Single seater design

[Nick Lettington]

You offset the axle for racing so you can
Get the driver lower to get weight lower
For less roll on cornering.

Yes... but the post seems to suggest a different approach!

[Malcolm Parker]

                If you want to sit between the torque tube and the o/s rear spring, you either need a rear axle with an offset diff or you need to rearrange the rear springs so that they are parallel. 
I have opted for the latter course in my single seater project.  I have shamelessly copied the Gordon England design used in Mrs Jo-Jo.  This involves twin rear cross-members and fabricated chassis outriggers that house the springs.
Mrs Jo-Jo had two seats, necessary for some races in the 1920's.  I have done away with the passenger seat and put compartments in its place that house the fuel tank and battery, thereby helping to equalise the weight distribution and aiding a low c of g.
I will attempt to post some photos of my set-up!

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How I started!

[Paul N-M]

Very very nice indeed!

[stuartu]

Thank you John, you've made my day!

Regards,

Stuart

[JohnD]

You offset the axle for racing so you can
Get the driver lower to get weight lower
For less roll on cornering.

Yes... but the post seems to suggest a different approach!

 Yes, we are talking about offsetting the driver to the one side and not having a passenger seat, the post bellow by Malcolm explains it a bit better

[Greig Smith]

We did it the other way around by offsetting the drive line & cutting & welding the diff to be a full offset. Here's a write up on the build

https://www.austinsevenfriends.co.uk/for...er#pid6446

Ciao
Greig

[Mark Atkinson]

Hi Malcom
That looks fantastic, are you intending to replicate the Anti Roll Bar and damper setup from JoJo?
VBR, Mark

[Malcolm Parker]

Thanks for the kind comments, Mark.  
I have pondered over the rear suspension shock absorbers for some time.   As you know, Mrs Jo-Jo had Hartford type friction shock absorbers attached to the extremities of the chassis outriggers, which were braced by a tube which possibly also acted as an anti-roll bar.   My device has quite soft rear springs and I was worried that the bottom of the drivers seat might bottom over bumps.  The ends of my outriggers are braced by a strong aluminium clad plywood bulkhead.  The detachable tail section will attach to this bulkhead in due course.  I decided that a pair of rubber bump stops would be a good idea to limit the rear spring deflection and it will also have webbing straps to limit any downward movement of the rear axle.
Mrs Jo-Jo spent much of her time at Brooklands which was notoriously bumpy even in the 1920's so she needed some good rear suspension and effective shock absorbers.   My device will be used for track days and the odd sprint or hill-climb which will be on smooth surfaces (unless I go off piste!).   Having attached some rubber bump stops at the back, I found that under the weight of the driver the suspension only has around 1" of movement before it is resting on them, after which the rubber stops are actually acting as the suspension medium in conjunction with the rear springs.  Initially at least, I will run without any rear shock absorbers, relying on the leaf springs for damping.  The rear axle is well restrained so will not be able to jump up and down to  any extent.  With only minimal rear suspension movement, I don't think any friction shock absorbers would do much at all?
If the suspension is something akin to an early Mini or a go kart I will be quite happy!
Photo of the main body tub which looks like something from the Russian space programme.    

[Mark Atkinson]

That’s beautiful work Malcom. Have you thought of the possible use of lever arm dampers? I know Frank Hernandez used them to great effect.

[Malcolm Parker]

I have a pair of Armstrong lever arm dampers which I could fit at a pinch.  I would have to fabricate some brackets to mount them behind the rear bulkhead.   I will try the set up without dampers initially.  Even with the lever arm type, I am not sure they would be doing much with such limited suspension travel and they weigh a ton!
Duncan shaped the scuttle fairing for me but I did the hard bit making a paper pattern!  His expertise will be needed to make the streamlined nose in due course.
I am currently thinking how I can connect a handbrake up.   It is my intention to mount the handbrake on the end of the cross-member at the front of the o/s spring housing, as per Mrs Jo-Jo.
Having got the main braking system arranged the body will have to go back on to sort out the position of the handbrake.