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.
This year was the hottest summer in history, we caught the last days of heat and sunshine in the start of august. 25-30°C the first three days, riding in shorts and t-shirt, amazing.
We started our trip at home, as usual, crossed Jylland up to Kolding where we slept the first night. On the second day we took the partially closed bridge over the “Lillebælt” and rode along the northern coast of Fyn. A short trip past Odense brought us to our second location, a modern shelter in Munkebo.
On the third day, we crossed Fyn from Nyborg to Bøjden. Like the other days, amazing roads and nature. Bøjden is the city where the ferry goes back to Jylland, here we also found our last shelter.
Please enjoy the pictures in the gallery, and the comments below. And of course, video footage from the whole trip.
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.
As per our tradition, we start the new season with a moped party in the easter holidays. Sadly the weather had forgot about us, we woke up to 10 cm snow. We kept the ride short and the party longer. Below are pictures and a video.