Tank Slappers and the Quest for Perfect Suspension 

I don’t even own a bike, anymore … and still enjoy these videos.

I like to think "tanks" was a puntentional typo. ~RF9

"Tanks" I see what you did there

I assumed tanks was just a child that never learned spell check... Or to wipe their own as.....

As they say in the mechanized marines... -Bob Gump

a true example of how to make people feel accepted without disturbing the flow of a great video ^°^ any bike of mine are gay as hell though >:)

That was such a well-scripted line, I genuinely paused the video to see who was discussing it in the comments 😂 Looks like it's also rather underrated.

Why does everyone have to accept people who make their whole identity about their sexual desires!? Why can't gay people just act like straight people and keep their sexual business to themselves!? Why do I have to approve of someone else's sexual desires when it's against my religious beleifs? Why don't my rights matter? Why do my rights have to be trampled for any group to have extra privelege over me? Just leave me alone and I'll leave you alone. Beleive what you want and ill beleive what I want. Im not trying to force gays to accept my identity so why are they trying to force me to accept theirs? Not only accept but affirm!! Im not affirming anything that is against my Catholic faith and is a sin! I'm not perfect but I strive to be. Stop trying to force me to denigrate my own values and religious identity to support your sexual identity. It has nothing to do with hate or homophobia.

@@CantTreadOnMe Chill out dawg it's just a joke, it wasn't aimed at you... ...wait a second

@@CantTreadOnMe So other people have to act differently to who they are in order to fit into your narrow-minded worldview? Live and let live man. If you don't like someone, just turn around and walk the other way.

Their three and four year old content is just as spectacular.Easily better then anything on tv today.

Motojitsu is what really makes people ride smarter and safer .

and he's really funny too lol

Mahalo

In every video of his I watch all of his comments are nothing but absolutely positive and talking about how well done his videos are. Its so cool to see someone consistently put out content thats always just next level and that so many people appreciate.

The more quality is in the content (he has the medal there) the less nuisance music and distractions are needed.

Of course he cares about compression that’s virtually what most of the video is about - damping,spring rates and compression!

Happened to me about 40 years ago on a Honda cbr400, going downhill at about 70mph. I'll never forget that experience. Nothing to do with suspension, more to do with wheel balancing.

Happened to me on an 09’ 1100 Hyper Motard, scared the dogshit out of me, I snatched it up into a wheelie and straightened the bars. I had to take a break until my knees stopped knocking, man what an F’d up ride that was. Be safe fellas ✌️

What level of butt pucker would you say that experience was? 🤔

@@deborahchesser7375what an insane way to save yourself lmao

@@jamespegg6418 same time span on a KZ550 Kawasaki. I tried to accelerate out of it. LOL,Nope.Just held on tight and slowed down.Wound up selling that bike pretty quick.

The jokes are rapid fire fast too, lmao.

fortnine.ca bien sûr. They're Nelson Rigg Adventure Dry bags, although mine are quite old. The new ones look like this: fortnine.ca/en/nelson-rigg-deluxe-adventure-motorcycle-dry-saddlebags - great bags!

Same, I laughed so hard I had to rewind because I couldn't hear the next 15 seconds worth.

@@FortNine Thanks!

I've just spat my lunch. Thanks Ryan!

Yo you got any of those jobs laying around?

@@Hoppitot lol let him go check in the back real quick

@@well_as_an_expert_id_say hell I aint doing anything dude can take 3 months as long as he finds something

wow id love to ride one , being mostly an off road guy in the past ive intentionally stuck with manually adjusted suspension but maybe im missing out ?

Eh, another MS rider and I would be just as happy without it. Only a few times its ever felt like it was doing really well and the rest of time just soso. I would just as soon have a standard set of forks and shock that are tuned well. Eliminate all that electronic involvement and expense. I should have bought the base model...

@@BrevityBuzz yet Ducati and Kawasaki market it as skyhook

The only situation in which a semi is preferable

As someone designing FSAE suspension, one thing i realised very quickly, is there IS a theoretical perfect solution, and that's continuous adjustment in real time, if that's unfeasible, there is simply no perfect setup and that's just it. So as long as you're in the ballpark, it's good enough, simple as that. From there tuning the suspension to personal preferences is the only thing to be done and you're as near perfect as it's physically possible without electronics.

@@AntaresSQ01 CDC sounds cheap and easy to DIY from a programmers standpoint

@@PartikleVT Yes but as mentioned in the video CDC or otherwise also known as DDC has limitations. It's very good indeed, and easy in concept to implement, but in practice a lot of man hours go behind designing a reliable system that stays accurate even after hundreds of millions of adjustments. The programming is also difficult behind it as it's making a lot of adjustments, how can it tell the difference between a wheelie on a downwards slope vs the road suddenly dipping out from under the wheel such as riding off a ledge? It can't. To be honest in such a scenario it doesn't matter that it doesn't know because the damping will need to be softened on initial impact and then hardened once the wheels land but there are a few scenarios where it can "trip out". And then accurate BMS units are just expensive, again that have to stay reliable and accurate for a long time. The type BMW uses can register lean angles to 2 decimal points 100 times a second. Don't get me wrong they are entirely feasible to implement, but as we can see, there is a reason the bikes that have them START at 15k (with a few rare exceptions) and most near the lower end actually have very cheap forks with DDC picking up the slack in terms of ride quality. A true high end electronic suspension unit like the Öhlins Semi actives cost 3-4 grand for a reason. Trust me, they aren't making big margins on those systems.

@@AntaresSQ01 I can see how the system gets larger and larger and requires more and more sensors as you start adjusting it.

@@AntaresSQ01 Hi, I have actually designed and patented (US9561701) an active electromechanical suspension that will use the suspension travel to charge the battery. It is even lighter than a standard suspension. I installed a prototype on my motorcycle several years ago and made a video. I have not been able to update the prototype for a while, because I am trying to manufacture an EV (scooter) that uses my other 2 patents, but if you are interested then let me know. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-7J9_Zq-C0d8.html

The "Honda" part of the phrase "V-Four Honda" is likely what saved you. Not that nobody has ever died on a Honda (of course they have), but Honda itself has always had a very strong focus on rider safety and reliable mechanical design - they stake their honor on their bikes because it was what they made for many, many decades before bothering with the car business. The fact that the bike recovered itself so quickly is a testament to their engineering. Meanwhile, you have stuff like the Harley Death Wobble, which comes out of nowhere for seemingly no reason whatsoever (bike moving in a perfectly straight line on a flat freeway), and is difficult to safely recover unless you are at low speed and lucky. I've read that it has something to do with the "rubber mount" design they use to save a few bucks in parts cost and manufacturing, and the only way to eliminate it is with aftermarket parts.

@@martuuk8964 The death wobble is caused by harmonics. It's stupid, but on some road surfaces the slow low end heavy a** cruising long bore v-twin's rocking will line up with the road surface's bumps. And like an extra kid jumping to super bounce another on a trampoline the extra shock at the right time sends the bike's engine off kilter at an unwanted angle into an uncontrollable lift. Thing is, there's no way to know. Engine speed is variable, and the speed the bike is going at to hit the bumps is also variable. It's one of those, "When the planets align the beast shall be summoned forth to lay waste to yon Harley.". And yeah, dampen the engine mount and it mostly gets rid of the problem. Not completely. It's just a basic design flaw of Harley. To get that distinctive Harley sound the engines are slightly unbalanced. No way around it if a customer wants a Harley to sound like a Harley. That sound is a holdover from before precision engineering engines and modern build tolerances. It's why even other cruisers that borrow the Harley aesthetic don't sound like a Harley. German and Japanese engineers won't let anything out the door that's designed unbalanced, they can't even conceive of doing so.

The man of culture 3:37

Where?

@@THEGEEK2001 Budapest University of Technology and Economics in Hungary.

@@benceringbauer9477 doing MEng eng too. Goodluck bro

@@THEGEEK2001 Thanks. To you as well. We’ll need it:D

That barrier was coming fast!

Thanks

ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-hgKOvJRnpko.html Full video

i'm not sure if at that stage is a save anymore or just pure luck :}

@@duroxkilo definitely the leg kick at the end that saved him 🤣🤣 I think it was just luck!

that one got me as well....😂😂

And the Godfather parts

@@MozzaBurger88 Both were. But I didn't get the Hitler joke about fully active suspension. Unless that was a joke about the anacronym being too close to fascism.

The bullet proof crop top got me in this one

@@gregorylagrange the "final solution" "Endlösung" for the Nazis was the genocide of all jews....

If you were going 120, you deserved to go down.

Yah, highway construction, going on for miles on 295, they didn't really cone up or warn anyone they were doing some pavement work in one area. I hit it and went airborne at about 85 mph on crappy uneven road, then the wobbles come in. Luckily it all sorted itself out in about a second or so, though it seemed like an eternity. My butthole was so tight I bet you couldn't have pulled a banjo string thru with a bulldozer when that finally ended. I just vaguely remember saying to myself, don't lose the handlebars but don't fight them, off the throttle, let it settle out. Thankifully it heard my prayers. Don't want to go thru that again.

The humor is so witty, these videos are totally worthwhile even for cagers!

That's not correct. There can always be conditions that will result in a tank slapper no matter what other settings you have. It is built into the geometry of the front steering and the shape and dynamics of the tire. All you need is for the front to get light over an irregularity in the road and that will set it off. A damper, which they all now have stops a small initial deviation from amplifying. Suzuki thought they could get away without one on the new 96 GSXR 750. It did make for quicker steering, except for the tank slappers. I know from experience. I fitted an after market Ohlin's steering damper mounted on the frame with a bracket Steve Martin gave me. From his superbike which needed a damper too. To much damping is bad but you need some and no amount of other setting can fix that. There is an inherent stability problem in all castoring wheels. Which is why supermarket trolley wheels do what they do. Did you have damper at Phillip Island?

It's a DAMPER not a dampener. We aren't putting wet rags on our necks to cool down.

@@JF-lt5zc well done. You picked up a typo, which has been corrected. Thank you. So you use one? Anything of substance to add?

My 1984 GPZ900R/ Ninja 900R has some skinny forks but it had an ADV system which is a gas charged system to supplement the front springs. Haven't experienced a tank slapper on this bike (provided the system is maintained) and I've tried after doing constant wheelies and going off mounds at railroad crossings.

@@marcusgeorge1825 It's not a typo issue. This term is misspoken over and over when it comes to suspension and it drives me nuts. If you (proverbial) are going to speak with authority about something, get the language right. And I do use and adjust the dampers and spring rate on my bikes, both motor and pedal. As for wet rags, sometimes I use them to cool off on a hot day or if I'm not feeling well. :D

Haha, last time i cleaned up, i found the VHS under some dust. I would be totally up for that!

Dude I’d actually pay to support a version of that

Him and Motojitsu together would make the ultimate riding school

@@1Fine69c No, thanks. Can't stand motojistu

@@boo_ why is that? i think hes a good instructor

it would be heavy on a bike and probably only practical on heavy baggers

It doesn't change damping in way ryan describe here. Also drive c5 with hydro. Its cool system but far from mentioned here. It just can engage sport, harder setting depending on driver inputs.

C6 has adjustable damping and one of the operating modes is actually called skyhook.

Noticed the same thing on my new zx6r, kinda scary coming from a 300 lol

@@kawininji8874 Go get a shop to sort out your suspension settings if you're struggling to find the right ones yourself. A new supersport should not have tank slappers when set up right. Even my decade+ old second hand R6 can go full out without issue.

Always make sure to adjust your rear preload when riding with a passenger or with heavyish luggage. A few months ago I took a pillion for the first time ever. Only rode for maybe 10 minutes without adjusted rear suspension (I can only adjust preload on my 2012 V-Strom 650) and without adjusted tire pressure. It felt very wobbly and I was not confident at all. A few days later we rode again, but this time with properly inflated rear tire and preload set to maximum. Oh wow, what a difference! It almost felt as riding alone; even the tight u-turns were no problem. Now that I think about it, in hindsight the steering felt very light, I mean it felt like there was not much load on the front tire. I didn't experience any wobbly feeling, but I suspect I might have if I had been really aggressive with the throttle. So next time I think I'll adjust the front preload as well in order to shift the center of mass a bit forward. By the way, if you ride very aggressively (very fast acceleration) you might want to look into an aftermarket steering damper.

Accelerating hard enough to cause the front tire to just skim the road surface can also induce a slapper, when those little stones and cracks in the road surface begin knocking that front tire off alignment with the direction of acceleration, and a lack of weight allowing the front wheel to pivot.

@@exothermal.sprocket Yeah and gravity of moon is also possible to cause slappers.

My bike doesn't have ABS and I was wondering if you can feel it/notice it when braking?

@@joshslater9835 of course you can feel it. ABS allows to steer while braking fully, not just slide forward.

And the spring rates on bikes with dual rear suspension not matching perfectly (Harley Dyna).

Wheels not weighted properly can also cause them, and on super sports too much weight on your wrists can also cause them as well. I'm especially conscious about this on my r6.

@@Matty_Ice9 Yes, balancing or tires with wear or new poor quality tires can increase chance of it to happen. I had those. Also totally had forgotten, but in my youth I had a pocket bike - too firm grip would make it wobbly instantly! 🤔 Crazy sensitive steering, would not like that on an bike going over 25 mph 🙃

And mis-adjusted forks in the triples shortening trail too much causing an overly nervous front end

And uneven fork oil levels due to a leaking seal or pitted fork tube

Engineers just can't help telling other people that they are, in fact engineers. Even after they are retired 😄

@@SavedbyHim wasn't Ryan an engineer himself?

@@hugoflores5806 Doubt it, otherwise we'd know for sure lol

@@hugoflores5806 I partially recall that he had an undergrad in Physics. Not 100% sure tho.

F9 and DanDanFireMan are what im using to study How to Ride a bike, f9 creates Very scientific videos, Dan watches motorcycle fails and gives tips How to avoid crashes. They completely changed they way i see motorcycles, especially becouse here in Brazil the trafic is pure caos and lane splitting is normal

Here just for this comment 😂 worrickshir?

Yup, that made me laugh. Let’s hope he doesn’t go to Leicestershire 🤦‍♂️😂

Or Worcestershire ;)

You all beat me to it!

Not that I have any authority in this matter whatsoever, but I approve. ~RF9

I gotta say, I have an odd sense of pride, every time I receive my order from FortNine. Love seeing the name on the box, love explaining it to others, and what it represents.

I would agree except he stocks Chinese made products. We are feeding a Communist beast and it won’t end well.

All of it. Someone said he also talks about motorcycles, but I dunno...

Yes!

Check Dave Moss' tunning channel!

Ask the Superbike teams? They will agree with you!

@@andrechagas4549 Is that the guy who tells everyone to set their sag correctly most of the time, because they all jacked the preload up to max.

It's frigging Witchcraft if you don't do it often and on different bikes.

@@madman432000 full ergos and fork / shock setup

You can't have damping without some sort of non compressible liquid. Designs with non serviceable damper cartridges exist but those are also prefilled with fluid from factory. Makes sense to use oil, it can double as lubricant to the moving parts as well. Fork oil is essentially hydraulic fluid specially formulated to prevent foaming under rapid movement.

@@frankthetankricard makes sense to me! ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-RXJKdh1KZ0w.html

Hum…Canadian Bacon with that Maple Syrup?

@ᴛᴇ𝒙ᴛ ᴍᴇ ᴏɴ ᴛᴇʟᴇɢʀᴀᴍ @𝑺𝒊𝒓_𝑭𝒐𝒓𝒕𝑵𝒊𝒏𝒆𝒆 hello?

Probably weren't doing any wheelies (certainly not by accident) with a 250. So for little bikes, usually not a problem.

@@jakegarrett8109 It was certainly a reliable steed. Maybe that's why I loved it.

@@leftcoaster67 250 is a great class for reliability. Good fuel economy, not so much power that they can break stuff (if they are decent quality), nothing too crazy to work on like synchronizing 4 carburetors, engine inspection and maintenance is similar to that of a lawn mower (and its very open and easy to get to compared to crammed in 4 cylinder engines), and of course takes like 1 qt of oil and everything super easy to maintain. Often even air cooled so no coolants to flush, just oil and that's it! My 250 Chinese Honda clone was pretty good, its biggest weakness was a weak frame (and one crazy 14 year old that would sometimes clutchless slam through gears WOT down the highway, but hey, I was that 14 year old so I can't complain too much, haha!). Made new engine frame mounts out of heavy sheet metal, and reliable as could be. I still got 90 mpg driving WOT doing 65 mph on gravel and pinned whatever speed it would do on highways. It even did 109 mpg with 2 people riding when my dad drove it, so not bad, and other than changing tires pretty often didn't have to do too much. Also changed sprockets for higher speeds (duel sport enduro, so they probably didn't plan for it to do 75-80 mph), did better than my skill level off-road too. I would be driving that right now but its parked halfway across the country, and if I spend 2 or 3 days non-stop driving it to me, well I'd make enough to pay for almost half of another one (and I'll probably move back close to it anyways and have to drive it back again). Otherwise not bad, very lacking for passing on highways and weak going into 50 mph headwinds, but other than that it was a fun reliable bike.

You could affect the amount of unsprung weight. If most of the spring has to move towards the end that compresses first it would act as unsprung weight. But to be fair, the amount of weight in the spring versus the wheel, brakes and lower fork is pretty much negligible.

After thinking about it some more there's also the effect of "waves" through the spring. Basically it takes a little time for the force to travel through the spring, and for the entire spring to equalize. The wave would travel faster through the stiffer part of the spring. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-10-QGhm5hgc.html Sorry for babbling, not at all meant as coming at you, it was just interesting to think about :)

@@kaggen No need to apologise. I am learning a lot of new things thank you.

Can u pls explain i dont get it

​@@hardnachopuppyit's a pun - he calls fully active suspension the _final solution_ which you cant say anymore since then

i find the electronic suspension on the 1100 ATAS amazing. my gf and i weigh around 400lbs together with full gear and it only has ever bottomed off road. bike stays completely flat over potholes.

the solution might just be to lose weight at that point

@@miraclerouge2313 Wow, what a silly reply. Any large bike should be able to carry people properly and safely, even the somewhat larger ones. At 5' 8" & 180 lbs. in full gear, losing weight is NOT going to be practical for me, so your advice is just foolish. The 'Load Range' of MOST bikes is what we are talking about, and few come from the factory with decent load range. kwalms AT has the refined suspension, which is a credit to Honda for either listening or testing. Mine is one of the first, and not so refined. And I have had many others, all lacking in load range for even average people and load to properly set the sag, much less ride even moderately aggressive So if someone is other than a daily rider with minimal gear and load, the range is typically pathetic. This is probably why there are so many aftermarket suspension folk out there, demand for a better suspension is high, especially when it comes to the Dual Sport and Sport Touring crowd.

​@@alanrobinson2901 you said it's borderline pathetic for anyone over 150lbs, and 150lbs is actually the middle point of a healthy weight for someone who is 5'8, and it doesn't become unhealthily underweight until 6'3. maybe they should ship with heavier springs for north america but at least in japanese manufacturer's case their largest market is much smaller in size

@@miraclerouge2313 im 6ft4 and weigh 190lbs and im still skinny, your point is shit bro. Whats your height and weight?

Where's the fun in that? Drive a car.

The straightforward solution.

Just because steel spring suspension was "good enough" for customers who are now focused on entertainment gadgets.

Yes, it got bad rep for poor maintenance I guess. My dad had 3, I also had 3 and still blame myself for selling the first of those because of "small" issues and it ended up going for scrap. I never got to the bottom of this, but I think the bad rep was "it leans too much" (older ones especially, but they kept the wheels firmly planted unlike the funny swing axle cars of their time), "it's too soft" (apparently people equate a bumpy ride with sporty aspirations"), but guess what, the moose test speed record is still held by the 1998 Citroen Xantia Activa. And finally, I guess what killed 2 of my 3 Citroens is a terminal hydraulic fluid leak (the first one did too, but I had that one repaired before selling it). But they all had 250.000+ km on them, and then people forget that other cars would have had springs, shocks etc replaced multiple times already...

@@MaartenvanHeek In my family we have had/ has nine large Citroën. 4 CX, 3 Xm, one C5 and the glorius C6. Only once have I had a major hydtaulic leak, it was on an 20 year old CX and was easy to fix by the roadside.

@@Svarthammarholet in my case it was on a 20 yo XM strut return line (fixed same night), second was a Xantia under the (hot) engine block so could not be fixed roadside and had to be towed, by that time including upcoming MOT repairs it was a total loss. Third was a diravi on another XM, after having it repaired 3 times in 3 months I was done with that car, as you can imagine :)

@@MaartenvanHeek In my experience it pays of to find a meccanic that really knows and love these cars if you want to keep them alive and healthy. They are in many ways completely different from all other brands. And ahh yes the good old Diravi, best ever power-steering in the history of automobiles..

Noticed that too but not a suspension expert so wondered if I had got it wrong 😑

the soft section of spring is what is causing the section with a wider gap to act in a progressive manner by preventing it from twisting and creating a shorter functional wire, increasing spring rate. this makes it the stiffest at the section closest to where the "soft" coils are. the short twists are not really a part of the spring, as far as springing functionality goes, more an accessory to the spring that using funky fysics to trick it into behaving nonlinearly. kind of like preloading negative twist onto the wire so when it is compressed, the section closer to the tight coils will not want to twist as much

Chalk board diagram shows advised position for installation, does it really matter? The spring reacts as a single unit, invert the fork assembly the spring still reacts the same.

I don't think it matters. The soft part of the spring will compress the most at first no matter if it is at the top or the bottom. All forces are linear.

@@flechette3782 The issue was his pointing, not his aversion to the laws of physics.

Corect side is the right side. Because it's just right!

@@hraharahra Then you shall be easier to kill in the joust

@@foxtrotoscar4284 Not if I am left handed! Which I am not.

@@hraharahra Then we joust at dawn! best of luck to you good sir

The spring would act the same regardless of which end was "up".

@@avsystem3142 Yeah, he pointed at the harder spring rate to show softer and the softer spring rate to show harder though.

Precisely! ~RF9

I guess "perfect" suspension would be a hover craft.

Same

You'd probably lose a lot of feel KTM motocross/supercross test riders will swear that the air suspension is much better and even pro riders saw how the lap times got faster... but they all hated the lack of feel, which made them likelier to crash so it was abandoned

@@DiegoRuiz1991 I'm not riding on dirt, I'm rounding twisties and cruising down the highway.

@@h.d.h - It's about the same: you need to have enough feedback to never go past what the tyre can endure

After a coupla years on a multistrada, yeah- it stays on. You spend 6mos pointing out to yourself when it doesn't feel like a REAL suspension, then give up and concede that it works.

You just described semi active suspension. Semi active uses springs, active uses no springing, the hydraulic pump reacts to pressure sensors to perform the task of the spring.

@@davidcolin6519 EM stands for electromechanical springs. Semi active systems only control the damping of the shocks.

No. In my Understanding the difference between active and semi active is, wether the controlling system can apply it’s own force into the suspension or not. CDC, as described in the video, only controls the damping coefficient and therefore can only vary the reactive force acting against the suspension movement. Active Suspension, like The Bose Version, can introduce additional force or power with electric motors or hydraulics. Therefore they require quite a bit energy. Mercedes has a Active Suspension called ABC, where they move the mounting point of a traditional steel spring with hydraulics.

@@matthiasvolk6006 You used a lot of words to repeat what I just said.

@@matthiasvolk6006 Well, considering an application of force requires a pump of some sort, and not having a pump requires springs, in what way does your definition differ from what I said? Aaah! the Mercedes method of getting around an F1 ban on active suspension! I see! So, why don't you tell me why you would have a spring in an active Systemj, other than to subvent a competitor rule? Or am I just being thick? Because I remember the Lotus system in its development phase ( I was in the same class as Clive Chapman, Colin Chapman's son) and it was very, very clear to both Colin and everybody else that an active system used computer controlled hydraulic rams/pumps etc to produce active suspension. That M-B may have come up with a system that uses springs just means that their system is semi-active, and I'm sure that they would claim the same. But enough about that, why don't you tell us all how a spring works in a system that is specifically designed to not use springs?

Or I will, when I can afford a 30k bike.