I bought a Piaggio / Vespa Grillo some years ago at a moped market, got it very cheap and it ran. But it was filled with defects, but i planned to restore it anyway, as i tend to do. The plan was to use it for my annual moped holiday, so it had to have more storage space and a variomatic system to climb larger hills with all the added weight.
The frame wasn’t in a good shape, by coincidence i found a nearly complete one for cheap, with an ok original paintjob and lots of good parts on it. So i made the best moped out of all the parts.
The engine got some small upgrades to carry all the weight, and maybe a little added fun 😉 Watch the galleries below and check the descriptions for further details.
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.
My trusty Motobecane TM4 had some issues that i’ve pushed off for some time now. The original cylinder was a bit weak and the engine needed some new bearings. The moped has sat many years, only had 1200 km on the odometer when i got it. That has led to condensation in the engine, everything above the oil level was a bit rusty, and especially the ignition side mainbearing.
The engine is easy to work with, took me 5 hours including cleaning and making my own gaskets. New bearings and seals.
My german model had a Gilardoni R2051 cylinder mounted, i’ve never been truly happy with it. I got myself a N2052 model with a bit longer port duration. I like the way it rides now, more power over all. Maybe i’ll upgrade the carb at some time, at the moment it’s a Dellorto SHA 14.12 that i’ve drilled to 13,5 mm venturi.
When i’m riding long trips with my phone for navigation, i drain the battery pretty fast. On my Kreidler i have a 12V 80W system, more than enough power to charge my phone. But most of my other mopeds can only provide 6V and 17-18W. I’ve found a solution to charge a USB device that is ready to buy and mount. It’s a german made bicycle dynamo adapter, the model number is M172N and it’s made by a company called Kemo.
It’s rated at 0,8A charging current and it’s able to take an input voltage of 6-70VAC.
I have it mounted on my Vespa Bravo at the moment and it works great. You obviously need to turn the lights of to charge. The stock ignition only makes 18W and i have a 15W and 4W bulb connected.