Campa Bora 50 wheel 2013 question

[poppiholla]

Is it possible and save to use 25mm tubes on the 2013 Campagnolo Bora 50 wheels? I mean the wheels that are 20mm wide and not the new 2015 generation that are around 24mm wide.

[Calnago]

That's a good question as I've experimented a lot with this on my Colnagos. Yes, 25mm tubulars will glue up just fine on the pre 2015 Boras. However, on my C59, I found there to be just barely enough clearance under the fork and a lot of road grit would get thrown through there. The clearance was so tight that the chatter was annoying. It would also scrape the paint off the underside of the fork crown it was so tight. I preferred them to the 23mm or 22mm Veloflex tubs however, because they proved to provide a little more stable ride. Perhaps the larger volume provides more damping, etc. but that sudden spring "twisting" feeling that you can get with very narrow tires was reduced. This is a stability issue quite different than the stability issue caused by wind pushing you around. I wish Veloflex still made the 24mm width as that is my favorite width in a tubular for all road use.

Fast forward to 2015 and I was a very early adopter of the newer Boras. Mostly I wanted to see if the new profile would allow a 25mm tubular to sit a bit lower on the rim, due to a better rim bed radius more closely matching the 25's. And guess what, it did. In fact, it was perfect. It provided just enough extra clearance on my C59 that all chatter from road debris was gone, and the clearance was just right. In contrast, the tighter radius of the rim bed in the pre 2015 Boras is great for 23mm or less tires, but tends to push a larger tire up a bit (like to say like a push up bra).

And the wider rim of the newer Boras did add some extra stability again, over just putting 25's on the older rim. But as far as gluing them up goes on the older rim profile, there were no issues. So, if clearance issues are of no concern on your frame, then you'll be fine. I will say that a 23mm tubular fits the pre 2015 Boras perfectly. A 25mm tire looks a bit bulbous on the rim, and in my case I had the brake pads adjusted so that there was a bit of squeeze getting the wheels out with 25's, even with the brake release open. And the new 24.2mm width of the new Boras is jussst right in my book. Especially for a tubular, you wouldn't want it any wider really, unless you're running really really fat tubulars. Clinchers are a whole 'nother story.

[poppiholla]

Hi Calnago,

Thanks for your reply. Very very helpful. I ride 23mm Veloflex carbon tubes on the pre 2015 Bora's. This is fine indeed, but I was wondering if 25mm would work. I assume that I will have the same clearance issues on my Dogma 65.1 as you described on the C59. Maybe I will try it, but I am very pleased with the Veloflex Carbon tubes. Too bad that Veloflex doesn't make them in 24mm.

Ciao

[Calnago]

Actually, I "think" the Dogma 65.1 has more clearance, at least under the fork crown, so you could be fine there. There was less clearance at the chain stays however. Still, I suppose you just have to try it. Veloflex Roubaix's used to be 24mm and I stocked up on a few of those for my Nemesis rims. That's when the Carbons were 22mm. Then they increased the Carbons to 23mm (which I like), and increased the 24mm Roubaixs to 25mm, which I would have preferred if they left in the 24mm size. Another option you might try is the new Specialized Turbo Cotton Tubulars. They are a 24mm width and I have heard good things about them, but have not tried them yet myself.

[fogman]

I have 2015 Bora 50 tubulars (24.2 mm wide) mounted with 25 mm Vittoria Corsa CXIII Isogrip. On my Dogma 65.1 there is no clearance issue at the fork crown. The clearance is a little tight on the left chainstay with about 2 mm between the tire and frame. These wheels are stiff laterally so no evidence of scuff marks on the inside chainstay. I race on these wheels and have not noticed tire rub when sprinting or climbing.


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