, or so. I assume that there is a linear relationship between rolling resistance and psi, so that between the high pressure and smallest area of road contact, these would be--all other things being equal--the fastest tyres.

I wonder how the rest of you feel about that? What are you riding on? 19, 21, 23 mm? Is a narrower tyre less advisable on a tri bike than a road bike because of the bike's lower inherent stability? Just a few geek questions here. Obviously, a super light weight, narrow, high pressure tyre won't be any good to you if you can't stay upright!

Regards to all.