Understanding Steering Axis Inclination

[@billwatkoskey3224]

Excellent explanation. The only thing I would add is that...The difference between SAI and the center line of the tire is called Scrub radius. Offset rims have a wider scrub radius. This is where death wobble and tire chop becomes an issue.

[@bigbothoee8617]

By far the best explanation I've seen clearly experienced thanks for this very helpful

[@garthrichert5256]

Have never seen such a clear explanation. What you made in order to show us about inclination was so good. Thank you.

[@dokuaasiedu9766]

As someone who has zero knowledge about how cars are made, this video has really helped a lot. Wow, I feel so knowledgeable now. You, sir, are a great teacher.

[@ziggassedup]

Just like back in school but way more fun...Excellent explanation sir.

[@jgilk1]

You make complex things simple

[@krazy45cat]

This the kind of stuff most folks don't have a clue on what you are talking about . Tons of hrs just in the planing , not to mention the fab work to make it work . I love this kind of stuff .I'm always ready to learn ,Gerry

[@rareearthfab5511]

This is a GREAT video and demonstration of steering axis inclination. The best on the web! I have used this video a BUNCH of times to explain to the Jeep guys what they are doing with large offset wheels and the effects on straight line stability over bumps that these changes make. Your demonstration and explanation is very well done. Thank you for taking the time to make the video!

[@groutaone]

Thanks for watching and for your generous comment

[@cj15941]

This is a HUGE thing when it comes to custom bike building! The camber plays a huge part in where the steering axis is and how a machine handles in the rough stuff. Thank you SO MUCH for being able to put this into words!!! I'm sharing it on all my social media outlets right now!

[@user-pu5ie6bh7m]

Really good demonstration I am calculating how the rolling resistance force act on the steering axis and I didn´t understand it until now with this video

[@rheniformer]

Very nice demonstration, Throw caster angle in the mix and it really gets interesting. One thing I wish more alignment mechanics grasped is; infinite handling characteristics exist within the "Green Zone" on the alignment screen. I watch time after time they look at the screen and every thing is in the tolerance zone - out she goes! Many times customers bringing a car in for not feeling just right, following cracks in the road etc. and the car is put back in the yard without a single adjustment because the measurements are within the "Zone", you teach someone off the street to do that in a couple hours. That's a really big zone when your talking thousandths! You can change a vehicles handling performance dramatically if the mechanic knows what he is doing and is willing to apply it, the results can be astounding!

[@dragkid185]

I really appreciate you going into this much detail on you buggy build, very few people are willing to give out their ideas like you do.

[@805ROADKING]

R&D at it's best!! Well explained and demonstrated Mate!!☺

[@LeftyLucyRightyTyty]

You can also call it Kingpin Inclination Angle(k i a)..I know in certain racing applications, centered in the tread patch (zero scrub) is desireable..very good demo, sir...

[@1941paco]

Oh Hell Yea!! Been watching this build with great interest......and this video was very well explained, nothing works better than a physical demonstration. Keep up the great work! I think you will have a really smooth riding powerfull machine there.....don't forget to name it.

[@lejink]

Interesting stuff, suspension is a complicated subject.. If there's more you could share I'd love to learn about it

[@MoviesasStories]

It really helped ...Wow..You actually made it look so easily understandable..

[@ravindernegi2374]

excellent explanation. groutaone will you explain the caster angle impact on car handling with your rc wheels illustration.i need to know how the forces act on negative and positive caster settings on. wheel

[@lakerdrinker]

My "Mad Scientist" friend always making my brain hurt....LOL The stuff I learn from you is unreal. Thanks

[@suryanaik3991]

Thank you very much for making it so simple and understanding

[@msturtev78]

Very interesting and well put together as usual. Thank you very much for what you do.

[@chance90064]

Awesome and great demonstration. I'm going to be making some trikes soon. I'm trying to learn about the steering geometry. Keep the videos coming!!

[@Micscience]

I agree when things taught this way it is so much more powerful. I get it now much better thanks man I appreciate the time you took to do this.

[@40nmugzy]

REALY CLEARS UP THE MYSTERY OF WHEEL GEOMETRY

[@paulgumper]

Thanks for that explanation. I wish you'd been an instructor when I was in school.

[@robertmichael8687]

Great explanation and demonstration, thanks!

[@brianb5779]

Something so simple but yet helped so much, thanks alot. Building my own setup and being first time and learning all this stuff to incorporate its nice to see basic explanations. Thanks for the video, i havent looked yet but hope you cover the other issues in more vids. Take care, Brian

[@MikePalmer42]

Elegantly simple explanation top job

[@w056007568]

That's terrific and answers a few points about our challenge truck!! Taller, wider tyres with a different offset!! I notice your suspension arms are adjustable for this reason to allow adjustment in the light of experience?

[@azarealbheri6876]

Wow!!Great idea to use the hinges.Understood the topic lot better!!Thank you. And if you can post mire videos on the parameters to consider while making a buggy in the suspension and steering sector especially you will definitely help many people like me.Because many students participate in SAE Baja an ATV competition that is held in many different countries.

[@ianmcknight7310]

Fantastic, very well explained. Thankyou.

[@patrickede31]

Fantastic explanation. Thank you so much for explaining that.

[@Tonygue3978]

do you know the difference in handling when the pivot point is either towards the inside or outside edge of the tire?

[@Kapco78]

Great job on the explenaton of the geometry. I also want to mention that I am completely jealous of your shop.

[@murraymadness4674]

It is also called KPI king pin inclination, and you didn't mention a key feature that it makes the wheels self-straighting, that resistance to going back is because it must lift the vehicle to rotate, so the position of least resistance is straight.

[@PredatorAlan]

very nice informative video

[@nitrosport5]

So groutaone, if you dont mind me asking you a question. On my 89 Honda pilot, i have a set of aftermarket adjustable +2 arms, and am using a set of front disk brake spindles and hubs from an 04-05 trx 450R. I never ran the pilot with the stock brakes and +2 arms as the stock bakes were trashed so i cant compare, But my pilot is pretty dodgy. It does not take much input of the steering wheel and it will want to zip one way or another. And, once i turn say half way one way, it really wants to pull the wheel the rest of the way. When i installed the TRX450 hubs, i had quite a bit of positive camber vs the stock hubs. I adjusted that out with the heim joints on the lower arm as well as the balljoint on the lower arm as both are adjustable. I currently am sitting at about -1* of camber. If i increased this amount of camber do you think that this would help my handling? Or could my issues be caused by bump steer since the kit used the factory location of the tie rods in the center of the machine and the geometry is not correct for the longer arms? Some of the true long travel kits use a set of intermediate tierods that will bring the pivot point of the tierods out to the same location as the a-arm pivot and i have debated about trying to install somthing like that one mine. thanks groutaone! keep up the good work!

[@groutaone]

nitrosport5 I'm curious where your caster angle is at, like a shopping cart wheel sometimes flips around not knowing where to go because of little or no caster

[@James4cefalo]

groutaone i use that same analogy all the time when trying to describe castor angles lol. nitrosport5 how much are you towed in? i wold think you would need to be in the ballpark of 1/16 to an 1/8 of an inch towed in and about 7 to 8 degrees of castor to get you at-least close.

[@nitrosport5]

James Cefalo its hard to measure the amount of toe in I have with all the bump steer it produces. But with the machine settled with rider weight I'm about 1/8" toed in. I will have to measure my caster angle

[@prancstaman]

Nice!! Front wheel drive cars depend on the offset of the rim more probably so the unibearings will last longer.

[@prancstaman]

***** Plus to keep the steering wheel from turning too from acceleration and deceleration.

[@DriveShaftDrew]

very good demo and info for all thanks for sharing it was interesting to say the least

[@mattriella6776]

excellent job simplifying the whole idea on how SAI works , what about when it comes to Toe out on turns?....or YAW......lol....i was just kidding....but on a serious note , what formula you use to build the control arms , the overall design looks like it would be really stable , i like it.

[@mobra66]

hello groutaone I have an question for you.I build an buggy and i want to use rods ends at the steering wheel like you use at the long travel buggy, but I don't have any details for the dimension on this rods ends.I'm from romainia and here its more complicated to find this rods ends, but I find a shoop who can gets me the rods ends but the problem is I don't now the dimension of this. can you help me with dimension of rods ends? thanks and sorry for my bed english!

[@groutaone]

alexandru radu Sure, I use 1/2 x 1/2 inch at the rack and 3/4 x 3/4 at the wheel end of the tie rod, I use a large one by the wheel because I can get more articulation from it

[@mobra66]

thanks

[@Ethericbikes]

hey have you finished the long travel buggy or have time and life made you put it on hold? was always very interested in the build since you do such good job explaining things and would love to see it done one day and ripping!

[@TufdogsPlace]

That's some good stuff. Thanks for sharing.

[@R1FamilyR1]

Very cool stuff here. Thanks for sharing.

[@fabiorobertoalonsode]

Thanks a lot! Here in Brazil I have zero information about suspension

[@srivishnu1217]

excellent explanation sir!!!

[@idriwzrd]

Good explanation and animation. What forums do you prefer for this kind of project?

[@That_Teal_fummins]

Thats why when you put wheel spacers on there hard on front end parts

[@jerrygibbs2148]

also when you choose your spindles just remember they have spindle degrees to choose from as well say you were choosing an impala or larger gm No 2 spindles they are designed with 8.75 degrees of spindle angle where a something like a mustang might have 10 degrees in it from the factory what those numbers really mean is that would be the degree of inclination at 90 degree fore or aft ....and nobody is going to do that, but what that will tell you is when setting up your camber and caster and say you turn the wheel about to 10 degrees at the wheel then you put that much caster and camber into it and you will have zero camber or caster gain and your tires will stay in full contact with the road..and give you a full contact patch at the ground . and that will increase your corner speed if that is what you are after as well

[@RamblinAround]

Interesting stuff...great explanation.

[@danielholmes2517]

how do you know all this stuff?

[@DanielNoest]

Thank you for this information, Sir!

[@mazdalorean]

Thanks. That was very informative.

[@beeqool]

so if i put bigger than stock tires on lets say atv, the steering will not be optimal?

[@groutaone]

beeqool Hard to say as your pivot point may actually move to a better spot than it is now. When suspension is designed at the factory they rarely get everything perfect but good enough that drivers are happy, have a look at your wheel on the machine and see if you can spot where the pivot point is now.

[@beeqool]

groutaone i cant im too poor for an atv it was just a curious question. but i didnt know that they rarely get it right thats weird.

[@groutaone]

It's more like there are many interpretations of what is correct by different manufacturers and these interpretations change over the years as new ideas are brought into the mix, like if you compare 50 year old suspension ideas to what we have today or years from now

[@beeqool]

groutaone ahh that makes more sense to me. engineers should know what they do but market dictates things too. i just know that my dad complains that suspension parts are to thin on new cars.

[@volkandeniz0048]

I like it, very good job

[@arunarya3252]

Very nice sir

[@Supercrewchief]

Great video. I had no idea... Thank you!

[@AKASHGUPTA4055]

great explanation! thanks

[@moscowfragfest]

Cool demonstration, you should do a similar one for your suspension setup/articulation. Do you use autocad or anything to figure out the geometry?

[@groutaone]

Paul Sowinski Thanks for watching, I just make it up as I go along, no programs except for trial and error and sometimes trial and errors with an S :)

[@TorontoDrivingVideos]

groutaone you should try the free program emachineshop, I don't know anything about autocad but I tried this and it was just like drawing on a napkin it was really easy to use, probaly just as easy to use than a video editing software. they give away the software for free hoping you will order parts through them but even if you dont you can still use the software

[@xaviertwilight7855]

Thank you that was helpful

[@405brandon]

awesome video

[@DanielHunterUSA]

Great job

[@sainigulshan8596]

nice brother keep it

[@PhunkBustA]

very informative, thanks

[@samburris9068]

excellent work bud..! only 17 so there isnt a whole lot of cash but.. still want to build a buggy. do you think 3000 is a reasonable price to get everything.? rrrr?

[@groutaone]

teenage TECH Thanks for watching, sounds like a tight budget but if you could use used ATV wheels, shocks brakes and engine and such the cost could be reduced if not it's going to be up there

[@samburris9068]

ya i figured so. if i could id buy a really cheap small car for drive train .. would you recommend that?

[@voltron63]

WOW ....made me think..

[@dannyr2976]

So clear, so simple. Thanks, eh!

[@skiingslasher1991]

Very interesting!

[@g6qwerty]

So that's why my car turns in easier into the corners with the stock 195 70 R14 rims than with the 205 55 R16

[@roadl1roIl25zzz]

很棒的模型

[@weskjar1505]

cool stuff thanks

[@follow_fraser3081]

Oh my poor 4runner with its -38mm offset wheels. Gezzz....

[@darcyfunk]

See kzbin.info/www/bejne/iYanfniaZseAkKs for more info on steering offset or scrub radius. Some positive offset or scrub radius is preferable in sports and road racing cars as this provides the driver with good feel from the front axle. Negative and zero scrub radius feel numb. If you drive each back to back to back I am sure you will appreciate a properly setup positive offset setup. In the case of equal mu (μ) situation between the two front tires under braking the induced moment of one tire is balanced with an opposite moment from the other tire. Carrol Smith wrote a number of books detailing road racing chassis setup and design including Tune to Win, Engineer to Win etc. see www.carrollsmith.com/books/. I worked with him on a Formula Atlantic team.

[@steffenjensen5018]

Nice !!

[@nunyabizzness9414]

Im thinking im thinking i need some chicken wings

[@dethkon2284]

Flip the one with the angle upside down

[@talon0863]

cool thanks

[@giuseppefacciolini4651]

Ciao

[@sammymac2866]

Cool, had always wondered why that was set up like that. Great job at explaining