The bike is holding up, but I would not say that the bike is holding up well. The 640A is designed as a race bike - light and powerful. Unfortunately that means they had to sacrifice something, and the key missing component is a balancer in the compact single-cylinder engine. It vibrates like a paintshaker.
The vibration doesn't actually bother me that much, although other riders have complained more bitterly. What worries me is the toll it takes on mechanical components. Bolts do not like to be vibrated. When subjected to such torture, they slowly unscrew themselves and then leap off the vehicle the first moment they taste freedom. Vibrating metal parts tend to fatigue and break.
Here's the list of casualties so far:
* One sheared pannier bolt (in AZ) and two pannier bolts vibrating out, one on each side. Partly I blame the design of the Happy Trails luggage rack.
* The small metal hanger that holds the handlebar cabling in place broke. It's a minor part and not particularly important, but it gives you an idea of the mechanical stresses that are in play here:
* The most severe problem so far, found after the WRC trip. An oil leak caused by a loose head bolt:
Overall, these are pretty minor issues and I'm very happy with the performance of the bike. I don't think any other bike would provide the same quantity of grin-inducing fun
both on and off-road. When I'm on highways I often wish I had a twin-cylinder 990A instead, but every time I leave the pavement I'm reminded how much this bike kicks ass.