I have a set of 404 (dimpled version) that I want to use on a cross/gravel grinder bike. The reason is because the rear has a Powertap that I’d like to make use of. I found one comment that 35c was the widest that Zipp recommends but I can’t find anything to confirm that. I actually have the tires mounted and they look great but before I rode them I wanted to ask if there was a safety reason not to do this.
Obviously these are run at lower PSI so I wouldn’t think there would be an issue but am not sure. Thanks for any advice, or at least good advice 
Sorry to reply to myself but for future reference … I contacted Zipp and they said it was safe.
Just remember, UCI rules on CX tyres is now 33mm wide (it use to be 35mm, which might have been what you saw previously)
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Did not know that. Thank you.
Just remember, UCI rules on CX tyres is now 33mm wide (it use to be 35mm, which might have been what you saw previously)
This only matters if you’re doing a UCI race.
I ran the old 404s (non-dimpled) with 34c Grifos with no problems down to about 25 PSI.
With 35’s, I hope you built up the base of the rim channel with Belgian tape and a lot of Vitoria mastic one…
If not the tyres are likely only glued on the tip of the rims edge… Which at Low pressure off camber are very likely to peel off…
If you are not sure on this check out articles by Leonard zinn on this.
Also if UCI it’s 33 inflated… Not rated… Some run big some small…
An officious bastard will ping at .m over …
These are clinchers so no glue involved.
Pointless now as I just ordered a bike with disc brakes, so I’ll move these back to my tri bike for training and move the power2max to the gravel bike. Has been good to learn some more details about offroad riding and racing, though.
Deffo less glue required then… 
But if your doing CX with clinchers you will want to end up tubeless, otherwise it’s just one snake bite after another …
Suggest Stans iron cross or grail, the later can tolerate road pressures hence make a great gravel grinder or road wheel too…
I run grails on my CX bike… Tho iron cross wheelsets have been in very good sales…
What disc bike did u get…
Thanks for the info. I sincerely appreciate it. This is a bit of a new area for me. I’m looking at a set of tubulars on eBay right now specifically for racing CX and training on my tri bike. I have tubulars for racing on my tri bike, even though admittedly I am new at them but have done enough research I know what I’m in for.
I got (am getting when it comes in) a Giant Revolt. It seems perfect for what I want, which is mainly long distance gravel rides and maybe some CX rides/races. If I find I really enjoy it I can upgrade but I got a great deal. It’s kind of an odd looking bike but has great geometry for me and fits a wide variety of tire widths. Anything that can get me off the busy roads is a good thing.
CX tubs are great… The wider / shallower the radius the easier / better the glue job…
Also clincher tubeless allows more tyre option per wheelset if your race conditions may be changeable… Also CX tubs more exe than clincher…
But tub use better for pure grip… No doubt…
Many using farsport 25mm tubs as they are so cheap…
All the best anyway…
Oh and don’t be surprised if you end up on mtb trails on it… They are heaps of fun…
Awesome! Thanks for all the great info. I’m excited to be getting into this world. I’ve been riding single track more the past six months or so, and while I enjoy it, I still prefer longer distance stuff. Offroading riding seems to be exactly what I want.
Just remember, UCI rules on CX tyres is now 33mm wide (it use to be 35mm, which might have been what you saw previously)
This only matters if you’re doing a UCI race.
Or any race that uses UCI rules and the decide to enforce them.
The next local CX race around my parts is a National Points race, so UCI rules will be enforced - So in many ways, this was an FYI to myself saying I can use only one of my two sets of CX tyres.