running 21 mm tubular tyres on new wide Boras

[Calnago]

From the Campagnolo Bora Tubular User's Manual:
"• Check to insure that the diameter and cross-section of the tubular tire you plan to use are compatible with the dimension of the rim."
There is no mention of what specific (minimum/maximum) tire sizes are compatible with these rims.

Ok @Fogman, I know you and a few others have been obsessing over the new Boras. I can't even remember which one is which anymore. But I think one of your main concerns is whether a 25mm tubular on the new rim width will fit in a Dogma, correct? Well, yesterday I had a Dogma at my house and just for you I thought I'd throw my new Bora Ultra 35's in it with the 25mm Arrenbergs mounted. Here's how they looked:








So... not a ton of clearance, but totally fine if you're running tubulars. Also, keep in mind that there's no brakes on here. Some brakes reduce that clearance that you see. Of the current brakes out there, I think the new Shimano brakes offer the best clearance and design of any of them, including Campy .
Also, none of the above clearances apply if you're talking about the clincher versions. I would bet a 25mm clincher version on the new rims will sit higher than than the tubulars and probably have less clearance. On the other hand, running a 23mm clincher on the wider rims may be just fine, at least much better than running the 23mm clincher on a narrow rim.

And in reference to your post about the wording in Campy's manual about checking to see that the tire and rim are compatible, I suppose they are expecting you to be able to determine that from looking at how the interface is between whatever tire you are working with. You should be fine running 23mm-25mm tubulars on this rim without even thinking about it. Don't think I'd run smaller than that, and I have decided that 25mm is the largest I would want in a road tire and I'm a bigger guy at 200lbs/90kg. That's not to say you couldn't run a bit larger tire that 25mm on these rims if you desired to, but for me personally, that won't be happening.

[bm0p700f]

That loads ov clearance. My race bike has less and i have to be careful which tyres i run. I think campagnolo brakes will fit fine over those 25mm veloflex tubs.

[Calnago]

Yes, loads of clearance for these tires and wheels. It's not my bike. But @Fogman's been asking if these would fit in a Dogma so since I had one handy I thought I'd check it out for him.

[fogman]

Thanks @Calnago. Those pictures are just what I was looking for.
In reference to the brake caliper clearance, one must also consider where the brake mounting hole is located vertically on the frame/fork for each manufacturer.

[Calnago]

That distance should be very consistent. There are standard frame dimensions which manufacturers adhere to. The bigger difference determining whether there will be clearance enough or not is the design of the brakes themselves. In this respect, the new Shimano brakes have excellent clearance which is unaffected by how far you have to "open up" the brakes to accommodate a wider rim. On the other hand, Campy skeleton brake arms will tend to lower on top of the tire as you open them up for wider rims. SRAM and TRP brakes can sometimes pose clearance issues on wider rims with 25mm and bigger tires as well. If you're considering clinchers I might want to try them with your setup. If you're going to run tubulars then I think you'll be fine and the pictures show the clearance pretty well and shouldn't vary too much from that.

[mrgray]

now running 25 mm tyres on these boras and have to say, you notice the difference. much more comfortable. also as far as using aged tyres go and any assistance that may give re: puncture protection i'm not sure. both aged tyres now punctured and gone in ~ 1,000 km of riding.

pit stop has been my friend however and it was only the size of the tyre gash that led to me changing - could still hold air.

[fogman]

I dry mounted Vittoria CX III 25mm tubulars on my Bora One 50 Dark Label wheels and they seem to give me a little more clearance than the Veloflex Arenbergs would have.