Let's start this discussion assuming that I know very little about bicycle tires and what makes a tire good or bad.
About a year ago my wife and I bought a pair of GT Traffics (hybrids I guess) and began our bicycling to everywhere we need to go. This week I was cleaning the bikes and oiling the chains and doing basic preventative maintenance when I noticed long cracks in the sidewalls of the tired on both our bikes. The following conversation went something like this:
"I think we need new tires"
"What? It's only been a year since we got the bikes!"
"Well look at the cracks."
"Well those tires didn't last long."
"How many kilometers do you think we've gone"
*quick calculations of commuting to work, classes, and camping trips*
"Oh . . ."
"Somewhere around 3000km then."
"We need new tires."
So I don't know if 3000 kilometers is a good amount of distance for a set of tires but it has been through rain and snow and over mostly roads but frequently on dirt paths. the tires are Schwalbe Road Cruisers and the size is 700x40.
Now I have a few questions: From what I have read my rim should be able to take other sizes than 700x40, like 700x35/32/28, is that right? If I can get different size tires what size would you suggest? I mostly ride on either sidewalks or the road through the city. A friend of mine who is an avid cyclist and who also got me back into cycling suggested Schwalbe Marathons, good suggestion?
I will be heading to my LBS sometime this week to buy some new tires but I thought I would try and find some information beforehand so I at least know what I am looking for. Thanks.