Piaggio/Vespa Moped Speed Calculator

Yet another moped speed calculator, specifically for Piaggio/Vespa/Gilera belt driven mopeds, like the Ciao, Bravo, Si etc.

My own testings show pretty accurate results, you typically need to input a little higher tyre size, because the rim size isn’t measured at the furthest point of the outer edge. Cross check with the tyre circumference. The pulley diameters should be measured on the outside of the belt, so wrap one around your pulleys and measure the diameter with a caliper. In some pulleys the belt sits lower than the outer diameter.

You need MS Excel, OpenOffice, LibreOffice, GDocs or similar to open the file.

Piaggio/Vespa Moped Gearbox Ratio Calculator

Another spreadsheet to calculate moped stuff. This one is pretty simple and used to calculate the gear ratio of a 4 shaft reduction gearbox, found in various Piaggio mopeds.

Just count the teeth on the shafts corresponding to the ones shown in the picture, and plot them in the orange fields.

You need MS Excel, OpenOffice, LibreOffice, GDocs or similar to open the file.

Piaggio Moped Clutch

Everything you need to know about the Piaggio clutch, as found in many single speed Piaggio / Vespa Mopeds. I.ex. Bravo, Ciao, Citta, Si, Grillo etc.

I’m explaining how the clutch works and how you take it apart to service it.

Moped Speed Calculator

Another spreadsheet i’ve made, to calculate the speed of your moped at a given RPM. You need to know the details of your engine, gearbox, sprockets and rear wheel. You can find most of it in a spare parts catalogue, or simply count the teeth on all sprockets.

Moped Speed Calculator

Only type in the blue fields!

If you want to calculate the velocity for a single speed engine like a Puch Maxi, just type the same value in “1 Gear” in the primary and secondary fields. I’ve made the file up to a 6 speed gearbox.

You can use MS Excel, OpenOffice, LibreOffice or a similar program.