ive been on a binge of these videos! such a good teacher, better than most of the lecturers at my uni!

Really good video. Great aha moment when you described how self-aligning torque drops off before you reach peak slip angle.

Here to apply tire knowledge to racing RC cars on asphalt... I see I've just scratched the surface. Thank you for the videos... I'm now off to binge watch!

Why couldn't college have been as interesting and exciting as this? You've just taken some of the 'least exiting' physics motorsport has to offer, and made it fascinating. Keep up the excellent work, Kyle!

This is the best explanation of how tires work I've found so far anywhere! Makes it totally clear how to make the most of them with driver's inputs!

Thank you so much for covering the section about Off Road. No one really talks about this stuff.

that part about overdriving a little since you cant feel the difrence in torque is an amazing explanation never knew that before, make me feel better about my overdriving in the sim(although i do grain a little to much sometimes) great vid learn alot thx!

The video is too good !! It would be very useful if you could make two more videos 1. A video explaining the details of tyre construction and how that affects slip angles 2. A video on all the factors which affect tyre grip such as KPI angle, camber, tyre pressure, castor and more detail into the friction ellipse. Thanks !

Great video. Love the additional insight into off-road tires.

Superb! I thought I knew about slip angles and stuff already but this went way more in depth into the traction of a tyre. Have to watch a few parts again to make sense of 100% of it. Thanks for taking the time to share your knowledge.

Learn Engineering brought me here. Clear description of the relationships in the equations you use (in fact, cleared up an unclear point about tire width and frictional capabilities I had in my physics courses). Subscribed.

You did a great job explaining tyres!! Hats off to you for that !! Can you please make a video on The effects of Kingpin Inclination, Caster , Camber , Slip angle of the chassis in another video ( as mentioned in 20:15 minutes in this video) ?

Wow, been looking for a video like this for ages... FINALLY! Thank you, subbed!

Best video I have seen on this topic! Please do a video on how different top F1 drivers use their tyres differently during entry apex and exit of a corner. I think most dirving coach cant explain it the way you do. Thx

hadn't heard the explanation of peak self aligning torque vs peak lateral grip before, that explains a lot! would love more detailed videos like this.

You have an amazing depth of knowledge in these things. I have seem a few videos in this regard on youtube but none of them compares to yours.

Thank you. You helped immensely with my school project.

Fantastic video Kyle! Really well explained :) I learn as much from your videos as I do from the Motorsport Engineering degree I'm working towards! If you could do videos on the suspension stuff that'd be fantastic! Keep up the good work :)

Awesome video, great explanation ! Thank you for your channel

Fantastic stuff Kyle, subscribed and every video on your channel queued up for watching. =) One thing that I think you could also have been mentioned (though I don't know how relevant it is these days, since radials are so dominant), is that the peak slip angle doesn't necessarily just increase with softer sidewalls and decrease with stiffer sidewalls, the rest of the construction matters tons as well. Some of the old bias-ply racing tyres of the 60s and 70s had incredibly stiff sidewalls, much stiffer than what we see these days, yet they also could have peak grip at very high slipangles, even at 10-12 degrees and beyond, with very little falloff as well. Compared to radials though they had very soft and floppy treads, so the deflection was happening there. It is my understanding that when radials started to arrive at the scene they still were building them with "traditionally" stiff sidewalls, making them just insanely sharp compared to the old bias-plies, and it took a while before they got their heads around how the sidewall behavior of a radial should differ from a bias ply. Today of course modern race car tyres combine aspect of both constructions. Talking with a guy who built and raced cars in the 70s and lived through the transition from bias-plies to radials, he said that one big difference was how much more camber they had to/could use on the radials. Bias-plies were often happy at low angles of -1.5 to -2.0 degrees, radials usually going well past -2 degrees for best performance. Do you think this was in part due to the sidewalls on the bias-plies generally being stiffer, so there was less tread rollover during cornering and hence less need to compensate with camber? He also mentioned that with radials you often got even more cornering performance running so much negative camber that the tread wasn't sitting flat anymore, actually lowering the contact patch size, the camber thrust effect could be so strong. It wasn't sensible to do though, and lead to such immense tyre wear issues that you were better off not doing it (reminds me of endurance GT3 cars running something like -3 or -3.5 degrees of camber at the front, whereas Michelin recommends -4.5 degrees front and rear for Porsche Supercup cars in sprint races).

Awesome explanation!

Very very helpful been looking alot into this recently especially the off road part

Fantastic video Kyle! I would have specialized in vehicle dynamics instead of powertrains if I had a teacher like you! As a suggestion for one of your next videos, could you discuss suspension design and tuning in detail? Keep up the great work!

Great video, finally someone covering this topic in more detail on KZfaq! I have a few questions about load sensitivity though. I've been looking at a lot of tire data in the last few years, particularly racing slicks, and what's weird to me is that the load sensitivity curve on many of those is the opposite of what is typically understood, including in your video. The curve starts dropping almost immediately from a high friction coefficient (2.0 or more) then gradually levels to a horizontal line at high load. I suppose it has to do with the materials used in the compound, most of which is not rubber, but can you explain why that happens in more detail? Also, in your experience, do high performance slick tires have the same zero load friction coefficient in both lateral and longitudinal, or the chemical interlocking with the road actually leads to different coefficients due to different contact patch shape (i.e. a much wider tire)? If so, do you think the friction coefficient then gradually levels down in both lateral and longitudinal directions as more load is applied and the contact becomes primarily classic friction contact (i.e. as the coefficient drops to 1.0 or less). And lastly, how much does the friction coefficient drop exactly, what defines to what level does it drop, does it even drop to zero at very high loads? Sorry for the long questions, but I'm really interested in all that and it's also needed for a project I work on.

Amazing Video! Cleared a lot of my concepts. I have also subscribed your channel on you tube. please make more and more such type of videos.

dear kyle, kindly use a MIC so that your lectures would be more clearer thank you

Just found your channel and I have been enjoying them immensely. I have a saying "In the religion of auto racing, the tire patch is god and all efforts must be in service to it. Worship false idols at your peril."

Discussion on off-road tyres, longer, skinnier contact patches with no ABS offer more braking when the wheel is partially locked so that the front edge of the tyre is clearing the road of loose gravel allowing the trailing section of the contact patch to run over a surface with a better coefficient of friction. A wider contact patch uses a higher percentage of the tyre for clearing and has a lower ratio of contact patch on the cleaner surface.

Finally, an explaination of tyre dynamics that does not go through trearing through Pacejka and M&M One thing to note though: Tyre curves include an elastic range where the car's response is almost linear and there is little slip happening, so we can accelerate or brake and still be nowhere near wheelspin/lockup As long as we keep to this range, the longitudinal forces act parallel to the heading of the rim, so in a corner they actually produce MORE cornering force and keep further from the bounderies of the friction eclipse, rather than closer to it Braking has the advantage of slowing down the car, so it can be used to trail-brake when you come in fast. Power has the advantage of also removing tyre drag so can produce even more cornering force, but increases speed and can thus only be used in short corners.

Good videos mate. Keep them up

Great explanation!

Might be worth making another video to expand on this about how tires work in wet conditions This one is great though, everything you do with a car (arguably) is to manipulate the tires, so people need to understand this one!

Brilliant vid!!

Do you have a video on the aerodynamics of tires? The reason I ask is, I was curious as to whether the fender on a motorcycle serves an aerodynamic purpose or if it's strictly to protect from debris. The same question applies to open wheel cars that have the fenders that turn with the front wheels.

Top notch, keep them coming. Would be nice if you broke down each section into more detail and separate out the videos. Cheers for your efforts

Very good video.

great video

Brilliant!

Please make a video about caster, camber, and all of the things you mentioned that you said you would cover if someone asked you to!

Amazing Video!!! Cleared a lot of my concepts.. Can you also please do a video on Understeer & Oversteer... and wheel alignment(Castor, toe, kingpin and cambr) effects?? Thanks a lot!!

u badass bro keep them videos coming

Your the real OG

nice work

sorry i am lazy at commenting but its cool video. 100% worth watch. thnx!

Thank you for this very informative talk. Just one question: HOW/WHERE can we find those data for a specific tire ?

You're legit dude.

Hi Kyle, very good video. The other factor not mentioned as how much the road surface itself plays a role in friction and tyre performance. Asphalt ain't asphalt, particularly the aggregates that go into them when you are racing on tracks across the world, there are marked differences across the globe and the microtexture (sub 0.1mm level) changes as a result. Microtexture is what primarily gives tyres grip, macrotexture (0.1-10mmlevel) is a measure of the voids that allow water shedding. If interest check out literature about the international friction index (IFI), tyres are half the grip equation, the surface is the other half.

A lot of off road tires, especially for dirt/gravel rally have very diff sidewalls to keep the tire side as close to 90degrees as possible to cut into road surface

I like how to don't fck around with your presentations. Cool. :)

Dude, could you recommend me some books where I can learn how to design suspension? Not talking about tune, but creating it from scratch. When a company creates a new design for an old car like a Mustang or Camaro. How to start learning about it? Thanks and great videos (only found your channel today)

I'm designing a hill climb open wheeler, Hayabusa engine at rear BUT thanks to formula libre rules and using cfd from the web I can generate 4 times the vehicle weight at the tires so, 4g cornering and braking. So the tires have to have accept a 4:1 ratio of normal force and 6:1 ratio of lateral force. I imagined that tires for high downforce cars would have a higher vertical stiffness, BUT, to my surprise the Avon data for FSAE is around 1000 lb/inch and Indi Lights are around 1500 lb/inch. I also notice the tire diameter increases with speed and downforce. So for the indi lights the 1500 lb/inch is not as big a % of sidewall deflection because the sidewall is higher. This is the limit of my understanding having looked into it all for about a week. I suspect there are a lot of people who are wondering how it all works, just as I am. I have a pdf that shows what I have found out but have no idea how to send it to you. Cheers John

Hello good sir, I understand what you are saying because I a driver and I have experienced these concepts. The average person needs keywords and definitions. LATERAL GRIP is a keyword and needs a simple definition so ppl without experience can visualize it. Write it in big bold letters and define it!

liked,subscribed.... good job.helpes me in my sae works........

Make a video on selecting the proper tire threadwear and width. I have never seen one.

i will like to see if you can make a video on dragracing and tires.. how digg grip and peak grip and etc.

PLEASE PLEASE PLEASE do a video on suspension geometry PLEASE I've never been able to find a decent video on it

I think the reason why oversteer is used in off road is to use the dynamic friction of the wheels to push the car through the corner. Like a centripetal force pulling the car around a bend.

Thank you for the ortographical precisation. As a foreigner I never understood if I've to write "tyres" or "tires", and how to translate "gommista", the worker who changes the tires on the cars (tyre worker I read)

I was hoping you might go into more detail on the effect of the portion of contact in transition, the section of the patch coming into and out of contact with the road which is travelling at a different speed to the road surface. You touched on patch shape, I started thinking about target contact patch shape and how to achieve it, have you some thoughts on this ?

Could you possibly make a video of designing suspension around a given tyre data. I know this is incredibly in depth but maybe just talk about recommendations for geometry based around this data. I know Avon have tyre data for their FSAE tyres. Also could you make a video going over force based roll centres?

Great video, can you explain how audi lmp1 hybrid system works.

Is it possible to build a system into a rim that can fit under an existing tyre (no modification to the tyre itself) that can circulate fluid within the tyre to help regulate pressure and temperature?

Thank you for making such great video KYLE, I am currently working on suspension of formula SAE cars and i don't know why i even want springs on this things assuming perfectly smooth road. Can you explain why i need to have body roll in my car. And how lateral weight transfer helps in cornering of car? how roll centers height with set of springs and ARB reduces/increases weight transfer?

I have an interesting question... Say you had a car (assume 50:50 balance, neutral suspension balance etc) with the same tire width and compound front and rear - but the front tires had stiffer sidewalls, and the rear much softer ones. If the car is at maximum lateral load in a very long corner (like a skidpad), would it behave as though it had 4 wheel steering? (slip angle in the rear greater than the front at maximum lateral load)

Wait, so does the narrower contact patch have less rolling resistance? Sorry if its a dumb question, im new to this stuff.

So is slip angle relative to the amount that the contact area is turned vs the rest of the wheel, or the amount that the contact area is turned relative to where the tire is actually going?

whats your take on tires with camber built in to the carcass? (Smaller inner sidewall aspect ratio). I run hoosier a6 315mm to autox and run michelin pss on the street and found some really interesting tires that are supposed to but a compromise between the two (11/32 tread), and I already run >-2.5 degrees camber up front and >6º positive caster.

Can you do a video about Ackerman? I generally know what it is, like: turning radius, inside tire scrub, blah-streetcar-blah, etc.; but I want to know about racing applications. In Karting, it is used to increase (more Ackerman) or decrease (less Ackerman) chassis "jacking" due to front end geometry. What I'm interested in is the application in full size racecars. They don't "jack" the way karts do.

whats better for drag or sraight acceleration on street

tire air pressure devide by weight/load on tire =square in("^) of contact patch. eg3420lbs ÷80psi 42.75"^ 3420lbs ÷40psi =85.5"^ now narrow tire say 235 will have a long skinny patch, 310will have a short wide patch . aspect ratio the 2nd number in the size will also play into the patch shape under static and dynamic load. load rating vs construction is a 3rd factor. eg my 235/85R16lt 10pr LR E toyo ht at 50 psi /2500lbs/2 1250lbs per tire, had stiff side walls with minimum rear stearing from warn shackles(parts in hand to repair) change to a different brand with all the same"rating " now the truck has sever rear stear(initiate the turn ,straiten the wheel and use the throttle to change trajectory, I some times have turn out as the ass swings out to stay in the curve and not hit the in side wall.)@70psi. it fills like a low tire when over inflated(lifting the sholders) at 40psi it fills like a flat, but a full contact patch@at 37% load capacity. (.5) 50/1250=25"^ old toyos (1)40/1250=31.25"^ Vs (2)70/1250=17.85"^ 1) good, brakes and forward bite flat wear patern, bad corners must be taken @5 under the advisory. 2 )mediocre brakes and forward bite center wear(still has casting tits 1.5"both sholders3000mi in) good cornering +20 on the advisory .5)old toyos flat patch grate corners brakes and forward bite same 50mph advisory @80-90mph chears

question: at 12:30 you draw 3 lines, where the " lightest car" has more slip angle at a low Fn than the other 2 . that incorrect isnt it ? not only will a lighter car on the same tyre have a smaller slip angle it will also generate more corner force .

what is the the difference between final gear and the last gear of the gearbox?

i would like to recommend you one important thing. Do promote your videos. ;)

U said the narrower tyres will be better used in speed racing compared to that of wider ones due to energy loss in latter. then why does f1 cars use wider tyres.??

I love to watch your video. but your voice is to quiet. Can you turn up the gain or put mic closer? I watch on my phone and all the way and can hardly hear you.

This is why Fernando Alonso had such a weird driving style in 2005/6

V VOLUME!!!!!

I can't hear shit without headphones...and I don't have headphones. Possible to edit and improve sound?

dont start this vid at 20:11. out of context, it seems a bit too racey.

Too long