Anyone running camber on their front tyres?

[vodka child]

Looking at how most set up their rig, either through clocking the axle tubes or the chubs, a combo of both, or some other options pretty much everyone runs castor (king pin inclination) Seems to range from 8* to 30* from build threads I’ve read, but not read really about anyone running camber on their rig.

Working on GT race cars we run various degrees of negative camber depending on track design, surface, tyre compound etc but the net result is so under load the outside tyre in a turn is pushed to be upright and offer the maximum contact patch of rubber, rather than being pushed past vertical and dealing with a diminishing contact patch. The logic seems to make sense in crawling to, though the loads and speeds aren’t there as they would be in a track environment, the same principle of contact patch etc would remain.

I’m going to give this a go with maybe 4.5* of negative camber see if it helps the tyre when turning offer a flatter contact patch and be able to grab and pull the rig onto the desired line. Anyone already done this doing this, thoughts, comments etc??..........................

 

[JeremyH]

Camber will be difficult to adjust on these cars as most knuckles only allow the shaft to pass through at an angle parallel to the ground. IMO, the only way to achieve some camber would be to use the VP 8* C's and their regular knuckles. I dont know if they will work together though...

I can see camber helping in "off camber" sidehills...."thumbsup"

 

[Beest]

I like where this is going. "thumbsup"I was talkin this over with my machineist/enginer buddy. I think it could work, but making/modding the parts would be a B**ch. alot of hours at the mill.:shock: Havta make new knuckle from scratch.... and open up inside of c to clear the additional angle of the cvd. Good idea. keep us posted.8)

 

[jcboof]

I know it has been done on the rear of bergs, but not on the front. Good concept, but the steering would be all kinds of wonky, especially if there was a good amount of caster involved.

 

[vodka child]

on a race car there is very little vertical movement in the suspension and with e an antiroll bar the front axle is effectively tied together so the camber absorbs the force/energy across axle and pushes the outside tyre, the one under load to a more vertical position increasing the contact patch

For a crawler there is a huge amount of vertical movement in the axle,say an average of 4-5" articulation, but little mechanical force generate through the tyre and rock surface, soon as the axle articulates the contact patch of the tyre changes significantly, I have tried some VP 8* chubs set up with caster and then used a set of EGRESSor knuckles with a couple of degrees toe out which i was already running.

On the flat the tyre obviously has a reduced contact patch, but add in some articulation and the contact patch is great, instead of reducing the area offering mechanical grip it increases it giving some really good bite.

There isn't a huge amount of camber so the axles (Super 300s) aren't being rotated through a significant angle but enough to get the bite i was hoping, the steering isn't all over the place - setting up the servo and tie rod took a few cracks due to the way the servo arm and tie rod angle changes through the servos sweep.

It's all a bit Heath Robinson right now and sure one of the vendors on the site could create something much better, but going to carry on running this and see how it checks out.

Be interested to hear if anyone else has done this and what they found etc.
Cheers

 

[NGreen]

Correct me if I'm wrong, but don't XR-10 and VP 8* knuckles incorporate camber change during the sweep of the knuckle? As I understood it, that was the purpose of the angled kingpin, so that during straight line driving, you had zero camber but as the tires enter a turn, the camber changes in relation to the sweep of the knuckle. I think you'd find that the low side tire during straight line driving with a good amount of articulation would have an increased contact patch with some more camber, but then again, the upper tire as a result has less of a contact patch. So I think you'd be chasing a diminishing return on your investment with a solid axle rig. With an independent suspension set up, you could see some benefit I think, but on a solid axle rig, you're not going to see the benefit you're looking for as it is a trade off between tires. And then also, consider when articulated and in a turn, you're wanting that upper tire to be doing the pulling and with a diminished contact patch due to the camber angle, you don't get that. You get a more off balanced rig with the one tire doing all the pushing because it now has the most traction due to camber. Again, it's back to a solid axle vs independent suspension.

Edit: I just double checked and yes, there is a large amount of camber change during the sweep of the knuckles with XR/VP8* knuckles even with 0* of castor.

 

[JeremyH]

I know it has been done on the rear of bergs, but not on the front.

Yep, Fishmaxx rotated his rear housings by 90* and then shortened his lockout arm which gave them a bit of negative camber. He said he liked that setup especially on sidehills.....

 

[vodka child]

Quite a few cars that run a solid rear axle also run rear negative camber - Ford Mustang, with the race version running a fair amount. The comments about the front only working due to independent suspension are partly true, the effect is much more pronounced and the benefits more obvious but it's still possible with the solid axle set up of the MOA crawler.

It is a diminishing return though as already said but like all things it's always a compromise on set up, the camber I have running now seems to be pretty effective when side hilling and the bite on uphill turns is good. It's NOT the solution to any and everything and all that, but messing around with the set up i'm pleased with where it's going.

Will keep driving with it and tweaking the set up see where i end up - Dr Franks Berg is running the 8* chubs and knuckles and as said in the posts above the the camber does change, from the pics that he posted up, I might go that route once knuckle weights are available for those knuckles or just see how the set i already have works out.

Good to hear the comments back guys cool to hear defo gives me stuff to think about, cheers guys "thumbsup"

 

[SkaldidDog]

Back when Nabil was getting shafted he had a cambered front setup on his LCC one day.

One day.

 

[NGreen]

Quite a few cars that run a solid rear axle also run rear negative camber - Ford Mustang, with the race version running a fair amount. The comments about the front only working due to independent suspension are partly true, the effect is much more pronounced and the benefits more obvious but it's still possible with the solid axle set up of the MOA crawler.

It is a diminishing return though as already said but like all things it's always a compromise on set up, the camber I have running now seems to be pretty effective when side hilling and the bite on uphill turns is good. It's NOT the solution to any and everything and all that, but messing around with the set up i'm pleased with where it's going.

Will keep driving with it and tweaking the set up see where i end up - Dr Franks Berg is running the 8* chubs and knuckles and as said in the posts above the the camber does change, from the pics that he posted up, I might go that route once knuckle weights are available for those knuckles or just see how the set i already have works out.

Good to hear the comments back guys cool to hear defo gives me stuff to think about, cheers guys "thumbsup"

The examples you provided are all race cars at high rates of speed with roll center changes, cog changes and body roll on flat terrain (or relatively flat compared to rock crawling). I think you could compare this to rock crawling at high speeds, but at low speed, I think you'll find a distinct difference between the desired effect and what you see in a GT circuit. I'd almost go as far to say the principles are similar, but in application, the terrain, speed, suspension geometry, and weight ratio all play too much of an effect to be able to compare on road racing to rock crawling.

I agree, you could probably see some benefit out of additional camber on a REAR axle, non-steer set up. I still think you'll put way too much effort into a front axle, steering set up when you could easily run angled kingpin c-hubs and knuckles and get the desired effect.