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tadpole suspension
malakiblunt - 25/10/04 at 09:35 PM

any one got any thoughts on tadpole suspension design?
im currently planing on a F1 style front aero wishbones and monoshock, with a below ground roll center,and VERY stiff in roll,

Rorty - 26/10/04 at 01:25 AM

quote:
Originally posted by malakiblunt
any one got any thoughts on tadpole suspension design?
im currently planing on a F1 style front aero wishbones and monoshock, with a below ground roll center,and VERY stiff in roll,


Sounds like my Hammerhead trike. I put the static roll centre below ground, run very soft springs on the shocks and then use an anti-roll bar for cornering stability.

malakiblunt - 26/10/04 at 11:05 PM

Hi Rorty
exelent great minds think alike!

good site btw

Hugh Jarce - 26/10/04 at 11:24 PM

quote:
Originally posted by malakiblunt
Hi Rorty
exelent great minds think alike!

good site btw


Mediochre minds seldom differ!

I'm sure Rorty won't mind you copying his design, but he may object to his product names being misrepresented.

malakiblunt - 28/10/04 at 12:03 AM

the fact that we have reached they same conclusions over suspension geometry i think has more to do with logic and reason than plagarism,
a below ground roll center is the logical soultion for a trike because of the enforced ground level rear R/C as it is common knolage and good practice to have the front R/C lower than the rear asumeing a rear weight bias.And with such a low R/C very stiff roll controll becomes absolutly essential.
apart from that they only things are trike designs have in comon is the Number of wheels.

dpaws - 11/9/11 at 06:47 AM

quote:
Originally posted by malakiblunt

a below ground roll center is the logical soultion for a trike because of the enforced ground level rear R/C as it is common knolage and good practice to have the front R/C lower than the rear asumeing a rear weight bias.


I'm afraid I'm confused - why would you design a rear weight bias on a reverse trike? I would have thought at the most 33% aft of the front axle, if not further forward....

How would this alter the ideal position for the static front R/C? I had casually assumed as high as possible to avoid the outward weight transfer and thus the tendency to pick up the inside wheel?

How would the use of front wheel drive alter this roll centre requirement, if at all?

Much obliged.....

Benzine - 11/9/11 at 07:06 AM

lol @ 7 year bump. malakiblunt was last online nearly 7 years ago still, he might have got an email notification

[Edited on 11/9/11 by Benzine]

smart51 - 11/9/11 at 07:07 AM

The best place for the CofG on a trike is just inboard of the 2 wheeled axle. If you only have 33% of the weight behind the front axle, there's a risk of tipping up under braking.

snapper - 11/9/11 at 07:27 AM

I've just unwittingly gained some more knowledge of suspension geometry and design.
I love this forum.
Ta.

dpaws - 11/9/11 at 07:45 AM

quote:
Originally posted by smart51
The best place for the CofG on a trike is just inboard of the 2 wheeled axle. If you only have 33% of the weight behind the front axle, there's a risk of tipping up under braking.


More confusion, sorry - I was referring to the position of the calculated CofG.

smart51 - 11/9/11 at 05:56 PM

Sorry for the confusion. Imagine hanging a plumb weight from the CofG. If you accelerate the weight swings backwards, if you brake it swings forwards. if you corner it swings to the side. If the point on the ground it points too is outside a line drawm around the tyres, you tip over. N ow if your CofG is right under the front axle, every time you brake, you tip up.

The higher your CofG. the further back you need it to be. This reduces your cornering, so you want CofG to be as low as possible. Ideally, you want it equidistant from the sides of your "triangle" and low enough for 1.5g or more of cornering, braking and acceleration.