Bicycle Mechanics - to many flat tyres!!

I am fairly new to using a road bike and recently bought a second hand one. Over the last month I have been having increasing numbers of flat tyres. This came to the most frustrating point recently when over period of two days I had 5 burst tyres>

Could this be that I need new tyres??. The punctures are on both wheels.

What could other reasons be??

any suggestions on how to establish the cuase would be most appreciated.

Punctures appear not to be at same point each time

it is possible that you are mounting the tire wrong. Unlike a fat mountain tube, it is very easy to pinch the inner tube between the rim and the bead of the tire, causing it to puncture the inner tube.

also your pump guage might be off, causing you to over or underinflate your tires

It also might be your rim tape. if it is crooked or just plain worn, the spoke heads might poke your inner tube

there also might be something inside your tire, poking the inner tube.

these are all I can think of right now...

burst tubes are really not common while riding. I personally have never had one, nor have ever seen somebody have on. I have burst 2 tubes by pinching them, but that usually happens within 15 minutes of mounting them.

A possibility is that there is serious damage to the tire itself meaning that no matter how well you mount the tube, it will pinch inside a hole in the tire or tirewall itself. This effectivly means that the tire is shot should this be the case. What you want to do is take the tire off the bike and look at it carefull (often works best looking from the inside out) for any sort of hole that is much larger than a pinhead or such.

When a tire wears, it thins, obviously. It is possible that your tires are so worn that they are allowing punctures. If you get yourself some kevlar weaved tires, and mount them properly, your flat problem will be virtually non existent.

Also, feel carefully along the back side of the tread. There may be a bit of glass or other tiny sharp object that's pierced the tire & is popping your tubes.

It seems to me that engineers could come up with some solid material - maybe some type of dense foam - that would take the place of the inner tube. But of course the tube makers would't be too pleased, so i don't expect to see it.

Tubes also wear out over long periods of time. As you got the bike second hand and it's a road bike it could of had the same tubes its entire life.

When you next get a flat take the tubes out fix the puincture if you have to. Inflate the tube out of the bike and inspect for cracking. It's typically at the edge where the tyre meets the rim. If all your punctures are along a concentric ring it could be this or a tyre/rim defect.

In most cases the tubes are replaced before they have a chance to wear too badly and it is very common.

The reason we still use inner-tubes or at least air in tyres is because it is the best substace by a mile. It's rederly available cheap and easy to get in the tyre and give vastly superior performance.

There are various solid tyres that claim to be very near the performance of pnumatic tyres but actually perform a lot worse.
http://www.greentyre.com/
Is one such company.

There are also foam inserts which require a fair ammount of skill and force to fit and don't work as well as air. Finally there is rubber foam that is inserted into the tyre and when cured it expands.

The disadvatage is they don't absorb shock very well. They are heavy and hard to fit to the point where beads can break during fitting. They are more expensive and the solid tyres grip poorly.

What pressure are you putting in dude?

Brendon

Thanks for the info, D. I didn't know there were any out there, even bad ones.:-> Possibly it's just something that not enough R&D has gone into yet.

But why not more tubeless tires for clinchers?

Check that the spoke heads do not protrude into the innter tube. Feel the edge of the rim hole, to make sure its not sharp (and use some emery cloth if it is). Use a good rim tape such as Velox. Use a reasonably good quality inner tube, and a kevlar-belted tyre (Not kevlar beaded, which replaces the steel bead for lightness and foldability).
Choose a tyre width suitable for your riding (25mm is good for general road bike use), and keep the pressure close to the max recomended on the tyre.

All this should reduce your puncture rate to a couple a year.

are you in an area with goatheads or other plants which grow thorns on their stalks, seeds or leaves?

tube goo (puncture sealant) might help if you are in a place like this (typically southwestern states).. or maybe, like me, you have to dodge used herion needles on the side of the road, i imagine they would blow a tire if you hit one.

this stuff is easy to apply yourself and relatively inexpensive, however it adds constant slow-down inertia to your tires, as well as plain ol' weight.

What about body weight? I've had 3 tube blowouts, on 3 new tubes, in the last 400 miles. I'm a new rider and may be way off but I'm starting to wonder if it isn't the fact I'm 6'6" and 255 lbs. Is there a point where one may simply weigh more then the tyre/tube can handle? I've taken all of the obvious steps but will still spend the next hour putting on yet another tube. I don't see max weight listed on bike tyres as it is on auto tires.

i got a couple punctures this last week due to bad tires... the rubber on the tread began to crack all over.. i'm going to get new tires, but i'll also put on "mr tuffy" strips.. it was 19.26 for a pair of mtnbike strips, a little less for road.. but it's basically a protective strip that rests between the tube and tire, so you can run over a lot of stuff with no damage... maybe not nails, but who knows, would still probably help with a puncture like that. guy at the shop also said they'd make a good boot in the case of a slit tube.

kim