Yamaha lists an Assist and Slipper clutch for the Exciter 155 VVA on its Vietnam page (retrieved 23 September 2026). It is the most rider-friendly piece of technology in the manual-clutch underbone class - here is what it actually does.
The two functions
Assist: ramps inside the clutch basket press the plates harder under engine drive, so lighter clutch springs can be used. Result: a lighter lever pull and stronger drive without slip under power. Slipper: on hard deceleration, the mechanism lets the clutch slip slightly when back-torque spikes - for example a hard downshift into a wet corner - so the rear wheel does not lock or hop. In plain terms: easier pull going up through the gears, calmer rear tyre coming back down.
Why it matters in Vietnam
The Exciter is a traffic bike as much as a weekend bike. A lighter lever is a genuine health feature across an hour of Hanoi clutch work. The slipper function matters on mountain descents - the Hoang Lien and Ha Giang style roads where riders engine-brake hard behind buses. It is not a licence to downshift carelessly, but it is a real safety margin over a conventional clutch like the Winner R’s (Honda publishes no equivalent feature for it).
What it is not
It is not a semi-automatic: you still operate the lever. Riders who cannot yet handle a clutch should still start on the rotary class - our gearbox comparison explains the difference - and the price-published rental classes here (Wave and Sirius, 150,000 VND/day) are exactly that. Contact us to confirm current availability of the Exciter.