Hollowtech II Bottom Bracket: What Size?

The Hollowtech II bottom brackets provide the best balance of stiffness, strength, weight and rotating performance. Bottom bracket upgrade, what size do I need? Measure the inner diameter and most importantly, the width of your frame's bottom bracket shell. Assuming you have a BSA threaded bottom bracket shell, which is commonly used before 2010 and beyond, the width varies from 68 to 100 mm. 68 mm (Road) 73 mm (Mountain) 83 mm (Downhill) 100 mm (Fat Bike) Road bikes and hybrid bikes share the same shell width - they are all 68 mm. Trek 720 Multitrack Trek Madone 5.5 Peugeot PB-9 Mountain bikes’ bottom bracket shells are 73 mm. Specialized Ground Control Trek 930 Singletrack Trek Fuel 90 Devinci Chuck S Downhill bikes are 83 mm and fat bikes are 100 mm. The installation The Hollowtech II bottom bracket comes with spacers to fit 68 and 73 mm bottom bracket shells. There’s a 2.5 mm gap on the drive side to install either a chain guide or a derailleur with bottom bracket mount. These are optional and you could use a spacer to fill the gap. Install the spacer on the drive side. Starting from the drive side, turn it counterclockwise and use the tool to tighten it. On the non-drive side, turn it clockwise. Parts installed: Hollowtech II Bottom Bracket: Shimano Deore SM-BB52 RaceFace Aeffect Crankset 175mm with 30T Narrow Wide Chainring RaceFace Chester Pedals #hollowtech #bottombracket #mtbupgrade Danyo Sports Channel Episode 125 Youtube:    / danyosports   Reddit:   / danyosports   Facebook:   / danyosports   Instagram:   / danyosports   Twitter:   / danyosports