by Calnago on Mon Mar 16, 2015 6:46 pm
@fogman: Keep in mind that I am referring to tubulars, and not clinchers. And what I'm saying is that the new Boras have a seam well (groove) in the middle of the rim bed which the old Boras do not. So, I'm thinking that this "might" allow a teensy bit more room for the tire to sit lower, but not much. The other thing I was hypothesizing in my mind is whether, because of the wider rim bed, is whether a wider (25mm) tubular might not be as "squished" and push upwards as much as it would in the older narrow profile. So far from my measurements, and one set of arenbergs, it seems that I am indeed getting maybe a millimeter or so more of clearance under the fork crown of my C59 or EPQ, which is just adequate enough to not bother me at all. So I am happy.
If you are running clinchers on wider rims, I can't say how it will sit in your particular case. I will say that if you put your current 23mm Conti GP4000S II tires on a wider rim, from my experience you will have less clearance under your fork crown than with your current Shamals. How much, I'm not sure. I've yet to see a new 2015 Bora Clincher. But the super wide Enve 3.4 front rim (clincher) is problematic with 25mm clinchers in some frames. On my C59 for example, a 25mm Conti 4000S II clincher sits so high it will not even fit in the dropouts all the way without hitting the fork crown first.
@joestralia: I promise that the next downpour we have here I will take the new Boras out and give them a thrashing in the rain. Don't expect miracles though. They are carbon, the pads are the same and water is never friendly for braking performance on any wheel. I'm not expecting them to be too much different than the current boras.