Yamaha YZ490 two-stroke 2-wheel drive: Testing the forgotten prototype
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- Опубликовано: 30 янв 2021
- Back in 1987, Yamaha wanted to test a two-wheel drive motocross bike and this very special YZ490 was born.
Using all mechanical components specially made in England, the bike was tried and tested, then eventually went into a private collection.
We got our hands on this unique 34-year-old air-cooled YZ to see how it works, and put it through its paces in its natural environment - on the mud and on slippery hills. 
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Fascinating. Didn’t even know something like this existed.
Suzuki did this two decades ago if I'm not mistaken
1958 Rokon had 2WD.
And they still make 'em.
Sure Honda also played around with hydraulic front drive too.
There's been race bikes modded by Christianson that are 2wd
They have new versions that are driven by a drive shaft and they are so dope
Your test ride is all about riding the bike like a motocross bike from what Im seeing. Ride it like an enduro and do some tech and hill climbs to really evaluate the bike for what it is.
There you go!!!
Thank you
Mx version seems stupid but xc enduro would be perfect.or snow
This is the MX version, the other prototype was an enduro 600 if you listen at the start of the vid, when he explains that.
@@stigmartin3072 he knows that.we all are saying it sucks for that tho. Lol enduro seems way more fitting. Or hill climbs or sloppy loose terrain like snow and mud.technical areas
Christini awd has there own bikes and conversion kits for some KTM's and Honda's
Exactly my thought
I get more and more tempted to try Christini AWD ride, I wish, maybe one day in my life time
My bro just bought a Christini awd ....basically a Honda crf250x frame and running gear with a two stroke gas gas etc 300 engine with electric start.. Much simpler system than this YZ and works very well Not heavy either and much better chain system.
Much neater with the shafts, totally.
This Yamaha just looks weird to me, the christini kit is much more refined.
only a shame, they only have 4 cycles avail, i rather like 2 cycle
@@Steve25g original Christini kit most popular was KTM 300cc 2t
The rotor and caliper up at the bars is craziness
Take your fingers off with that in a tumble
That bike is a real trail slayer, such a cool oldschool thing. It's great to see how many more companies now are trying out two wheel drive systems
I remember reading about this bike in the uk motocross magazines years ago nice to see its still around 👍
The front rotor is wild! Needs a guard to protect your leg from getting sliced open
Yeah, the government would never allow us to have that. You might get your hair caught in it lol.
@@savage22bolt32 just think about what you said . Does it seem right? Just something to ponder on ..
@@aaronr1328 right lol. "Allow us", stop giving them the power to make decisions for you.
The worst part to me is that if the front chain broke, you wouldn't have a front brake.
@@aaronr1328 you don't get subtle sarcasm
the OHLINS 2WD hydraulic system on the WR250 and R1.... awesome. It was before its time.
I'll bet she'd kickass at hillclimbing! Can't believe I'd never even heard of this prototype. Nice bike and that 490 engine is a sweet beast too.
I thought the same too because you could put your weight over the front and not worry about losing grip to the rear
The bike is 34 years old in 2021,
Not 24 years old, but still a great bike
7:47
@@PietriGuitars The first commenter just didn't watch or pay attention to the whole video. They correct them selves in the video so no need to make a comment about it.
All of that effort and ingenuity... And a drum brake in the rear! HA!
Yeah Yamaha was a bit asleep at the wheel in those days. The 490 was still a cool bike, though, even if it was technologically behind the other brands.
I actually kinda like drums.... don’t write them off! Well maintained,they are pretty adequate imhp
@@supertramp6011 at least if you aren't riding it, at least fast. Or it's not really possible to go fast with drum brakes 😁
yes on that year, and model production bike, thats whats called a prototype, only modify the experimental part.
@@miikasparf2613 its not the brakes that limit speed, and most drum brakes would lock the rear wheel if you tried, from a manufacturing point of view the biggest advantage of discs is they are cheaper to make and fit, a good reason to convince people they are better.
Yamaha YZ490 is a whole beast, it does not need 2 driver
They have been making 2 wheel drive bikes for a LONG LONG TIME... Might not be in the big commercial names but there is a ton of mid 70's-late 80's 2 Wheel drive bikes all of it started with the original diesel/fuel oil high torque low speed "TOTE GOAT's" they were primarily used in southern america for the super steep and insane elevation changes in the Peruvian and Chilean mountains.
You guys from the UK are cool. You aren't afraid to ride your vintage bikes. If they was in the US it would be a dust collector
Nope
I ride mine
Dust collectors are for museums
And sawmills
Cheers from Washington State
Good lord. It's a Rokon for men born after 1949. A beautiful brilliant monstrosity.
*"What size chain should we run?"* *YES.*
I rode a Christini ktm300 with a recluse clutch and trellborg studded tires for awhile. My friend bought it, $15,000 before the clutch and tires. It was like cheating in the worn out nasty trails in wintery Pennsylvania. Heavy though.
Man, that bike sounds so sweet!
Im sure someone else has commented, but there was a WR450 back in the early 2000's that Yamaha did with a joint venture with Ohlin's that was two wheel drive also, which would be good to see you ride.
Think it was a hydraulic drive that one
sweet utilitarian set up, i love the odd inventions of the 80s& 90s...i remember those super fat tire 2 wd cycles, shaft drive 2wd bikes, there were a few that actually went into production, but nothing was fast, this is the fastest one any one ever made...like he said its less usefull than it is just cool... that coolness inspires
They still exist, hell they are even old now
The ROKON is 2WD and made still in USA.There's a cheaper 1,but sorry to say I forget the maker.
This YZ was built by a company called Sunshine motorcucles and it was featured in Performance Bikes magazine in the late 80s or early 90s. I am sure its this one as the front disx was repositioned this weird way the cv joint carrying power through the steering moment I beleive was from a mini. It was tested i think by a great motorcycle journalist called John Robinson. If i remeber correctly he described the sensation of the front wheel only gripping and traction applying when the back slid or spun in a opposite lock slide whilst on power the front would be pulling as well, so it always felt rwd until traction was lost at rear. He described as fabulous. The front wheel was freewheeling as it was slightly higher ratio specifically because the front was airborne alot and so was not adding to traction anyway. I belive they did a first 2wd on either an it490 or a maico which was super heavy. I do not think many commenters on here have the real understanding of wngineering skill to say this is good or bad, it was an experiment and the fact it lasted so long is testament ro the HQ British engineering that went into its design and testing. There are many reason 2wd did not take off, lack of necessity being one, not many riders need 2wd, and jts extra expense would put people off. Google Rokon 2wd, this is the rider/bike type that 2wd is for farmers,forestry workers, outland camping...etc.
I remember this experiment well, there was also a French built 490 called the Savard 2x2. It used a swingarm type front suspension if I remember right. Then later the Christini system, which I believe got raced in the Dakar rally a few times.
The original 2wd bike is still made in u.s. by rokon. They been around since the 60s. But new are kind of expensive for $8 to 12k
Ya but the Rokon is more of zombie apocalypse machine the YZ is a dirtbike
Blown away never even heard of this machine and looks incredible for the era 😳 pure pulling machine lol You ride it like a boss too 👍🏻
I’d like to see Yamaha bring back the gold rims
unreal . what a machine YZ490 trench digger. a had a YZ250 J back in the early 80's fantastic bike. the 250 was water cooled. plenty fast enough. i valued my life so the 490 was out of the question. Those YZ490 's i remember seeing them in elizabeth st melbourne for $1800 brand new. how things have changed and the prices.
I used to have a 490, that bitch was brutal. Would damn near break your foot on startup, was so damn fast, you needed "Tons of space" to ride it". vibrated like crazy!!!! Damn I miss that bike.
Yea...those old big singles would rattle your dentures.
Same brother. Good to see and hear it again.
Oh come on it wasn't that bad. I had an '84 RM500 and at the time I weighed all of 140 lbs and I started it just fine. You just had to put all your weight into it, commit to the kick and follow all the way through without fear or hesitation.
Yep, the vibration was insane, after an hour of riding my hands were numb, had to peel my hands off one finger at a time. Fun as hell though.
@@nicstr28 What are you people talking about? I owned many motorcycles including CR250 and RM500. The 500 was no more rattley or vibe prone than any other. It was throatier and torquier and maybe a little more of a handful in terms of weight and size for sure, but no more fatiguing in terms of vibes. In fact I was much less fatigued riding my RM500 than I ever was riding my CR250. I get the sense there's people here that are just lying about riding big bikes and merely repeating myths they've oft heard from other liars and exaggerators.
Thank you! I had never heard of this bike. Very interesting piece of MX history.
Makes you apriciate how well engineered the christini really was looking at this monstrosity.
The TW 200 needs this upgrade.
Tw350 or 450 maybe.
That’s gotta have a flywheel effect like no other 😆. I’d freaking love to play on it.
Nice to see engineering beyond the BOX of approval
An older man that got me into hill climbing used to have a yz 490 he said it was insanely fast. Never seen one in person myself though
I could see a version of this working with a hub motor from an ebike and run it off a slightly bigger starter battery just to use occasionally in tough spots. It's like when you are stuck at the top of a hill and your buddy just pushes the front wheel to turn it to get a tad bit more momentum.
With the electric bikes coming out an electric 2wd version might be more cost effective with a drive hub.
We don't talk about those here
Unsprung weight
Too heavy, but I think the Ohlins 2x2 hydraulic drive would be a perfect match for electric
lol who wants that? We want more wheel sliding and wheelie popping
This has been explored with some success. The problem is mid drive motors can provide plenty of power and controllers are capable of ramping torque precisely enough to make an extra drive wheel unnecessary. From a practicality standpoint hub motors do not do as well off road for a variety of reasons, and off road is the only place 2wd makes sense. A second motor mounted to the fork with a transmission connected to the front hub would work a little better, but the question would become is the added drive wheel and overall increase of torque enough to outweigh the added weight and need for additional batteries.
That just looks so fun.The area I used to ride was so sandy and the front wheel pulling would've saved allot of guys from dumping over.Thanks for the review.
It's definately been "forgotten". Great vid! 👍
But that sound!!! Love it. Love that they tried.
That front brake is CRAZY
Imagine crashing, having the throttle stuck, and fingers going there 🙈🤣
@@miikasparf2613 fingers get sliced off
That is unique and special. Great video. It was great to see the thing in action.
Like the other comments I didn't know it existed since I am past my prime (80 years old) I enjoy watching Enduros and would have loved to see it in action starting and stopping on a hill just like in actual Enduro conditions.
Those 490's sound so awesome! It was a great machine
I've owned 3 yz490s and have never heard of this awesome find
That's so crazy, weird and cool with the front disk near the top of the fork like that.
Christinie has perfected this and sells compete Motorcycles ready to ride.. I think the Modify Gas Gas bikes The front wheel is geared 20% slower than the rear wheel.. the front wheel free wheels until the rear wheel spins then the front wheel starts pulling too
By perfected do you mean breaks constantly under heavy use and handicaps the bike in ways you never imagined? 😄
@@infidelmat XD
This bike was tested by Vic Eastwood (RIP) on a very old episode of Top Gear way back in around the late 80s. I have it recorded on VHS. .
It's certainly strange seeing the front brakes up that high, looks like a spare disc if you didn't know better lol
Had an 85 YZ490, it was raw power, broke my ankle on that bike, and kept riding it. Finally got a CR500 later in life and I think the YZ hit harder.
In 86 or 87 i smashed 8 teeth out on radiotor cap, severed my top lip on the number plate and was unconscious 3 days. YZ80
@@badcampa2641 I had the last air cooled yz80(81?), it was a quick bike. Seen some vicious injuries from dirt bike misadventures. Really vicious, squeaky voice now, probably, injuries. My cousin lost his front teeth, wheelstanding a bicycle, that parted ways with its front wheel. (Nuts got twisted too, he said). “The exuberance of youth”, they call it. (Bloody idiot, is what dad’s usually say?).
I think my YZ80 was 82/83/84, i got that wheelie machine second hand, it was a better bike than i ever was a rider. It may have twisted my nutsack but im glad that i cant remember lol
Sweet video showing stuff most people would never see.
Wow!... Crazy Set Up. Thanks for Sharing
never seen before, thank you for sharing
My 1982 YAMAHA IT 465 head had to be machined in the combustion chamber as there was no clearance for the wiseco forged piston. These are very high maintenance as even in the aftermarket "clymer" workshop manual recommends piston ring checks every 1000 KMs. Now with piston designs W/out circlip reliefs & screw on adapter's pistons can be perfected as when a ring tears at a port skirt it's beyond repair & over $2k to replace & rebuild it's not worth the trouble. Now lots of replacement parts are non existent & have to be "hand made" from billet or home made casting.
Not much info about traction comparison. Fantastic thing to ride and show. Thanks!
Nothing better than a crispy 2 stroke 🔥
Brilliant piece of engineering right there
What a bit of kit. Fantastic bike😍👍💙
What a beast. That bike would be mint with or without the FWD. 👍🇦🇺💪
I remember being a kid and seeing this bike in one of the mags back in the day. I’m 43 now.
When I was your age I was 45
@@oregonjeeper7977 🤣
Grew up on the 80s 2 strokes and NEVER heard of yammy doing this, but that front chain is quite "sketch" mate 👍 great content
I wish you would’ve shown how it’s able to steer without the chain coming off. Also I imagine you’d need a big bore bike to run a setup like that.
It would have to have something similar to a drive shaft in a pickup truck. Splined shaft inside a hollow shaft to slide in and out, but also have a couple u-joints for turning.
That’s the coolest I never knew one existed!!!
That's an interesting idea, and for me it's nice to heat a 2 stroke again
I think I saw a TV programme at the time this bike was made and Vic Allan was testing it. Takes me back.
Lucky to have that one mate.
not that i’m some sort of expert but i’ve never seen this bike i’ve had some 87 and 89 TTs and this is bout the exact same but two wheel drive how cool !! GRETTINGS from the US. 330 let’s go.
Swedish Yamaha rider Mats Nilsson was winning world biggest enduro competition, Gotland grand national around 2000 on a two wheel drive Yamaha.
I was looking for my old comment because I've seen this a few times. As a kid with a 490 in the late 80s I loved that bike. The power was fairly smooth and predictable compared to most big 2 strokes.
It should be in a museum
Absolutely incredible design.💥💥🔥🔥😎
I can see this being an advantage on the beach races.. 😯
Brilliant!!! Absolutely "Gobsmacking". Genius video.
That spinning rotor just waiting to cut your knee in half
Masterpiece Presentation
I remember seeking this A LONG TIME AGO, SWEEEET
Right now… you go find the guys that built this bike…and put them in charge of the first space mission outside the galaxy.
If anyone could build the machine to do it… those guys could.
Simply a brilliant machine here.!
The most important component is the clutch at the top of the first chain up from the countershaft. It allows the front to freewheel until the rear is spinning above a point dictated by a difference in gearing from rear to front. Rocon's original 2wd Trailbraker used this method though the drive used a shaft and had no suspension so it used only 3 chains, not 5 like the Yz. But cleaver work with the cv joint under the steering axis to allow the drive to rotate.
That's my local pit rode there few timed . Lovely bike there
Nice bike always a 500 class 2 stoke fan and heavy yes but power game on!!!!!!!!!
A great machine. Clever engineering.
Sounds of my childhood . Great old smoker
That thing is totally sick 🤙. Would love to have my YZ250X 2x2. Gotta get some moly lube on that front chain though, doesn't fling or make a mess.
Damn. The mechanics are insane.
That thing is mean!!! I bet she's heavy, but unstoppable for tight trails!
Still a good lookin bike, good ol 490's 👍
The real advantage this bike has is going to be in situations where rear wheel drive causes instabilities. You never put it through such a test.
I put together a mountain bike (bicycle) with a front hub motor. So essentially 2wd. While climbing steep rough terrain with RWD only; when you break traction, thats it you stop. With the front wheel also pulling and digging takes pressure of the rear giving you an advantage, with the odds of keeping traction essentially doubled. I plan on making a hybrid bicycle one day. With a petrol motor, and front electric hub motor as a trail bike for camping.
one way bearings. clever and needed.
thats the baddest bike ever conceived of!!!! what a beast!!!!
Didn’t Christini do a kit for relatively recent KTM and Honda’s?
Yeah I think you can still get one. The problem is their much heavier than a regular bike and don't give any advantage to an experienced rider. They are pretty cool though.
@@keshmo12 agreed. Disadvantages outweigh the benefits,especially as rear wheel does 90 % of the heavy lifting?...
Pretty cool. Must be so different to ride.
Pretty cool stuff
I like it !!! Neat information. Thanks.
There is a group in Aus which have added a hub drive front hub drive motor to their sur ron light bee. Greatly improved the off road ability for it to climb hills, and your talking a 50-70kg bike all up.
It looks like the front drive is going through a one way clutch with maybe just a very slightly lower ratio which is smart. It only really puts power to the front wheel when the rear is slipping.
Neat great bike. That was awesome
I have a Rokon, and have ridden all manor of sport, adv and dirtbikes in the roughest terrain in the USA. The Rokon's capabilities will blow your freeking mind. It will go places a $100,000 rock buggy cant go. I find it hard to believe the y havent perfected 2wd dirtbikes yet.
BTW the base Rokon weighs just 200 lbs. Only 6-7 hp though. 35-40 mph doesnt sound fast, but believe me it is almost scary with no suspension and all those gears moving!
I had an 87 yz250, Yamaha makes a nice 2 stroke, wish I would have kept it. Bing bing!
Love the bike thanks for the video
Next video pressure washing the bike
I rode a mates it 490, those things were fierce.
You would of thought this would shine on any Hill stage
yamaha did a 2TRAC wr426 a few year later and there must be some of them in the UK I remember bidding on one on ebay a few year ago
I have a 2 trac I'm just in the process of recommissioning it as its been stored for a few years .
Maybe we should do a side by side test
Ohlins did r/d iirc ? and R1 version .
I want to try that bike so bad!
That is an awesome bike!!!