Heath
Regular readers of Classic Trial Magazine may recognize the name ‘Propol’ that is written in large letters on the Fantic pictured. A few issues ago we brought you news of the work done to Heath’s Fantic 300 original rear shocks by Jean-Paul. It is he who is the man behind the Propol name and in the course of exchanging emails he sent a very interesting image of a bright orange Fantic mono-shock that he had developed back in the early 80s, well before Fantic themselves released the 301 model in 1985. Obviously we wanted to know more, so who better to tell the story than Jean-Paul himself... Article: Jean-Paul and Heath Brindley
First some explanations concerning the birth of the PROPOL... In 1982 I bought a Fantic 240: it was a fantastic motorcycle and much better than the Ossa Gripper which I was riding before. But despite the abilities of the machine, it was the pilot who did not progress! I had dreamed of another motorcycle with a single shock absorber and a lowered centre of gravity with the fuel tank under the saddle, a reduced size and multiple geometry settings – steering column on ball joints with the possibility of changing in a few minutes, for example. With these ideas in my head I kept the engine, front fork, wheels and mudguards from the Fantic 240 and I threw all the rest away. I pulled out the cutter, the welding machine, purchased some tubing and I started on my dream. A Free Hand Much of the materials used were salvaged from old workshop items, such as fuel cans; even some larger aluminium plate from an armoured vehicle was used to make the fork yokes. It was a case of anything goes to realise what I had envisioned.
As I had a completely free hand to try anything I wanted it was decided to route the exhaust through the swing arm, so not only was the swing arm made into a silencer with access for cleaning and re-packing but the frame also became part of the exhaust system. It is not often noticed straight away that there is no visible exhaust pipe except for the small front curve coming from the engine cylinder, but as soon as you have been made aware you start to trace the
route used and can see how much work had to be done to achieve this. Only the left side of the swing arm and the centre box are used for the silencer. What I call the ‘central box’ is the part under the shock absorber. To adequately control the exhaust noise the sound wave must first be split, by using perforated baffles and internal walls to force the gases to use different lengths of travel hence ‘splitting’. This central box is therefore not empty but contains these famous baffles and various walls. But you must be able to maintain all this and clean it from time to time, so as you can see in the images a way in was provided.
Your Choice
Another Propol design and one that is much more visible is the multi-adjustable steering head. Using threaded ball-joints the head angle can be infinitely adjusted to suit the conditions and rider preference. And the beauty of this method is that the adjustments take just a few minutes. Many of the sheet parts were first cut out and modified to fit in cardboard, often completely discarded and started again. The seat/tank unit was first made using cardboard and then a polyester mould was created to enable the final item to be constructed from Kevlar and polyester. The first rear suspension unit was made from a combination of a Suzuki motocross spring and the main parts are from a Mini car. Later on the machine was fitted with a progressive TRP unit. As you can see there are no linkages so this improves the action considerably.
In Action
After nine months of fabrication, testing, modifying and rebuilding the Propol machine was ridden by friend Pascal at a trial in Wavre, Belgium. It was even ridden in one of the most famous World rounds, again with Pascal holding the handlebars, at Bilstain in 1986. The machine drew a lot of attention and featured in several magazines of the time. One even did a comparative test against the JCM 240 and the Fantic 301 in September 1985. One funny moment, captured in an image here, is when the machine had to be noise tested for the World round … the noise examiner had no idea where the exhaust outlet was to start conducting the test. Rider Pascal could hardly contain his laughter!