Front to rear balance point

[bigd003]

I've never really considered this too much. I did try bb's in my wheels, but it slowed me down and ,ade me nosedive hard when bashing around.

[BOWTIE]

dropped the weight down close top 5.5lbs by losing the weight slugs.


balance point is about 1/4 back now.

[Duuuuuuuude]

Here's a thought...how does everyones rig balance without the wheels/tires? I tried mine just for the hell of it and it put the weight balance an additional 1/2" forward.

[romulus22]

[silentcircus]

I'm going to have to try that this afternoon and find out.

[JeremyH]

Originally Posted by Duuuuuuuude

Here's a thought...how does everyones rig balance without the wheels/tires? I tried mine just for the hell of it and it put the weight balance an additional 1/2" forward.

Mine would be exactly the same....I dont add weight to any of my tires.

BTW, I have focused on bias more than overall weight for quite some time. I have never been one to run a light truck. I just get the weight down low enough that it doesnt hurt digs and uphill climbs, then focus on the bias.

[Duuuuuuuude]

Originally Posted by JeremyH

Mine would be exactly the same....I dont add weight to any of my tires.

BTW, I have focused on bias more than overall weight for quite some time. I have never been one to run a light truck. I just get the weight down low enough that it doesnt hurt digs and uphill climbs, then focus on the bias.

I decided to totally change chassis' and setups the other day. I also stripped all the weight out of my wheels. My rig now sits at 4.5 lbs...keep in mind I still have to put the dig in, but that is nearly 2lbs less than what I usually run. The bias has always just kind of worked out...I never put a whole lot of thought into it. It'll be interested to see what happens when I keep all this in mind.

[silentcircus]

Originally Posted by JeremyH

Mine would be exactly the same....I dont add weight to any of my tires.

BTW, I have focused on bias more than overall weight for quite some time. I have never been one to run a light truck. I just get the weight down low enough that it doesnt hurt digs and uphill climbs, then focus on the bias.

I do add weight to the wheels, and I'm also not one to run a light truck. At an ounce and a half less than six pounds, I think this is as light as I want to go. I don't like the way lighter rigs bounce and hop while trying to climb inclines.

I've worked on the 60/40 bias since I started putting it together while trying to keep the weight as low in the chassis as I can. Right now, the only things over the top of the rims (not the tires, the wheels) are about 90% of the ESC, the receiver, a few wires and of course the top frame rails and tops of the shocks. Everything else is below the top of the wheels.

[ripper7777777]

Originally Posted by EeePee

You're always way off.

I find mine to typically be at the front edge of the skid plate. Or close to it.

ROFL!!!!!!!! Man that has to be the best reply EVER!


I don't have anything to add, just loved the pic.

[EeePee]

Originally Posted by ripper7777777

ROFL!!!!!!!! Man that has to be the best reply EVER!


I don't have anything to add, just loved the pic.

Not joking, it took me 13 tries to get it balanced with a clear shot. My finger gave out twice.

[Nabil]

Originally Posted by EeePee

Those two variables are directly correlated. No?

in one way yes when you are looking at the horizontal aspect of cg (the balance point thing you guys are doing here). but if you are trying to keep the front end down on a climb then i feel front weight is more related to the vertical aspect of the cg (how high of the ground)

[vodka child]

I work as an Engineer on GT cars racing here in the UK and Europe and for circuit work we spent a lot of time with weight balance (static weight distribution) and specifically corner weighting (aka cross weighting) -
Corner weighting percentage compares the diagonal weight totals to the car’s total weight. To calculate cross-weight percentage, add the RF weight to the LR weight and divide the sum by the total weight of the car.

The aim to keep the car level when cornering and dial out under steer (push or tight in NASCAR speak as the term under steer I think is more of the European thing)/over steer (loose in NASCAR speak) when induced by the steering angle and weight transfer. For circuit work we have specific aims and use a digital scale set up to view the weight front to back and across the diagonal allowing us to change spring weights, camber, caster etc.

For rock crawling (something I’m still new to) the aim will be something very different, ideally I would assume you’d want the corner weighting set up so each wheel is being pushed down with the desired force – likely more rear pressure than front?? But having each wheel on a common axle with the same force (unless you need to dial out axle twist with a shaft set up?) Rather than having 4 wheels each of which being pushed at a different rate, having that will affect adversely how the rig performs. Having the desired corner weights you can look at static weight, this can only be affected by physically moving weight around in the rig, circuit racing with fuel consumption etc you have to seek a happy medium so that the car handles well both full and empty of fuel. For the crawler as the weight remains static I would have thought a slightly more front biased weight but one that give as low COG as possible would be the better option than a simple 50:50. Coming from a circuit racing background and trying to apply the same set up logic I know doesn’t work, so it’s a case of taking what is common and applying that in my case, then learning through set up changes and advise from others

Being a newbie I’ll be reaching for my coat now and await the hail of corrections……

[C*H*U*D]

[vodka child]

I just switched to a Beetle Juice V3 chassis and figured I'd check the balance as I was building the chassis up. Even with just the bare chassis together the balance point was just at the front enge of the skid plate. Adding the axles moved the point about 1mm further forward.

I'm going to try and get 4 small digital scales to check the corner weight, the lop sided balance that some have seen when balancing their rigs isn't really a true indication of how the rig will perfrom since this doesn't take into account the spring rates and dampers. The vertical force on each wheel is a better indication of what your rig will do when looking at side to side weighting - you can have a car that is left side heavy (static weight) when suspended when you try and balance it suspended in mid air but when flat on the ground you can adjust spring rates to equal out the force/load applied on the side tyres.

[joesbruiser]

Originally Posted by vodka child

I just switched to a Beetle Juice V3 chassis and figured I'd check the balance as I was building the chassis up. Even with just the bare chassis together the balance point was just at the front enge of the skid plate. Adding the axles moved the point about 1mm further forward.

I'm going to try and get 4 small digital scales to check the corner weight, the lop sided balance that some have seen when balancing their rigs isn't really a true indication of how the rig will perfrom since this doesn't take into account the spring rates and dampers. The vertical force on each wheel is a better indication of what your rig will do when looking at side to side weighting - you can have a car that is left side heavy (static weight) when suspended when you try and balance it suspended in mid air but when flat on the ground you can adjust spring rates to equal out the force/load applied on the side tyres.

You should also be able to shift weight from corner to corner with small amounts of preload on individual uppers.I know we use this when setting up drag cars and I use it if I have a RC Crawler that wants to dart left or right when you pin the throttle to say launch up a smooth slippery slope.

[4xFord]

Bump for a cool thread! My berg is 5lbs 1.5oz as pictured. 5.3oz added per front wheel.

[slowngreen]

My balance point usually stays about the same, right about the front of the skid, the only thing that changes is the weight. If I lose any in front or back, then I try to lose the same amount if possilbe on the other end.

[losikid]

i usually have mine balanced on/around the pin that goes through the lower links on the front side. (front part of the skid)

[articzap]

Can't wait to go check my truck and make changes if need be.

[Jeepkid]

My Xr is dead nuts, and I never thought of checking it like this until I read this thread.