I drank the Grand Bois (Panaracer) Hetre koolaid recently. The main advantages to this tire are: wide cross-section (42mm), smooth ribbed tread, thin, supple casing for low rolling resistance and a supple ride, Kevlar puncture protection, and Kevlar folding bead. So it's a relatively lightweight tire, durable, smooth rolling with low rolling resistance. What's not to like?

I couldn't be happier with my recent conversion, which I built with these tires in mind. These tires are such a treat, whether on the road or on a fire trail. I went on my first real trail ride on this bike, and I was grinning ear to ear the whole time.

That said, if you simply want a bike that can run wide tires, you can always buy a new Surly Cross Check for about $400. It has room for 50mm 700C tires, or 40-something mm 700C tires with fenders. (A friend fitted 50mm Fat Franks *with* fenders, but it took some finagling). I spent that much just converting and powdercoating my frame, but then again, I really wanted Hetres, so it made sense to go that route and not something like a new Cross Check.

Another thing to consider in a conversion, aside from brake reach, is BB height. Conversion will generally cause the BB to drop about 8-15mm, and if the bike being converted already has a relatively low BB, this may cause problems with pedal strike, especially if you plan on using the bike on fire trails or rocky, technical mtb trails. And this is especially true if you prefer extra long cranks.