Mountain Bike Stem 31.8mm Clamp, 40mm Length, 3 Degree Rise, Short Handlebar Upgrade For Road, BMX, Cycling, CNC Aluminum 6061 T6, Four-Bolt Bar Clamp, Lightweight 112g, Easy Install

31.8mm MTB Stem 40mm 3° Rise CNC 6061-T6 4 Bolt Single
✔️ 31.8mm clamp, 28.6mm steerer, 40mm length, 112g, 3° rise, 4 bolt

This compact stem attaches to the front fork and connects to the handlebars, ideal for upgrading or building a light, sturdy cockpit on road, mountain, BMX, and fixed-gear bikes.

✅ Handlebar diameter 31.8mm (1-1/4 in), steerer diameter 28.6mm (1-1/8 in)
✅ Length 40mm, rise 3°, weight 112g
✅ Material CNC aluminum 6061 T6, four-bolt clamp
✅ Suitable for road, MTB, BMX and DIY bike upgrades

💡 What is a mountain bike stem used for and how does clamp size affect fit?

A handy explanation of stem function and sizing for cockpit geometry.

- clamp size 31.8mm matches most handlebars - length 40mm and rise 3° influence reach and handlebar height - four-bolt clamp and CNC aluminum build secure grip - compatibility with road, MTB, BMX upgrades