120 kph Victrix

How much grinding did you have to do? Also, I can't see it from your photos - what is the model of the Pirelli tire? Thanks!

Second image was meant to be this....

Careful there! At higher speeds the tire will slightly grow in circumference, and you may see the result on your cross member there, and possibly on the tire!

I had the same trouble with a winter tire the same "size" as the summer tires, but my vR one requires a smaller size for winter tires which I found out the hard way. At rest there was still about 2 or 3mm clearance to the motor sitting just in front of it, though I could not actually get to the right angle to actually capture it in this pic:

But above about 50km/h the tire expanded sufficiently to start rubbing on one the motor cooling fins, which actually heated it up so quickly that the controller soon dialled back the maximum current, first from 135A down to 100, and then down to only 70A, which was a royal pain in the behind while trying to limp back home :-(

I only received the owners manual of the vR one after this ordeal, and it clearly stated that summer tires should have the size 130/70-12 (like mentioned in the CoC), but winter tires should only be 120/70-12, thus beeing about 10mm less in diameter than the larger 130/70-12 winter tire, but very close in diameter to the 130/70-12 summer tire.

Thanks! Yeah, the cross-member is pretty bulky and I'm not sure if it is solid aluminum or hollow. If it is hollow in that area, grinding too much off might not be a good idea... Do you think it is solid or hollow?

I could not find a 140/70-13 size tire for sale in the US. And I thought the 150/70-13 (your size) might be too big. Looks like you made it work! I like both the additional elevation in the rear and the higher top speed :)

EDIT: as for vertical clearance, I think there is enough, if the shocks are in good condition. I measured that I have about 20-25mm (sorry, forgot the exact #) beyond where the stock tire top point is under the seat. I weigh over 200lb with gear plus a 150lb passenger, so solid 350lb: specifically tested for vertical clearance with a piece of foam glued under the seat to see if there would be any rubbing. On my old bike there was a little, on my new bike now, even at the softest suspension settings there is no rubbing in that area, and I did go over some speed humps deliberately, to try to compress the suspension more than it would compress in normal riding. //end EDIT

As for removing one of the three planetary gears, wouldn't that create uneven pressure on the shaft/bearings and cause premature wear over time?

I took about 3mm off with a 5" grinder, but the cross member is very thick as you can see so can take more off, if need be
I Rode it at 120kph and inspection shows no sign of touching, rode on muddy gravelly roads and nothing unusual
no clogging no mud build up.
The tyre is a Pirelli DIABLO 13 150/70 M/O 64S
PS. I remove one planetary gear (the most loaded) at 20,000ks this reduces the whining noise substantially
Now done 52,000ks, no propblems.... happy with my sneaky bike!
Cheers
Peter

I remove one planetary gear (the most loaded) at 20,000ks this reduces the whining noise substantially
Now done 52,000ks, no propblems.... happy with my sneaky bike! Peter

Exciting! Can you tell more about this? No drawbacks?

Of course there are drawbacks in taking one of three plantery gears out!
Firstly this causes extremely high lateral forces on the bearings of planetary wheel carrier, sunwheel and/or annular gear that they were not designed for, thus potentially overloading them and causing them to wear out prematurely.
Secondly the same goes for the cogs of all gear wheels, as they must now bear 33% higher load each.

Technically this procedrure is bound to end in catastrophic gear failure - the only question is, how soon...

The same goes for the cogs of all gear wheels, as they must now bear 33% higher load each.

It's not 33% higher, it's actually 50% higher, but this should still be well within factor of safety which should have been used for the original design.

In most gearbox designs, 4.0 is the typically used factor of safety figure for this type of component, which means that each gear should theoretically be able to withstand 400% of its maximum anticipated loading without failing. Therefore "catastrophic gear failure" is unlikely to occur (unless the designer of the Vectrix gear reduction unit used a significantly lower factor of safety than they should have).

A constantly engaged fixed gear reduction gearbox driven by an electric motor should not experience sudden high impact loads on the teeth like a manual gearbox does when the operator forcefully slams it into gear while the input shaft is still turning (or deliberately drops the clutch at high engine rpm to spin the wheels from a standstill).

Alan

It will be interesting wich drawbacks will the vectrix have , if the front tire is replaced with a large diameter wheel too.

The rear swingarm is hollow inside.

It's not 33% higher, it's actually 50% higher,

Correct. About safety factors: all I know is that the planetary gear is the one single most criticed mechanical part of the VX1, mostly due to the noise it makes. What I do not know is how high the max. rate of torque (current) increase is in a Vectrix VX1. Several high-powered electric cars, most notably Tesla Roadster and Model S , have sufferend premature gearing failures due to their increadibly high torque increase gradients that electric motors are capable of and such high-powered cars like to sport in order to impress their passengers. That can be almost as bad for gear life as a manual shift under load...

.

Wow, that was highly enlightening post, Kocho: a "." ;-)

Yup! ;-) Until there is a delete button...

Wow, that was highly enlightening post, Kocho: a "." ;-)