Spyder +2 steering problems

[Craig Elliott]

I'm not 100% sure I've go this right so happy to stand corrected if I haven't. If the steering is to self centre, the castor has to be set so that the left to right turning axis of the wheel as it steers is tilted forwards towards the top of the wheel - i.e. the steering axis of the wheel where it touches the ground is behind that at the hub and the top of the wheel. If I read your post correctly I have a feeling that you've got the castor setting shims on the wrong side of the wishbone joint and in effect the steering axis of the wheel is tilted backwards from bottom to top. So worth checking with Spyder as to which way round these should go.

[types26/36]

As they say ?a picture speaks a thousand words?

[bcmc33]

If I read your post correctly I have a feeling that you've got the castor setting shims on the wrong side of the wishbone joint and in effect the steering axis of the wheel is tilted backwards from bottom to top. So worth checking with Spyder as to which way round these should go.

I'm really showing my ignorance now.
I've had my front suspension apart a number of times and have never seen any shims.
Where do they fit and what do they look like?

I fitted the wrong track rod ends last year and could only get zero toe-in and the car drove like a pig - very poor directional stability, but I don't remember the self-centering as I was afraid to let go of the steering wheel.

[Craig Elliott]

BMC33 - yes they were news to me but the OP said he'd fitted them. Looking at the diagram, which is indeed worth 1000 words, and the Lotus manuel it does look as though the OP has it set up right - 3 degrees of positive castor. My thinking was muddled (basically I'd thought that you'd have to have negative castor to get self-catering when actually you need positive because the contact patch of the tyre/ground needs to sit behind the turning axis of the steering).

OP, just to check - does the spyder set up use trunnions at the end of the bottom wishbone or a ball joint?

[stugilmour]

If I read your post correctly I have a feeling that you've got the castor setting shims on the wrong side of the wishbone joint and in effect the steering axis of the wheel is tilted backwards from bottom to top. So worth checking with Spyder as to which way round these should go.

I'm really showing my ignorance now.
I've had my front suspension apart a number of times and have never seen any shims.
Where do they fit and what do they look like?

I fitted the wrong track rod ends last year and could only get zero toe-in and the car drove like a pig - very poor directional stability, but I don't remember the self-centering as I was afraid to let go of the steering wheel.

+1 on Brian's request. Was a while ago when I put mine together, but don't recall shims on the upper wishbone assembly, or their description in the Spyder assembly instructions. Could be mistaken of course, or done my assembly incorrectly. Julian or Craig, do you have a pic?

My Spyder supplied suspenders used stock configuration trunnions (also supplied by Spyder). In general I understand the Spyder front suspension is essentially the same as stock, possible differences being adjustable ride height shocks, tubular wishbones rather than pressed steel, and thru rods for mounting the 'bones rather than welded in place studs attached to the frame towers. I cannot recall a diagram with the assembly instructions, just a list of steps. I think the basic dimensions should be the same as the Workshop Manual.

HTH

[alan.barker]

i thought you need negative castor. Imagine when you push a shopping trolley. The wheels need to trail behind.
Maybe i am missing something
Alan B

[types26/36]

Positive castor is required to achieve self centring, take a look at the angle of the front forks on a normal bicycle which is a perfect example.

[c42]

Hi Alan

Please excuse the rough drawing, the shopping trolley relies on positive castor. When you extend the turning axis line to the ground (A) and then extend the load line to the ground (B) in both examples you will see that the load line is behind the turning axis line for both the trolley and the Lotus.

Scan.pdf

(72.88 KiB) Downloaded 424 times

Hope this helps.

Regards
John

PS Sorry if the scan is not horizontal!

[alan.barker]

thanks Brian and John, you're both right. Maybe i am starting to have a "brain" problem
Alan B

[andyhodg]

Hi

Perhaps a silly question but have you checked that the trunions haven't been screwed fully home when assembled? That can lead to binding on one side or the other whichever way you turn the steering wheel.

Andy

[ecamiel]

Are you using stock wheels? chassis problems change kingpin angle?
A big change in wheel offset will create your symptoms.

Eric

[julianaston]

Are you using stock wheels? chassis problems change kingpin angle?
A big change in wheel offset will create your symptoms.

Eric

The wheels are minilite ala Spyder Zetec, and the suspension uses ball joints above and below, rather than trunnions.

It is possible that loaded movemnet is stiffer than unloaded, though I dont see how I can change that without replacing the bottom steering joints (already done the top).

Interesting about the spacers/ shims though. They are designed to fit in the top wishbone joint, but could be a further mod. I will get some pics of these out shortly.

Meanwhile, attached is a rudimetary diagram of the spacer

Julian

[bcmc33]

Interesting about the spacers/ shims though. They are designed to fit in the top wishbone joint, but could be a further mod. I will get some pics of these out shortly.

Meanwhile, attached is a rudimetary diagram of the spacer

I'm really interested in this spacer - I don't see it specified in the parts list.
Maybe its because I don't have access to the definitive parts list - does anyone else?

[peterako]

Hi Peter
...
How is your +2? Does it centre?

Cheers

Hi Julian,

Sorry for the late reply...and teh discussion has moved on quite a bit

You asked about my +2.

It doesn't self-centre in the same way as a modern car. Actually. It goes the direction I point it in.

Meaning, if i steer slight o teh left/right and let go of the steering wheel on a cambered bend it will continue on that trajectory.

BUT...this is (in my opninion) the way it should be. And the way I like it to be.

If I steer a large amount to left/right the car will 'self-center' on the flat.

But if you turn a large amount the car turns very sharply indeed

My steering is very light, when moving.
I'm old skool about steering while the car is stationary....I try not to!
Remember there is no powersteering (Just noticed you're not on trunnions)

And while it is light when moving it is also very direct.

I use the standard 165 R13 tyres which will be lighter to turn than your tyres.

Best of luck,
Peter

[julianaston]

Thanks Peter.
You could put mine on full lock (not saying much I know), and it would not straighten.

Think I will take it to a wheel aligner and see what they say.