front uprights

[Cement Legs]

I'm trying to come up with an alternative design for our front uprights. currently we are set to use steel tubing with attachment points welded on the main piece. After some consideration and hopefully some inovation as well I've come up with a design that I think will suit our team much better (ie more adjustability with less work). I know it depends on many factors but I'm just curious what thickness of material, 6061, teams are using for this type of process.

Secondly, for teams that are shimming the top of their front upright for camber adjustmentsare you using wedge shapped shimms to keep from moving your roll center when you go from say one degree of camber to 4 degrees. If not are you setting up the system to have the ideal roll center for camber settings that your would prefer for events like the autocross and endurance. Therefor just accepting the suspension as is with the adjusted camber for other events like the acceleration and skid pad.

And lastly, would a press fit for the spindle be enough assuming a tight tolerance with a "nail type head" comming from the inboard side of the upright?

Cheers

[Denny Trimble]

Howdy,
I think 6061 is a less-than-ideal material for uprights. The only reason to use it instead of 7XXX would be that you're welding your uprights out of sheet, and to be honest we've had bad luck with welded aluminum structural stuff. Make sure your welder is good, and leave a lot of room for post-heat-treat finish machining, because of warpage.

You should look into steel sheet uprights. We used to do steel tube uprights, but recently our boxed uprights have doubled in stiffness compared to the previous design, at the same weight.

They follow the same design idea as aluminum box uprights, but you can use 1/3 the wall thickness for the same stiffness and weight, and slightly increase the diameter of your box sections for a little more stiffness. Plus, the hardpoints don't take up as much space. If you're constrained on outside dimensions, steel will give a more efficient structure than aluminum or magnesium.

Our steering arm mount is inclined to be parallel with the upper control arm at some nominal ride height, so camber adjustments create a minimal IC location change. Also, we rarely adjust outside of -.75 to -2.0.

We've used that type of press-fit spindle for several years. Make sure you account for your expected operating temperature, and find out how much your aluminum will expand at that temperature, and make sure it's still a press-fit http://fsae.com/groupee_common/emoticons/icon_smile.gif You can do a shrink fit (spindle in freezer, upright in the oven, assemble quickly) to help things along.

[Cement Legs]

Hey Denny, to be honest I really like the way some people reply on this site, objective and factual, with just a little touch of "but I kinda like it like this". I appreciate it because you don't come off sounding like someone whos telling me what to do, rather more like someone with good honest experiencial feedback. http://fsae.com/groupee_common/emoticons/icon_wink.gif

Anyway, when you say boxed uprights, what is different than using normal steel tubing? I guess I'm just not familiar with the term 'boxed' in this context.

[Denny Trimble]

Well, instead of using square or rectangular tubing, you can weld up (or fold and weld) trapezoidal or other crazy tapered box shapes. Then the structure connects your bearing bore to your control arm points efficiently, and you can change the taper and thickness of each plate.

You can see this on our rear uprights from 2004:
http://students.washington.edu/dennyt/fsae/dsnrprt-images/pages/iso-rear%20small.html

Yeah, I like these forums too.

[Cement Legs]

WOW! Denny that model is impressive. Really nice work.

Yeah I guess I can see why you would prefer steel with that setup. I remeber seeing some posts of people claiming less than 2 lbs for upright and spindle and that kinda makes it more believable now.

Cheers

[Angry Joe]

I agree on going with steel if you're making it from sheetmetal and tubing. One thing I hate seeing, though, is uprights basically consisting of one tube in bending with a bearing support stuck in the middle.

If you're going with aluminum, machining from billet is probably the best. It won't be quite as light as a good sheetmetal upright, but manufacturing is easier. We did use shim inserts to adjust camber, they were machined so that you simply loosened the upper mounting bolts and slid them in.

http://www.we-todd-did-racing.com/wetoddimage.wtdr?i=wNjcxMTg1NnM0MTNkZmQzMXk1NDE%3D

Just don't put rod ends in bending like we did! (oh the shame...)

[MikeWaggoner at UW]

You can also make hollow aluminum uprights. You can incorporate ribs that help with stiffness. The bond surfaces can be easily milled using a taper mill.

[alfordda]

Denny-

How are you adjusting camber? Is it through shims on the monocoque side?

[Denny Trimble]

With a big hammer...

But seriously, there are inserts in the steering arms that have their attachment holes drilled at various lateral offsets. Swap 'em out and the steering arm is at a different lateral location relative to the upright for camber adjustment.

[Buckingham]

To answer the orignial post:

We ran 6061 uprights last year. They never broke. We drove last year's car almost four days a week, every week from early march through May. 6061 is a lot cheaper, more machinable, and nearly the same stiffness.

This year we will be using 7075 because I went into the forest and chopped down an aluminum tree.

[Ben Beacock]

Last year we used 3mm 6061 sheet. We overcame the warpage problems with some jigging. The welders were both a bit questionable (the machine and me) and we broke one in testing. However, with a new welder and a welding course over the summer I think they should be much better this year.

[Ballzac]

Hi everyone,

For those of you who have successfully used steel sheet metal in the past, I was wondering what kind of sheet and how high the yield strengths of the sheets were. Also, how much did these weigh? We had nice billet aluminum uprights last year that were pretty light, but I wanna try a cheaper, simpler upright this year.

Thanks.

[Cement Legs]

Hey http://fsae.com/groupee_common/emoticons/icon_mad.gifJoe, that upright is soooo similar to the one I designed about 3 months ago. Our setup was rectangular and not tapered with just a touch of kingpin but that gives me confidence to go back and revisit it. I guess since all of our attachment points will be bolt on (ie steering and brake mounts) we could go ahead with 7xxx series. What is the thickness of that material Joe, at the center it looks like about 2"?

Does anyone have any experience working with Fortal(http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=45025&item=3857472240&rd=1)

Cheers

[Travis R]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Ballzac:
Hi everyone,

For those of you who have successfully used steel sheet metal in the past... <HR></BLOCKQUOTE>
I'm rebuilding the uprights in one of our old cars using .071" 4130

[Gareth]

Not a huge deal, but 7075 is actually more machinable than 6061. The only reason, except for cost, to use 6061 is because you need to weld. If it's high heat and no welding you use 2024, otherwise it's 7075 all the way. Straight out of Engineer to Win.

[Denny Trimble]

Gareth, nice photos by the way. I agree 7075 is more machinable, it's less prone to welding to the tool. But, 7050 is far better than 2024 at high temperatures. 2024 is still better than 7075, but 7050 is the real deal. It's not commonly available unless you're within driving distance of the Boeing Surplus metals yard...

Check out the ASM online handbook if your university has a subscription. They have yield strength vs. temperature data for all the alloys.

http://students.washington.edu/dennyt/fsae/al_yield-vs-temp.jpg

[Amos]

We built ours from 70 thou wall 4130 too. Not a problem in sight! They were pretty complex and if you seriously want the manufacturability simpler i wouldn't go with fabbed uprights.

I built our front uprights it consisted of making the jig (obviously) then jigging all the parts up making aluminimum sheet templates for the cromolly, a fair bit of filing, then placing all the cromolly sheet on for the dude that welded them up for us... (Awesome work Alex). This probably took me a few days to make, so obviously its a little longer than an hour or two in an NC mill!! (But my time doesn't cost as much i guess).

As for performance they seem fine after a few weeks of testing and the OZ event.

[Big D]

Maybe this is straying slightly from the original topic, but what stops most teams from adjusting camber at the inner points (chassis side) of the A-arm?
You would be able to have a lighter, stronger upright, and less unsprung weight. Is it just a practicality issue, of having to mess with two shims instead of one, that makes it less desireable?
Looking through RCVD, and some other books, I have not seen any argument for one over the other... maybe I need to take a harder look through RCVD, but I dunno... ideas?

[Denny Trimble]

UTA has done that for a while:
http://students.washington.edu/dennyt/fsae/Comp_Pics/uta/

[Patrick W. Crane]

So have we.

[fsae racer]

Denny,
That graph is certainly interesting, but I cant see the temperature of an upright going above 200f or even 150f. I dont think ours even become much more than warm to the touch but not even to the point where you would need to pull a finger away. We are currently using dead spindles, but would a live spindle see higher temps because of the bearing? Just trying to see what I am possibly missing hear.

[Denny Trimble]

Nick,
You're right, our uprights never get over 150 or so, live or dead axle. It's more important for the diff and for aluminum hubs with brake rotors attached.

It's just good to know there's stuff out there that's up to the task.

[Cement Legs]

I was actually going to use 7075 for our front hubs as well. What type of temperature ratings have people been getting on their hubs and differential carriers? I would love to have experimental data myself but this is our first car. http://fsae.com/groupee_common/emoticons/icon_wink.gif

[TomF]

Delft have used 2024 last 2 years I believe. CNC-milled them and closed by glueing instead of welding. Worked pretty well, although we had some problems with our spindle which broke one time at the rear. But this was steal and might have been designed a little bit optimistic from a fatigue point of view. But we certainly believe adhesives are a nice alternative to welding....

[rjwoods77]

I was planning on welding or glueing a cnc'ed upright to close it off. What type of adhesive did you use? Will that adhesive have info that can be looked up so I could determine the amount of bonding area necessary? If I weld i would have to use 6000 series but if I could glue I could use the better aluminums.

[James Waltman]

Rob,
Adhesives can work very well if they are done properly. They offer some serious advantages over welding. We have used adhesives with great success for major structural components on the last several cars (about ten years?). You can check out the website to get an idea (especially the Viking 35 sections).

The real keys to it are surface prep and joint design. Structural adhesives are great in shear but absolutely worthless in peel. A good room temp cure two-part epoxy should be in the area of 3500psi shear strength. I am big fan of Loctite's E-120HP. Spend the extra money on the manual dispenser and disposable static mixing tips and it's a breeze to work with. If you are willing to use an elevated temp cure adhesive you should be able to get a 1-part epoxy good for about 5000psi shear strength. I recommend 3M's Scotch-Weld 2214 (cures from 250?F to 350?F). If you search the forum for epoxy you will get a few good results (and quite a few that have to do with carbon fiber so consider yourself warned).

Mike Waggoner mentioned hollow aluminum uprights earlier. He made a pretty sweet set of those before he went off to grad school at UW. He may be too humble to post pictures of them - so I will.
http://dot.etec.wwu.edu/fsae/v35/bonding/images/Upright%20-%20Inside%20both%20halves%20at%20once_JPG.jpg
http://dot.etec.wwu.edu/fsae/v35/bonding/images/Upright%20halves%20bonded%20together_JPG.jpg
http://dot.etec.wwu.edu/fsae/v35/bonding/images/Bonding%20the%20uprights_JPG.jpg

I really like the idea of bonded in shear plates. You can take an upright like the one that Angry Joe has on the previous page and bond thin plates over all of the holes. I guess it's sort of half way between what Angry Joe has and the one I put above.

[rjwoods77]

Wow. Thats nice work. Thanks for the connect. Did you guys use the internal webbing for more thatn just bonding. I know it contributes to strength and all but the design i was working on concentrated on a thick outer dimension to provide strength and rigidity. Think of that upright. But machine out all the insides to a shell of whatever thickness. Then i was going to glue or weld a capping plate. Was going to utilize tounge and groove notches to mechanically link the plate to the upright to keep the plate from shearing and peeling. Then use the weld or glue to bond it together. That way the glue/weld just calmps and the loads are put through the tounge and groove. Just like in woodworking. Glue just bonds but the strength is in the mechanical connection. I just need to figure out how much bonding surface I need to keep it together. Thanks again. Shoot me an opinion about what I just said.

[rjwoods77]

In addition, this method will require one cnc'ed upright and a laser cut alum capping plate instead of 2 cnc'ed pieces.

[Big D]

Looking around at what people are doing with steel, it seems like a lot of teams use just a simple stub at the top and bottom, instead of capturing the end of the A-arm in double shear. I like the idea, clearly it works, and is a cleaner instalation, but what is the word from the judges on it? Do they approve?

[Travis R]

Double sheer would obviously be better.

[Mike T.]

Not in all cases...especially if you're looking at the installation as a stiffness issue. Stresses will of course be higher, but there shouldn't be any reason not to do it as long as the stresses aren't too high for the material and you can show a judge some kind of justification. If you think about it, the boxed structure is only supported from the top or bottom, unlike other places where a double shear mount would be used, such as a inner control arm pickup or bellcrank mount, where it is supported from the side. It's not nearly as effective unless the boxed structure is pretty bulky, and thereby heavy.

Big D, it doesn't seem like the kind of thing that has a 'yes' or 'no' answer to it, since whether it's a better option depends on your manufacturing method, diameter, height to the center of the spherical attached to it from the base, etc. You just have to be able to reasonably justify your decision to use the design to them.

[jack]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR> Double sheer would obviously be better. <HR></BLOCKQUOTE>

UWA won design, twice, with the top a-arm stud on their upright in single shear (bottom as well?), but what do they know?http://fsae.com/groupee_common/emoticons/icon_wink.gif

[Nihal]

How does the fatigue strength of those various Aluminums compare at temperature? Is it a roughly 1:1 drop in fatigue strength with yield strength?

[James Waltman]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Rob Woods:
Did you guys use the internal webbing for more than just bonding? <HR></BLOCKQUOTE>

Mike is the one to ask about the design intent because he did it. I'll go ahead and answer though because I'm the one that bonded them together so that trumps design intent. The bond strength all comes from the perimeter joint. Some of the ribs ended up with adhesive on them because that's how it worked out when I applied it.

I think your idea for tongue and groove should work. Lately we have been doing a lot of our parts with a big pocket and a small ridge around the (inner pocket) perimeter. We use our water-jet cutter to make plates that bond onto that ridge and cap the pocket. The depth of the ridge is the thickness of the plate and the width varies depending on the part (maybe .100"� to .400"�?). It's a great way to get hollow parts with a single operation on the mill and the plates are all self jigging. We also get to use 7XXX series aluminum because we don't weld it.

Your tongue and groove method should eliminate peel. I'm not sure how easy it would be to cut the groove. A t-slot cutter may mean large internal radii on your main part.

Time spent on making parts truly self jigging (for welding or bonding) is well worth it.

It seems like you don't want to trust the adhesive to provide any strength. It's worth running the some numbers to see how much shear strength you can get from a well designed joint. (Surface area of joint subject to sheer loads) x (bond strength) That's math that even I can do. Joints in peel are worthless.

[rjwoods77]

Cool. Sounds good. When i talk of tounge and groove I am speaking of the way the drawer in your dresser is put together. Just intermeshing teeth. I worked at a sheetmetal fab place a long time ago. All of their folded 3d structures attempted to do this in the welding lines. Takes alot of the shear and peel off the weld. Thanks for the hookup. This is gunna be cool. There are no ill effect by using the single stage high temp stuff is there? I could just do that in a non-food oven right?

[Denny Trimble]

As a point of clarification on single shear studs in uprights, I'll add some comments here.

We'd always followed Carroll Smith's "double shear or else" rule of thumb. But, after seeing UTA and UWA with single shear uprights in the design finals last year in Detroit, I had to ask the head design judge "what's the deal?". He replied something like "as long as you don't thread something into the upright and rely on that, there are a few ways to make it stiff, strong, and reliable".

Back to making parts... Oh, and James, we got a 2/3 pitch band saw blade for the aluminum we got from you guys, it kicks ass. 8" x 8" cut in 30 seconds or so... http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Jimbob]

Hey Amos,

I'm pretty sure we made our uprights from 28 thou (0.6mm) sheet? 70 thou seemed a bit thick.

James

[Frank]

single shear is lazy,

no respect from our team for single shear

uprights weigh less than 600grams front and rear

http://www.uq.edu.au/fsae/2004%20Photos/DSC00082.JPG

[Denny Trimble]

It's not a question of laziness or weight, it's stiffness vs. weight.

[adrial]

Frank,

Would you mind telling me how much the fronts weigh with the hub, brake rotor mount, brake caliper mount and bearings?

[Sam]

I tend to think that with the lack of judges with a racing background (in FSAE-A at least) thinks like this issue tend to be overlooked.

[FSAEracer03]

I'm surprised to hear the judges accepted single shear... that's generally a no-no in automotive engineering. Does anyone have any photos of info on what Cornell did last year? That'd be interesting to see.

[Cement Legs]

Im kinda curious whether the teams that went single shear on their uprights used larger rod ends to have a thicker bolt to make up for the difference?

[jack]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR> that's generally a no-no in automotive engineering. <HR></BLOCKQUOTE>

just about every modern car i have looked under has a couple of things in single shear.

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR> Im kinda curious whether the teams that went single shear on their uprights used larger rod ends to have a thicker bolt to make up for the difference? <HR></BLOCKQUOTE>

i cant speek for other teams, but we have an older car with lots of miles on it with 5/16 outboard sphericals in single shear, and they hold up fine.

[Big D]

quite a debate I sparked here, innit http://fsae.com/groupee_common/emoticons/icon_smile.gif

The reason I brought it up is to do with the different materials teams are using. With aluminum, it makes perfect sense to go double shear, since you need a relatively large volume of material anyways, due to the properties of aluminum. So your "box" that captures the end of the A-arm is going to be thick and rigid.

If you build with steel, as was my thinking when I threw this out there, your material is thin sheet, and building a little box out of it to accomplish double shear will quite possibly be more flimsy than a well anchored single shear stud.

****START OF RANT****
Not to call either method wrong, I think it is a toss-up as most things are. Not everything needs to be double shear either, take an honest look around your car. Everyone has plenty of very important things in single shear.... like, say, your engine mounts, brake calipers, sprocket, or brake rotors. If you went to the extreme to take EVERYTHING out of single shear, your car would be repulsive to work on, and probably weigh 600lbs.
****END OF RANT****

Ok, now that I am done ranting, to the teams that have run these ends in single shear, did the judges tear you apart, or were they cool with it? I see HRP selling single shear uprights for sedans, so our cars should be no challenge to do that way, right?

[Ben Beacock]

another thing to consider re: single vs double shear is that by making the box to double shear you lose space to move that joint out vertically when the corners of the box or bolt head get close to the inside of the rim. Last year we used countersunk bolts when the upright ended up too close to rim to use a normal bolt. To secure the bolt, we drilled through the edge of the bolt head/upright and pop-riveted it in place. got a comment from a judge that it was quite an innovative way to secure it (he hadn't figured out a way himself)

[James Waltman]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Rob Woods:
There are no ill effect by using the single stage high temp stuff is there? I could just do that in a non-food oven right? <HR></BLOCKQUOTE>

Rob,
There are no problems that I know of that come from using an elevated temp cure epoxy. You'll need to make sure all of your fixtures/setup can handle the temperatures. I would recommend that you make some parts that you can test destructively. The non-food oven is probably a pretty good idea. We have an oven here at the shop that we do all of our heat-cure stuff in. Although, I think that I remember Travis using the oven at our house last year to post-cure some 2-part epoxy. My girlfriend let it go but I'm pretty sure she didn't like it. She was cool with us storing pre-preg in the freezer though.

[Angry Joe]

Double shear is nice, but engineering is about compromise. There are no absolutes. Rumor has it a few teams mount their wheels in single shear http://fsae.com/groupee_common/emoticons/icon_redface.gif

[Kevin Hayward]

On the issue of Single Shear in uprights I thought I'd mention that we first ran sheet-metal uprights with single shear mounts in 2002 (Oz). Carroll Smith really liked them. Unfortunately for the FSAE community there are students coming through that do not get to see that Carroll's knowledge and engineering ability went far beyond the sum of his books. Further still it is dissappointing that people who read his books feel that they can speak for him.

There are a lot of examples of uprights with double shear mounts in FSAE that would not perform as expected. For Franks benefit I believe that the only laziness in design is in not having thought out the problem and tested it thoroughly after implementation.

When it comes to components like uprights I cannot see how it is acceptable to not perform considerable off-car testing before installation. If this testing occurs you would be able to verify your design whether it has single shear or double shear mounts.

For the sizing query we (and I believe UTA do as well) use 5/16" sphericals at the upright and 1/4" sphericals inboard. Given a shear failure of a bolt (which by the way is not the main failure mode of the upright) a 5/16" in single is equivalent to a 1/4" in double.

Stiffness can be an issue but one that is easily solved. Also need to watch that threads are not loaded in bending. Simply bolting on the a-arm to the upright is a definite no-go.

Hope some of this helps ... and doesn't inflame.

Kev

UWA Motorsport

[NovaCat2005]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Big D:
Maybe this is straying slightly from the original topic, but what stops most teams from adjusting camber at the inner points (chassis side) of the A-arm? <HR></BLOCKQUOTE>

Am I correct to think that adding/removing shims at the upright also changes the KPI? And changing the KPI affects the scrub radius and camber/steering angle relationship. I would think that if you only wanted to change camber, then shims on the chassis would be the way to go, or if you wanted to play with the KPI as well as camber, then shims on the uprights is the way to go. Are there teams that do both? I'm thinking of doing both just to add more adjustability to our car.

[Icke]

@NovaCat2005

It's a good idea to add more adjustability to your car but try to adjust every position in an independent way from other thinks. Sure, some things have influence to each other but you should try to minimize these influences(?).
Adjust camber at the frame and IRC, RC and KPI at the upright. Design your upright as an assembly so you can change each part in less time.

[Wilso]

I think the above statement is backwards. If you shim at the upright the KPI will NOT be affected. However if you shim on the inboard side, both KPI and camber will change in the same amount.

But here's another question, assuming I am correct above. Can changes in camber affect scrub radius without a change in KPI? It's probably negligable, but has anyone considered it?
Also, does changing KPI and camber the same amount (inboard shims) leave scrub radius unchanged?

[Icke]

@Wilso

Make a sketch in your design-software (solidworks or so) an draw in your suspesion pionts and alter them. You will answer your questions by yourself.

[NovaCat2005]

@Wilso

Changing camber by adding/removing shims at the upright will change the camber of the wheel, and it will change the location of the upper and lower ball joints in the tire coordinate system. This should change the KPI.

[Denny Trimble]

Yeah, but who cares what the KPI is in the tire frame? KPI with respect to the ground plane determines the camber change and ride height changes vs. steering.

If your camber is -3 and your KPI vs. ground is 3 (zero KPI in the tire frame), you still have camber change due to KPI.

Am I missing something? Is there a case were KPI in the tire frame is important?

[NovaCat2005]

Wilso
You're right. I guess I do have it backwards, thanks.


Denny
Yeah, that makes sense that if you have zero KPI(to ground) zero caster and some camber that ride height changes will be zero. I'm reading Milliken and it appears that he defined KPI from the centerline of the wheel. Then he goes on to talk about the effects of KPI with respect to ground. Page 710 for you kiddies with "Race Car Vehicle Dynamics"

[NovaCat2005]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Wilso:
Also, does changing KPI and camber the same amount (inboard shims) leave scrub radius unchanged? <HR></BLOCKQUOTE>

It would appear so becuase the balljoint/contact patch geometry that creates scrub radius is unchanged.

Although, I have been known to be wrong about these things. http://fsae.com/groupee_common/emoticons/icon_wink.gif

[Big D]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>I think the above statement is backwards. If you shim at the upright the KPI will NOT be affected. However if you shim on the inboard side, both KPI and camber will change in the same amount. <HR></BLOCKQUOTE>
Yeah I guess I had that backwards too. Although, I still believe in the merits of inboard adjustment on the basis of less unsprung weight, simpler upright, and possibly a stiffer installation. KPI and Camber probably won't change more than a couple degrees from some middle ground you select in the initial design anyways, so maybe it is an ok comprimise.

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Wilso:

But here's another question, assuming I am correct above. Can changes in camber affect scrub radius without a change in KPI? It's probably negligable, but has anyone considered it?
Also, does changing KPI and camber the same amount (inboard shims) leave scrub radius unchanged? <HR></BLOCKQUOTE>

I had been thinking about this too. If you have some static camber, then the middle of your contact patch will move over with the lean of the tire. So even though you have a certain scrub radius in the tire frame, it would be less in the ground frame. (assuming neg. static camber) So for NovaCat... I think it depends which frame of reference you are looking at.

[fade]

for inboard camber changes what happens to your RC location?

[Dan B]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by fade:
for inboard camber changes what happens to your RC location? <HR></BLOCKQUOTE>

It depends on what plane the adjustment is in. I made sure the inboard adjustment was in plane with the upper control arm so that changes in the static RC would be reduced.

[Icke]

I'm sorry! Forget all my statements above. I'll think about it again.