Thread: D1 v D3

Independent suspension has the major drawback that when the wheel travels up, the pivot point travels down, reducing ground clearance at that point.
With a solid axle (D1) when the wheel travels up so does the whole vehicle, increasing ground clearance, D1's do rule, Regards Frank.

Not quite that simple D3/4 air suspension models the system actually forces the other wheel to seek ground so has similar effect to solid axle. One reason why they are so good off road.
Coilers are not as effective when cross axle'd.

If it were a beauty contest there would be a clear winner. The D3 is a pretty ugly vehicle, I much prefer the look of the D1.

Ever wondered where Landrover got the idea for the D1 styling from?

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Originally Posted by CaverD3

Not quite that simple D3/4 air suspension models the system actually forces the other wheel to seek ground so has similar effect to solid axle. One reason why they are so good off road.
Coilers are not as effective when cross axle'd.

It cant be any simpler, "for every action there is an equal and opposite reaction", a simple law of physics, the pivot point at the bush where the bottom suspension arm connects to the crossmember will move down if the other (outer wheel end) moves up, has no choice, it's the law, Regards Frank.

Originally Posted by Tank

Independent suspension has the major drawback that when the wheel travels up, the pivot point travels down, reducing ground clearance at that point.
With a solid axle (D1) when the wheel travels up so does the whole vehicle, increasing ground clearance, D1's do rule, Regards Frank.

I'm a little confused by this statement, surely as a suspension system even a solid axle should move relative to the body and it has a pivot point.
What you are describing is not a suspension system just a wheel mounted to a chassis.

I understand that live axles have much more ability to drop and that the reaction on one wheel has an opposite reaction on the other. Definitely a solid axle has it's advantages in some off road situations however the huge unsprung weight and the inability to articulate wheels independently does mean that it is not as comfortable or as responsive.

D1, D2, D3, D4 and Defender they are all just vehicles designed with different and evolving parameters. In my instance I need a vehicle to drive day to day in the city and then to escape on the occasional weekend either towing a 1.2 tonne camper or carting a tent and gear to out of the way places. The D3/D4 is the best compromise I could find for those needs.

Originally Posted by Tank

It cant be any simpler, "for every action there is an equal and opposite reaction", a simple law of physics, the pivot point at the bush where the bottom suspension arm connects to the crossmember will move down if the other (outer wheel end) moves up, has no choice, it's the law, Regards Frank.

That law is for energy, eg why a rocket engine propells the rocket, the recoil from a fired gun, not the mechanics of levers.

With an independent suspension when it's lifted from static ride height like that you do lose droop travel, but most solid axles that are lifted lose a respective amount of droop travel too, as (usually) only standard dampers are used, often the springs used have the same free length as stock, only the rate is increased, etc. etc. (not saying this is the case with Terry's, I have no idea what he's done to the D1)

You have to do a bit of work with the RRC/D1/110 suspension to maximise it's performance and take advantage of potential travel increases, (dampers, damper mounts, bushes, etc.) otherwise they are both just a tyre and obstacle clearance increase.

Originally Posted by Graeme

That law is for energy, eg why a rocket engine propells the rocket, the recoil from a fired gun, not the mechanics of levers.

Totally wrong, Regards frank.