I'm looking for a rear tire for climbing power only. The surface is a combination of bare tree roots and loose rocks. I'm not interested in cornering, downhill, hardpack or a 'fast' cross country tire. To give you an idea imagine your in a race thats 50 yards uphill with a 10 percent grade. In the past I've been very happy with the 'tried-n-true' Panaracer Smoke. Are there any tires that are clearly better climbers??? What do you think??