Originally Posted by
sherbornpeddler
Jim, Do you normally ride sewups for commuting? Do you think they are more, less or equally prone to flats on MetroBoston roads? Do you carry a foldup spare and glue or just inflate enough to hold it on and avoid powering through turns? What pressure do you run your sewups when commuting?
So many questions!
I've ridden sew-ups for commuting more than I ought to! It's really the choice of which bike. Usually I'll ride something else but this week I just felt like riding my uber-bikes, the Masi, the Motobecane, and the Gazelle. The Gaz has Veloflex Masters, a 23mm high-end clincher, but the other two have sew-ups. One reason (I rationalize) for commuting on sew-ups is the speed of fixing a flat on the road. When I really don't want to be late for some meeting at work, I'll rationalize like that.
The only down side is the time and aggravation it takes to fix one, and eventually the cost of replacing one.
I don't think sew-ups are especially prone to flats. Whatever I hit today would have cut through a clincher too. Most of my sew-up flats have been like that. But the thinner tread does make a difference compared to a more utilitarian tire like the 25mm Pasela TG/PT or Gatorskin. The light clincher wheels on the Gaz used to be on the Masi, and in about 1000 miles I wore a set of Vittoria Open Corsas so thin they were like paper. Then one commute I got 4 flats which was a wake-up call to replace them. For high-performance tires my experience has been that Vittorias are more prone to flatting than Veloflex. In fact, I don't believe I've had a flat on a Veloflex tire yet except for the screw I picked up in the Gaz's front (clincher) tire. But that could be all by chance.
I carry two spares, both already glued up and folded. Of course the glue is a contact cement (as you know) so it adheres to the rim quite well even after it is dry. Of course I'm not bombing down Mont Ventoux, just the minor hills between Waltham and Woburn.
As for pressure, I like all my tires, sew-up or clincher, pumped up. "Ordinary" clinchers get 120psi, the Gaz's clinchers gets 140psi. The sew-ups usually start at 150 because they have latex tubes which can lose 30psi in a day. I can get pretty good pressure in one with my frame pump though I've never measured it.
Some people in the C&V would say I'm crazy. Others swear by sew-ups and high pressure. Me? I just like how they feel.