Group Buy - Improved 2b Wishbones

[Guest old_timbo]

Apart from the difficulty in setting the camber angle, there is not much wrong with the wishbone themselves. However they could be redesigned to give more caster without having to muck around with the mounts. Also the bottom ones bend quite easily and it is important to get the shock mount in the right place to stop this.

The 2B steering suffers a lack of self-centring and feed back and this is something I am working on improving. I had to fit a new front cross member after a prang so installed it 6 mm further forward to give more caster. It made a small improvement. I looked at the toe in of the rear wheels, found this was far too big, and reset it using shims under the front rear hub mounting bolts (I already had camber wedges fitted) and this made a big improvement, but still not good enough. So next I'm working on a plan to make the top wishbone adjustable backwards by modifying the front mount. I think I should be able to get about 15mm of adjustment, but I recon only half of this should be needed to get the caster somwhere near what the text books say it should be. Shame the suspension and steering wasn't designed right in the first place, it wouldn't have cost any more to make.

 

Tim

[Guest salty_monk]

The standard 2b double wish bone setup is not perfect, it tends to under steer mid corner as weight shifts and the camber on the out side wheel goes positive, also the steering feals light and unconected with the road. there are a few things that can be change that make a big different with out a full redesign and the cost in doing so. These are fitting longer stub axel adaptors and ether moving or fitting 2b2 wishbone at the top to increase the castor. on my own 2b i played about with the suspenion quite abit this made the car a lot quiker and give more feed back. these parts are avalible as they are standard on the new 2b2 as well as other inproved parts, most of which will fit earler 2b. the sliding pilar converion is very different.

 

Richard

 

So if I read this right you have a longer stub axle adapter & a new top wishbone available already that sorts out most of the issues? If so what's the applicable cost?

 

I knew you'd done something with your old one cause we'd talked about it briefly before.

 

Cheers,

 

Dan

[Guest Dan_Beeston]

OK, I've lined someone up to run a simulation and come up with a proposed wishbone geometry...........

 

Assuming the chassis pick-up points are fixed, can anyone easily measure their positions relative to a known datum? (see images attached)

[Guest Dan_Beeston]

p.s. for the side view we can use a datum on the floor if it's easier, just so long as we know where it is! :-p

[Joel]

OK, I've lined someone up to run a simulation and come up with a proposed wishbone geometry...........

 

Ooh get you with your funky tyre pattern

Well, my car's sitting around not doing much so I could strip the front suspension down at the weekend and get some measurements - I was going to do it anyway to change the cycle wing brackets and the top-hat adaptor. You know what my measuring is like though...

 

It would be interesting to hear a bit more from Richard about the 2B2 top wishbone

[Joel]

p.s. for the side view we can use a datum on the floor if it's easier, just so long as we know where it is! :-p

 

Could we use the front leading edge of the bottom wishbone tube, or the centre-line through the bolt holes?

[Guest Dan_Beeston]

Cheers Joel, Powerpoint engineering at it's best

 

We can use whatever point makes the measuring easiest really, just need to know what it is! Have you got a laser-level? that might help?...........

[Joel]

Right, I've made a start but for some reason it still won't let me attach an image - it says 'Attachment space used 5.38MB of 5.37MB', but I don't have anything attached! Any ideas Mat??

 

Anyway, Dan I'll email you what I've got so far. The main problem is the infill panels get in the way of measuring stuff, so if anyone has a 2B chassis without the infill panels currently fitted who could take some measurements, it'd be much appreciated....

[fry61]

Joel, I've got my 2B+ up to rolling/running chassis stage if you can tell me what measurements to take from where I'll be pleased to do same. Please bear in mind that I need a big KISS factor in the instructions.

[Guest Techmage]

As a pillock owner, this thread is not totally relevant to my suspension changes, however this

thread on the locost forum appears to be very relevant to both RH owners who wish to

upgrade their wishbone setup or indeed pillar owners looking to change to wishbones.

 

One interesting point is that the top rear pivot should be further away from the

ball joint centre line than the front top pivot.

 

ie

A B

 

<--front---

 

C

 

where A is the top front pivot point

B is the rear top pivot point

& C is the ball joint

 

Untill I read this I had assumed a simple V shape was the preferable option.

 

http://www.locostusa.com/forums/viewtopic.php?t=1438

[Joel]

Joel, I've got my 2B+ up to rolling/running chassis stage if you can tell me what measurements to take from where I'll be pleased to do same. Please bear in mind that I need a big KISS factor in the instructions.

 

Ahh - I finally figured out I'd exceeded my maximum attachment quota!

 

Anyway, I think I've taken all the measurements we need from the front (which hopefully you'll see in the attached image), so if you could do the same from the side that would be great.

 

Cheers.

 

P.S. Dan - I forgot to say, my ground clearance up to the bottom edge of the lower wishbone chassis tube is 205mm

[Guest salty_monk]

If number is sufficient I have contacts both in UK & abroad where these could be manufactured....

 

Dan

[philshelton]

I think for it to feasible the wishbone mounting points need to remain as they are IMHO otherwise it will put many off the idea.

[Guest salty_monk]

I agree...

[Joel]

I agree...

 

I agree too.

 

Purely on a speculative point though (and I'm not suggesting we actually try this), I was looking at my car today, and there's room to create a new top mounting point for the coilover, by welding in a bracket between the top and bottom chassis tubes, with a brace going to the opposite side. It would mean creating a new hole in the infill panel, but that's no big deal. You could then set the coilover to pretty much whatever angle you wanted, and eliminate any issues with clearance on the top wishbone.

 

Just a thought