F1technical.net

Jersey Tom wrote:Establish your geometric and functional constraints... and really the rest just falls into place.

JT,

If only that were true!

The first thing you normally do is lay out your suspension's static pivot points, pushrod angles, rocker ratios, roll centers, cambers, casters, ackerman, toe angles, etc. Then you check for clearances under all conditions of steering lock, and suspension bump/droop. And that's when you find out that you have all kinds of interferences in your suspension parts.

As for new uprights on a 230kg(?) open wheel chassis with limited aero downforce, I'd recommend machined aluminum billet uprights and duplex angular contact bearings for the stub axles. Make sure that all of your suspension spherical joints are mounted in double shear, and that all of your suspension A-arms and links are loaded in tension/compression, and not bending.

Finally, since the powerplant/transmission is from a Yamaha motorbike, I'm assuming that the final drive is a chain and sprocket. So you'll want to be careful with your rear suspension's dive and squat geometry.

Good luck.
riff_raff

xpensive wrote:

Jersey Tom wrote: ...
Establish your geometric and functional constraints... and really the rest just falls into place.
...

Truly priceless information, imagine to have all that inside knowledge.

Say what ya want. I've designed uprights on 3 cars, two of them FSAE. How many have you done?

It really is as simple as that. No need to complicate it. The guys designing the suspension and steering geometry are pretty much gonna decide where all 3 pickup points need to be, as well as the spindle offset. Brake guy is going to determine the radial placement of the caliper. Whether you're using deep groove or angular contact ball bearings, your wheel loads are pretty much gonna decide what size you have to use. All that's left is to connect the dots - especially on these cars where you don't have to worry about being able to pass air through to cool rotor and pads, etc.

IMO the more difficult thing when doing these parts is good DFM. Billet aluminum and steel weldment are the two popular choices. If you're going to take the billet aluminum approach, work with someone who has considerable CNC experience or chances are the part is going to take entirely too long to make.

I was surprised at all the uprights I've had, that none of them seem to spin so freely.

I always expected them to spin with little to no resistance...

please can anyone tell me where i can get the details for best reservoir type shock absorbers?

Depends what you mean by "reservoir type". All hydraulic dampers have a reservoir of some kind, I believe.

there is certaainly a price limit on your damper ? if not you might look not much further than Dynamics ,Ohlins ,Penske..