Thursday 27 February 2014

Engine as a stressed member in motorcycles. what does it mean ????





Engine is a vital component in maintaining the stability of a bike. The weight of the engine is usually responsible for lowering the center of gravity. In olden days during the start of motorcycle evolution, it was placed behind and also in the front wheel, but eventually it got failed and in the end, placing it in the middle of chassis was proved to be successful for getting good stability and handling which was still followed till date.





Rotary type engine used in front wheel

Apart from various types of frames used in a bike, the placement of an engine can be a stressed member or a non stressed member.

An engine which is a non stressed member is a primitive one in which the engine is placed inside the frame along with rubber mounts and bolts to dampen the vibrations caused during the operation which  forms a total support.



Here in HH Passion Pro, the engine is enclosed by the chassis - a good example for a non stressed member.





Now we move on to the stressed member type.



In a stressed member the engine itself forms an integral part of a frame. Here it looks like a jaw holding an object or otherwise the engine is a structural part and load bearing component suspended with the help of bolts. The engine never rests inside the frame like the previous one. Modern day sports bikes and cruisers are mostly of this kind.

The deltabox chassis of Yamaha R series


The pros are reduction in overall weight, mass centralization better handling and stability which can greatly influence the performance. This concept is also being used in cars and other automobiles where performance is the key factor.







In Ducati monster the stressed engine concept is clearly visible ........