Suspension uprights?

[dp35]

I'm trying to learn about the uprights of F1 cars, as well as those of other high level race cars, such as LMP's.

What type of metal (or carbon?) are they made of?
What type of wheel bearings do they use?

I have a track car, and its wheel bearings & uprights are the weak link, preventing it from running larger or stickier tires. After learning a little about these parts, I'm amazed at the amount of side load these parts handle on race cars, especially endurance racers that do it for up to 24 hours.

[Jersey Tom]

Depends on the car. The old Lola champcars used to have welded sheet steel uprights for a long time I believe.

In an F1 car I'd imagine either titanium or an aluminum metal matrix composite. With carbon I think you'd be hard pressed to find a resin that stays hard at elevated temperatures around the brakes.

Wheel bearings I dont know. Someone posted a cut-section drawing of an F1 spindle assembly not too long ago, it looked like two spaced angular contact or deep groove ball bearings.

A tremendous amount of radial load goes on those bearings from the complete overturning moment at the spindle (tireMX + LR*Fy). May even be more of a limiting factor than the axial force.

[scarbs]

Generally there are a few options. For highly loaded uprights fabricated steel or Ti is common, this is time consuming but for a team with a skilled fabricator is a cheap option. Then there are cast (or CNC’d) versions. These can come in suitable alloys of Aluminium, magnesium (rarely), Ti or commonly in F1 MMC. Depending on the bearing cooling vane layout the upright can be a mix of methods with a fabricated finned bearing carrier and cast extensions welded on. Up until the development of investment cast Ti, this was the most common method for F1 and one make series.
Some years John Barnard Ex McLaren and then Current B3-technologies MD, offered to develop a Carbon composite upright for F1, this was never taken and never even reached a prototype stage.

Look a crptechnology.com, CARP are ‘the’ Cast Ti and MMC experts, their website has a forum where you’ll get excellent information direct from the company and other experts.


In terms of layout F1 cars used to have the bearing held in a vaned cage to pass cooling air through to the brakes and around the bearing. Nowadays the upright is more shrunken around the bearing and thus cooling air for the brakes passes around the upright (rather than through it). Wishbone mounting tends to be via a camber plate for the upper mounting, the bearing in a horizontal attitude to take the radial loadings, while the lower wishbone mount tends to be vertical, this is pass the vertical loads through to the pushrod, at the expense of radial loads, as a result the lower wishbone joint tends to be of a much larger diameter.

Wheel bearings in F1 car very large ceramic angular contact roller bearings. Costing around 3-4k each they aren’t an option for all but F1.

Try looking at SKF or Cerobears websites.

also.....
http://scarbsf1.com/RBT_Upright.jpg
http://scarbsf1.com/upright.jpg
http://www.flickr.com/photos/scarbsf1/s ... 822715795/

Mail me if you need more info…

Scarbs…

Scarbs@scarbsf1.com

[Jersey Tom]

Damn. Those bearings are no joke.

[Carlos]

Fabricated steel FSAE upright. Steel City Racer Wollongong University Australia.
This should give an idea of whats involved.

[RacingManiac]

That Wollongong one looks very similar to mine as well, this is my 2007 Upright for the University of Toronto FSAE car...


http://www.fsae.utoronto.ca/2007/pictur ... ight01.JPG

I am not sure about the bearing in F1 but I am sure Scarb's post and knowledge fills in that info nicely. For FSAE we use 2 deep groove ball bearing with a pre-load spacer for the car. The load rating and such are perfectly adequete for FSAE application. Most actual full size vehicle are more likely to use taper bearing.....which are way heavier for our car....

As for the construction, I think fabricated steel upright is still used in upper echelon motorsport, just not F1. Peter Elleray's Le Mans Bentley in 03 still uses a fabricated steel design as well.

[Jersey Tom]

I'm all about billet, high speed machining. Uprights in < 2 hrs each!

[RacingManiac]

I think billet do afford a bit more freedom in terms of design and packaging, but as a student team anywhere we are limited to whats available to us....and CNC is not a plentiful resource...lol

I am quite surprised though the options available in the upper level, as CNC Billet, fabricated steel and the uber-expensive MMC casting are all utilized....

[scarbs]

Try looking at Lotus Elise Series 1 uprights (bearing carrier) they are the extruded aluminium. You can still buy them new quite cheaply and are rated for quite high loads. Just machine up some bolt-on clevices and camber plates and away you go.

[Conceptual]

AWESOME info Scarbs! THANK YOU!

And for the FSAE racers, have you looked at these? I'm sure if you email Ben, he would help you out for a decal on the car!

http://www.coatesengine.com/wheel_bearing.html

Chris

[RacingManiac]

The elise one will be way too beefy for a FSAE car...and the current Toronto ones works quite well and its been 3rd years in that basic design(with slight dimension change from year to year to optimize kinematic and packaging).....we do get our wheel bearings for free from NTN, and you can't find smaller/lighter ones for FSAE cars....

AWESOME info Scarbs! THANK YOU!

And for the FSAE racers, have you looked at these? I'm sure if you email Ben, he would help you out for a decal on the car!

http://www.coatesengine.com/wheel_bearing.html

Chris

[dp35]

The car I have is an Ariel Atom. The rear wheel bearings seem to be a weak point, especially if you want to run slicks or wider rear tires. More rear traction is desired on these cars, because they have approx 40/60 front/rear weight bias, and tend to oversteer at the limit. They work great with more traction at the rear end.

The Ariel's rear uprights are made from sheet metal, similar to the FSAE one's shown in this thread. The upright isn't really the problem, the bearing is. But to use a larger bearing, a larger diameter upright would be needed, and hopefully not a different axle.

Building new uprights is not something I will likely ever do, but the thought of it got me curious about race cars.

Thanks a lot for all the info so far.

[Jersey Tom]

In what way specifically are the wheel bearings an issue?

[dp35]

In what way specifically are the wheel bearings an issue?

Rear wheel bearings have been known to fail, causing damage to the upright, hub, brake rotor, etc. Hubs have also been known to break when slicks are used. I believe the wheel bearing used was from an older Honda Civic, and apparently it can't handle lots of hard side loading. Considering the car's light weight, it shouldn't be a problem, but stickier tires destroy the bearings.

[Jersey Tom]

Find out what the dimensions of the thing are. You may be able to find something else that will fit with minor modification and will work.

http://medias.ina.de

Heap of bearings.