Ummm. Yeah, but does that take into account the physics involved in what Stepfam was saying. I bet it's some exponential equation. Just sayin... Somebody help me out here.

Several times in my last 22,000 miles, my mechanic has reported that something penetrated my Marathon Plus tires and was stopped by a Mr. Tuffy. It's clear that these tires do not, by themselves, protect against all flats.

I've never used thorn resistant tubes, and have assumed them to be mythical. If they are such a good dea, why didn't them make them for cars?

Paul

We must have better roads in Georgia than many of you have where you ride. Or maybe we are fortunate in not having some of the varieties of thorns that plague other areas. Whatever it is, I have been able to avoid frequent flats while using tires without heavy, protective casings and with normal tubes. Not that I never get flats, but not often enough to make me want to sacrifice road feel and light weight in search of more protection on my fast road bike. Most of the flats I had in my early years of riding were pinch flats from running too low pressure in skinny tires while I was a heavier load. I did come across a few specific tires that were more prone to cutting, so I avoided them.

On my other road bike, though, which is more likely to go on a dirt or gravel road occasionally or venture through a very rough section of road, I run Panaracer Pasela TG tires which do have a protective belt but are lighter than some of the really armor clad tires out there.

I think you have to weigh your priorities and your experiences. For myself, on my fast road bike, I go for a light, supple feeling tire that has good tread life. If I have problems, I adjust to them.

There must be some regional differences.

Denver has the goatheads and I'll bet cactus spines could be a problem in some places.

Nearby I have a wildlife refuge that has dikes I'll ride my hybrid on and I always end up with hundreds of short thorn barbs in my tires and having to replace the tubes. The ride can be worth the hassle.

But as far as road riding in the SE US goes I'm with the Dawg. I've had other issues like a rim tape that moved and exposed a nipple-bed enough to pinch a tube. Or some bad tires that separated at the bead.

Bottom line is I can go several thousand kilometers, wear out the tires in fact, before I'll have an "intrusive" type flat. And until recently my riding was all over the SE. (Please don't let the flat gods know I'm writing this)

I do avoid heavy urban areas, I ride where the cars go (I believe they clean up the bad stuff for us) and I'll try to avoid obvious broken glass. I still will put my glove covered hand on my front tire to sweep it off after encountering obvious glass, something I was taught to do in the old tubular days.

I weigh about 180lb (That's only 82 kilos, I love metric!) and inflate the Conti GPs I use to 100lb front and back.

You're right BD. This is a bike I use for commuting and flatting can be a real pain if I'm pressed for time. I've already sacrificed speed for rack and fenders, etc. Having extra road protection is a priority. Of course, this just means that I need another bike that is lightweight and more nimble. That day is coming...

I just had a low tire this am I run Marathon (700x35) plus and slime light tubes. My low tire was the result of a bullhead in my side wall. The tube sealed its self all I had to do was add air. Southern CA has a lot of bullheads this year do to a rainy winter