"my question is if this is bad"

Wouldn't think it would be good.

"adn if so, if there is a way to prevent it?"

Don't ride in the rain? I *think* this only happens to rims that have a second cavity above tube. I don't *Think* that water actually gets into the tire area rather the second cavity. The only way I can see keeping it from happening is sealing the areas around each spoke and stem that go thru the rim and thru that cavity. OTOH It's really not a big deal to pull the tire, deflate it and get most of the water out of the stem hole. Another option woudl be to get a different set of rims for rain riding that don't have that cavity.

~Matt

I'm not sure. On rainy days, I usually ride outdoors and try to dismantle both of my tires/tubes overnight to let them dry...JUST IN CASE. I'm not sure if water is actually dangerous but I know it stays in my tires for at least a few days after a wet ride.

I'm unfamiliar with these wheels but my Hed Jets used to fill up with water quite badly since they were just a carbon aero fairing over a aluminium wheel. I called Hed and they told me to drill small holes in the fairing close to the rim. I still had to do a lot of shaking if I go caught in the rain but it was a solution, albiet a pain in the butt one.

You cn get water in most any rim/wheel combo if you ride often enough in hard rain. During these periods it is probably not a bad idea to check on once a week or so. I learned that the hard way and rusted the metal eyelets on a rim once as well as the nipple heads.

bump for teh a.m. folks

Water in the wheels... from a dynamic standpoint it's not good also. Even though the effect is not as dramatic you can appreciate the effect by spinning a raw egg vs a hard boiled egg. It depends on how much water gets trapped in there. The worst was when I had trapped water freeze in the rim over night. There was a noticable imbalance.

Corrosion was already mentioned. Just remember that you are picking up the fine grits and any chemicals (salt?) and driving them into that rim cavity.

---

Jay