Front Wheel Bearings

[Frank]

I was wondering that if people are NOT using tapered roller, what are you using? What bearing spacing are you using?

Commments much appreciated..thx

I am considering 30mm/47mm/9mm sealed deep groves with 60mm spacing...

or

30mm/55mm/13mm sealed deep groves with 56mm spacing...

Frank

"These cars feel great..SIDEWAYS"

[This message was edited by Frank on April 18, 2003 at 11:17 AM.]

[Frank]

so out of 92 poeple who have viewed this post..

no-one can shed some light on what size bearings they are using?

Frank

[Kevin Hall]

Something to be said for a roller bearing setup........tried, tested, can't think of a production car, or trailer, or anything that is under continual radial and thrust loading that even runs deep groove ball bearings.

You mention that you don't expect them to last long. What will the judges think of that.........what will you think of that when they get sloppy during an endurance run, and your wheel which costs $300 strikes an upright or something to that effect because of a $3 bearing.

Don't get me wrong, it may work, and work well. I just don't know if anyone has tried it. If they have, then perhaps its their little secret, because it is saving them 2 lbs per corner http://fsae.com/groupee_common/emoticons/icon_smile.gif

Good luck!

Kevin Hall
University of Saskatchewan
Engine Guy in Need of Help

[Frank]

Thanks Kevin,

I have exactly the same concerns, but i think the weight saving is near none.

Here's 2 design options I've come up with, it's for "circle track wheels" and "wilwood dynalite singles"

http://www.users.bigpond.net.au/franko/hubs.jpg

http://www.users.bigpond.net.au/franko/hubs2.jpg

they both weigh the same, almost the same stress in hubs.. the taper design gives slightly more in the stress raiser (circled in red)..

the taper design is a 29mm OD / 18mm ID spindle
45449 NSK tapers, and a 36625 seal. In fact, the axial load here is so small that it is outside the spec recommended by NSK. Still, the bearing life should be high.

the deep groove design is sealed 6006's, with a 30mm OD / 20mm ID spindle.. I've specified bearing clamping pressure that causes 30Mpa of preload in the spindle, the bearing life is definitely lower, but again, the usual problem, you only know static loads in cornering, and bearing calcs are near useless for these dynamic situations....

I noticed that Kiezer "Direct Mount" wheels use a pair of sealed bearings... and it seams a method used on ATV's..

Kiezer say they are 1 inch internal diameter..

personally i'm not too happy about 1 inch spindles, i want to use 30mm spindles...

i just thought that by knowing the keizer bearing dimensions, and by asking feedback from teams who have used them, i could figure if my bearing calcs are "conservative enough"...

Moeye / Josh C (anyone from Illinois or Texas A&T??).. can you guys give me any feedback about the Kiezers??

Thanks again..

Frank

http://www.keizerwheels.com/2003_web_project_i00002b.jpg
http://www.keizerwheels.com/2003_web_project_i0000cc.jpg
http://www.keizerwheels.com/2003_web_project_i0000f0.jpg
http://www.keizerwheels.com/2003_web_project_i0000da.jpg
http://www.keizerwheels.com/2003_web_project_i0000bc.jpg
http://www.keizerwheels.com/2003_web_project_i000140.jpg
http://www.recreationunlimited.com/bearing&seals/atvbrng.htm

"These cars feel great.. SIDEWAYS"

[This message was edited by Frank on April 20, 2003 at 10:30 AM.]

[Travis Townsley]

Gentlemen,

In most current car designs with live spindle (wherein the spindle rotates with the wheel), the manufacturers have gone to ball bearings. This is true of both rear wheel drive and front wheel drive cars. (Note that the drive axle, by definition is a live spindle.) Taper roller bearings are frequently used for fixed spindle (front uprights on conventional rear-wheel drive cars) and in trailers, and most heavy-duty applications. (Note that racing, as far as bearings are concerned, is a light-duty application because of the relatively large bearings in relationship to the load.)

The ball bearings most often used are double row, angular contact bearings with solid outer races and split inner races for assembly and setting preload. The ball bearing has the advantages of having lower rolling resistance, and fixed setup. It also reduces the number of seals per corner from four to two. For racing purposes we frequently have to adjust the preload by grinding .0005"� or so from the inner side of one inner race to eliminate the slop that causes brake pad kickback with outboard (read front on SAE cars) brakes. For an example of an upright design using this type of bearing refer to this doucument (http://www.taylor-race.com/pdf/ACF17C.pdf). This should give an idea of how it is done. The size of the bearing is also shown (64mm x 34mm x 37mm)

The wheel bearings used by Champ cars consist of a live spindle with a needle bearing to contain radial loads, and a ball bearing to react out the axial loads, spaced about 4"� apart to contain bending loads. This is a neat way to go, but increases the design complication.

If you are using two ball bearings at each end of the stub axle, a 25mm x 47mm x 12 mm bearing would suffice. (MRC 105KSZZ) Deep groove bearings are, surprisingly, not necessary, since the loads are far less than the capacity of the bearings. The real factor determining the size of the bearings is the bending load absorbed by the spindle, which usually dictates a larger bearing than necessary to carry the load.

Hopefully this is of use to you.

Craig Taylor
Taylor Race Engineering
craig@taylor-race.com

[Frank]

Thankyou Craig / (and Travis?)

Frank

[Eric Wort]

We didn't have any problems at all with the Keizer front or rear wheels themselves. We used the 1 inch spindles with ball bearings without a single problem in a long summer of testing after competition.

The brakes we bought to go along with those front wheels proved to be way too small. This year we designed our own center section to use the Keizer outer wheel pieces. This way we can run a bigger brake rotor without having to make a special rotor mount.

We're using the same splined rear hubs also. Last year we ran the splines through twin splined bearings, which worked well but was on the bulky side. We're doing something similar this year, but the splines don't go all the way through to the bearings.

Eric Wort
UIUC Formula SAE (http://dilbert.cen.uiuc.edu/soc/sae/formula/)

[Frank]

Thanks Eric,

I spoke to Keizer,

They said they use a pair of 1641 bearings...

sorry, but I have to talk metric

25.4mm/50.8mm/14.3mm

They said they use 30mm centreline spacing...wow that's close..

Eric can you confirm this is the centreline spacing you're using please???

That should give my 30/55/13's with 56 centreline spacing about 3.5 times the life of the keizers..

or my 30/47/9 with 60 spacing a bit less life..

I'm still not that keen on 25mm axles though, unless the stress concentrator at the inner bearing mount is removed / reduced....

But then again, I'm using calcs, not testing knowledge, and i cant afford a failure.

Regardless, I guess it goes to show just how "unconservative" you can be with bearing calcs on these cars.

Frank

"These cars feel great..SIDEWAYS"