so i just got some vittoria corsa evo cx tubulars for my 650c zipp 909 wheelset. i tried stretching the but over the wheel and noticed that there’s VERY little room between the top of the valvestem and the top of the little cutout on the disc. there’s obviously no way a standard pump will work. and i’m not even sure if the little ‘L’ shaped adapter will fit!!!
i THINK the vittoria valvestem is 42mm…
will this not work? am i screwed? or will the little ‘L’ shaped adapter fit in the miniscule space between the top of the valve and the top of the cut out?
is anyone using the corsa evo cx with zipp discs? i don’t think the corsa evo cx comes in different valve lengths…just one length (at least as far as i can see on their website).
I had the same problem…it is annoying eh? You need to find tires that have a very short valve or make the cutout hole larger so that you can use larger stems and have more room for your elbow to get in and out. Luckily I knew a guy that is a carbon fiber genius…so I opted for him making the cutout hole larger. He did a wicked job but I was super nervous about it. It was a brand new disc! After he did it…and I raced on it, I had wished he had make the whole even larger…getting the elbow in and out is still a tricky job.
SIDE NOTE…a lot of people put a sticker over the cutout hole when they race…for aerodynamics. Try and find one if you can…it looks cool.
That is the 900 disc correct ?? I had the same problem with a Bonty RXL Pro tubular on my size 700 Zipp 900 flat disc wheel. Had to enlarge the valve access hole - a Dremel tool with one of the little cylindrical sanding discs works very nicely. Do one side at a time and go slowly. The sanding disc cuts through the outer CF shell and foam core very easily. In the case of the size 700 I accidentally hit a solid CF structure so be aware of that and check after every mm of material removal. The other nice thing about the cylidrical sander is that it creates a circular cutout with no sharp corners which can propagate cracks. Good luck.
Edit - You can also send it back to Zipp who can do it but of course will charge for it. But I would assume that the warranty on the wheel wouldn’t be compromized in any way. IIRC the first run of Tangente tubulars had the long valve stems which wouldn’t work with the Zipp 900 disc’s which was there only offerring at that time. Awkward (:-).
Thank you for this post. This is why I love Slowtwitch.
I will be performing surgery in the next week or so on the pristine-looking wheel I bought in ST Classifieds.
Fundamentally, I refuse to trash a wheel because somebody else decided 42mm valve stems are now the standard length. Next thing you know, they’ll stop making 650c bikes for short people altogether and then I have to take up competitive knitting
Happy to help with something over a year old - the search function works. (
I first discovered the issue when I tried to test Christine Thorburn’s flat disc wheel with a Crono on it over 2 years ago. The mechanic who glued the tire on (this was the start of the “too much glue” thing) somehow inflated it but I couldn’t get the adaptor onto the end of the valve. Had to give it back for modification which he did with a straight blade which left some square corners which are cracks waiting to happen. Good luck with your work - just take it slow and check your work. Also a good idea to use one of those paper breathing mask - I think the CF particles aren’t good to breathe ??
I’m still working on your Valentine’s Day mix tape, baby.
I took 1st place AG today at the local Oly tri. Big training for the next 1/2 IM starts now because the weather isn’t freezing or raining daily (finally). That music will carry me through training for IM Canada as well.
