billg

I have a Specialized Crossroads elitte bike and it is very much unreliable becuse the tubes get pinched by the tire or rim. Specialized refuses to remidy the problem the wheel is a Weinmann ZAC-19 and the tube is a Nimbus Ex 7700X38C. The tubes get pinched because the tire does not properly fit the rim. I have gone through at least 6 tubes in the last month and I do not trust the bike to get me anywhere. I had new tubes on the front and back I haden't even turned the bike over, the wheels in the air and the &*##! tubes both lost their air in a mater of a couple hours. The tubes that cmae with the bike lasted a couple years but the new specialized tubes (700X28/38C Thin 27X1-1/4 1278830728) are useless junk. can anybody recomend a non-specialized thick tube that may be more reliable? ANd has anybody else had these problems with Specialized?

twahl

Are you running pressure on the high end of the range? Sounds like it's not a pinch to me, if you are losing air without riding, and it also does not sound like a tire not fitting properly if they were fine for a couple of years. Sounds to me like maybe something has gotten in the tire, or the tube and tire aren't being seated properly.

seely

It sounds like you aren't doing something right. How are you installing the tube? Are you using levers? Are you making sure the tire's bead is set before you inflate fully? Is your rim strip still intact? There are billions of ZAC 19's out there and I can't say I've ever seen one do anything like this. Usually a leaky tube is operators error, or a bad rim strip. How much pressure are you running?

DieselDan

There are ways to prevent pinch flats, but troll bait gets trown back to the 'gator pond.

scrantr

Did you recently replace the tires? I have these rims on my rain beater hybrid, on a wheelset purchased from Nashbar. They were terrible wheels to start out, not at all built properly - Once I got the spoke tension up sufficiently they stayed true and haven't broken another spoke, but that's a different rant. The reason I ask about tires is that I have a lot of trouble getting tires to seat properly on these rims. They seems to be just a little larger in diameter than they should be, so tires won't seat without overinflating them a bit, then backing off the pressure. Check to see if the bead on both sides has really moved out to seat on the rim properly. If it hasn't, there will be more sidewall covered by the rim in one spot than elsewhere on the wheel. Once they seat, they are fine, but getting there is a bit of a drag.

SteveE

Nope! I've got a Specialized Crossroads that the kids ride and haven't had any problems in the 3 years we've had the bike.

dereknc

Yep, my guess is maybe the rim strip has moved. It happened to me. The tube gets pushed straight into the spoke hole.

roadbuzz

Your solution to the problem is kind of like calling the radio station 'cause the volume is too loud.

Do a post-mortem. Remove the tubes carefully, without losing their orientation, or changing the tire orientation relative to the rim. Locate the the leak(s) in the tubes. Check the location on the tire and rim corresponding to the leak in the tube. Is the tire ruptured? Anything lodged in the casing that could damage the tube? Is the rim tape in good shape? If all that is okay, then maybe you're damaging the tube when remounting tires!

If you have questions or come across something suspicious, post it to the bicycle mechanics forum.

If there's something wrong with the rim, take it to the shop, and if you have a case for warranty replacement, deal with them, and let them deal with Specialized.

P.S. Thin tubes are useless junk. Get a standard weight tube, pretty much any old brand is fine.