Vespa Cross Bravo

I will be competing in a cross event later this year, a two hour moped cross event held by me and my friends from the Small Pistons. Our goal is to ride machines that are restricted in a way that they are close to a stock moped. A small class with a maximum of 50 ccm and mostly stock parts and original engine cases. That’s the one i will compete in.

I had an old Bravo frame in my pile of moped parts, and a lot of other surplus parts.  I only had to buy a cylinder, airfilter and other smaller bits. So it was an easy choice to make.

There are only two 50 ccm tuning cylinderkits available, one from DR and one from Athena. The latter seemed to be the best choice, but both are pretty mild.  Since i’m using the stock engine case, a 13 mm carburettor will be the largest i can fit. It will be driven by a fixed pulley transmission, as variomatics aren’t allowed in this class.

Check the build progress of the frame, from start to finish here:

The engine build can be seen here:

The bike is running as it is now, but i will do more tuning of the cylinder and further adjustments of the clutch and gear ratio.

A quick video of the first test drive: