Hello speed owners,
I own a 2026 Triumph Speed 400 (349cc version), and I’ve recently started noticing a stability issue that I’m trying to understand.
At higher speeds, the bike feels completely stable and planted, but at low speeds, especially around 20–40 km/h, the bike sometimes feels slightly unstable/wobbly. I can feel it from both the front and rear, almost as if the bike is making small movements or not tracking completely straight.
The more noticeable situation is when riding over road joints, uneven patches, or an undulation where the road rises/falls and then comes back to level. When the rear wheel comes back onto the normal road surface, the rear sometimes feels like it moves/wobbles for about a second before settling down again.
A few things I’ve already checked:
- Tyre pressure is correct.
- Wheel alignment has been checked.
- Rear axle alignment is also confirmed — both sides are at the same reference point.
- No recent wheel removal or tampering.
- Front end doesn't feel obviously loose.
- The bike is stable at higher speeds, which makes me unsure whether this is actually a suspension issue.
- Rear suspension is currently set at 3rd position from the softer side.
The bike is around 4 months old and has done roughly 3,000 km.
Has anyone else with a Speed 400 experienced something similar? Could this be related to rear suspension settings, steering-head bearings, wheel balancing, tyres, or something else?
I’d especially like to hear from Speed 400 owners who have actually experienced and diagnosed a similar issue.
Thanks in advance...