@@Offroadvehicleengineering No worries, it’s the truth. If I may suggest something, it would be to use some kind of 3D printed simplified suspension system in your examples.
@@AirForceJuan747 thanks for the suggestion. I have been experimenting with using 3D CAD models, but it slowed the video production process right down. I think you’re right that a physical model might be the way to go. I will keep experimenting!
Another great video. I have a Jago Jeep which suffers from this quite badly. Not knowing what I was doing it was a devil of a job to pin it down. If I'd been aware of this effect 10+ years ago we'd have had it cracked in minutes.
A question. Do leaf sprung suspension systems suffer from roll steer, given the axle is restricted to more or less vertical movement? I ask as my truck is leaf sprung.
Hi Stephen, thanks for the question. They certainly can do, because the spring is responsible for the longitudinal location of the axle. Since the spring is moving through an arc then you get the same effect as you do with a radius arm. The difference tends to be that leaf springs usually have the shackles for both front and rear axles either facing back, or facing forward, so you end up with crab steer rather than oversteer.
I have seen it stated many many times that understeer is desirable, yet given the nature of physics, and the fact we are trying to get a moving object to change direction with two little contact patches, I’d say understeer is inherent before considering roll steer. And only worse on constant 4wd vehicles. That is to say, I feel a little oversteer a good thing in suspension geometry. I did say a little. For me having the front at about zero degrees (neutral ) and the rear around 3-4 max. But degrees don’t mean much without considering link length.
I’m intrigued to know why you think understeer is inherent. A lot of SUV type vehicles have a heavy engine but quite a light rear structure. That does give them inherent longitudinal stability (like a dart), but it also means that the front axle tends to be much better planted than the rear. These vehicles tend to be designed to carry a heavy load in the back and consequently are stiffly sprung, but when they’re empty they end up with a lightly loaded rear axle with too much spring stiffness and consequently roll stiffness, which is a recipe for oversteer. The reason understeer is usually more desirable than oversteer is that drivers are more naturally able to compensate for it - you just turn the wheel a bit further. Where rollsteer is concerned it’s also more desirable to have a bit of understeer (rather than oversteer) because roll oversteer has a positive feedback loop - the roll creates more steer - the steer creates more roll!
The level of PowerPoint Picasso is what makes this channel so underrated.
Roll steer is how my 110 negotiates mini rount abouts so nimbly!
Most underrated channel. Keep up the good work and it will pay off.
Thanks Juan, very nice of you to say so!
@@Offroadvehicleengineering No worries, it’s the truth. If I may suggest something, it would be to use some kind of 3D printed simplified suspension system in your examples.
@@AirForceJuan747 thanks for the suggestion. I have been experimenting with using 3D CAD models, but it slowed the video production process right down. I think you’re right that a physical model might be the way to go. I will keep experimenting!
Another great video.
I have a Jago Jeep which suffers from this quite badly. Not knowing what I was doing it was a devil of a job to pin it down.
If I'd been aware of this effect 10+ years ago we'd have had it cracked in minutes.
Hey man great channel!! I'll recommend it to my peers! Just keep making such exhaustive content please
Thanks Jay!
A question. Do leaf sprung suspension systems suffer from roll steer, given the axle is restricted to more or less vertical movement? I ask as my truck is leaf sprung.
Hi Stephen, thanks for the question. They certainly can do, because the spring is responsible for the longitudinal location of the axle. Since the spring is moving through an arc then you get the same effect as you do with a radius arm. The difference tends to be that leaf springs usually have the shackles for both front and rear axles either facing back, or facing forward, so you end up with crab steer rather than oversteer.
I have seen it stated many many times that understeer is desirable, yet given the nature of physics, and the fact we are trying to get a moving object to change direction with two little contact patches, I’d say understeer is inherent before considering roll steer. And only worse on constant 4wd vehicles. That is to say, I feel a little oversteer a good thing in suspension geometry. I did say a little. For me having the front at about zero degrees (neutral ) and the rear around 3-4 max. But degrees don’t mean much without considering link length.
I’m intrigued to know why you think understeer is inherent. A lot of SUV type vehicles have a heavy engine but quite a light rear structure. That does give them inherent longitudinal stability (like a dart), but it also means that the front axle tends to be much better planted than the rear. These vehicles tend to be designed to carry a heavy load in the back and consequently are stiffly sprung, but when they’re empty they end up with a lightly loaded rear axle with too much spring stiffness and consequently roll stiffness, which is a recipe for oversteer.
The reason understeer is usually more desirable than oversteer is that drivers are more naturally able to compensate for it - you just turn the wheel a bit further. Where rollsteer is concerned it’s also more desirable to have a bit of understeer (rather than oversteer) because roll oversteer has a positive feedback loop - the roll creates more steer - the steer creates more roll!
Ahh! Like a skateboard !