FSA Grid Boost Wheelset 27.5″ 28H 6-Bolt TA15 HG11. The FSA Grid Boost 29″ Wheelset is built for aggressive off-road riding offering the strength and width needed for modern trail and enduro bikes. With Boost hub spacing and a durable aluminum rim profile it delivers stability and control on technical terrain. This wheelset is ideal for riders who demand reliability and performance on rugged trails.