600 hours of talent and passion
Each one of us likes to customise our own motorcycles a little and it’s even more the case with older machines. But when one discovers the Terrot 175 owned by Frenchman Didier Choquet it takes it to another level, as he reckons it’s taken him 600 hours of talent and passion to create. Wherever you look at his motorcycle, innovation and engineering creation can be found in all areas. Absolutely everything is artistically machined in-house. The opportunity to discover more about this totally unique motorcycle was accepted without the shadow of a hesitation.
It is under a pleasant paschal sun that I arrive at the home of Englishman Hamish Eadie. In the company of Philippe Mercier we arrive for the third time to a friendly meeting of old motorcyclists who have been gathering for seventeen years. The varied areas to be ridden include twenty pretty kilometres of tracks and trails with shifting relief, to the delight of the forty regulars who would not miss this annual ride-out for anything in the world. Didier Choquet is already waiting for me, enjoying the sights and sounds, but he is also excited by the beauty of the course and the quality of the tracks. In his eyes it is indeed one of the most beautiful trials in the southwest of France, and our tandem of Anglo-French organisers is already planning a two-day meeting in 2018.
While admiring the exceptional finish of his 175 Terrot we listened to Didier describing his creation: “I always liked to ride on post-war French motorcycles and in particular four-strokes, and it is true that the preference of lovers of this generation of motorcycles is orientated most often towards the Terrot. It was technically superior to their contemporary AMC or other Motobecane machines. Indeed their dry-sump engine launched in 1929, well before the equivalent English motorcycles, ensures better lubrication and cooling that benefits their reliability. I have already built three Terrot 500cc machines. Some time ago at the Ventoux Classic Trial we even formed a team Terrot with the 500 that was ranked 7th out of 46 teams. Since then I wanted to move to a 175 as it’s lighter and more manageable, and here is the result: 84kg with a full fuel tank”.
The fact that it is completely covered with polished aluminium parts and with its black end tank decorated with the famous Terrot logo the Didier 175 gives a clear impression of lightness. So how did you learn all your skills, we asked: “I spent a large part of my life as a qualified boilermaker, and all of my life I have loved working with different metals and materials.
“In 2008 I sold my metalworking/boiler making company which employed a dozen employees and it has left me with much more time to tinker a little on my motorcycles. Originally this fuel tank was equipping a road-going Terrot so I reduced it by 9cm in width and 4cm in height. It is, along with the engine, one of the few parts that I bought, because it is not in my philosophy to buy a complete motorcycle and then to strip it down to tinker with it and make to fit my own needs. Above all I like to make as many parts for my motorcycles as I can myself.”
Didier explains about the ‘Home Brew’ frame of his 175: “The steel frame takes the round shape of the back loop of the Greeves of the 1950s but with modern fork geometry. It contains about 1.5L of oil but the hoses are not visible, which keeps it cleaner, but you can check the circulation of the lubricant through the small window at the top of the frame. At the front end are original forks from a Yamaha TY 125 but the yokes and the handlebar clamps are made in a local village where I can get small engineering jobs carried out. As I am rather tall the machine handlebar yoke is high enough to provide me with a suitable riding position. At the rear I have mounted a pair of modern shock absorbers which work well and are connected to a steel swinging arm. As for the wheels I renovated Akront 36 hole wheel rims and then ‘mated’ them with the Terrot hubs, which are a little heavier than I wanted but keep it original. The brakes were very poor and for safety’s sake I ‘bonded’ a very special lining to the brake shoe. I put them in the oven and take the temperature up to 200°C for 45 minutes. Then I turn the brake drum in the lathe and match the brake shoes to the same circumference, once again in the lathe. The results provide very effective brakes. A pair of IRC tyres was also fitted to the wheels. The chain guard and the small saddle are also personally made. The last job was to fit the polished aluminium mudguards”…It all sounds very simple, I might add!
A Special Engine
If you think the frame and its components are special you will soon find that this is the tip of the iceberg, as we now look into the engine. Didier: “Inside the cylinder block we find a slightly larger piston that increases the cylinder capacity to 186cc without risk of impairing the reliability. At the time Terrot announced a power of 15bhp but I think I may have found a few more. I also modified the engine crankcase so that the gearbox oil provides better lubrication to the crankshaft, a small defect of the original Terrot. Whilst I was inside the engine I machined a clutch housing, in which sits, smooth and slim, discs from the 125-200 TLR Honda. I also modified the clutch housing so that the actuating arm is on the top of the engine to preserve it from damage.
“The ignition comes from a Kennedy electronic model but I preferred to keep the original Amal carburettor. The stainless steel exhaust system consists of a tube that penetrates to the end of the home-made silencer. Part of the tube inside the silencer is pierced with numerous holes until it reaches the best compromise between performance and the sound level. The kick-start lever currently comes from a 50cc Italian motorcycle but I am in the process of machining one in 7,000-grade aluminium, which will prevent me from having to fold the left footrest to start the machine every time. The air filter is made from 1,000 grade aluminium, which is much softer to work with. It was also made with the French influence of the machine in mind, and retains the small butterfly tightening filter with the looks of the glove-box zippers from Citroën, I love their shape!”
When we tell you that this guy Didier is an artist ... In the end this authentic marvel stands him at only 2,800 € of parts; engine (300 €), tank and paint included, which remains very reasonable. That is until we put a price on his labour, which runs around the 600 hour mark. Profitability is no longer the essential concern, it’s the pleasure of the realisation of the concept.
For its first official trial it validated almost all the modifications carried out by its designer. Starting without a problem with a nice but reasonable sound she sets out to face the areas of this friendly rolling countryside. The riding position is well suited to the rider and between its handling, its contained weight and its compact geometry, it all works very well. The local terrain also makes it possible to check the effectiveness of the braking and the well-damped suspension, which provide very satisfactory grip.
As for the engine it’s quite lively and smooth, but on the other hand it does not have the range of power when you need some extra speed. It ‘peaks’ out far too early and Didier is already considering a modification: “As soon as I return to the workshop I will remove the camshaft and take it to a specialist to rectify its profile. And while he takes care of this I will fit a smaller gearbox sprocket. The torque available should stand it without problem. And then I could also finish and install my own kick-start!”
The enthusiasm from this guy is incredible. But when we come to the question of possibly making other Terrots the answer is a clear no. “I’ll stop with this one that I will keep for myself. But soon I will look at the English motorcycles, in fact I already like a little idea which is in my head…Uh yes for the Ventoux 2018 trial I plan to introduce myself at the start with a 100% Triumph team. But not with the ‘Tiger Cub’ model as it would be too simple, no I think with the 350 Twin. With three motorcycles to complete I can keep myself occupied without becoming bored!”
Aluminium can be found all over the bike, including the engine cover, location brackets and the sump shield.
Moved out of harm’s way to the top of the engine is the clutch actuating arm.
The circulation of the lubrication oil in the frame can be checked through this small window in the top of the frame.
600 hours of work and passion are evident here!
From this side it almost looks like a production machine.