Bike stem and handlebar: how to choose the right ones

The stem: length and angle

The stem connects the steerer tube to the handlebar. Its two key parameters are length and angle.

Stem length

Length is measured center-to-center (pivot axis to handlebar center).

Impact on handling: a short stem makes steering quicker (less lever arm). A long stem stabilizes steering but slows direction changes. In MTB, the trend is very short stems (35-50 mm) combined with wide handlebars.

Stem angle

The angle is measured relative to the horizontal (or steerer tube depending on manufacturer).

• 0 to 6 degrees: low, sporty position. Handlebar at or below the steerer pivot
• 6 to 17 degrees: intermediate position. Most common (plus or minus 7 degrees is the universal standard)
• 17 to 35 degrees: high, comfort position. Upright back, ideal for city riding or neck pain
• Tip: flipping a positive-angle stem (+6 degrees) turns it into -6 degrees, lowering the bar. Handy for testing before buying

The handlebar: width, rise, and backsweep

Flat bar (MTB)

• Width: from 700 to 800 mm. The rule: shoulder width + 2-4 cm for MTB. In Enduro/DH, often 780-800 mm. In XC, 700-740 mm. You can always cut a bar that's too wide (hacksaw or pipe cutter), but you can never make it longer
• Rise: from 0 to 40 mm. A flat bar (0 mm) gives a low position. A bar with 20-40 mm of rise raises your hands without changing the stem. Useful if your stem is already short and you want to go higher
• Backsweep: from 5 to 9 degrees. The rearward angle of the grips relative to the bar axis. 5 degrees is neutral, 9 degrees is more natural for the wrists. Some "ergonomic" bars go up to 12-15 degrees
• Upsweep: from 0 to 5 degrees. The upward angle. 4-5 degrees is common in MTB, it relieves wrist strain

Drop bar (road)

• Width: measured center-to-center of the drops. Should match your shoulder width (measure between the two acromions). 40 cm is common for 40 cm shoulders
• Drop: vertical distance between the top of the bar and the bottom of the drop. 120-130 mm is standard, 115-120 mm is "compact" (easier to reach the drops)
• Reach: horizontal distance from the top to the front of the drop. 70-85 mm. Short reach = hand closer to the brake lever in the drops
• Flare: the outward splay angle of the drops. 0 degrees = parallel drops (classic road). 12-16 degrees = gravel (more stability and comfort)

Clamp standards

Two standards dominate:

Important: the stem clamp diameter must match the handlebar diameter. A 35 mm bar won't fit a 31.8 mm stem, and vice versa.

Materials: aluminum vs carbon

• Aluminum (6061/7075 alloy): strong, affordable ($20-80), slightly heavier. 7075 is stiffer and stronger than 6061. Recommended for most riders
• Carbon: lighter (30-50% weight savings), better vibration damping, more expensive ($80-300). Note: carbon doesn't bend before breaking. Use a torque wrench at the manufacturer's spec (4-6 Nm for stem bolts, 5-7 Nm for bar clamp). Never use regular grease — use carbon assembly paste instead

How to choose based on your riding style

1. Wrist pain in MTB → try a bar with more backsweep (9 degrees instead of 5) and possibly some rise
2. Feeling unstable on descents → shorter stem (40-50 mm) + wider bar (780 mm)
3. Back pain on road → shorter stem or more angle, compact bar (reduced drop)
4. Want more aero on road → longer stem (110-130 mm), low position
5. Starting gravel → flared bar (12-16 degrees) + 70-80 mm stem

Want to know which handlebar and stem are compatible with your bike? L'Atelier identifies your model and recommends dimensions suited to your body and riding style.