Why 27.5 (650B)? You are lighter and more nimble than a 29er and roll over obstacles better than a 26er. Fits smaller riders than the 29ers too. The 27.5 mountain bikes will have the best of both worlds. The agility of the 26″ wheel and the big wheel experience of the 29er mountain bikes. 26vs27.5vs29er Wheels The only thing you have to do is a bit of tuning and assembly. Sizing Guide: 17 inch = Small/Med | Standover = 29″ | fits* up to 5’8″ 19 inch = Medium/Lr | Standover = 31″ | fits* up to 6′ 21 inch = Large/XLrg | Standover = 33″ | fits* 6’1″ and taller (*approx. sizing – your final choice is up to personal preferences. Suggest min 2″ crotch clearance from Standover) Frame Oversized Bearing 4Bar Link Pivot, Formed TIG Welded 6061 Aluminum Triangle with Hydroformed Downtube. 4Bar Link Rear Triangle with replaceable rear derailleur hanger Fork / Rear Suspension 27.5″ FORK, SUNTOUR SF13-XCT-MLO-DS ALLOY BLACK CROWN / KS CoilOver with adjustable preload, damping and LOCKOUT Crankset SUNTOUR SQ 22Tx32Tx44T(for 27-SP)x175mm Bottom Bracket SUNTOUR-CBT CARTRIDGE Pedals Mountain Platform Front Der SHIMANO ALIVIO Rear Der SHIMANO DEOR Shifters SHIMANO ALIVIO 27-SP BLACK Cassette SRAM PG-950 11-32T-9 SILVER Chain KMC Z-99 STEEL SILVER Hubs Sealed Ball Bearing Disc with QR Axles Spokes Stainless Rims WTB SPEED DISC 650Bx32H ALLOY BLACK Tires WTB WOLVERINE 650Bx2.2 BLACK Brakes Tektro Novela Disc Brake 160mm Rotor front/rear Brake Levers SHIMANO for disc Headset CaneCreek VP-A42E Sealed Bearing threadless 1 1/8 in Handlebar Black Finish Aluminum 6061 T6, MTB-W:620MM, ALLOY BLACK Stem Black Finish Aluminum threadless EXT:90MM(13″~17″)/105MM(19″~21″)x10 DEGREES, ALLOY Tape/Grip WTB Saddle WTB SpeedV Seat Post Black Finish Aluminum 27.2mm x 400mm (insert min 2 inches below lowest top tube weld / maintain clamp collar tightness) Seat Post Clamp Alloy Quick Release (Note: Front triangle of 17″ size does not require a toptube/seattube gusset)