I've read that many Vectrix VX-1 have a front wheel wobble felt around 35mph. That has been the case with the two VX-1 I owned as well: one has 17K miles on the odometer, the other is brand new (130 miles when I bought it off the liquidation auction, around 1,500 miles now). Both bikes have the factory Pirelly tires in the rear, the new one has the factory tire in the front, and the old one had a Diablo version in the front.
It only happens if I let both hands off the handlebars and coast at around 35mph. Never happens with even the gentlest of control with one or both of my hands on the handlebars. I don't feel anything being loose in the suspension, and I don't see any obvious issues with the wheels and tires. There are also no vibrations riding it, just the wobble at that speed (at slower and faster speeds there is no wobble).
Anyone know why is this happening and if there is a fix?
yes!
1- Throw the pirellis into the bin, and install good, well-balanced tires, like Michelin citygrip.
2- Do an automated tire-balancement on the front wheel (rear wheel there's no axle, it is difficult to have the rim balanced, only manual procedure).
http://en.wikipedia.org/wiki/Tire_balance.
If possible, ask the automotive technician to use zinc weights instead of lead weights.
Hmmm, I thought the Pirelli Diablo was a pretty good tire for the front, no? And the original stock Pirellis weren't too bad either? Yes, I am partial to Michellins on my cars, so probably will try some next on the bike too. But the Pirellis are supposed to be stickier and sportier and I like that. Hard to tell from reading on scooter forums... Thoughts? I don't like the zig-zagging groove in the middle, but I doubt it's causing the wobble...
As for balance, I have manually balanced my rear tire and wheel on the bike: trial and error - just moving the weights around till vibrations at speed are minimal when the wheel is spinning with the bike on a stand. Vibrations are only felt at near top speed and not too bad either. I don't feel vibrations from the front and the rims are true. But I may have it rebalanced at a bike shop nevertheless in the Spring.
This doesn't help, but when my tyres were new I had no wobbles. It's only as the front wore that the wobbles started...and only when you don't touch the bars...it's weird how almost no pressure on the bars stops it.
Anyway, 25,000km on the front now and it's pretty much ready for replacement.
I tried many different kind of tyres,and I can assure you that the original pirellis are the worst tyres. Any other good tyres will give you lower vibrations at top speed and better handling in sharp turns. Your life is not worth the price on these new tyres.
I had the same very light grip/no hands intermediate speed wobble in a non-vectrix scooter. It was greatly reduced by changing to Pirelli Diablos from the cheap Pirelli SL26's. The wobble in no way ever affected control at any speed - but it was an annoyance.