Bicycle Mechanics - Bulge in Tire

Greetings,

I noticed last night while I was installing a new computer on my bike ('03 K2 Mach 2.0) that the rear tire Vittoria Zaffiro has a bulge in the side of the tire. I looked at it closely and the tire is properly seated in the rim.

Should I be concerned? Would this bulge indicate a weak spot in the tire? FWIW I have almost 800 miles on the tires. This afternoon Donna and I will be riding a route that is near my LBS so I'm going to take the bike into them to have a look.

Thanks in advance for any feedback.

Zack

i'm not as sure about bicycles, but if it was a car i'd get a new tire. they do get weak spots sometimes.

Zack,

I Second Shaharidan's view. Though you dont say how serious the bulge is, it is often due to failure of some threads in the fabric casing of the tire. This is a serious weak spot. I ignored a bulge once - only for the sidewall to blow out. It made a hell of a bang, and it is a very good thing that it was the rear tire and not the front....


Just as an aside, do you use a pressure gauge when inflating tyres? I would recommend it (apologies if you do already). It is hard work to over inflate, but just as bad to run under pressure - there is an increased risk of pinch punctures and sidewall damage.

I'm sure the lbs will be happy to help,

Good luck ,

Ed

Several things will cause a rear tire to bulge:

1. A defect in manufacture
2. Hitting an obstruction that damages the casing
3. A cut or small puncture
4. A damaged rim bead, i.e., a fold in a kevlar bead or the cottom bead tape pulling loose

It happens and it's frustrating given the cost of the high performance tires that so many of us use. You can usually find any damage if you inspect both the tread compound, bead and inside casing. Nailing a rut usually scuffs or bruises one or both of the sidewalls.

If you find you have a bulge in a tire while you're out riding and are concerned about riding on it you can usually put a reinforcing boot (folded dollar bill, a GU or PowerBar wrapper or strip of cardboard) under the bulge to reduce the amount of the bulge until you get back to your starting point and/or until you can get a new tire.

If you find one in a new or relatively new tire right after putting it on take it back and ask for a replacement. If the shop says "sorry, it's used" contact the US importer and ask if they'll replace it (most will in the name of customer service and good PR).

As livngood says. Check it and if the bulge is not from ride damage take it back to your shop, if it is fairly new, and they should replace it. If they say no then try BikeMine 800-223-3207

Just a quick follow up. LBS guys said it was busted threads on the side of the tire. They didn't have the same tire in stock but put another one on so I could ride tonight. I'm giong back tomorrow to get the tire swapped.

Thanks to all who replied.

Zack