Handguards are standard on trail bikes and rare on Vietnamese city bikes, which is odd, because a rider’s hands are the most exposed part of the body on two wheels: first into the cold air, first into the rain, first into the hedge.
What they do
Three jobs. Wind: in Hanoi’s winter mornings, the difference between guarded and unguarded hands is the difference between feeling your levers and not — the cold-start and winter context is in cold-start-motorbike-winter-vietnam and winter-riding-motorbike-hanoi. Weather: guards deflect rain spray from lorries and keep gloves dry, which keeps hands functional — gloves alone struggle in sustained rain; see riding-gloves-vietnam-climate. Impact: in a low-speed fall the bars and your hands hit the ground first; a solid guard can save levers and fingers.
The two types
Plastic deflector-style guards mount to the bar ends and block wind — cheap, light, fine for commuting. Full wrap-around guards (aluminium spine with plastic shield) also mount at the bar clamp and genuinely protect hands in a fall and brush off road-side vegetation on rural routes. The wrap-around version needs bar-end and clamp mounting compatibility, and must not interfere with levers at full lock — check cable and lever clearance before buying.
The honest assessment
City riders on scooters benefit mostly in winter and rain; the fall protection is a bonus. Riders doing mountain trips, dirt sections or overgrown rural roads get the full value — the post-fall inspection habit in checking-motorbike-after-fall-accident is lighter work when the levers survived. Guards add a little width: if you filter through gaps at bus-window distances daily, you already know whether that matters.
Buying notes
Vibration-damped bar-end mounting also slightly helps the buzz through the bars. Check that mounting bolts are lock-washed — guards eat vibration and loosen like everything else in Vietnamese riding. If a guard bends in a fall, replace it; bent guards push levers out of line.