Sell a bike for 4k , and then sell the parts separetely for 8k. Rob your costumer and with that money develop new things. They are worst than apple and can stick their shiny new cilinder in their asses.
@@derbigpr500 I meant it on a broader context. Not all ideas and concepts yields good results, but they always go that extra mile into putting effort to try something out. A clear sign of their success is they way they got into the US market and rapidly became a global player. Turns out people like reliable, innovative and price compatible cars/bikes.
@@nick4506 Honda also made a torsion bar valvetrain. It totally worked but they only did it on a single model, the CB450. Or the gear driven valvetrain which was only used on the VFR series. That’s the sort of thing I was referring to. Not so much if it was heavily beneficial, but more if it worked or not. Though, I’d argue that the torsion bar drivetrain is beneficial in a maintenance sense.
@@Indarow do you mean valvetrain? for the CB 450. they could only fit two valves per cilender because of how wide the tortion bars are. and the vfr got the gear driven cams to try and fix the cam life issues honda was having on their 80s v4 bikes. turns out it was heat treatment and oil issues that stopped that. yea this stuff technically works but other factors make it so they cant really be used anywhere else.
Thank you Scott. I'm 59 and I remember all the development of the project. Fantastic technology. I wonder if development had continued, as for example in F1, what would have happened, especially considering how the regulations allowed greater creative freedom in the 1980s. Would it have worked? I am passionate about motorcycles, and until today, I use the NR 750 as an image for my channel. Greetings from a Brazilian subscriber.
I was 13 years old when i saw that machine at the practice sessions of the 1981 British motorcycle Grand Prix at Silverstone. Freddie Spencer was riding the Honda NR 500 GP at that race. You have to remember you had push starts at the time, not standing starts like you have today in MotoGP. Now this oval piston machine was very difficult to start with a push start, and Freddie Spencer was practicing this over and over again in the pits strait because of this. It had an amazing sound though compared to the twins. It's an anecdote my dad always comes up with and now i saw this video popping up, so funny.
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Hi, in 2008 I noticed one in a parking lot in Ajax, Ontario and had to say hello and ask the rider about the bike. It had just over 100,000 klms on the odometer and was burning a touch of oil. He just topped it up a bit as needed. No major failures or rebuilds and he had enjoyed the bike, he had bought it used in good condition. I suggested he contact Honda, they might like to see an example of a long term survivor. I remember when it launched and could not afford one at the time. I was very happy to see a running bike so many years later. She still looked like sweet ride.
I have ridden the NR750. It is incredible. The bike was heavy, partly because it had an insanely heavy exhaust. The bodywork was carbon fibre that would chip so easily and the paint alone cost $7,500 per bike. The engine was extraordinary. It just revved and the torque was so flat you hit the rev limiter all the time. Not very powerful by fireblade standards of the time I think about 100HP. The designer was very unhappy that it got strangled because of the push for power limits in EU. To make it up to him Honda took one, changed the exhaust and ECU and used it to set some world records. Very cool turning up at my mate's work on it but was only allowed to borrow it for an afternoon.
A long time ago, I read a bike review (MCN I think) between an NR750 and a VFR750 (same type of bike of course, except the NR had oval pistons). They thought it was a lovely bike to ride, but were disappointed, that performance wise, it did not offer much more than the VFR.
@@cameronfarris7171 before the launch of the NR, Honda confirmed a European company that would be able to recondition the engines- I got that from one of the test riders at the time ; )
It looks more like the double rods were to balance / control torque from twisting the piston within the cylinder ( elipse-inder?). With a single rod supporting it in the middle, it could seize very easily
that's what I was thinking, it was to prevent wedging. I wonder if it would have been better to have a single rod in the center but rotated transversely
Yup, first thing that popped into my mind for having two rods per piston as well. The slightest force imbalance across the piston face could massively increase drag on either side and wedge it, got to make certain this cannot happen.
I drove a CB400 four as a teenager and had all the fun in the world. Many times regretted selling it. My dreams were so real that I woke up to look for it in the garage when cruel reality kicks in. Awesome engine. Then older brother bought the CB 750
Lovely bike. Myself and my mate had one and they were just lovely little bikes. With a piper exhaust they sounded immense. Never heard any other bike sound like it with that exhaust on 😊
Honda also made legendary two stroke engines. They have twice as many power strokes per revolution. Closer to running off pure explosions, like a jet engine.
The 'Big Bang' engines that went into the NS 500 and the NSR 500 of the early 1980's . They were totally evil to try and ride. Can't remember which one of the riders it was but they likened it to a bucking bronco, ever time you open the throttle it 's just trying to throw you off.
Honda brought two of the NR750 F1 bikes to Australia for the Swan Series, don’t remember the year. I did see them race at the Oran Park round. Very cool bikes
I was there as well, I had a piece of the fairing off one of them, can't remember now if was Mal's or Rob's bike, after they bined it during practice. Not sure what happened to the piece now. Oh well. Have to admit, they went like scolded cats and sounded like nothin else.
“And in 1983, they had a virgin that achieved 130HP.” Great video! Very interesting stuff, and very well explained! Honda has always been one of my favourite brands.
Remember having a poster of this on my wall in my teen years, one of the best looking bikes to come out of Japan.... Ever. This was like the Bugatti Veyron of motorcycle technology, they even tinted the windshield with a thin layer of titanium rather than using plastic film
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I had a model NR500 I built as a kid and I could never get an answer on why it was oval pistoned. Thank you for finally answering it. Still remains a mystry how they manufactured the block and did things like hone the cylinder walls as this is all done with a simple rotating honer but would be pretty difficult to properly machine the oval cylinder walls.
Why? Well, aside from Mr. Honda's dislike of 2 strokes, by the time Honda started work on this engine, the other Japanese manufacturer's had managed to... "persuade" (by means that nobody will discuss to this day) the FIM to; - increase the 2-stroke displacement limit from 350cc's (which had made them competitive with a 500cc 4-stroke) to 500cc; - ban any type of "forced induction" - like a supercharger, while at the same time allowing the use of expansion pipes. Which, on a 2-stroke, accomplishes the same thing - just pulling the intake charge in, instead of pushing it (and which doesn't work on a 4-stroke engine); and finally - limiting the engines to 4 cylinders. All of which made sure that no 500cc, 4 stroke, 4 cylinder engine stood a snowball's chance in Hell against a Kawasaki, Yamaha, or Suzuki 500cc race bike. Until this engineering tour-de-force Honda reared it's sadly almost-but-not-quite head...
@@zuzuzaza98 You're quite right, but four strokes also use the pulsations in intake- and exhaust systems to reach more than 100% filling of the cylinder - even 120% of volumetric efficiency can be reached. I explained this in a simplified version as an appendix to my book "Honda's Four-Stroke Race History 1954 ~ 1981".
The biggest draw back to this engine was machining parts for it. At that time CNC machines were nowhere near as advanced as what we have nowadays so this design costed an absurd amount to make.
Yes, i was mentioning this. Today using an elipses creating and recreating acurate tolerances woukd be a breeze. Apparently VW picked up the idea in the early 90s, while simultaneously developing the vr6, which met the higher standards they were looking to achieve at that time in an easier fashion, thus developmeny on an oval engine ended there and has been left from what i could find. In laymans They turned a 1.6 into a 2.3 using oval pistons the engine took up as much room as the 1.6, and i believe it was a boxer engine. Man i really wish i could focus on developing something like this and like still pay the bills/provide for my family lol. I often find myself "reinventing the wheel" on everything i work on, few times after exhausting all possibilities i look back and think, "why didnt i just follow everyone else, smh". Mostl, i can look back and say, "i certainly learned a great deal". And every now and then my wheel comes out better than anyone has ever imagined.
@@bihgolphatdictergud746 I remember , actually getting piston rings properly seated was a big issue. And the piston materials at the time were overcome by the piston velocity FPS, and scored and galled at over 25,000 rpm. Its hard to get any lube film to work when the rings simply push it off instead of riding on top of it. I can only imagine what that moment of piston reversal does to the connecting rods at nearly 30,000rpms... CRAZY
If people have not said this ,or I missed it above, the main problem to me seems to be the piston rings cannot float and rotate so run the bore in properly to seal things. Plus If they needed replacing they would be unlikely to fit the bore after it was run in as any irregularity in manufacture or wear in the previous rings would be set in stone so to speak.
I went to the bike show at NEC Birmingham back in 91 and Honda had a whole stand dedicated to the bright red NR750 with cutaways of the engine - possibly the same one in the B roll. Mind blown.
I'm not the biggest Honda fanboy, however this is the one of the two brands that i really respect and that's because they're the biggest engine manufacturer in the world and they have fuck load of experience building engines. Every time i hear different brands of bikes working (from the same category and class) i can hear how Honda is the only engine that sounds so smooth and up-beat.
Without people like these Honda engineers and the man himself, full of drive and passion, im frightened we will all eventually become uniform and bland. We need these free spirits and other thinkers to keep driving.
The 92 NR750 was used for a lot of the RC45 race bike. The engine converted back to round pistons, the fuel injection, the single swing arm. Then Honda made the 98 VFR800 off the RC45 with very similar looks the NR. That’s why the VFR800 platform was so well engineered, it’s mostly from the NR750 minus the exotic materials and pistons. It was the Everyman NR750 and help Honda recoup their investment on the project.
Its honestly so impressive that they managed to get a 500cc 4 stroke to have the same power output as a 500cc 2 stroke, even with the extra 20kg thats just insane to me
All my life I have been drawn to elegantly engineered vehicles, and the end point of that quest has almost always ended up Honda. In motorcycles it was CBXs and ST-1100s, and even now at almost 70 years old, my daily driver is a '98 CRV with a 5 speed. I have no doubt that Honda's habit of pushing the envelope with what some call hairbrained schemes has resulted in un-surpassed engineering at the consumer product level.
6:29 "matching their two stroke rivals" not really ! 130 HP the 500cc two strokes were capable of WAY MORE than that, those bikes were EASILY the most powerful, bad tempered crotch rockets on the planet, the top riders like Doohan, Rainey, Gardner all those guys had balls of steel because of the SAVAGE power that would come on as they would roll on the throttle coming out of a corner, just a fraction too much twist on the throttle meant the difference between the bike just exploding with extra horsepower JUST at max lean angle and then loosing traction on the back end resulting sometimes in high sides that were fucking awful to watch, Doohan suffered greatly from this when his leg got mangled, I know how that feels because it happened to me too, steel rods and all...
Carbon fiber monocoque chassis, carbon wheels, cross-mount radiators.... it was a spaceship. You have to love the willingness to take it to that degree. As I remember it at the time, this was pretty closely followed by the motoring press and while most of the race community were doubtful, every one respected the effort. I remember a picture from a race and 3 Honda mechanics pushing a NR to tech and a bunch of mechanics of other teams lining up to salute. People appreciated what they were trying to do and, I think, that this was the descendant of the Honda 5-cylinder 13-speed 125cc GP bikes of the 60's that made possible the Japanese wave most of them now worked for.
Honda had always made multi cylinder engines fir racing. The NR should have been a V8, but regs made them merge 2 cylinders into 1. Crazy to take it on. Interesting that once they accepted two strokes they dominated 500GP racing with first the NS 500 (another bit of outside the box thinking) and more successfully the NSR500s
Not to geek out or anything, but the bike pictured @7:04 is an ns500 two stroke, not the nr500 oval piston. The original nr750 did fairly well in endurance racing before the road bike was launched....
Driven Media, I like y7our style and great sense of humor. This coming from someone who has listened to Radio for decades and has developed a good ear rand inner vison so I could understand the personality i was listening to. A family member inherited our old Honda Civic and we now own a 2019 used Toyota. The parts never broke. They always were replaced after wearing down.
Well that's why I like this content aside from ideal's ... The engineering perspective ... Is hammered into the script ... EDIT It's cool what one do with constraints
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it wasnt crazy or mad.. Honda ONLY made that design choice because they understood the breathing capacity of 2-stroke vs 4... NOTHING to do with cramming 8 valves into a cylinder.. it was totally about the limits at the of piston speed & metallurgy .. piston rock becomes a serious problem once past the 1-1:5 bore stroke ratio for 4-strokes.. at that time .. so Honda defined the specs their prefered v8 would need.. & siamesed the cylinders together.. the rest just followed engine engineering convention.. twin conrods is a blindingly obvious need
I have designed engine using oval valves. Instead of 4 per cylinder, just 2 oval. Area of oval valves is much bigger than 4 individual. Better intake and exhaust flows.
@@golf398 Thanks for input. It never progressed beyond design stage. Goal was single lifter to keep mass low. Sealing might be issue, since it can't rotate. Valves would be CNC to fit precise CNC cut in heads. It turned out that single oval valve weighs more than 2 round valves. Overall goal was to increase Volumetric Efficiency.
Good talk, I always wondered about it. I also remember that it was said that the engine was twisting frames of bikes and the cars they put it in. But I do remember V4 oval 23,000 rpms
As a layman who doesn't know much about engine design, I'm amused that the "crazy" idea to overcome a 4-piston limit regulation was just to combine every pair of pistons into one. It looks like it's just an 8-"cylinder" design but with the neighboring chambers connected. I'm not sure why it's considered a "miracle" to have worked, but it's nice that it did. Fun design.
Funny how normal technology has come along, now with current tech, modern motorcycle engines can produce over 200 hp pr liter in a four cylinder 1000. So scale it sown to 500 cc, hp pr liter will increase slightly, so 130 hp on a 500 cc normal four, would be easily attainable
The NR750 for me is just a stunning bike. A bike shop near to me had one for sale at £125k so I had to go and see it in the flesh. I wasn’t disappointed. It still remains my all time favourite Honda regardless of its low power figure. Awesome.
126 hp was almost the most powerful of any bike in 1991 and that included 1100cc GSXRs etc. Besides, power was not really the main point. The 750 NR racer had around 160 hp. Do the math and it is same as modern superbikes.
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"The engineers have since admitted that they didn't know if they were experimenting or just being foolish..." I'm reminded of one of Adam Savage's greatest quotes: "Remember kids, the only difference between screwing around and science is writing it down."
It almost begs the question of what qualifies as a cylinder. It's no longer cylindrical and has two connecting rods. The engine as a whole resembles a V8. It's really a fantastic feat of engineering around a questionable rule. I wish Honda was still like this. They used to be genuinely innovative and focus on cool things. Fast forward to today, a base Civic isn't offered with a manual, they don't offer any RWD cars, and their most "enthusiast" car is an over styled FWD commuter car that dealers mark up to $50,000. Oh how times change.
@@manoo422 you know what, you're right, i was thinking a single oval piston would be better than instead of having 2 smaller pistons, but it would just be more efficient to have one larger/longer stroke piston
@@denvera1g1 Its swing & roundabout really the increased area can be mitigated with less cooling. They did it for the increase in piston area allowing 8 valves to be fitted because BHP is proportional to valve area, and they wanted BHP!
This is the most practical reason for things like racing, space exploration, deep sea exploration etc. The wild engineering generates spin off technology that benefits humanity and moves us forward
I see three immediate problems. (1) keeping the two connecting rods perfectly balanced with each other. (2) keeping the rods exactly the same length. (3) Keeping the rods perfectly timed to each other on the crankshaft. Get any one of these issues off is going to result in twisting of the piston both vertically and horizontally in the ... can you even call it a cylinder? I wonder how much one of the 200 bikes goes for today.
HONDA has no match in any sport or any engineering madness. Porsche (the one and only theoretical ideally approach to something called perfect) was Prince and Honda Michael Jackson. Proof: amazing quality street cars and racing result in all categories... Cheers!
Wow, you just taught me something I didn't know, I've had a few Honda's including a VFR750, Now a Honda 2001 CRV Rd 5 speed, currently as a second car with a Hyundai 2012 i30 gd active 6 speed manual. I hate automatics, I have a mt03 as well.
"Who wants to see this engine in a car?" ✋Yes, please! Would love to see a version of it power an F1 car---just for kicks, its time has probably passed otherwise. I remember the Honda NR, gorgeous bike, fueled many a teenage wet dreams... 💓Given the number of technological advances on the bike (beyond the oval pistons and 32(!) valves: the single arm for the rear wheel, the carbon fiber build, the exhaust under the seat, etc. which have all become industry standards), having it be the price of a Porsche 911 seemed perfectly reasonable at the time. It now trades for 40-50% higher than a new Porsche 911 on the second hand market!
MARVELOUS! 👏👏👏👌 I'm 50, and, I remember most of it's history, and, being completely awestruck on first seeing it (after a bloody ice cold, long and boring ride on the M40 (GSX400F) from Slough) at the NEC Birmingham (WHY THE F have a bike show in OCT/NOV time?!?!?!)... Anyway, WOW what a machine. Those that don't know, just don't understand why Honda really are some genius guru's when it comes to automotive magic. I think 🤔 If memory serves, some bike mags were saying it was priced at £38,000... FOR A FRIGGIN' BIKE! hahaha Having said that, and even though I loved screaming around on both my CG125 (😉) and CB250N, I was a Kawasaki man at heart (cut my wrist and I bleed GREEEEN!) hahaha. Brilliant episode, loved it! 👍 😎🇬🇧
Imagine this engine with the toxic aluminum beryllium pistons from the V10 F1 days? I have been amazed that Honda came up with engine designs SO groundbreaking that said designs are now banned from entire racing series. F1 has a clause specifically stating "the pistons shall be round" . Moto GP banned six cylinders way back due to Honda 6 cylinders owning the competition in the sixties. The whining of the other motorcycle companies was fantastic. Great video. Thanks.
I seriously respect Mr. Honda sticking to his hatred of 2 strokes so much that something goofy like oval pistons were invented. We need more of this in our world.
Scott, you are right except for one thing, you said "Measuring wasn't as exact as it is today" which is completely wrong. Even back in the 50's and 60's the craftsmen were measuring accurately boring with a tolerance of 0.001mm or 0.000039" inch far superior to what we measure today. The Swiss made a machine called SIP Hydroptic-6 Jig Borer to achieve this and it is more accurate than computer driven machines of today.
@@historyZZ uummmm 1000 nanometers is just a micrometer which 0.001mm which is what I already wrote. Also measuring down to that small is one thing but to bore or hone to that accuracy is another.
A CB 4-cylinder with oil filter centered came onscreen just as you said what great 4-stroke engines Honda made. I agree! As long as you don't crossthread the steel oil filter bolt into the aluminum block. Don't ask me how i know....
ducati also made a 8 valve v twin , the 888 . as for HONDA'S 8 valve it was sold in new Zealand as a VFR 800 , a 800 cc big brother for the 750 . it's retail was around 23k .
For me the idea was "we would need a V8 for a four-stroke, but are not allowed to use more than 4 cylinders. What do we do?" Look at the layout, it is in principle a four-valve V8. With normal round pistons the engine would look exactly the same. Just a little modification to get individual combustion chambers and the cylinder block changes.
I always say that just because you can do something is not enough reason to do it. Sochiro Honda thought differently and made things work which nobody else considered feasible or worthwhile just because he could. Very much 'glossed over' in this video is the insane amount of engineering this took- even just getting the rings to apply even tension across all faces in light of changing cylinder temperatures was a herculean task. Easy in a circle, darn near impossible in an oval. And ditto on piston clearances, skirt design, and even bore machining. Then to bring it up to the level they achieved... Putting a man on the Moon was probably easier than this. Sochiro Honda was an under-appreciated genius in his own right.
4:23 Was there gas of the Tail pipe? And the kickstand Sparked ? or did the Motor , turn over from The wheel turning ,, and No rings , burned the oil , making Smoke ( this Seems unlikely)
I remember the days when Honda was doing this motor for the racing bikes, the NR, they apparently had lots of trouble getting it work, with many joking that the NR stood for "Nearly Ready"
It seems like it would vibrate a lot with so few large pistons banging about. I haven't read all the comments to see if someone already brought this up.
The NR750 was over priced at $50,000 and didn’t make enough horsepower when there were cheaper alternatives out there. It was a very limited production bike. I remember seeing one on display at the USGP at Labuan Seca. Very attractive bike.
Seems I recall these engines making it into a limited number of cars. I remember an article in a magazine at the time claiming 300 horsepower, also. Unless I'm mistaken.
Combustion chambers can be any shape, long as you don't have flat fold or pinches where preasure can find a split able way out. The result of folds on edges.
When engineering goes so far down a rabbit hole it becomes art.
@@alunesh12345 and what relevance does this have to do with the comment?
@@Marcanov06 Jesus made you realize. Palus shaped piston is the best
True... Working kinetic art...
@@alunesh12345 bro shutup
@@alunesh12345 God so loved the world he decided to completely obliterate everyone and commit genocide quite a few times
MotoGP: V8 is banned.
Honda: let me just.... Merge these cylinders into four big ovals ... Its a V4 i swear
thats glorious
Displacement is still a thing.
More like a V2+? 😬
@@Greatlakessailing yes but volumetric efficiency improves with more cylinders
how is it a v4 bro
Thinking outside of the box is the reason for Honda's success
You got that right Bro
Except it isn't, and this was a bad example, hence the fact it never took off, since it was just inferior to round pistons.
Sell a bike for 4k , and then sell the parts separetely for 8k. Rob your costumer and with that money develop new things.
They are worst than apple and can stick their shiny new cilinder in their asses.
@@derbigpr500 I meant it on a broader context. Not all ideas and concepts yields good results, but they always go that extra mile into putting effort to try something out. A clear sign of their success is they way they got into the US market and rapidly became a global player. Turns out people like reliable, innovative and price compatible cars/bikes.
Thinking outside the cylinder
Such a classic Honda move.
“I wonder if this will work?”
“Oh look at that! It worked!!… well, we’ll never do that again.”
cause it didn't work. like it ran but it still wasn't competitive. and now with the rules written the way they are it's not worth it.
@@nick4506 Honda also made a torsion bar valvetrain. It totally worked but they only did it on a single model, the CB450.
Or the gear driven valvetrain which was only used on the VFR series.
That’s the sort of thing I was referring to.
Not so much if it was heavily beneficial, but more if it worked or not.
Though, I’d argue that the torsion bar drivetrain is beneficial in a maintenance sense.
@@Indarow do you mean valvetrain? for the CB 450. they could only fit two valves per cilender because of how wide the tortion bars are.
and the vfr got the gear driven cams to try and fix the cam life issues honda was having on their 80s v4 bikes. turns out it was heat treatment and oil issues that stopped that.
yea this stuff technically works but other factors make it so they cant really be used anywhere else.
@@nick4506 thank you for the correction! Yes, valvetrain is what I meant.
Mechanical four wheel steering. Still don't know why this isn't mainstream. They spent a lot of money and time on that development.
Thank you Scott. I'm 59 and I remember all the development of the project. Fantastic technology. I wonder if development had continued, as for example in F1, what would have happened, especially considering how the regulations allowed greater creative freedom in the 1980s. Would it have worked?
I am passionate about motorcycles, and until today, I use the NR 750 as an image for my channel. Greetings from a Brazilian subscriber.
TF ...
It's the first I seen a Jesus bot ...
@@alunesh12345 Matthew 6-5 dude.
@Neat Bigs Such a fantastic machine, Neat Bigs. Fantastic. Greetings from Brazil.
What was interesting, they could have made an oval piston 2 stroke and all the math would then turn in their favor
@@aidanmargarson8910 Who knows, but it´s a great idea. Greetings from Brazil.
I was 13 years old when i saw that machine at the practice sessions of the 1981 British motorcycle Grand Prix at Silverstone. Freddie Spencer was riding the Honda NR 500 GP at that race. You have to remember you had push starts at the time, not standing starts like you have today in MotoGP. Now this oval piston machine was very difficult to start with a push start, and Freddie Spencer was practicing this over and over again in the pits strait because of this. It had an amazing sound though compared to the twins. It's an anecdote my dad always comes up with and now i saw this video popping up, so funny.
Believe in JESUS today, confess and repent of your sins. No one goes to heaven for doing good but by believing in JESUS who died for our sins. For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.(John 3:16)❤️😎❤️😎❤️😎❤️
Hi, in 2008 I noticed one in a parking lot in Ajax, Ontario and had to say hello and ask the rider about the bike. It had just over 100,000 klms on the odometer and was burning a touch of oil. He just topped it up a bit as needed. No major failures or rebuilds and he had enjoyed the bike, he had bought it used in good condition. I suggested he contact Honda, they might like to see an example of a long term survivor. I remember when it launched and could not afford one at the time. I was very happy to see a running bike so many years later. She still looked like sweet ride.
I have ridden the NR750. It is incredible. The bike was heavy, partly because it had an insanely heavy exhaust. The bodywork was carbon fibre that would chip so easily and the paint alone cost $7,500 per bike. The engine was extraordinary. It just revved and the torque was so flat you hit the rev limiter all the time. Not very powerful by fireblade standards of the time I think about 100HP. The designer was very unhappy that it got strangled because of the push for power limits in EU. To make it up to him Honda took one, changed the exhaust and ECU and used it to set some world records. Very cool turning up at my mate's work on it but was only allowed to borrow it for an afternoon.
it's facinating engineering but i'd hate to think about how you'd go about rebuilding one of those engines now
A long time ago, I read a bike review (MCN I think) between an NR750 and a VFR750 (same type of bike of course, except the NR had oval pistons). They thought it was a lovely bike to ride, but were disappointed, that performance wise, it did not offer much more than the VFR.
@@cameronfarris7171 before the launch of the NR, Honda confirmed a European company that would be able to recondition the engines- I got that from one of the test riders at the time ; )
@@ianalderton6683 Did you work at HRE-G ?
@@neilberry7345 18 years bike designer from 1992 until 2010, what a great time we had : )
Don't forget that Honda also made the RC211V which is a V5 configuration for MotoGP.
2:53 I suspect it's more to do with the preventing the piston racking in the bore given the width.
You should do a video on Honda's V5! That was an experimental motorcycle engine that actually performed incredibly well.
What?
The v5 was raced
@@jackryan4313 they raced it in motogp when they switched from 500cc two-stroke to a 990cc 4-stroke. I think it was RCV211V?
How in the hell
@@marcusjr80
Correct. Vale’s first 4 stroke championship wining bike.
It looks more like the double rods were to balance / control torque from twisting the piston within the cylinder ( elipse-inder?). With a single rod supporting it in the middle, it could seize very easily
Bit of piston wobble eh haha
that's what I was thinking, it was to prevent wedging. I wonder if it would have been better to have a single rod in the center but rotated transversely
Yup, first thing that popped into my mind for having two rods per piston as well. The slightest force imbalance across the piston face could massively increase drag on either side and wedge it, got to make certain this cannot happen.
I drove a CB400 four as a teenager and had all the fun in the world. Many times regretted selling it. My dreams were so real that I woke up to look for it in the garage when cruel reality kicks in. Awesome engine. Then older brother bought the CB 750
Lovely bike. Myself and my mate had one and they were just lovely little bikes. With a piper exhaust they sounded immense. Never heard any other bike sound like it with that exhaust on 😊
Honda also made legendary two stroke engines. They have twice as many power strokes per revolution. Closer to running off pure explosions, like a jet engine.
NSR500 😃
The 'Big Bang' engines that went into the NS 500 and the NSR 500 of the early 1980's . They were totally evil to try and ride. Can't remember which one of the riders it was but they likened it to a bucking bronco, ever time you open the throttle it 's just trying to throw you off.
Honda brought two of the NR750 F1 bikes to Australia for the Swan Series, don’t remember the year. I did see them race at the Oran Park round.
Very cool bikes
I was there as well, I had a piece of the fairing off one of them, can't remember now if was Mal's or Rob's bike, after they bined it during practice. Not sure what happened to the piece now. Oh well. Have to admit, they went like scolded cats and sounded like nothin else.
“And in 1983, they had a virgin that achieved 130HP.”
Great video! Very interesting stuff, and very well explained! Honda has always been one of my favourite brands.
Remember having a poster of this on my wall in my teen years, one of the best looking bikes to come out of Japan.... Ever. This was like the Bugatti Veyron of motorcycle technology, they even tinted the windshield with a thin layer of titanium rather than using plastic film
Believe in JESUS today, confess and repent of your sins. No one goes to heaven for doing good but by believing in JESUS who died for our sins. For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.(John 3:16)❤️😎❤️😎❤️😎❤️
@@alunesh12345 don't bring God into this FFS
@@alunesh12345 I don't recall ever reading motorcycles were ever sins in the bible bud.
@@owenward2924 it is a bot my man.
I remember back then there were rumors that the bike cost was approaching one million dollars. It could be with the amount of R&D time put into it.
I had a model NR500 I built as a kid and I could never get an answer on why it was oval pistoned. Thank you for finally answering it. Still remains a mystry how they manufactured the block and did things like hone the cylinder walls as this is all done with a simple rotating honer but would be pretty difficult to properly machine the oval cylinder walls.
The oval piston engine (0X engine, developed in 1979) was a product of Honda's drive to conquer technical challenges.
These days, it'd be banned because the regs say 4 "cylinders"
A cylinder with an oval cross section is still a valid cylinder.
Well I understand what you are getting at, but there are many types of cylinders, check out the parabolic cylinder for example.
Rules: "1.3L, two cylinders only"
RX7s: "yup, nothing to see here..."
Cries in Triumph
it says maximum of 4 cylinder...means can be 1 2 or 3 or four
Why? Well, aside from Mr. Honda's dislike of 2 strokes, by the time Honda started work on this engine, the other Japanese manufacturer's had managed to... "persuade" (by means that nobody will discuss to this day) the FIM to;
- increase the 2-stroke displacement limit from 350cc's (which had made them competitive with a 500cc 4-stroke) to 500cc;
- ban any type of "forced induction" - like a supercharger, while at the same time allowing the use of expansion pipes. Which, on a 2-stroke, accomplishes the same thing - just pulling the intake charge in, instead of pushing it (and which doesn't work on a 4-stroke engine); and finally
- limiting the engines to 4 cylinders.
All of which made sure that no 500cc, 4 stroke, 4 cylinder engine stood a snowball's chance in Hell against a Kawasaki, Yamaha, or Suzuki 500cc race bike. Until this engineering tour-de-force Honda reared it's sadly almost-but-not-quite head...
You're wrong - of course it works on a four-stroke! Learn about pulsations in intake- and exhaust systems.
Wait, I thought expansion chamber is used for pushing air-fuel mixture back into the cylinder, so its not wasted and then making more power
@@zuzuzaza98 You're quite right, but four strokes also use the pulsations in intake- and exhaust systems to reach more than 100% filling of the cylinder - even 120% of volumetric efficiency can be reached. I explained this in a simplified version as an appendix to my book "Honda's Four-Stroke Race History 1954 ~ 1981".
The biggest draw back to this engine was machining parts for it. At that time CNC machines were nowhere near as advanced as what we have nowadays so this design costed an absurd amount to make.
Yes, i was mentioning this. Today using an elipses creating and recreating acurate tolerances woukd be a breeze. Apparently VW picked up the idea in the early 90s, while simultaneously developing the vr6, which met the higher standards they were looking to achieve at that time in an easier fashion, thus developmeny on an oval engine ended there and has been left from what i could find. In laymans They turned a 1.6 into a 2.3 using oval pistons the engine took up as much room as the 1.6, and i believe it was a boxer engine. Man i really wish i could focus on developing something like this and like still pay the bills/provide for my family lol. I often find myself "reinventing the wheel" on everything i work on, few times after exhausting all possibilities i look back and think, "why didnt i just follow everyone else, smh". Mostl, i can look back and say, "i certainly learned a great deal". And every now and then my wheel comes out better than anyone has ever imagined.
@@bihgolphatdictergud746 I remember , actually getting piston rings properly seated was a big issue.
And the piston materials at the time were overcome by the piston velocity FPS, and scored and galled at over 25,000 rpm.
Its hard to get any lube film to work when the rings simply push it off instead of riding on top of it.
I can only imagine what that moment of piston reversal does to the connecting rods at nearly 30,000rpms... CRAZY
@@frosthoe Hence the appeal of rotor engines.
Pistons and con-rods are so very 19thC...
Nope...getting the rings on the piston to work was the biggest hurdle.
@@ValkyrieRiderIPT which ties back to my comment on how difficult it was to machine parts for the engine.
If people have not said this ,or I missed it above, the main problem to me seems to be the piston rings cannot float and rotate so run the bore in properly to seal things. Plus If they needed replacing they would be unlikely to fit the bore after it was run in as any irregularity in manufacture or wear in the previous rings would be set in stone so to speak.
Imagine the look on the guy's face when you take it in for "a quick re-bore".
I went to the bike show at NEC Birmingham back in 91 and Honda had a whole stand dedicated to the bright red NR750 with cutaways of the engine - possibly the same one in the B roll.
Mind blown.
I'm not the biggest Honda fanboy, however this is the one of the two brands that i really respect and that's because they're the biggest engine manufacturer in the world and they have fuck load of experience building engines. Every time i hear different brands of bikes working (from the same category and class) i can hear how Honda is the only engine that sounds so smooth and up-beat.
great generators
When I was a kid I drooled over the NR and the Ducati 916. Always had a thing for bikes that did it different. Norton is on that list too.
Without people like these Honda engineers and the man himself, full of drive and passion, im frightened we will all eventually become uniform and bland.
We need these free spirits and other thinkers to keep driving.
The 92 NR750 was used for a lot of the RC45 race bike. The engine converted back to round pistons, the fuel injection, the single swing arm. Then Honda made the 98 VFR800 off the RC45 with very similar looks the NR. That’s why the VFR800 platform was so well engineered, it’s mostly from the NR750 minus the exotic materials and pistons. It was the Everyman NR750 and help Honda recoup their investment on the project.
Imagine 3 oval piston each side with free valve tech with twin turbo diesel. Pure torque on a car
Imagine a rotary engine. rotary valves disc or tube/rod,
@@joefish6091 ah yes dorito ❤️
I remember Moto Magazine in Greece bought that bike only to be able to test it and admire the technology that was used on it. Good times.
I reckon gp culture will have a tough job copying this vid and passing it off as their own idea
Its honestly so impressive that they managed to get a 500cc 4 stroke to have the same power output as a 500cc 2 stroke, even with the extra 20kg thats just insane to me
That's the kind of crazy engineering I love to see
Honda is the best. Cool video.
All my life I have been drawn to elegantly engineered vehicles, and the end point of that quest has almost always ended up Honda. In motorcycles it was CBXs and ST-1100s, and even now at almost 70 years old, my daily driver is a '98 CRV with a 5 speed. I have no doubt that Honda's habit of pushing the envelope with what some call hairbrained schemes has resulted in un-surpassed engineering at the consumer product level.
First change for pistons in decades! Very interesting!
6:29 "matching their two stroke rivals" not really ! 130 HP the 500cc two strokes were capable of WAY MORE than that, those bikes were EASILY the most powerful, bad tempered crotch rockets on the planet, the top riders like Doohan, Rainey, Gardner all those guys had balls of steel because of the SAVAGE power that would come on as they would roll on the throttle coming out of a corner, just a fraction too much twist on the throttle meant the difference between the bike just exploding with extra horsepower JUST at max lean angle and then loosing traction on the back end resulting sometimes in high sides that were fucking awful to watch, Doohan suffered greatly from this when his leg got mangled, I know how that feels because it happened to me too, steel rods and all...
Carbon fiber monocoque chassis, carbon wheels, cross-mount radiators.... it was a spaceship. You have to love the willingness to take it to that degree. As I remember it at the time, this was pretty closely followed by the motoring press and while most of the race community were doubtful, every one respected the effort. I remember a picture from a race and 3 Honda mechanics pushing a NR to tech and a bunch of mechanics of other teams lining up to salute. People appreciated what they were trying to do and, I think, that this was the descendant of the Honda 5-cylinder 13-speed 125cc GP bikes of the 60's that made possible the Japanese wave most of them now worked for.
Honda had always made multi cylinder engines fir racing. The NR should have been a V8, but regs made them merge 2 cylinders into 1. Crazy to take it on. Interesting that once they accepted two strokes they dominated 500GP racing with first the NS 500 (another bit of outside the box thinking) and more successfully the NSR500s
Not to geek out or anything, but the bike pictured @7:04 is an ns500 two stroke, not the nr500 oval piston. The original nr750 did fairly well in endurance racing before the road bike was launched....
There’s some mighty crazy engineering in motorcycles!
Driven Media, I like y7our style and great sense of humor. This coming from someone who has listened to Radio for decades and has developed a good ear rand inner vison so I could understand the personality i was listening to. A family member inherited our old Honda Civic and we now own a 2019 used Toyota. The parts never broke. They always were replaced after wearing down.
Well that's why I like this content aside from ideal's ...
The engineering perspective ...
Is hammered into the script ...
EDIT
It's cool what one do with constraints
Believe in JESUS today, confess and repent of your sins. No one goes to heaven for doing good but by believing in JESUS who died for our sins. For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.(John 3:16)❤️😎❤️😎❤️😎❤️
Souichiro is a man after my own heart. What a legend.
it wasnt crazy or mad.. Honda ONLY made that design choice because they understood the breathing capacity of 2-stroke vs 4... NOTHING to do with cramming 8 valves into a cylinder.. it was totally about the limits at the of piston speed & metallurgy .. piston rock becomes a serious problem once past the 1-1:5 bore stroke ratio for 4-strokes.. at that time .. so Honda defined the specs their prefered v8 would need.. & siamesed the cylinders together.. the rest just followed engine engineering convention.. twin conrods is a blindingly obvious need
I have designed engine using oval valves. Instead of 4 per cylinder, just 2 oval. Area of oval valves is much bigger than 4 individual. Better intake and exhaust flows.
@@golf398 Thanks for input. It never progressed beyond design stage. Goal was single lifter to keep mass low. Sealing might be issue, since it can't rotate. Valves would be CNC to fit precise CNC cut in heads. It turned out that single oval valve weighs more than 2 round valves. Overall goal was to increase Volumetric Efficiency.
The Fenrir motorcycle in FFVII was claimed to have an 800 HP twin oval-piston hybrid diesel engine.
Hybrid diesel yuck
Good talk, I always wondered about it. I also remember that it was said that the engine was twisting frames of bikes and the cars they put it in. But I do remember V4 oval 23,000 rpms
long live the 2 stroke engine the purest ever!
@qwerty mnbvc true. injection minimizing the unburnt fuel though
As a layman who doesn't know much about engine design, I'm amused that the "crazy" idea to overcome a 4-piston limit regulation was just to combine every pair of pistons into one. It looks like it's just an 8-"cylinder" design but with the neighboring chambers connected. I'm not sure why it's considered a "miracle" to have worked, but it's nice that it did. Fun design.
Funny how normal technology has come along, now with current tech, modern motorcycle engines can produce over 200 hp pr liter in a four cylinder 1000. So scale it sown to 500 cc, hp pr liter will increase slightly, so 130 hp on a 500 cc normal four, would be easily attainable
Or the last of the two stoke GP bikes making 200+ from 500cc V4s!
@@bennyb.1742 BS
The NR750 for me is just a stunning bike. A bike shop near to me had one for sale at £125k so I had to go and see it in the flesh. I wasn’t disappointed. It still remains my all time favourite Honda regardless of its low power figure. Awesome.
126 hp was almost the most powerful of any bike in 1991 and that included 1100cc GSXRs etc. Besides, power was not really the main point. The 750 NR racer had around 160 hp. Do the math and it is same as modern superbikes.
@@tygapaul Yes your right sorry.
I was wondering if the shape of those bores can even be called cylinders. I just looked it up - yes.
They aren’t “oval” though. There’s no “straight” line on a oval.
#TeamHonda my 2010 EXL Pilot is at 182K miles and burns zero oil and leaks nothing. Runs perfect. I love it!!
A video about NRs with no sound of an NR in it? What?
Believe in JESUS today, confess and repent of your sins. No one goes to heaven for doing good but by believing in JESUS who died for our sins. For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.(John 3:16)❤️😎❤️😎❤️😎❤️
This oval piston 8v per cylinder was also used in a race car as well
Would you put rings on an oval pistons? Or would they be called loops?
"The engineers have since admitted that they didn't know if they were experimenting or just being foolish..."
I'm reminded of one of Adam Savage's greatest quotes: "Remember kids, the only difference between screwing around and science is writing it down."
It almost begs the question of what qualifies as a cylinder. It's no longer cylindrical and has two connecting rods. The engine as a whole resembles a V8. It's really a fantastic feat of engineering around a questionable rule.
I wish Honda was still like this. They used to be genuinely innovative and focus on cool things. Fast forward to today, a base Civic isn't offered with a manual, they don't offer any RWD cars, and their most "enthusiast" car is an over styled FWD commuter car that dealers mark up to $50,000. Oh how times change.
I was wondering how they did the piston rings. These are some cool engines!
yikes, $50K for a bike!... or should that be more like $2K for the bike and $48K for the engine?!?! :-)
Old enough to remember and have lusted for that bike. Unfortunately (or maybe fortunately) it was unobtainiam. Thanks for the walk down memory lane.
In theory, the oval piston could increase efficiency by reducing the surface area for heat to escape
How would it do that...an oval has far greater surface area than a cylinder of the same volume..!!?
@@manoo422 you know what, you're right, i was thinking a single oval piston would be better than instead of having 2 smaller pistons, but it would just be more efficient to have one larger/longer stroke piston
@@denvera1g1 Its swing & roundabout really the increased area can be mitigated with less cooling. They did it for the increase in piston area allowing 8 valves to be fitted because BHP is proportional to valve area, and they wanted BHP!
This is the most practical reason for things like racing, space exploration, deep sea exploration etc. The wild engineering generates spin off technology that benefits humanity and moves us forward
I see three immediate problems. (1) keeping the two connecting rods perfectly balanced with each other. (2) keeping the rods exactly the same length. (3) Keeping the rods perfectly timed to each other on the crankshaft. Get any one of these issues off is going to result in twisting of the piston both vertically and horizontally in the ... can you even call it a cylinder? I wonder how much one of the 200 bikes goes for today.
Um this is a problems for all engine.....
Maybe an I shaped (Like a steel I beam shape) connecting rod would help.
I have a old interceptor with the v4 oval position 700cc motor they sound absolutely amazing
Didn’t know they actually used them on production bikes. Thought it was only the NX racers
HONDA has no match in any sport or any engineering madness. Porsche (the one and only theoretical ideally approach to something called perfect) was Prince and Honda Michael Jackson. Proof: amazing quality street cars and racing result in all categories... Cheers!
Solid investment... The motorshop around the corner has one in the showroom. Value currently sits around 150.000 euros
Does it bother any other engineers out there that the “oval” headed piston wasn’t oval shaped- it was stadium/pill/discorectangle-shaped.
In the sheet metal business, we used to call that shape an "obround". I don't know why.
Wow, you just taught me something I didn't know, I've had a few Honda's including a VFR750, Now a Honda 2001 CRV Rd 5 speed, currently as a second car with a Hyundai 2012 i30 gd active 6 speed manual. I hate automatics, I have a mt03 as well.
"Who wants to see this engine in a car?" ✋Yes, please! Would love to see a version of it power an F1 car---just for kicks, its time has probably passed otherwise. I remember the Honda NR, gorgeous bike, fueled many a teenage wet dreams... 💓Given the number of technological advances on the bike (beyond the oval pistons and 32(!) valves: the single arm for the rear wheel, the carbon fiber build, the exhaust under the seat, etc. which have all become industry standards), having it be the price of a Porsche 911 seemed perfectly reasonable at the time. It now trades for 40-50% higher than a new Porsche 911 on the second hand market!
Yep watched Freddie Spencer on a nr500 and it sounded phenomenal back in the early eighties.
MARVELOUS! 👏👏👏👌 I'm 50, and, I remember most of it's history, and, being completely awestruck on first seeing it (after a bloody ice cold, long and boring ride on the M40 (GSX400F) from Slough) at the NEC Birmingham (WHY THE F have a bike show in OCT/NOV time?!?!?!)... Anyway, WOW what a machine. Those that don't know, just don't understand why Honda really are some genius guru's when it comes to automotive magic. I think 🤔 If memory serves, some bike mags were saying it was priced at £38,000... FOR A FRIGGIN' BIKE! hahaha Having said that, and even though I loved screaming around on both my CG125 (😉) and CB250N, I was a Kawasaki man at heart (cut my wrist and I bleed GREEEEN!) hahaha. Brilliant episode, loved it! 👍 😎🇬🇧
Imagine this engine with the toxic aluminum beryllium pistons from the V10 F1 days? I have been amazed that Honda came up with engine designs SO groundbreaking that said designs are now banned from entire racing series. F1 has a clause specifically stating "the pistons shall be round" . Moto GP banned six cylinders way back due to Honda 6 cylinders owning the competition in the sixties. The whining of the other motorcycle companies was fantastic. Great video. Thanks.
I seriously respect Mr. Honda sticking to his hatred of 2 strokes so much that something goofy like oval pistons were invented.
We need more of this in our world.
Would love that kind of experimentation today
Scott, you are right except for one thing, you said "Measuring wasn't as exact as it is today" which is completely wrong. Even back in the 50's and 60's the craftsmen were measuring accurately boring with a tolerance of 0.001mm or 0.000039" inch far superior to what we measure today. The Swiss made a machine called SIP Hydroptic-6 Jig Borer to achieve this and it is more accurate than computer driven machines of today.
I'm fairly certain computer driven hardware could do more then 1000 nano meters. Is that needed? Probably not.
@@historyZZ uummmm 1000 nanometers is just a micrometer which 0.001mm which is what I already wrote. Also measuring down to that small is one thing but to bore or hone to that accuracy is another.
@@hommie789 oh I thought it was. 00001 my bad. I guess that's 10000x
Many many years ago, this was a available for the small block Chrysler engine. It turned the V8 into a massive V4.
This video is wrong, in 1960's Puch made a 'twingle' engine sold in Sears motorcycles that had two rods and an oval piston...
@@BuzzLOLOL The Puch Twingle engine (1913 through 1970 ...) had two pistons with separate rods using a sort of twin-bore double-cylinder.
43 years later... "This is new!"
A CB 4-cylinder with oil filter centered came onscreen just as you said what great 4-stroke engines Honda made. I agree! As long as you don't crossthread the steel oil filter bolt into the aluminum block. Don't ask me how i know....
Wouldn’t anything other than a circle have more drag and ring length per unit of displacement?
ducati also made a 8 valve v twin , the 888 . as for HONDA'S 8 valve it was sold in new Zealand as a VFR 800 , a 800 cc big brother for the 750 . it's retail was around 23k .
i have seen and touched one For real when i was in my late teens.. Amazing bike to see that has some resemblance to the NSR car
Aren’t the rings supposed to rotate to reduce grooving?
I'm totally with you, I want to see this in a car!
For me the idea was "we would need a V8 for a four-stroke, but are not allowed to use more than 4 cylinders. What do we do?"
Look at the layout, it is in principle a four-valve V8. With normal round pistons the engine would look exactly the same. Just a little modification to get individual combustion chambers and the cylinder block changes.
I always say that just because you can do something is not enough reason to do it. Sochiro Honda thought differently and made things work which nobody else considered feasible or worthwhile just because he could. Very much 'glossed over' in this video is the insane amount of engineering this took- even just getting the rings to apply even tension across all faces in light of changing cylinder temperatures was a herculean task. Easy in a circle, darn near impossible in an oval. And ditto on piston clearances, skirt design, and even bore machining. Then to bring it up to the level they achieved... Putting a man on the Moon was probably easier than this. Sochiro Honda was an under-appreciated genius in his own right.
4:23 Was there gas of the Tail pipe?
And the kickstand Sparked ?
or did the Motor , turn over from The wheel turning ,, and No rings , burned the oil , making Smoke ( this Seems unlikely)
In 1988 they imported one through Canada and was on Palomar Mountain with I believe cycle world at the time was doing a write up on it.
I remember the days when Honda was doing this motor for the racing bikes, the NR, they apparently had lots of trouble getting it work, with many joking that the NR stood for "Nearly Ready"
A very old issue of Popular Mechanics from the early 80’s had a big article on Honda’s oval piston project.
It seems like it would vibrate a lot with so few large pistons banging about. I haven't read all the comments to see if someone already brought this up.
The NR750 was over priced at $50,000 and didn’t make enough horsepower when there were cheaper alternatives out there. It was a very limited production bike. I remember seeing one on display at the USGP at Labuan Seca. Very attractive bike.
Ever thought about doing an episode on the RC211v racing bike honda made with a v5 engine layout?
it goes beyond admiration bc it shows those men cared for what they did and made science fiction real
So that’s the base of the NRG500 on GTA ?
Back in the 80s it was reported that these engines were turning 22000 and wining races. At least that is what they told us at Honda.
The NR750 is one of if not the greatest sport bikes ever created.
Hell, it even inspired the design of the Ducati 916.
Seems I recall these engines making it into a limited number of cars. I remember an article in a magazine at the time claiming 300 horsepower, also. Unless I'm mistaken.
Combustion chambers can be any shape, long as you don't have flat fold or pinches where preasure can find a split able way out. The result of folds on edges.