In the spring of 2015, with the help of Trek, SRAM announced a Boost hub spacing standard, which basically widens front hub spacing from 100 to 110 millimeters, rear hubs from 142 to 148 millimeters, and moves the flanges out a few millimeters on each side. To help smooth the consumer transition from pre- to post-Boost life, a handful companies are offering adapters to retrofit hubs to Boost frames and forks.
My everyday trail bike is a 135mm-travel-travel Stumpjumper FSR 29, and I recently went from a 2015 model year to a fresh, 2017 version. As expected, the latter is equipped with front and rear Boost spacing. A few weeks after receiving the new ride, I was off to join some buddies in the southern Sierra Mountains of Kernville, California, for our annual camping and riding trip. Whenever I drive more than a couple of hours to ride I like to bring a backup wheelset. “The Kern” is about a 12-hour round trip for me, and I have plenty of backup 29er wheels, which now don’t do me much good. Specialized has a lot of bikes in the marketplace, and many of those are equipped with their Roval line of wheels. If a rider wants to make their current Roval wheels Boost compatible, Specialized offers Boost conversion adapters for select 2013-2016 Roval models.