When the founders of our sport put the first mountain bikes together in the late 1970s, they were often called “klunkers” or “fat-tire” bikes. Back then, most road bikers seemed to turn up their noses at the new fat-tire bikes.
Bigger tires were heavier, and that was the worst thing in the world in the eyes of
most road bike riders who would normally do anything they could to make their bikes
lighter. Since the bigger tires did offer advantages in the dirt, they were assumed to
be a necessary evil of the new sport, which soon became known as mountain biking.
Even in the early years of our sport, the best mountain bikes were often the ones that
were the lightest. In general, the more money you spent, the less your bike would
weigh. In the world of mountain biking, everyone knows that lighter bikes have an
advantage when it comes to pedaling uphill, but there’s a new school of thought when
it comes to tire sizes. Maybe those bigger tires, with their improved ride quality and
traction, could be faster overall. It’s a question we field here at Mountain Bike Action
often: What’s the deal with the new plus-sized tires, and should I be using them? We
set out to perform a quasi-scientific experiment to see if the yaysayers or naysayers
are right when it comes to riding those big, fat, plus-sized tires.
27. 5+ vs. 29er
The contenders: The Ikon 29x2.2” (left) vs. Ikon 27.5x2.8”. Our riders liked the
29er better for our dry cross-country loop, but they liked the 27. 5+ tire better
for descents, loose dirt and sandy sections.