Life saver. I’m finishing my auto body technician ticket here in Canada and part of the last year of schooling is suspension and alignment cause we have to understand how that stuff works. Yet i have almost never had an experience with suspension or adjustment so you are saving my life for this test !
@justins462 It's connected to the flywheel which is connected to the crankshaft. So as the engine rotates, the torque converter rotates, forcing the liquid inside to circulate, and finally spin the transmission shaft.
Even though I knew about some aspects (camber, toe-in/out) I had no idea so much went into the steering. I'm building my first race car and I'm trying to learn as much as I can about suspension and adjustment. Thanks for the videos.
+Nermin C. Get an old "steve smith autosports" book. Depending on the kind of racing you do, the learning part is often skipped. Most people just go straight to what chassis builders tell them to do. The builders have years of experience and often have learned the science then changed it to "standard" setups and things to do to modify the handling characteristics without really explaining correctly the "why".
@engineeringjtc Yes, I understand what you're asking. It does not matter which direction you turn. If you understand the diagram to the bottom left, and simply mirror it, this is what occurs when you turn the tire the other direction.
Changed my caster 2.5 degrees. Went from unsafe to perfectly normal. 8.5 caster to 6. On Jeeps they call it "Death Wobble", any vehicle w a rigid front axle is susceptible to this extreme shimmy. Turns out this alignment parameter is the most important to cure it. Thanks for the video :)
@EngineeringExplained Yes, I was a little confused at what you were getting at, right up until you showed us your chair and then it all fell into place. Thanks!
If you aren't sick of me typing yet, you might be after this post! :) You've covered one important aspect of Caster angle and how it relates to a car's suspension but you've left out what I consider Caster's most important feature. Caster turns to camber when you turn the wheel. Caster and Kingpin angle (See your Steering Axis Video) tend to fight each other in this regard but on most production cars you will get negative camber gain on the outside tire and positive camber on the inside tire. This has a profound impact on keeping a tire flat to the pavement. This is far more important than the self centering effect of caster. Cars during the 60's have generally very low caster angles and poor kingpin inclination and the result of turning a corner quickly in a car made in the 60's will show huge amounts of positive camber on the outside wheel as a result. By upping the caster angle and tweaking control arm angles you get a much flatter contact patch and much more front end grip! :)
One big advantage is camber gain when turning. The higher the caster the more the tyres lean into the turn, usually resulting in better cornering grip. Best case scenario: You can lower static camber to increase straight line grip and increase caster to maintain cornering grip. More caster increases jacking though, which can affect corner weighting, and partially diminishes the effect of steering lock, so it's not without downsides. It also makes steering much heavier.
@oldskoolcooper You pretty much always want positive, at the worst neutral. Since Formula cars are going at much greater speeds, it wouldn't surprise me if the caster angle they used was much smaller than on everyday cars.
I agree with you, but it's a nice way of showing how if the contact point is behind the axis of rotation, the wheel will follow the direction of travel.
@@Korokukanas Actually I am from a different branch - Aerospace. Automobile was one of my electives that I chose because of personal interest. To be honest, I passed that exam with A+ but as an engineer, I failed. I live in a country where aerospace has not much career opportunities. Even though aerospace share common subjects with automobile and also I did interns in renowned auto companies, when it comes to job, my degree is a hindrance. Mechanical/ automobile Companies do not prefer aerospace engineers. So I have quit automobile/mechanical.
@@hariharanmurugappan5466 Yeah that sucks man. I would say start writing letters to Aerospace companies and showing interest in employment. Otherwise you need to move to Florida or Texas and try to get a job with NASA. Which is a complete crap shoot I know. Good Luck, don't give up.
I really enjoy watching your videos and have learned a lot from. I don't know how old you are but your look young and still you know all these things. I'm only 18 and problably don't know 1/4 the things you do but I am learning quit a bit. Thanks man
Thank you! This settles a disagreement on the meanings of caster & camber (Turns out I was wrong). We are big fans of 1/10th scale hobby-grade racing and C+C+Toe are incredibly important on such a small scale. Luckily, dirt tracks are a bit forgiving, however. Now I can go out to my shop and apply names to the adjustments I need to make, and to make those adjustments with a better understanding of what's happening. Thank you, again!
Does a change in wheel diameter affect caster? I'm guessing that there would be more caster from larger wheels because the intersection point between the vertical axis and the rotational axis is lifted higher from the ground. Please correct me if I'm wrong. Also, if you increase the caster in a car, would it become more difficult to steer because it just wants to remain true?
excellent visual...I've been teaching caster for 8 years as theroy and never considered that simple example. well done. consider it stolen. ...and thanks.
Thank you for the nice explaination and the simple but very understandable and interesting example. You can explain everything much better than my lecturer. I'd rather watch all your videos than sit 1,5 hours in the lecture.
Outstanding! When I drive in reverse at higher speeds is the steering more sensitive and some what hard to control because of the negative caster? I figure that if I am driving forward it is postive caster but if I am driving backwards it will automatically be a negative castor because I am sterring in the opposite direction. Is that right?
Yes, but I'd say the biggest reason it sames more sensitive is because the rear tires are steering, not the front (when going backwards). This makes the turning radius significantly smaller, and also the rear of the car will want to swing out.
Ahah! This diagram in the top left actually helped me to understand the steering axis-inclination a bit better! Very nice video. One question on steering axis inclination though: I can see how the inclination would pull the tire straight if turning one direction, but if the tire is turned in the opposite direction, would the inclination not push it up instead of down thus making the pull to straighten the tire only effective when turning one direction? I hope that made a little bit of sense....
Explaining is good and all, but some visual aid like at the end of this video would be nice for the other videos, as well. I only watched the video abotu camber and steering axis inclination, from the Suspensions playlist.
The contact patch does change as you explain but that's not what is returning the steering wheel. Pressure on the spindle due to caster angle causes stability and wheel return.
great vid man! can i ask you a question? this dont relate to the topic of this video but iv been wondering this for quite some time. a while back you did a video on automatic and manual transmissions and you explained what a torque converter is and how they work, but can you explain why they work? i guess what im getting at is how do they creat the pumping action?
A simple way to understand what it does, it changes the camber at different steering angles. So if you run a lot of negative camber with positive caster, your leading tire has a better contact patch at sharp steering angles. Hence why drift cars have a lot of negative camber in the front to allow more front end grip.
Hi Jason, I have a question, During the designing of the front suspension, does the axis of the Macpherson strut should pass through the center of the lower ball joint?
I hope I can get a reply to this one. I was wondering if there were any issues (if at all) with having a double wishbone setup with positive caster but having a coil over mounted to the lower arm, in a slightly negative angle. i.e. the caster and the angle of the coil over forms a "V".
Correct me if I'm wrong (since I'm not a kart racer), but isn't caster adjustment in karting largely a jacking issue? I've been given to understand that due to the spooled rear axle you need to unload the inside rear wheel if you want to get the kart to turn properly, which can be achieved with the jacking effect of caster. Too little = not enough jacking, too much rear grip, too much = too much jacking, not enough rear grip?
@engineeringexplained i want to ask that what is the caster angle of this chair is it having a zero caster as there is no angle between both the axis and the both the axis are parallel to each other?
My mum had a 2013 Mercedes-Benz C180. When the wheels were turned at full lock and you looked at the car front on, it was like there was a lot more negative camber on them. Does this mean there was a lot of negative caster?
I'm adding some 1/2" pads above my rear springs to raise my rear end and fix reverse rake (MK7 GTI). Do you know if anything other than camber will be affected and whether or not I should get an alignment after the install? Thanks
why does uneven caster cause pulling to one side? Do the wheel center slightly to one side? I understand that with camber the increased rolling resistance causes a pull but i dont get what forces causes the pull with uneven caster
How does the office chair not have a caster angle of 0? The wheel is rotating about a vertical line right? I see no diagonal line for the steering axis
Caster is just the angle. But then there are two arms (distances). The intersection between the caster axle and the ground level is a point, the horizontal distance between that point and the vertical line trough the center of the wheel is one of them (the other is the the almost the same, but instead of ground level us measured on the center of the wheel level. Office chairs have 0 caster indeed, but those two distances are not 0 ( and if caster is 0 they are the same, which is the distance between the center of the wheel and the vertical pivot axle of the "wheel bracket " ) 404 English l guess
What effect does extending my control arms have on the caster? Will the Caster become more negative or more positive with increasing length of control arms?
Is not negative caster on the wheel of the chair? Isn't Caster angle the KPI related with vertical line that pass thought the center of the wheel in the side view?
Awesome video!!! I like the way you explain things, it's just so easy to understand although the thing itself is so complicated. I'm crystal clear right now about what is caster and what the meaning of setting positive caster. But I am a little bit confused about the last part of your explanation, I kind of understand what you said about the positive caster in the normal office chair, but what is negative caster in this chair? What will it look like?
It would look like trying to push the wheel a direction and not having it follow, but stay in front. As you can see it always follows (this is positive), but when it's in front and you push against it, this is negative, and you can see it quickly flips around as this is not ideal.
Engineering Explained Ok, I got you. Thanks man, I will keep watching and learning and subscribing your videos just because they are so great and I can learn many things through it. Hope you will continue making great videos~
Nice video, but the example of the chair is not correct. This is called "trail" and is yet another variable amidst camber, castor and toe. Actually, the castor of the chair and shopping trolley is ZERO (its a vertical line), but it has x mm trail.
consider my car has positive caster (BMW e46). When I am moving backward (R gear), the steering wheel still can still center itself. It there another mechanism governing this behavior? Wouldn't a car with positive caster becomes negative caster when moving backward?
Geez, I really could have used all these videos back in 1999. When I used to play Gran Turismo 1, I had no idea what any of this meant. I just had all my suspension settings directly in the center of the bar. ----------l-----------
Sir, my car i20 front struts shockers are aligned perfect 90 degree with respect to ground when steering wheel is at normal or 0 degree position. However, the left shocker slanted bit about 30 degree approx with respect to its original vertical position when the steering is full turned to left. The same is for the right shocker when fully turned right. Is this change in vertical alignment normal??? Thanks.
Question, if my upper and lower balljoint studs are inline with each other, can I assume that's zero caster? And if so, would moving the lower balljoint stud "forward" increase or decrease caster? And lastly is the direction of positive caster angle different if the steering arm on the spindles is on the front or back of the spindle arm?
+Cuzntime studz have nothing to do with it. What counts is an imaginary line drawn through the center of the pivot points of the ball joints. Usually, the studs are in line though. Steering arm location has no effect at all. there can be considerations with steering arm with "ackerman" and how the linkage may deflect under load but in an ideal world the arm can be in front or behind the spindles.
IMO you left something out that has a significant role in suspension setup. Say you have 3 degrees of positive caster. If you were able to turn the wheels 90 degrees, that would introduce 3 degrees of negative camber on the outside of the wheel, and 3 degrees og positive camber on the inside wheel. This changes the way the vehicle handles and the stability when travelling straight or conering.
yes.bigger the difference between contact patch and turning axis at ground level, better it will cruise. (+caster will help you to ride a bike hands-free, since the front is always centering by itself. but harder to turn)
Hello~ I've got a question, is there an ideal caster for the rear suspension of a rear-wheel drive car ? If there is , what value would it be and why would we choose that value? Thank you!
+柯旭東 Since the rear-wheel doesn't turn, I don't see why would they put caster on it, other than space limitation concerns. For the front. Positive caster help the front wheel to go in line of the torque, but it also make turning very hard (more work for steering pump). So they have to find the right value of +caster, where that front wheel would turn in straight on its own and close enough to zero,so steering pump can work as less as possible. Caster of Zero would be dangerous, bcz front wheel would wobble at any road resistance. (I strongly suggest you do a little reading about motorbike's front fork, especially on those chopper bikes. Choppers are harder to turn, but cruise well because of their fork geometry. they have ++ caster angle) Hope I helped :)
+柯旭東 oh~ that one. I think if caster is zeroed, the wheel would have tendancy to turn into random directions everytime it pick a bump at any slight angle. But yeah, I'm not sure physically why it bumpsteers :)
Wait, you got me confused here. If a positive caster in a car is the top of a steering axle inclined backward, then how's shopping cart example of a positive caster? A shopping cart front wheels are always behind the steering axle. The top of the steering axle is inclined forward, not backward. What am I missing here?
Great explanation sir.Except your example,..in my own opinion,shopping wheel cart and chair wheel are example of a negative caster, not positive.correct me if I'm wrong.
hey there, please help me!! my passenger side wheel moved back so when I turn left or right the wheel hits the fender.. I need your help and I prefer fixing it at home:) tell me what the problem I have.. thanks from KSA
With positive caster, the steering axis trails the tire. Assuming you have a straight up tire, (no camber or toe), that tire is going to want to travel straight. So yeah, theoretically steering will be heavier because of added resistance.
since I changed my tyres, i have felt that the steering has gone too light(eveb though the new tyres are much wider) i.e. it is too easy to turn the wheel even when not moving. And while driving the car seems to sway aimlessly and the tyre would not straighten themselves. What could be the problem?
I like your videos but your example with the chair actually shows negative caster. Draw a line from the wheel axle to the steering axis pivot point and you will see what I mean. Vehicle control requires positive caster because it lessens the effect of vehicle mass on the wheel direction.
So the front wheel of a bicycle has negative camber? The patch is clearly ahead of the axis of rotation. This must be why the steering is so unstable when you're "leading" your bicycle by the saddle and walking alongside, you have to actively tilt it to adjust steering. The little tricycles kids use have positive camber though.
Got a new Car (Suzuki Vitara LY) and the steering doesn't return to center all the way, the wheel stays at about 20° if you don't push it back by hand. On most bends, I can let go and the car goes around by itself. It makes going in a straight line on the highway and changing lanes very difficult. How likely is if for a factory new car to have the caster angle wrong, be it by accident or by design?
Jasperrsworld that's my guess as well. Looks like my dealer didn't check/do the alignment after the new car came off the ship and now I gotta do an alignment on a brand new car and sending the bill to the dealer. Apparently they just bolt the cars together in the factory and the dealer has to do quite a lot to make it ready for sale.
Life saver. I’m finishing my auto body technician ticket here in Canada and part of the last year of schooling is suspension and alignment cause we have to understand how that stuff works. Yet i have almost never had an experience with suspension or adjustment so you are saving my life for this test !
Using casters to demonstrate caster, genius!
@@Korokukanas I’ve been better. I’m trying to find a different job. Have we met?
@justins462 It's connected to the flywheel which is connected to the crankshaft. So as the engine rotates, the torque converter rotates, forcing the liquid inside to circulate, and finally spin the transmission shaft.
Even though I knew about some aspects (camber, toe-in/out) I had no idea so much went into the steering.
I'm building my first race car and I'm trying to learn as much as I can about suspension and adjustment. Thanks for the videos.
+Nermin C. Get an old "steve smith autosports" book. Depending on the kind of racing you do, the learning part is often skipped. Most people just go straight to what chassis builders tell them to do. The builders have years of experience and often have learned the science then changed it to "standard" setups and things to do to modify the handling characteristics without really explaining correctly the "why".
@engineeringjtc Yes, I understand what you're asking. It does not matter which direction you turn. If you understand the diagram to the bottom left, and simply mirror it, this is what occurs when you turn the tire the other direction.
Changed my caster 2.5 degrees. Went from unsafe to perfectly normal. 8.5 caster to 6. On Jeeps they call it "Death Wobble", any vehicle w a rigid front axle is susceptible to this extreme shimmy. Turns out this alignment parameter is the most important to cure it. Thanks for the video :)
Very welcome, glad your car is now safe!
Not just Jeeps. All modern 4x4's lose caster as you lift them.
@DarkStyler94 Yeah, I try to incorporate them when I have the means to, glad it helps!
Excellent. Everywhere else only explains what it is not how it works exactly. Just what I was looking for. Thank you!
That chair is JDM AF!!
@EngineeringExplained Yes, I was a little confused at what you were getting at, right up until you showed us your chair and then it all fell into place. Thanks!
this is the best video on the internet, HANDS DOWN!
If you aren't sick of me typing yet, you might be after this post! :) You've covered one important aspect of Caster angle and how it relates to a car's suspension but you've left out what I consider Caster's most important feature. Caster turns to camber when you turn the wheel. Caster and Kingpin angle (See your Steering Axis Video) tend to fight each other in this regard but on most production cars you will get negative camber gain on the outside tire and positive camber on the inside tire. This has a profound impact on keeping a tire flat to the pavement. This is far more important than the self centering effect of caster. Cars during the 60's have generally very low caster angles and poor kingpin inclination and the result of turning a corner quickly in a car made in the 60's will show huge amounts of positive camber on the outside wheel as a result. By upping the caster angle and tweaking control arm angles you get a much flatter contact patch and much more front end grip! :)
UrPeaceKeeper When getting an alignment is it possible to have even tire wear and drive straight but Caster be off? If so, how would you know?
gonna need a video on that
One big advantage is camber gain when turning. The higher the caster the more the tyres lean into the turn, usually resulting in better cornering grip. Best case scenario: You can lower static camber to increase straight line grip and increase caster to maintain cornering grip. More caster increases jacking though, which can affect corner weighting, and partially diminishes the effect of steering lock, so it's not without downsides. It also makes steering much heavier.
@oldskoolcooper You pretty much always want positive, at the worst neutral. Since Formula cars are going at much greater speeds, it wouldn't surprise me if the caster angle they used was much smaller than on everyday cars.
Genius idea on the chair!
I agree with you, but it's a nice way of showing how if the contact point is behind the axis of rotation, the wheel will follow the direction of travel.
@Carrera911Fan Uhh I believe those cars are just lowered.
@blackeyebully Yep, search my channel I have videos on both.
Great explanation, thanks for this! I've struggled to understand this for a while, you made it easy to understand :)
Your awesome dude, just one litle advice, i noticed that you started giving real exemples, keep doin that ;)
All of your videos are so easy to understand. Thank you
Very good explanation. Clears up confusion massively!
Man you are my idol. I watched this 10 days back and I was easily able to recall this during my yesterday’s exam.
@@Korokukanas Nope. I failed that exam and am considering quitting it.
@@Korokukanas Actually I am from a different branch - Aerospace. Automobile was one of my electives that I chose because of personal interest. To be honest, I passed that exam with A+ but as an engineer, I failed. I live in a country where aerospace has not much career opportunities. Even though aerospace share common subjects with automobile and also I did interns in renowned auto companies, when it comes to job, my degree is a hindrance. Mechanical/ automobile Companies do not prefer aerospace engineers. So I have quit automobile/mechanical.
@@hariharanmurugappan5466 Yeah that sucks man. I would say start writing letters to Aerospace companies and showing interest in employment. Otherwise you need to move to Florida or Texas and try to get a job with NASA. Which is a complete crap shoot I know. Good Luck, don't give up.
@@Korokukanas Thanks man. I appreciate that. I ll keep trying.
Really appreciate your explanation for self aligning moment .
Thanks a lot!! 谢谢
Great and simple
Thank man
Yes, perfect example!
I really enjoy watching your videos and have learned a lot from. I don't know how old you are but your look young and still you know all these things. I'm only 18 and problably don't know 1/4 the things you do but I am learning quit a bit. Thanks man
I have a decent amount of years on you, and new hardly anything at your age haha. Good for you starting early!
Thank you! This settles a disagreement on the meanings of caster & camber (Turns out I was wrong). We are big fans of 1/10th scale hobby-grade racing and C+C+Toe are incredibly important on such a small scale. Luckily, dirt tracks are a bit forgiving, however.
Now I can go out to my shop and apply names to the adjustments I need to make, and to make those adjustments with a better understanding of what's happening. Thank you, again!
Does a change in wheel diameter affect caster? I'm guessing that there would be more caster from larger wheels because the intersection point between the vertical axis and the rotational axis is lifted higher from the ground. Please correct me if I'm wrong.
Also, if you increase the caster in a car, would it become more difficult to steer because it just wants to remain true?
Was rlly confused. Thanks for the office chair example!!!
excellent visual...I've been teaching caster for 8 years as theroy and never considered that simple example. well done. consider it stolen.
...and thanks.
Thank you for the nice explaination and the simple but very understandable and interesting example. You can explain everything much better than my lecturer. I'd rather watch all your videos than sit 1,5 hours in the lecture.
You're a great teacher.
Outstanding!
When I drive in reverse at higher speeds is the steering more sensitive and some what hard to control because of the negative caster? I figure that if I am driving forward it is postive caster but if I am driving backwards it will automatically be a negative castor because I am sterring in the opposite direction.
Is that right?
Yes, but I'd say the biggest reason it sames more sensitive is because the rear tires are steering, not the front (when going backwards). This makes the turning radius significantly smaller, and also the rear of the car will want to swing out.
+Engineering Explained and that explains why it's easier to reverse park into a tight car park
and why forklifts steer like that..
Thanx , a smart simple explanation .
Ahah! This diagram in the top left actually helped me to understand the steering axis-inclination a bit better! Very nice video.
One question on steering axis inclination though: I can see how the inclination would pull the tire straight if turning one direction, but if the tire is turned in the opposite direction, would the inclination not push it up instead of down thus making the pull to straighten the tire only effective when turning one direction?
I hope that made a little bit of sense....
Explaining is good and all, but some visual aid like at the end of this video would be nice for the other videos, as well. I only watched the video abotu camber and steering axis inclination, from the Suspensions playlist.
The contact patch does change as you explain but that's not what is returning the steering wheel. Pressure on the spindle due to caster angle causes stability and wheel return.
@TheSaikou96 Mechanical, I think that's what you're asking.
great vid man! can i ask you a question? this dont relate to the topic of this video but iv been wondering this for quite some time. a while back you did a video on automatic and manual transmissions and you explained what a torque converter is and how they work, but can you explain why they work? i guess what im getting at is how do they creat the pumping action?
your r the best one in explanation
A simple way to understand what it does, it changes the camber at different steering angles. So if you run a lot of negative camber with positive caster, your leading tire has a better contact patch at sharp steering angles. Hence why drift cars have a lot of negative camber in the front to allow more front end grip.
Well explained and great demonstration. Thank you!
Excellent explanation
Hi Jason, I have a question, During the designing of the front suspension, does the axis of the Macpherson strut should pass through the center of the lower ball joint?
Great video!
I hope I can get a reply to this one. I was wondering if there were any issues (if at all) with having a double wishbone setup with positive caster but having a coil over mounted to the lower arm, in a slightly negative angle. i.e. the caster and the angle of the coil over forms a "V".
Thanks for videos. I have a doubt. What's the difference between kingpin angle and caster??
excellent explanation thumbs up thumbs up
Thanks!
Correct me if I'm wrong (since I'm not a kart racer), but isn't caster adjustment in karting largely a jacking issue? I've been given to understand that due to the spooled rear axle you need to unload the inside rear wheel if you want to get the kart to turn properly, which can be achieved with the jacking effect of caster. Too little = not enough jacking, too much rear grip, too much = too much jacking, not enough rear grip?
Please explain the concept of torque action on tyres due to caster
@engineeringexplained i want to ask that what is the caster angle of this chair is it having a zero caster as there is no angle between both the axis and the both the axis are parallel to each other?
My mum had a 2013 Mercedes-Benz C180. When the wheels were turned at full lock and you looked at the car front on, it was like there was a lot more negative camber on them. Does this mean there was a lot of negative caster?
hey !!! sir thanks for ur help for all topics u explained
can u please explain
WHEEL ALIGNMENT and WHEEL BALANCING
thanks a lot .. for the lecture..
I'm adding some 1/2" pads above my rear springs to raise my rear end and fix reverse rake (MK7 GTI). Do you know if anything other than camber will be affected and whether or not I should get an alignment after the install? Thanks
why does uneven caster cause pulling to one side? Do the wheel center slightly to one side? I understand that with camber the increased rolling resistance causes a pull but i dont get what forces causes the pull with uneven caster
Very nice 👍 👍👍 👍👍 👍👍 👍 thank you
How does the office chair not have a caster angle of 0? The wheel is rotating about a vertical line right? I see no diagonal line for the steering axis
Caster is just the angle. But then there are two arms (distances).
The intersection between the caster axle and the ground level is a point, the horizontal distance between that point and the vertical line trough the center of the wheel is one of them (the other is the the almost the same, but instead of ground level us measured on the center of the wheel level.
Office chairs have 0 caster indeed, but those two distances are not 0 ( and if caster is 0 they are the same, which is the distance between the center of the wheel and the vertical pivot axle of the "wheel bracket " )
404 English l guess
When getting an alignment is it possible to have even tire wear and drive straight but Caster be off? If so, how would you know?
Thank you. Hot damn you're good at this!
That's a clean carpet.
😂😂
What effect does extending my control arms have on the caster? Will the Caster become more negative or more positive with increasing length of control arms?
Is not negative caster on the wheel of the chair? Isn't Caster angle the KPI related with vertical line that pass thought the center of the wheel in the side view?
I thought the same, but the steering axis is perpendicular to the ground and therefore in front of the vertical diameter of the wheel
Awesome video!!! I like the way you explain things, it's just so easy to understand although the thing itself is so complicated. I'm crystal clear right now about what is caster and what the meaning of setting positive caster. But I am a little bit confused about the last part of your explanation, I kind of understand what you said about the positive caster in the normal office chair, but what is negative caster in this chair? What will it look like?
It would look like trying to push the wheel a direction and not having it follow, but stay in front. As you can see it always follows (this is positive), but when it's in front and you push against it, this is negative, and you can see it quickly flips around as this is not ideal.
Engineering Explained Ok, I got you. Thanks man, I will keep watching and learning and subscribing your videos just because they are so great and I can learn many things through it. Hope you will continue making great videos~
Nice video, but the example of the chair is not correct. This is called "trail" and is yet another variable amidst camber, castor and toe. Actually, the castor of the chair and shopping trolley is ZERO (its a vertical line), but it has x mm trail.
consider my car has positive caster (BMW e46). When I am moving backward (R gear), the steering wheel still can still center itself. It there another mechanism governing this behavior? Wouldn't a car with positive caster becomes negative caster when moving backward?
It’s kinda weird watching one of his videos when he’s serious w/ out the energetic enthusiasm
Geez, I really could have used all these videos back in 1999. When I used to play Gran Turismo 1, I had no idea what any of this meant. I just had all my suspension settings directly in the center of the bar.
----------l-----------
Sir, my car i20 front struts shockers are aligned perfect 90 degree with respect to ground when steering wheel is at normal or 0 degree position. However, the left shocker slanted bit about 30 degree approx with respect to its original vertical position when the steering is full turned to left. The same is for the right shocker when fully turned right. Is this change in vertical alignment normal??? Thanks.
so, with positive caster, your camber would become more positive with increasing steer angle, right?
@EngineeringExplained Ok, thank you very much. I misunderstood the rotational axis. Pretty stupid of me, but thank you for answering
Does caster change with application or is it somewhat standardized?
Dose caster effect the spring up and down?
@nerdypielover It's fantastic, finally my handwriting is legible. Well, sorta.
So what the use of it in terms of performance?
Question, if my upper and lower balljoint studs are inline with each other, can I assume that's zero caster? And if so, would moving the lower balljoint stud "forward" increase or decrease caster? And lastly is the direction of positive caster angle different if the steering arm on the spindles is on the front or back of the spindle arm?
+Cuzntime studz have nothing to do with it. What counts is an imaginary line drawn through the center of the pivot points of the ball joints. Usually, the studs are in line though. Steering arm location has no effect at all. there can be considerations with steering arm with "ackerman" and how the linkage may deflect under load but in an ideal world the arm can be in front or behind the spindles.
I might be wrong but the it's more about the point that the track rod attaches to the hub that defines the castor angle
can you calculate castor wth the use of inclinometer and angle plates. goedendag
Do a video on bump steer, please.
IMO you left something out that has a significant role in suspension setup.
Say you have 3 degrees of positive caster. If you were able to turn the wheels 90 degrees, that would introduce 3 degrees of negative camber on the outside of the wheel, and 3 degrees og positive camber on the inside wheel.
This changes the way the vehicle handles and the stability when travelling straight or conering.
Is this the same as the angle of the fork in a motorcycle (or bicycle)?
+Stefanos Tsantilas That makes sense to me, yes.
yes.bigger the difference between contact patch and turning axis at ground level, better it will cruise. (+caster will help you to ride a bike hands-free, since the front is always centering by itself. but harder to turn)
Yes
Hello~
I've got a question, is there an ideal caster for the rear suspension of a rear-wheel drive car ?
If there is , what value would it be and why would we choose that value?
Thank you!
+柯旭東 Since the rear-wheel doesn't turn, I don't see why would they put caster on it, other than space limitation concerns.
For the front. Positive caster help the front wheel to go in line of the torque, but it also make turning very hard (more work for steering pump). So they have to find the right value of +caster, where that front wheel would turn in straight on its own and close enough to zero,so steering pump can work as less as possible. Caster of Zero would be dangerous, bcz front wheel would wobble at any road resistance. (I strongly suggest you do a little reading about motorbike's front fork, especially on those chopper bikes. Choppers are harder to turn, but cruise well because of their fork geometry. they have ++ caster angle) Hope I helped :)
+YC Y Thank you for your explanation.
I was wondering what impact would caster have when talking about bumpsteer haha
+柯旭東 oh~ that one. I think if caster is zeroed, the wheel would have tendancy to turn into random directions everytime it pick a bump at any slight angle. But yeah, I'm not sure physically why it bumpsteers :)
Wait, you got me confused here. If a positive caster in a car is the top of a steering axle inclined backward, then how's shopping cart example of a positive caster? A shopping cart front wheels are always behind the steering axle. The top of the steering axle is inclined forward, not backward. What am I missing here?
Ahhh, all is now clear. Thank you very much! :)
The effect your describing is trail, caster induced trail but trail none the less.
Great explanation sir.Except your example,..in my own opinion,shopping wheel cart and chair wheel are example of a negative caster, not positive.correct me if I'm wrong.
Thanks J.P.
What if when it straightens it doesnt come exactly in the middle. but just a bit to the left. How can that be addjusted?
hey there, please help me!! my passenger side wheel moved back so when I turn left or right the wheel hits the fender.. I need your help and I prefer fixing it at home:) tell me what the problem I have..
thanks from KSA
so what is the advantage of having caster angle in circuit racing /
Your the freakin MAN!!!!
theoretically, would adding positive caster just make the steering feel more heavy?
With positive caster, the steering axis trails the tire. Assuming you have a straight up tire, (no camber or toe), that tire is going to want to travel straight. So yeah, theoretically steering will be heavier because of added resistance.
since I changed my tyres, i have felt that the steering has gone too light(eveb though the new tyres are much wider) i.e. it is too easy to turn the wheel even when not moving. And while driving the car seems to sway aimlessly and the tyre would not straighten themselves. What could be the problem?
I like your videos but your example with the chair actually shows negative caster. Draw a line from the wheel axle to the steering axis pivot point and you will see what I mean. Vehicle control requires positive caster because it lessens the effect of vehicle mass on the wheel direction.
Thanks!
can u explain skid steering
So the front wheel of a bicycle has negative camber? The patch is clearly ahead of the axis of rotation.
This must be why the steering is so unstable when you're "leading" your bicycle by the saddle and walking alongside, you have to actively tilt it to adjust steering.
The little tricycles kids use have positive camber though.
hi, please help me
how castor helps in steerability
Isn't it positive caster if it is tilted towards the front of the axis?
You mean front end of the car? No, it is negative. If the column is tilted toward the, say wind shield, then we have a positive caster.
Got a new Car (Suzuki Vitara LY) and the steering doesn't return to center all the way, the wheel stays at about 20° if you don't push it back by hand. On most bends, I can let go and the car goes around by itself. It makes going in a straight line on the highway and changing lanes very difficult. How likely is if for a factory new car to have the caster angle wrong, be it by accident or by design?
Hamachingo thats just bad alignment all together
Jasperrsworld that's my guess as well. Looks like my dealer didn't check/do the alignment after the new car came off the ship and now I gotta do an alignment on a brand new car and sending the bill to the dealer. Apparently they just bolt the cars together in the factory and the dealer has to do quite a lot to make it ready for sale.