Hog-wilding
March 17, 2017 9:41 AM   Subscribe

As any motorcycle rider knows, some of the greatest fun you can have is a nice, sedate ride along a twisted mountain road. Sports bike enthusiasts sometimes like to make that ride a little more exciting. But every now and again, you get a big boy who shows the sports bikes how to do it.
posted by hanov3r (62 comments total) 5 users marked this as a favorite
 
Harley dude's tire slipped out a little bit for a moment there and my entire gut clenched instantly. This is scary enough doing it freewheel on a bike, not sure I'd want to do it with a motor.

Also, geez sportbike dude, give Harley guy a little space there. A handful of gravel and you're both toast.
posted by GuyZero at 9:44 AM on March 17, 2017 [4 favorites]


The tire slip in the big boy link was an obvious oh shit sort of moment but a couple of those close shaves on the rock outcroppings in that same video have a kind of aftershock fuuuuuuuck flavor to them that's a lot more potent. Eeeeesh.
posted by cortex at 9:49 AM on March 17, 2017 [2 favorites]


Harley guy is a squid.
posted by My Dad at 10:01 AM on March 17, 2017 [4 favorites]


no chicken strips on that harley.
posted by Sternmeyer at 10:01 AM on March 17, 2017 [2 favorites]


"a couple of those close shaves on the rock outcroppings in that same video have a kind of aftershock fuuuuuuuck flavor to them"

I don't ride but am friends with plenty who do, and I started watching this video mentally screaming ATGATT at the screen ... until I saw that first close shave on an outcropping and thought, "Doesn't really matter how much gear you wear if you pop your entire noggin off on a pokin-out rock."
posted by komara at 10:04 AM on March 17, 2017 [1 favorite]


*******
posted by lalochezia at 10:06 AM on March 17, 2017 [1 favorite]


Hope you don't hit a patch of gravel...
posted by clawsoon at 10:07 AM on March 17, 2017 [2 favorites]


Well, he had a helmet on, so at least his head would be intact in his casket.
posted by nevercalm at 10:15 AM on March 17, 2017


I ride, and I'm ATGATT - but shit, every part of me was saying "that's AWESOME" through that video.
posted by generichuman at 10:23 AM on March 17, 2017 [6 favorites]


I have driven that road in the first video many times. But in different old Land Rovers, so the driving dynamics left something to be desired. But the view is great.
posted by Harald74 at 10:29 AM on March 17, 2017


Obligatory shout out to the Calamari Race Team.
posted by generichuman at 10:30 AM on March 17, 2017


This last fall I was driving from Tennessee to Joyce Kilmer National forest in North Carolina. The quickest route there took us through some winding mountain roads on the TN/NC border. As we were driving deeper into the mountains we start seeing signs for something called the Tail of the Dragon. We start seeing stores advertising Gopro rentals and crotch rockets all over the place with riders wearing Gopros on their helmets. I think we saw a sign that advertised over 100 turns over the next ten miles. It was insane, I was driving a rental Toyata Rav 4 and I was surrounded by sports bikes, Corvettes and Porsches.

Once I adjusted to the pace, it was fun. There are a lot of turnoffs, which I used, and most of the riders were polite and safe. One asshead, in a Porsche, was driving way too fast and was mere inches from my bumper for a few minutes before I could turn off. I did see one aftermath of an accident. One biker dumped his ride on a corner but he didn't look hurt too bad.

I'd like to go back up there in my Honda Fit. Zoom zoom.
posted by zzazazz at 10:41 AM on March 17, 2017 [3 favorites]


Speaking as a long-time motorcycle racer, Harley Dude's definitely got skills. His lines are tight, and he's really good about not crossing the double yellow. I wish he'd put on some damn leathers though.
posted by hackwolf at 10:44 AM on March 17, 2017 [8 favorites]


It was wild watching him scootch all over the bike with those ape-hangers, reminded me of sidecar racers.
posted by Slap*Happy at 10:46 AM on March 17, 2017 [3 favorites]


every part of me was saying "that's AWESOME" through that video.

Meanwhile every part of me was clenched and sweating...that's why I switched from two wheels to four.
posted by Greg_Ace at 10:52 AM on March 17, 2017


he's really good about not crossing the double yellow.

He leans his head over the line a bunch of times which is a funny combination of risky and unavoidable, but yeah, at least he kept his wheels in his own lane. Dude can definitely lean.
posted by GuyZero at 10:54 AM on March 17, 2017 [1 favorite]


The Harley video, if I'm correct, is on Angeles Crest Highway, which my husband and I ride all the time. Total SQUIDs. I'd give them a million miles of room and come up on the rescue chopper in 20 minutes after they've gone over the side like someone does every weekend.

Yikes.
posted by Sophie1 at 10:55 AM on March 17, 2017 [2 favorites]


I once cornered deep enough on my old XS650 that I scraped the frame. I took a little break from riding for about 15 years after that.
posted by Stonestock Relentless at 10:56 AM on March 17, 2017 [4 favorites]


I am clearly missing some important motorcycle related gene because while I can appreciate the skill involved in the Harley video I have zero interest in ever trying that myself.
posted by Mr.Encyclopedia at 11:05 AM on March 17, 2017 [1 favorite]


something called the Tail of the Dragon.
The Dragon is actually 318 turns in 11 miles.

It's made of awesome.
posted by teleri025 at 11:06 AM on March 17, 2017 [1 favorite]


This is oddly similar to skiing, just with slightly more instant death.
posted by kleinsteradikaleminderheit at 11:19 AM on March 17, 2017 [2 favorites]


something called the Tail of the Dragon.

I once drove that road - in a 15+ year old VW bus, in the rain. Needless to say I did not reach GoPro-worthy speeds, but it was kinda fun to cruise it sedately enough to enjoy the scenery.
posted by Greg_Ace at 11:27 AM on March 17, 2017 [1 favorite]


The last link reminds me of an old joke:
Q: Why don't Harley-Davidson riders wave to other motorcyclists when they pass them on the road?
A: They are too busy hanging on for dear life!
posted by Multicellular Exothermic at 11:32 AM on March 17, 2017


I appreciate that the guy doing the filming, has the camera mounted on his helmet. Saves me a lot of work tilting my head properly to not get sick watching. I can't stand the ones where the camera is mounted to the bike.

There are many riders who feel that the most cool factor is found by passing sportbikes while riding a bike that is a clear disadvantage. I used to run into a guy at Deal's Gap who did it on a GoldWing. The corners of his side cases were ground away. You can also meet a lot of guys whose footpegs are ground to sharp points.

I used to want to be that cool but I got put off it, the weekend I was first on the scene for a couple on a Harley who went off the outside of a turn on the Cherohala Skyway (no gear!), and they got an ambulance an hour faster than they would normally, because it was already up there for a guy who got helicoptered out about two miles up the road, and when I got over to Deal's Gap it was blocked because someone had been killed.

I mean, you can develop your skills and that is super fun and awesome. But you'll still get passed by someone willing to take more risks. I guess I just got too old.
posted by elizilla at 11:33 AM on March 17, 2017 [5 favorites]


I appreciate that the guy doing the filming, has the camera mounted on his helmet. Saves me a lot of work tilting my head properly to not get sick watching. I can't stand the ones where the camera is mounted to the bike.

That's an interesting thing about it: it seems like it must be headmounted but has also been super duper stabilized independent of his actual head motion. You can see helmet bits dipping into frame now and then, and what looks like hints of the stabilization process rotating and translating the original frames enough that voids of no-content sneak briefly in at the corners. Took me a minute to really settle in on the fact that the footage wasn't just not-turning-with-the-bike but was weirdly glassy smooth. Gives it a strange uncanny feeling in exchange for making it easier to track.
posted by cortex at 11:38 AM on March 17, 2017


GoPro and the other action camera manufacturers have introduced much better and more aggressive image stabilization with the latest generation of cameras (Hero 5, etc). It makes helmet camera footage a lot more watchable.

I've started to see more people running chest-mounted cameras with active gyroscopic stabilization as well. It's pretty amazing; that kind of stuff used to cost tens or hundreds of thousands of dollars and weigh a ton.
posted by hackwolf at 11:50 AM on March 17, 2017 [2 favorites]


*remembers all those weekends in the Bay Area, just trying to drive safely to a trailhead for a nice backpacking trip without vehicular manslaughtering some suicidal person on a motorcycle*

*spits*
posted by gurple at 12:05 PM on March 17, 2017 [2 favorites]


whooo yeah that harley guy sure can not wear safety gear and make showy turns with a lot of lean i guess, 1:06 is just like: no no no no no no no no

i enjoy motorcycling very very much but i really don't like this kind of thing
posted by nixon's meatloaf at 1:04 PM on March 17, 2017


Stunt wingsuit jumpers and guys like this always get nice writeups after they've run out of luck.
posted by surplus at 1:54 PM on March 17, 2017 [2 favorites]


Big boy can get bent. Go to the track and keep this off the public right of way.
posted by andorphin at 2:20 PM on March 17, 2017 [8 favorites]


The baby apes were a nice touch.
posted by TedW at 3:09 PM on March 17, 2017 [2 favorites]


It shouldn't be much more difficult for a Harley to perform these maneuvers than a sport bike. The physics for both are pretty much the same.

The lean angle for a bike is the same whether a bicycle or Harley by the equation for circular motion:

tan(lean angle) = V^2/(g * r) where g is the acceleration due to gravity and r is the radius of the turn.

Note that there is no mass in the equation. Every bike leans at the same angle given the same speed and turn radius regardless of weight.

The centripetal force required to turn is proportional to mass (Fc = m*v^2/r) but the first order frictional force developed by the tire is likewise proportional to mass (Fr = u*m*g) so they cancel out. A heaver bike requires more centripetal force to turn but a heavier bike also produces more friction force between the tire and road by cancelling amounts. So bike weight really doesn't affect the turn.

Notice that the frictional force does not include area in the formula, so to a first order, it doesn't matter whether you have wide tires or skinny tires. They produce the same amount of friction. Where the formula breaks down is when the friction force per square inch starts to cause the rubber to separate from the tire -- a skid. So, at least up to the point of rubber failure, tire width doesn't affect the turn.

Another thing to notice is that the rider shifts his weight from side to side, hanging out over the seat and squatting. This is because the angle of lean is measured on the line from the tire contact patch to the center of mass of the bike plus rider. By squatting lower, the rider can lower the center of mass which means that the bike itself doesn't have to lean as far, even though the bike/rider combined mass has the same angle. This makes it quicker to go from left turn to right turn and back because the bike doesn't have to move through as great an arc when shifting from turn to turn. The rider is using his muscles to move the center of mass as needed for the turn. But it doesn't affect the performance of a single turn. It wouldn't make any difference if the rider sat up straight as long as the foot pegs don't scrape.

Where differing mass does make a difference is when going very quickly from turn to turn because it takes more effort to move the center of mass from side to side. But in this demonstration video the turns weren't that tightly connected.

So, bottom line, the Harley should perform about as well as a sport bike in these types of turns. Where a lighter bike has an advantage is in transitions between tightly connected turns and for braking and acceleration coming into and out of turns. That wasn't much of a factor in this demonstration video.
posted by JackFlash at 3:16 PM on March 17, 2017 [6 favorites]


JackFlash, are you taking into account the rake of the Harley's fork vs the sport bikes? The farther forward that front tire (and the greater the distance between the contact point of tire and ground and the line of the steering axis), the greater the resistance to change of angle. At least, that's my understanding.
posted by hanov3r at 3:57 PM on March 17, 2017 [6 favorites]


Pretty exciting stuff, but it's no Guy Martin.
posted by dazed_one at 4:02 PM on March 17, 2017


something called the Tail of the Dragon. e start seeing stores advertising Gopro rentals...
posted by zzazazz


Hi. I'm workerant. I'm a motorcycle nut. I own a motorcycle shop. And I'm local to the dragon (also known as Deal's Gap), as in, I live about 6 miles from Tabcat Bridge, which marks the north end. I ride mostly dualsport these days, but I raced with WERA for four years so I know my way around a sportbike. I also have a sidecar to carry around my dog.

Deal's Gap is a complete clusterfuck during the riding season, with out-of-towners and flatlanders overriding their ability and judgment. This is not an uncommon thing to see. I have to go through Deal's Gap fairly frequently to get to other places; I make a point of going through early in the morning or late in the evening.

It is always a treat to come up behind a skilled rider on any bike. The poetry of motion is a joy to behold. But for every one of this Harley guy, there are a hundred riders who brake in corners, run wide, target fixate and endanger everyone else on the road. Living near a 'destination ride' is a mixed bag, to say the least.

And zzazazz, the guy who rents GoPros? He's a friend of mine, super nice and very well respected around here. He used to be pretty fast on a bike but after his wife (on her F4i) hit a wild boar in the Gap and got pretty busted up, he switched to sportscars.
posted by workerant at 4:22 PM on March 17, 2017 [12 favorites]


So, bottom line, the Harley should perform about as well as a sport bike in these types of turns.

That is an extremely simplistic view of bikes and completely ignores *most* of the physics involved, rather than being able to say 'Physics supports them being largely the same'. Weight distribution, suspension geometry, tyre dynamics and shape, spring and damping (ESPECIALLY damping) dynamics. They are all factors of probably equal (or at the very least half as important) in magnitude to your simplistic example of purely mass and lean angle calcs.

it doesn't matter whether you have wide tires or skinny tires. They produce the same amount of friction.

This is just not true, as it doesn't allow for tyre shape, sidewall stiffness and contact patch size as a result. Contact patch is a massive factor in the ability to produce lateral grip. Yes a wider tyre won't be any better if it has a right angle shoulder, but a wider, better shaped and more compliante tyre absolutely produces more contact patch and so more friction. That is also ignoring tyre compound. A bigger, sticker, better controlled contact patch will be able to produce more lateral g regardless of lean angle.

Proof if this is that the sportbike following wasn't even trying by comparison, and the guy on the Harley was working HARD and was extremely good.
posted by Brockles at 4:45 PM on March 17, 2017 [9 favorites]


are you taking into account the rake of the Harley's fork vs the sport bikes?

In slow speed tight turns that effect would be more noticeable, but these turns aren't that tight. There is plenty of time to lean into them.

The biggest difference I see is foot pegs. The Harley has low foot pegs which can scrape the ground. Since both the sport bike and the Harley have to lean to the same angle in the turn, you can keep the Harley more upright by the rider leaning farther. What matters is the lean angle of the combined center of mass of bike and rider. More lean of the rider and less lean of the bike itself prevents the foot pegs from scraping. To allow for a much greater lean, the sport bike has raised foot pegs and to keep your knees out of your chin, moved to the rear.

So the extreme hiking out of the rider on the Harley is simply because it has low foot pegs which restrict the lean angle of the bike. The sport bike rider can keep a more comfortable upright sitting position and simply lean the bike over farther without scraping footpegs.

So that's the big difference -- foot peg location.
posted by JackFlash at 4:45 PM on March 17, 2017


Living near a 'destination ride' is a mixed bag, to say the least.

My ex-mother-in-law lived on US-9 , in the twisty bit a couple miles up from its start outside of Black Mountain NC. She dreaded sunny weekend days because it was such a go-to destination for enthuiastically-ridden loud-ass bikes.
posted by Greg_Ace at 4:48 PM on March 17, 2017


Proof if this is that the sportbike following wasn't even trying by comparison, and the guy on the Harley was working HARD

Proves nothing. The guy on the Harley was working hard because he had to keep his foot pegs from scraping. Hiking out more to keep the bike more upright. The sport bike rider could simply lean the bike more and sit up comfortably. Both had exactly the same lean angle of combined rider and bike center of mass. That's all it is.

As for tire shape, you are talking about auto tires which are rectangular in cross-section. The reason most bike tires have a round cross-section is so that the contact patch remains nearly uniform regardless of angle of lean. A bigger tire patch doesn't not increase friction. The friction is independent of contact area. What can matter is the maximum friction per square inch at which the rubber fails and begins to scrape away. But if you are below that threshold, it doesn't matter if you have skinny or wide tires. Note that supersport bikes doing 200 mph into turns don't have tires that are any wider than the typical recreational bike.
posted by JackFlash at 5:18 PM on March 17, 2017


Got a few minutes into all of these and thought "Yup, that's why they call them donorcycles."
posted by mhoye at 6:34 PM on March 17, 2017


Dammit, WorkerAnt, I either want a '70's toaster-tank tourer or an early-to-mid '90s vintage PD. The boxers after that got Goldwing fat. (Or an early '90s Honda Hawk GT, those are golden, or a modern Susie Doc Six Five Oh. If I can't get a classic boxer or the best small bike Honda ever built, I'll take the best thumper available today, thx.)

I have a mortgage instead. :(
posted by Slap*Happy at 7:15 PM on March 17, 2017 [2 favorites]


I guess the lines will be different in a wheelchair.
posted by marvin at 7:25 PM on March 17, 2017 [2 favorites]


I guess the lines will be different in a wheelchair.

I would pay a dollar to watch that video.
posted by Greg_Ace at 7:40 PM on March 17, 2017


I guess the lines will be different in a wheelchair.

What you want is a wide-track chair with a very low seat. Also helpful would be a buddy in a sidecar for ballast if you don't mind him climbing over your back for off-side turns. See video.
posted by JackFlash at 7:44 PM on March 17, 2017 [1 favorite]


As for tire shape, you are talking about auto tires which are rectangular in cross-section.

No, no I'm not. I am aware of the difference but not even all bike tyres are made the same (that Harley has a visibly more oval - although not square- cross section to the tyre than a typical sport bike tyre). They are like that for ride comfort and its part of the reason he had that throttle-on oversteer, because he was more on the shoulder when he went to full throttle. But not all bike tyres are the same shape and not all of them have the same sidewall construction (as in structure, not basic shape) and so some are better for maintaining contact patch on deformation in the lean than others. Also, different tyres have different compounds - sport bike tyres are usually much softer than cruiser/chopper tyres. Surely you aren't saying that tyre compound doesn't matter?

The friction is independent of contact area. What can matter is the maximum friction per square inch at which the rubber fails and begins to scrape away.

Those two statements are mutually exclusive. If friction can be measured per square inch, contact patch size*has* to matter. In addition the point the rubber fails and 'scrapes away' is tyre wear though load. This is what happens when you work a tyre, which is why they wear out. And why they leave black lines when a Harley slides in a corner. Rubber 'scrapes away' when it is being loaded and in general use all the time. So it is never *not* mattering as an aspect.
posted by Brockles at 8:40 PM on March 17, 2017 [3 favorites]


It looks like there are rubber pucks along the double yellow line...if so, good.
posted by bonobothegreat at 8:44 PM on March 17, 2017


Brockles in the House, yo. Actual expert opinion. When we disagree, he's always right. I build secure networks. He builds racing vehicles that win.
posted by Slap*Happy at 8:52 PM on March 17, 2017


JackFlash - not to put too fine a point on it, but you don't know what the hell you're talking about here. Like, you're into Pauli-esque "not even wrong" territory. If you'd like to learn why, or some of the really interesting engineering and physics behind motorcycle handling, I would highly recommend Tony Foale's book "Motorcycle Handling and Chassis Design: The Art and Science".
posted by hackwolf at 9:20 PM on March 17, 2017 [2 favorites]


There's an old New Yorker cartoon: "On the internet, nobody knows you're a dog."

Ignore appeals to authority at your own peril.
posted by JackFlash at 9:22 PM on March 17, 2017


Wow, instant nostalgia. 30 some years ago my somewhat unreliable 60 cubic inch Sportster and I ended up in a cabin way up Yerba something Canyon for a couple of weeks. Shoulda got a ticket for littering, after scraping so much metal off the pegs. Then I got to borrow a RD350, Yamaha's hot little two stroke. With its two extra gears and fresh Dunlop tires it just ripped up that road.
I liked my torquey Harley,but not even a XLCR was going to keep up with those short, lightweight rice-burners in the corners. Good times.

Now a 750 sidecar rig, neither as fast or as pretty as workerant's, is what get me and the dog down the road.
posted by ridgerunner at 10:03 PM on March 17, 2017 [1 favorite]


JackFlash's posts here need to start with "first, assume a spherical cow".
posted by deadwax at 10:26 PM on March 17, 2017 [3 favorites]


I guess the lines will be different in a wheelchair.

Not necessarily so much
posted by ridgerunner at 10:57 PM on March 17, 2017 [1 favorite]


Brockles in the House, yo. Actual expert opinion. When we disagree, he's always right. I build secure networks. He builds racing vehicles that win.
posted by Slap*Happy at 11:52 PM


I've run a motorcycle parts counter since 2001, which involves everything from supporting high-level club roadracers to outfitting bikes for the Trans America Trail. Everything Brockles has said in this thread has been correct. I'm very impressed with his knowledge; car dynamics and motorcycle dynamics are very different and I didn't know he knew this much about bikes. I definitely don't know as much about cars as he knows about bikes.
posted by workerant at 5:27 AM on March 18, 2017


JackFlash's posts here need to start with "first, assume a spherical cow".

I'm not sure what you are disputing. All objects moving in a curved path obey the basic laws of physics. The formula I provided for the angle of lean applies the same to a bicycle, a sport bike, Harley and even an airplane. They all will have the same angle of lean following the same curved path at the same velocity. Weight and size do not affect this physical law.

The sport bike rider can simply lean into the curve and achieve the proper lean angle while sitting upright. The Harley rider cannot achieve this same angle while sitting upright with his bike because his foot pegs would drag. So he has to hike out. This shifts the center of mass of the bike and rider combination to the side and downward. This means he can achieve the required lean angle to the center of mass while the bike itself is slightly more upright, providing clearance for the foot pegs. The Harley rider has to work harder, shifting his weight, to achieve the same lean angle as the sport bike.

So that's the basic difference between the sport bike and the Harley that you see -- the foot pegs -- which requires extreme body movements to compensate for. If you moved the footpegs up and back like the sport bike so that the bike could lean farther, the Harley rider could comfortably ride the curves sitting up the same as the sport bike.

The Harley rider is borrowing a technique used by supersport bike racers. They enter sharp turns approaching 200 MPH (and note that the tangent of the lean angle goes with the square of the velocity.) This means that the required lean angle, according to the laws of physics, is so extreme that even their skinny bikes with high foot pegs have a clearance issue. They use the same technique as the Harley rider, hiking out to lower and move the center of mass to the correct lean angle while allowing to the bike to be sightly more upright.

So is there something you dispute about the "spherical cow"? Is there something you dispute about the physics of the lean angle? It really is that simple. Any high school physics student can understand it.
posted by JackFlash at 9:04 AM on March 18, 2017


I'm not sure what you are disputing.

Probably this.

It shouldn't be much more difficult for a Harley to perform these maneuvers than a sport bike.

To make a Harley perform like a sport bike you basically have to be Erik Buell and to generalize his opinion of the V-Rod mill to Harleys over all, they're "too big, too heavy, too expensive and too late"

I'd like to have another HD to putt around on in the afternoons, but trying to keep up with a Ninja in the corners would just be silly.
posted by ridgerunner at 11:11 AM on March 18, 2017


I'm not disputing anything about the "spherical cow", it reads reasonably enough and would probably work well as a high school physics problem. It's pretty clearly a grossly simplified physicist's explanation though.

You have people who know bikes back to front explaining how you are not considering everything and how many of the equivalencies you draw are not as equivalent as you'd like and you don't seem too keen to listen to them. The cow is not as spherical as your model assumes.

I'd like to see you address suspension setup and damping differences (which are pretty big!) for one thing, but I'm no expert.
posted by deadwax at 2:52 PM on March 18, 2017


And I'm not disputing that there are a lot of differences between bikes. A sport bike racing a Harley on a twisty road is always going to perform better. In particular, since it is lighter, the sport bike can decelerate and accelerate faster allowing it to carry more speed into and out of turns.

But they weren't racing each other in this demonstration. They were just making a lot of high speed sweeping turns, showing how hard you have to work because you can't lean a Harley over like a sport bike. If you moved the foot pegs you could lean the Harley and ride through the turns comfortably and nearly effortlessly more like the sport bike. All the work and effort the Harley rider was doing was because he couldn't lean the bike far enough for the speed and turn radius he was riding. He did a good job of using supersport body movement technique to compensate.

Seems like a pretty good demonstration of elementary physics for those interested. Instead some people seemed to get into a bunch of grar about racing and other extraneous issues.
posted by JackFlash at 6:31 PM on March 18, 2017


All the work and effort the Harley rider was doing was because he couldn't lean the bike far enough for the speed and turn radius he was riding.

The problem you are not getting is that this statement - that the foot pegs are the only thing stopping the Harley leaning over and achieving similar performance to the sport bike - is fundamentally wrong. It is so fundamentally wrong as to be nonsensical. It is utterly false that suggesting something as simple as moving the footpegs is going to equalise the performance of a race-derived machine and a far heavier, more clunkily designed long distance cruiser.

The angle of lean physic calculations you posted have not even (in the slightest) been questioned. What has been challenged (I'd go so far as to say 'utterly refuted') is the facile notion that the angle of lean is the only thing that matters. Angle of lean for a bike is a given. What matters far more at that stage is how the bike uses significant chunks of physics and engineering knowledge to manage the many other aspects of bike handling that allow the bike to generate and maintain lateral g for a given lean angle - particularly in establishing and maintaining a maximal contact patch. Lean angle is not even close to being the only or presiding factor to ultimate cornering performance.

That is the same absurd level of ignoring what makes a bike handle as suggesting that 'simply moving the position of the door handles' would equalise the performance of a Ferrari and a Minivan.

But then, you often come into these kinds of threads with these wild ass, utterly unfounded, theories of 'fact' and are entirely resistant to any education to pull you out of your ignorance.
posted by Brockles at 9:01 PM on March 18, 2017 [2 favorites]


Also: The Harley rider is borrowing a technique used by supersport bike racers. They enter sharp turns approaching 200 MPH (and note that the tangent of the lean angle goes with the square of the velocity.)

No bike enters a 'sharp turn' at 'approaching 200mph'. None. Not one. In the history of all things bike. Moto GP bikes hit 200mph on the straights, but they do quite a lot of braking before the turns. Especially the tight ones. I found a Red Bull GP article from 2013 at Indy that says much the same thing as you state there, but it's a pretty flawed marketing puff piece. Track map and gearing charts show significantly lower actual cornering speeds - maximum they listed was about 125mph for the widest radius corner, all the sharper (>90 degree) corners were around 60mph, and these are probably the most capable road bikes, I think.
posted by Brockles at 9:13 PM on March 18, 2017 [1 favorite]


But then, you often come into these kinds of threads with these wild ass, utterly unfounded, theories of 'fact' and are entirely resistant to any education to pull you out of your ignorance.

I'm not sure what is provoking your snit about a rather benign subject. You may well be an experienced mechanic. You certainly profess to be. But you have demonstrated over and over that your expertise is based on rules of thumb and empiricism with a generous dose of pseudo-scientific woo. Your grasp of basic scientific physical principles is rather lacking. Maybe that is the source of your anger.
posted by JackFlash at 11:05 PM on March 18, 2017


JackFlash, you are condescending at the same time as failing to address any of the criticisms of your reasoning. You are not coming off well.

No one has questioned your basic physics, which is something you are intent on ignoring in your responses. I suspect a few people that have problems with what you've posted understand that physics at least as well as you do. The problem is that you keep reducing everything to this basic physics when the reality is more complicated. That doesn't mean your reasoning is wrong, but it is far too simple.

You need a more complicated model. A little humility wouldn't go astray either.
posted by deadwax at 11:26 PM on March 18, 2017 [2 favorites]


And hell, I personally think the people in the speedier videos are complete idiots that should have their bikes confiscated (and the people that appear to be in Australia are possibly actually running that risk). Why the hell am I debating this?
posted by deadwax at 11:28 PM on March 18, 2017


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