עמיתקס,אתה מוזמן.
שני נושאים.
1-מדוע בולם אחורי קצר,עם מהלך קצר,הם מטרה בפני עצמה.
2-מדוע מהנדסים מעצם היותםן מהנדסים,מוגבלים ביכולתם.
לגבי 1-קרא בבקשה קטע מצורף.
לא אוסיף כרגע מילה.
לגבי -2 קרא בבקשה קטע מצורף וגם שם,לא אוסיף כרגע מילה.
נתחיל כמובן ב-1.
ONE SHOCK OR TWO? THE FROTHY SUBJECT OF FRAPPUCCINO DAMPER OIL.
[The difference in the shock absorber stroke for different types of motorbike suspension]
In the good old days, motorbikes had two shock absorbers on the rear of the bike, as shown at the top of this section. As suspension evolved, the dual rear shocks were replaced with a single unit, but the question is why? The answer, it turns out, is pretty simple. In a dual-shock system, the suspension units are typically attached very close to the rear axle. This means that as the suspension compresses and expands, the shock absorber pistons are travelling in a stroke which is nearly the same as the full deflection of the swingarm. Hitting a large bump might deflect the rear axle upwards by 10cm and back, resulting in the same 10cm stroke in the shocks. Do this a lot and the shock absorber piston begins to behave like the plunger in one of those natty little cafetières or milk-frothers - it agitates the damper oil so much and so frequently that the oil begins to heat up and foam or froth. At this point it not only looks like frappuccino foam but it has about the same damping properties too, and thus loses its ability to perform as it should. This is known as fading shock absorbers.
Enter the single shock absorber system mounted towards the front of the rear swingarm. The swingarm might still have a lot of travel at the axle, but basic geometry shows you that closer to the pivot, the deflection is much less. This translates into shorter shock absorber movements which in turn means less opportunity for the damper oil to froth. The ultimate evolution of this is the complex link monoshock system (also shown above), where a complex series of levers reduce the shock absorber travel even further. Typically multi-link setups like this also have some amount of variance in them so that they have a different amount of deflection in the first part of the stroke to the that in the second. This means a single shock absorber unit can respond better to changing road surfaces, soaking up the smaller bumps and shocks with ease and comfort without sacrificing the ability to respond to the occasional mountain or pothole.
As a side note, you'll notice as you read the section on BMW rear suspension below that the monolever and first-generation paralever had a single shock but it was mounted close to the rear axle. This had all the disadvantages of a dual-shock system without any of the advantages of a single-shock system. For the second-generation paralever, the shock was moved closer to the swingarm pivot, thus bringing the design in-line with the small-deflection idea.
הלינק למאמר המלא:
http://www.carbibles.com/suspension_bible_bikes.html
שני נושאים.
1-מדוע בולם אחורי קצר,עם מהלך קצר,הם מטרה בפני עצמה.
2-מדוע מהנדסים מעצם היותםן מהנדסים,מוגבלים ביכולתם.
לגבי 1-קרא בבקשה קטע מצורף.
לא אוסיף כרגע מילה.
לגבי -2 קרא בבקשה קטע מצורף וגם שם,לא אוסיף כרגע מילה.
נתחיל כמובן ב-1.
ONE SHOCK OR TWO? THE FROTHY SUBJECT OF FRAPPUCCINO DAMPER OIL.
[The difference in the shock absorber stroke for different types of motorbike suspension]
In the good old days, motorbikes had two shock absorbers on the rear of the bike, as shown at the top of this section. As suspension evolved, the dual rear shocks were replaced with a single unit, but the question is why? The answer, it turns out, is pretty simple. In a dual-shock system, the suspension units are typically attached very close to the rear axle. This means that as the suspension compresses and expands, the shock absorber pistons are travelling in a stroke which is nearly the same as the full deflection of the swingarm. Hitting a large bump might deflect the rear axle upwards by 10cm and back, resulting in the same 10cm stroke in the shocks. Do this a lot and the shock absorber piston begins to behave like the plunger in one of those natty little cafetières or milk-frothers - it agitates the damper oil so much and so frequently that the oil begins to heat up and foam or froth. At this point it not only looks like frappuccino foam but it has about the same damping properties too, and thus loses its ability to perform as it should. This is known as fading shock absorbers.
Enter the single shock absorber system mounted towards the front of the rear swingarm. The swingarm might still have a lot of travel at the axle, but basic geometry shows you that closer to the pivot, the deflection is much less. This translates into shorter shock absorber movements which in turn means less opportunity for the damper oil to froth. The ultimate evolution of this is the complex link monoshock system (also shown above), where a complex series of levers reduce the shock absorber travel even further. Typically multi-link setups like this also have some amount of variance in them so that they have a different amount of deflection in the first part of the stroke to the that in the second. This means a single shock absorber unit can respond better to changing road surfaces, soaking up the smaller bumps and shocks with ease and comfort without sacrificing the ability to respond to the occasional mountain or pothole.
As a side note, you'll notice as you read the section on BMW rear suspension below that the monolever and first-generation paralever had a single shock but it was mounted close to the rear axle. This had all the disadvantages of a dual-shock system without any of the advantages of a single-shock system. For the second-generation paralever, the shock was moved closer to the swingarm pivot, thus bringing the design in-line with the small-deflection idea.
הלינק למאמר המלא:
http://www.carbibles.com/suspension_bible_bikes.html
