You can always tell the hot bike at a demo by how hard it is to get one to try. Whether due to excitement, skepticism, curiosity, or disbelief, usually one bike stands above the rest. In the case of QBP’s Saddle Drive event this year in Ogden UT, that bike had to be the new Salsa Bucksaw full suspension fat bike. It seemed that even those with no interest in fat bikes wanted a ride just to see what it was like.
As the first mass produced full suspension fat bike, the Bucksaw joins other new additions for 2015 to create the most diverse fat bike line up anywhere. While some of the companies are just releasing their first bike with the giant tires, Salsa now offers five different categories of fat bikes from rigid to full sus.
Curious why there needs to be such a variety of fat bikes? Find out next, plus details and actual weights for the Bucksaw, Blackborow, Beargrease, and Mukluk…
After nearly three years of development, the Salsa Bucksaw is finally here. When Salsa first started to think a full suspension fat bike could be a possibility, production fat bike forks didn’t even exist. Initially taking pieces of their Spearfish and Horsethief bikes and creating a prototype, Salsa used Maveric DUC32 and modified Lefty forks to test out the concept. Soon, Salsa started working with Dave Weagle to develop a new suspension platform for Salsa’s 29ers and Dave was instantly on board with the idea of a full suspension fatty. Eventually RockShox decided that they were on board with what we now know as the Bluto, but not before Salsa and Dave had already done most of the engineering for the frame.
Salsa is very keen to point out that this is not a fat Spearfish or Horsethief. Instead it is a purpose built bike, designed from the ground up. One of the most crucial points to the design was characterizing how fat bike tires perform. During the development Dave Weagle designed a rig that would dyno test fat bike tires to catalog how they handled at different PSI, with different width rims, and with different sized tires. This is the reason that the Bucksaw includes 3.8″ tires since the frame’s kinematics are engineered around that size tire on 65-82mm rims.
Designed with trail bike geometry but with 100mm of travel, the Bucksaw uses a 68 degree head tube angle and 444mm chainstays.
Even though the bike was designed around rims up to 82mm wide, the production bikes will ship with the 65mm Marge Lites. Not only do the narrower rims save about a half pound per wheel, the rims create a rounder tire profile that helps to reduce auto-steer. Technically, auto-steer is something found on all bikes which is when turning of the bike creates a lever arm from the contact patch that is off axis from the steering input. Due to narrower tires, auto-steer is usually not noticeable on most bikes. It’s only when you get into the bigger tires of fat bikes that it becomes more noticeable. Auto-steer is also more noticeable at higher speeds which means the Bucksaw is even more susceptible due to its incredible abilities. Considering all of the factors, Surly feels the 65mm rim and 3.8″ tire combination offers the best of both worlds.
The main frame and chainstays on the Bucksaw are made from 6066-T6 aluminum but the frame does use carbon fiber seat stays. Just in the seat stays alone, Salsa was able to save 245g. To match the RockShox Bluto 100mm fork up front, the RockShox Monarch RT3 provides 100mm of travel in the rear.
In order to clear the chainstays, the Bucksaw uses a pressfit 41 121mm wide bottom bracket. This is technically the same width as a 100mm threaded BB and uses the same cranks. A high direct mount front derailleur tab designed for doubles is key to allowing adequate tire clearance but keeping the ability for wider gearing.