What is a gravity tire??

Last year I needed new tires for my mountain bike. Since I don't do much mountain biking, my skills are perpetually at newbie level and my road bike was in the shop for extended frame repairs at the time, the LBS guy recommended Bontrager LT3, which are designed for easy single track as well as paved trails. They worked out fine.

http://www.bontrager.com/model/08058

Eventually the road bike repairs were completed and the mountain bike wound up back in its storage shed on my balcony, with the wheels stored indoors in a closet.

Last night I took the wheels out of the closet and found a worn spot on the side of the rear tire. I took it to the shop and they said they could replace it under warranty since I had not used it all that much. They replaced it with a Bontrager G1 tire, which is described as a gravity tire.

http://www.bontrager.com/model/08059

So what is a gravity tire?

I believe that would be a downhill-specific tire. The sort of thing gravity riders use--the folks who take lift chairs up to the tops of mountains and bomb on down. The sort of riding I have ZERO interest in ever doing.

So what if you need to ride up a hill?

It would be kind of awkward to have to return a free tire. Unfortunately I didn't notice the difference until after I left the store.