Herdtlé-Bruneau 1904 1¼ HP 119cc 1 cyl OHV 3402



Herdtlé-Bruneau 1904 1¼ HP 119 cc OHV water cooled auxiliary engine on Clément bicycle

Compared with the rather crude engines that powered many of the first generation of motorcycles, the engines built by Herdtlé-Bruneau were made with extraordinary precision. They used the most advanced methods of the day and were renowned for their high standard of finish. The engines were produced at the Rue de la Chine (later Rue Pelleport) in Paris from late 1903 until 1912. This excellent little engine was sold ready to bolt on to a bicycle frame, and was available with either air or water cooling. Notable is that the exhaust valve was overhead too, and despite the small capacity the engine was surprisingly powerful. This example has coil-and-trembler ignition but magneto ignition became available as an extra in 1905. From 1906 complete motorcycles were offered as an option and in 1912, toward the end of production, the company even presented a water-cooled V-twin auxiliary engine with a capacity of 271 cc.
The motocyclette we present here consists of a small size (26”wheels) pre-1906 Clément gents bicycle with an early H-B engine attachment. The cylindrical petrol tank is located behind the saddle. The top tube accommodates from back to front the leather case for the battery, oil tank,  water tank and the radiator for the cooling water. The water enters the water jacket at the underside of the cylinder, is heated up and rises through the return tube back to the radiator, where it’s cooled down again. The water tank holds an extra water supply to refill the radiator. The inlet valve is atmospheric, the exhaust valve is mechanically operated. This very early model has the exhaust valve construction on the side of the cylinder, 1906 and later models were fitted with exhaust valve located on top of the cylinder. This engine has the early bore x stroke dimensions of 45 x 75 mm, later versions have a bore of 48 mm and a cubic capacity of 136 cc.
Drive to the rear wheel is by round rubber belt and there is only a front wheel brake available, acting on the tyre surface. The carburettor is a Gamage floatless instrument. This delightful “miniature” piece of early technology is in largely unrestored and authentic condition and comes with bulb horn.