Originally Posted by Grenouille
Any downsides to these, apart from higher price and a little extra weight?
(I held some at my LBS last weekend, the difference in tire weight is less than the difference in my weight before vs. after thanksgiving turkey tomorrow).
Do you have specific brands in mind? Most tires have some level of flat protection, some obviously much more than others.
My Continental Touring Plus tires in 700cx42 are advertised to include enhanced puncture resistance. They're definitely much heavier-duty and just plain heavier than the stockers - I think they were Conti CityRide make, but not certain.
I add to the tires' protection by running Slime in my tubes. Between the two, I don't flat much, but still carry 2x spare un-slimed tubes + patch kit 'cause Slimed tubes cannot be patched.
The extra weight is far less important to me than is my ability to go out for a ride without having to worry about flatting along the way. Even though I mostly ride pavement, the local stickers (goat heads) are absolutely brutal on tires/tubes, even those which clame puncture-resistance.
That said, adding any mass to your wheels is a special case due to the wheels' rotation, which ends up magnifying the effect of the extra weight. It can be significant.
For my part, I find flats otherwise slow me down much more than heavier tires and a bit of Slime can. Others are horrified at the idea of even an extra ounce of rotating mass. Who's right? Who's bike is it, and who is the cyclist? The question is one which has no 'one size fits all' answer.