I love my car but.....

[Phil N]

@graham- hopefully mine broke before the chassis

@tony- makes sense what you say and to be honest the fact that they have all broken within 5000 miles means I won't be replacing them anyway, I never noticed the difference between this car and the last Westfield which didn't have ARB's so I doubt I'll notice now that they've been removed.

[Crunchie Gears]

For the uninitiated - ARB?

I'm by no means a suspension expert, but the little I've read on the subject suggested that a suspension system designed with the right geometry on a car with a low centre of gravity shouldn't need any anti roll bars. But most tin tops are designed from the passenger's point-of-view, so the suspension has to fit in a certain amount of space = imperfect geometry, & the roof is high to give a "light & airy feel" so the C of G is high. Anti roll bars are then used to tune some of the deficiencies out.

On a race car they can be used to tune the car to a particular track.

A seven is designed around the suspension so the geometry should be good, the C of G is about as low as you can get & there's little point tuning the set-up for a particular corner on the road so the ARB is less of an advantage. They also have downsides, as the outside suspension compresses in a corner, the ARB is trying to lift the inside wheel - not to serious at the front, but it's reducing traction on the inside at the rear, so then you need a limited slip diff to control wheelspin & it's all more weight, more complication & more expense.

They have their uses, but a properly set up road seven shouldn't need them.

I am not sure it is a simple as that. It is the relationship between the roll center and the center of gravity or particularly the moment. On a car typically the center of gravity is above the roll center so the moment makes the car lean when cornering. Conversely in a power boat the center of gravity is lower than the roll center so the moment makes the boat turn in to the turn.

So for example a 3 tonne Bentley Continent GT has a very high center of gravity but the roll center is very near the same point and so the body roll is very controlled.

What I am agreeing with is that suspension design without ARB can work very well and can control body roll and the inertia it can produce. This system works when it is wet as all four wheels do a share of the grip and if grip is less spreading the load works. It also works well where grip is high but not as well as the same suspension with ARBs.

The reason is that ARBs move the roll center on a line from the suspension's normal roll center position on a line to the center of contact of the tyre. This increases the moment stopping the car from rolling over and increasing the weight on the outside tyre. As there is an abundance of grip this allows one to corner faster.

That all said, on the road it is probably more flexible not to use them if the car does not roll to much (as this can in extreme can transfer weight to the outside wheels too and the inertia need to be handled) and on bumpy, gravel covered roads you have more contact with the road.

Sorry to go off on one

[jeffw]

ARBs are also used to balance a car front to back (or back to front) by stiffening an ARB which will shift grip to the other axle (and vis versa).

[DJ.]

It does seem crazy to spend a lot of time designing fully independent suspension and then start linking the wheels with a bendy form of beam axle.

[Crunchie Gears]

It does seem crazy to spend a lot of time designing fully independent suspension and then start linking the wheels with a bendy form of beam axle.

The issue is that you need your suspension stiffer in roll than in bump and ARBs help with this. They are not perfect but every suspension system has compromises.

The reason a stiff chassis makes it easier to design a suspension system as you can work with weight transfer (as Jeff pointed out ARBs can alter that too), the roll axis and yore. Therefore an independent system is designed as a whole so is connected if not physically. If the chassis is floppy then the suspension will do unpredictable things.

IMO the fury would benefit from ARBs as the roll center is low compared to the center of gravity, particularly on the front. The other alternative would be to lower the lower wishbone mount to the up right as that would raise the Roll center and so reduce the roll.

[Fury1630]

^ See, I tole you I wasn't an expert! ^

[b33fy]

It's all rock 'n roll to me too..

[Phil N]

This is turning into a mass debate

[Dick]

This is turning into a mass debate

Had to read that twice

[graham b]

This is turning into a mass debate

Had to read that twice

Rude boy