UN300 E Type Square Taper Bottom Bracket With 68Mm Shell And 122.5Mm Hollow Spindle For Lightweight Power Transfer, JIS Compatible, Fits Road And MTB Rigs, Ideal For E Type Front Derailleurs And Broad Setup
✔️ Lightweight hollow spindle; 68mm shell; 122.5mm length; JIS taper
Designed for JIS square-taper cranksets, this BB-UN300-E fits 68mm shells and 122.5mm spindles, making it a solid upgrade for road and mountain bikes. It's ideal for E-Type front derailleur systems and modern builds that value lightweight power transfer.
✅ JIS square-taper interface for secure crank attachment
✅ 68mm shell width and 122.5mm spindle length for common frames (68x122.5mm)
✅ Hollow spindle reduces weight while keeping strength
✅ English threaded shell with 1.37" (34.8mm) I.D. compatibility
✅ Supports E-Type front derailleurs for road/ MTB setups
✅ Durable black finish resists corrosion and wear
💡 What is a hollow-spindle bottom bracket and why pick it for road and MTB bikes?
Lightweight design helps with acceleration and improves pedaling efficiency while keeping durability.
- Hollow spindle lowers rotating mass for quicker response- Compatible with JIS square-taper cranks and 68mm shells
- Supports E-Type front derailleur setups for versatile builds
- Durable black finish resists corrosion and wear