Pedal motorcycle riding comfort due to its convenient operation, much of the vast number of City motorcycle enthusiasts especially lady 's favor. With China's road conditions gradually improved, major area already is a village village to connect highway, scooter has entered the country, plus some enterprises gradually increase the scooters off-road performance, thus increasing demand on scooter. But mostly, scooter belt transmission stepless speed change, coupled with the final drive mechanism itself characteristics, fuel consumption are generally larger. Although the current market has a lot of kinds of oil-saving device, but often because of complex installation, short service life and makes the promotion limited. Some technical staff through the theoretical analysis and experimental results, obtained a method of saving oil, it is recommended to the majority of motorcycle enthusiasts.

A : a theoretical analysis

By the belt transmission, without extremely gearshift principle that: the front pulley diameter smaller, a rear belt pulley of larger diameter, larger drive, to ensure that the vehicle is off to a fast start. As engine speed increases, the front pulley in six ball under the action of centrifugal force, along the mobile disk on the ramp to move outward, because the mobile tray on the right side of the supporting plate is fixed, only 6 ball is driven to move the disc to move to the left, and because the fixed plate is fixed, mobile disk the left fixed plate and a movable plate causes the distance between the narrows, belt due to certain width, the belt will be extruded to the pulley of the outer circle ( this width is bigger than the front pulley ), larger. Because of the length of the belt is certain, the front pulley becomes larger at the same time, the belt will overcome the pulley spring pressure along the belt wheel inner circle direction of motion, a rear belt pulley becomes small, transmission ratio becomes smaller, the vehicle into a high speed. Conversely, when the engine speed is reduced, the ball moved in, right before the moving plate, belt pulley is smaller, at the same time pulley becomes large, transmission ratio increases, the vehicle into a low speed, this is the belt transmission stepless transmission principle.

From the above analysis that: if the initial state ( idle ), the front pulley diameter increases, then in the motorcycle engine work each speed segments, the front pulley diameter corresponding to become large, pulley diameters are correspondingly reduced, thereby reducing the speed transmission ratio, whereby the engine turned the same revolutions, the improved vehicle more distance that fuel saving.

Two: Design

Pulley diameter before the initial state of the size is actually a mobile disc intermediate the sliding sleeve length decision. To make the initial state of the front pulley diameter became larger, must let mobile disk shift left, but at the same time the fixed position of the disc and cannot be changed, because the fixed wheel position change after effect of the former, a rear belt pulley in a plane, can damage the belt. In order to achieve the above two points, the only way is to shorten the length of the sliding sleeve, allowing the mobile disk with supporting plate left and move to the left, at the same time the right support plate with sliding sleeve and shortening the length of the same size as the thickness of the gasket, but not too much, so as not to affect the performance of the original car, sliding sleeve shortening length nor too much.

Three: project implementation

According to the support plate is fixed the different ways can be divided into two kinds of modified method:

A ) GY6, HONDA Dio50 models, supporting plate by sliding sleeve, a fixed disk, the power output end of the fastening nut firmly pressed on the crankshaft on the boss, such models improved more convenient. Remove front belt wheel, measuring the original sliding sleeve length, the lathe 3mm removed, when mounted on the crankshaft with 3mm is slightly larger than the diameter of the inner hole of crankshaft gaskets, refitted components.

B ) Ji'nan Qingqi AG series, due to the support plate by spline and from the sleeve to the fastening nut pressure fixed, so the operation is slightly more complex. When mounted on the supporting disc mounting position of the spline with a thickness slightly greater than the length of the spacer bare splines, for fastening electric startup disk, and a gasket made two shim thickness equals 3mm, then the parts can be complex. No matter which kind of way to note, the gasket bore and crankshaft clearance can not be too large, so as not to affect the original crankshaft dynamic balance.

Four : a test of fuel consumption

Technical staff in the test of two cars were manufactured in 1986 imported HONDA Dio50 and 1993 annual output of Qingqi AG50, two cars haven't improved fuel consumption is very large, after two cars with sliding sleeve shorten 3mm, two cars with some parameters.

Data shows, the improved despite the loss of some climbing ability, acceleration of the vehicle becomes soft, especially the rub friendly concern fuel efficiency has been greatly improved. This improvement has the advantages of simple operation, the vast majority of motorcycle enthusiasts to try.