Modern Vespa

Had a pair of 11inch Mitas MC20 Monsum whitewall tyres fitted to a 2014 Primavera 125 ie 3V which developed cracks around the tread blocks after 700 miles of use so decided to replace them for safety reasons.

It was apparent that there are fewer tyre choices for the 11inch wheels fitted to the 2014 Primavera so chose to replace the wheels with those from a later model Primavera. I found a used pair with good tyres from a 2020 model (500 miles only) that happened to be 12inch at a good price (worked out cheaper than a pair of 11 inch City Grips plus tyre fitting).

Tyres are now Pirelli Angel Scooter.

They fitted without any clearance issue and the existing centre stand did not need to be replaced despite the increased wheel size.

I also purchased a centre stand from a 2020 Primavera which is about half an inch taller than the earlier 2014 so will eventually get around to fitting (not strictly needed).

The 12 inch wheels offer a much more plush riding experience and has proven to be less twitchy than the 11 inch wheels. The only noticeable change has been a slightly slower pull away and the gearing now seems a bit taller so it takes longer to reach the same top speed as achieved with the 11 inch wheels fitted.

I prefer the styling of the 12 inch wheels over the 11 inch wheels so can live with the slight change in performance which is still good at 61 MPH (actual) compared with 65 MPH (actual).

At 100 KMPH (62 MPH) the speedo is less optimistic which works out to be 61 MPH (actual) with 100 KMPH shown.

With 11inch wheels on I regularly saw a top speed of 105 KMPH on the speedo and 65 MPH (actual) so not a great deal of difference and obviously the speed can vary by weather and / or road conditions.

My Primavera has a Polini Max High Speed 6 roller variator fitted with 12.5g rollers which increased acceleration noticeably and added 4MPH (over the stock variator) to the top speed in case anyone wanted to know where I get these figures from.

Very interesting read, thanks for posting!

Did you feel you hit a speed limiter with the 11 inch wheels, or was the 65mph max speed purely engine power limited?

When my 2014 Vespa Primavera was fitted with the stock Variator and rollers it would reach top speed approx 100 KMPH and you could feel the rev limiter kick in and it would go no faster not even downhill with a tail wind.

When I replaced the stock variator with a Polini Max Hi Speed 6 roller kit the Primavera accelerated faster off the mark and would achieve a higher top speed WITHOUT the rev limiter kicking in whatsoever.

Acceleration was slightly lower after swapping the wheels from 11 to 12 inch and top speed wasn't too far off from previously. The larger wheels have made the gearing slightly taller so the rev limit is still above the effective top speed but not so much that the difference is really noticeable.

The advantage of the bigger wheels is that the handling has actually improved and bumps are better soaked up. The other benefit is that there are a greater choice of tyres in 12 inch size including off road knobblies (Maxxis M6024) if you were that way inclined to fit!.