What's the advantage of Monoshocks?

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Caito
Caito
13
Joined: 16 Jun 2009, 05:30
Location: Switzerland

What's the advantage of Monoshocks?

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Hi guys, I've seen lots of formula cars that have monoshocks in the front and/or rear.

Apart from the advantage in weight(1shock+spring), is there any other advantage?

Why/when would you use monoshocks?
What happens in single wheel bump? As it seems, it affects the opposite wheel, even if there's no anti roll bar.


Some reference pic:
Image
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silente
silente
6
Joined: 27 Nov 2010, 15:04

Re: What's the advantage of Monoshocks?

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first of all, we have to make a difference from the first picture and the others.

Formula BMW monoshock system uses a normal T antiroll Bar, thus taking away one of the problems of commono monoshock arrangement, i.e that in roll you have something that slide on your suspension instead of turning around some axis.

Mygale Formula BMW solution is, in my opinion, very similar to a lot of other cars using a T bar arrangement at the front, with the only difference that here you have just a spring, in a way very similar to that of normal third springs on bigger cars. In this way you can control in a separate way roll and heave (or pitch), but you have no dampers acting in roll. I think this is one of the main advantage of monoshocks, together with lower costs beacuse of less parts. With Mygale solution youn probably have also a sensible weight improvement.

With this scheme, moreover, when you have a single wheel bump the suspension works in exactly the same way than with a common two shocks solution. The onlyn thing to consider is that, in bump, also antiroll bar blades are flexing, thus having another spring in series with the main one.

With the other solution, the one with a slider and belleville springs, the main advantage, together with the separation of roll and heave (or pitch control) is that you can have thousands of ways to set your roll stiffness.
But with these scheme, when one wheel wants to go up, the other must go down. Belleville springs inside the washer create a force that oppose this tendency.
Again, stiffness is not dampened, with the only exception of picture n°2, which seems to be a formula SAE. Anyway, because of the very small movement that you normally have, it is quite hard to have a real dampening effect there.

Another advantage, anyway, is that you can actually have a bar with two stiffnesses. Because of preload, in fact, you can have a certain stiffness till a point and then jump to a stiffness that is half of the first. But you normally are so stiff that you don't actually use this possibility.

marcush.
marcush.
159
Joined: 09 Mar 2004, 16:55

Re: What's the advantage of Monoshocks?

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a good damper does not need much distance to build force.If a Motorcyle steering damper is the right choice here is doubtful..