I was already tuned into motorcycles in 1972, but not MOTORCYCLES. The kid down the street had a Mini Trail 50, the couple with no kids had just bought themselves his and hers Honda Elsinores for Christmas – a 125 and a 250. They let us into their rumpus room to gaze slack-jawedly upon them in all their new-bike glory. I remember the nubs on the knobbies, and the fact that they looked huge to me. When you see an old Elsinore now, it’s tiny.

I was only thinking dirt bikes in those days; 16 and a driver’s license was eons away. And then Big Kev rolled past on his new Kawasaki Z1. Actually this must’ve been 1974, which I believe was the year of the striped gas tank and still my preferred Z1 livery. The basketball came to a halt; 10 pairs of adenoids hit the driveway as one. It was the first big streetbike I remember ever noticing. It was really too big, beautiful and powerful a thing to even aspire to, like Ginger on “Gilligan’s Island.” Holey moley. Lookit those pipes man.

I like the striped ones, which began in late 1974 along with silver engines instead of black.

I don’t think I’ve ever had the pleasure of riding one of the old beasts, but I’ve ridden bikes of the era. Basically everything happens slower, requires more effort, and gives less feedback – like aquarobics pretty much.

1972 was 46 years ago, though, and since we’ve only been building motorcycles since around 1900, I suppose you should expect quite a bit of progress: The Z1 got here about 61% of the way along our development curve. Given that, it’s slightly amazing how similar the new Z900 RS homage I’m off to ride next week is to the original. Let’s have a look at the specs, why not?


1972 Z1 2018 Z900 RS
Price $1,895

($11,372.90 in 2017 dollars)

$10,999 – 11,199
Engine 903cc DOHC inline air-cooled Four cylinder; 2 valves/cylinder 948cc DOHC inline liquid-cooled Four cylinder; 4 valves/cylinder
Bore x Stroke 66 x 66mm 73.4 x 56mm
Compression ratio 8.5:1 10.8:1
Induction Four 28mm Mikuni carburetors Digital fuel injection; four 36mm Keihin throttle bodies
Ignition Coil, points TCBI w electronic advance
Claimed horsepower 82 @ 8500 rpm 110 @ 8500
Claimed torque 54.2 lb/ft @ 7000 rpm 72.6 lb/ft @ 6,500
Transmission Wet multiplate clutch; 5-speed Wet multiplate clutch; 6-speed
Frame Steel double-downtube cradle Steel trellis
Front suspension 36mm telescopic fork 41mm inverted fork; adjustable rebound damping, compression damping and spring preload
Rear suspension Dual shocks; adjustable for spring preload Horizontal back-link swingarm;  adjustable rebound damping and spring preload
Front brake One 296mm disc, 2-piston caliper Two 300mm discs; 4-piston calipers, ABS
Rear brake Drum 250mm disc; 1-piston caliper, ABS
Rake and trail 27 degrees / 3.75 inches 25.4 deg / 3.5 in
Wheelbase 59.0 in 58.1 in
Tires 3.25-19 front; 4.00-18 rear 120/70 ZR17; 180/55 ZR17
Curb weight 546 pounds 472 lb
Seat height 32.0 in 31.5 in
Fuel capacity 4.7 gallons 4.5 gal

The Bureau of Labor Statistics’ online calculator says $1,895 in 1972 equates to $11,372.90 in October 2017, so prices are actually coming down! (And never mind that my personal limit of about $5k for just about any motor vehicle hasn’t changed in 15 years.)

Your classic big double-overhead cam Japanese Four is still in place – DOHC was a first for a big Japanese bike – though now it’s liquid-cooled, fuel-injected, higher-compressing and 10mm shorter of stroke. Those changes result in 34% more power at, surprisingly, the same 8500 rpm, even though the new bike’s 36mm throttle bodies have way more intake area than the original bike’s 28mm carburetors; 34% more torque arrives 500 rpm sooner on the new bike. One extra pair of gears in the transmission allows you to shift gears more.

We’re still using round steel tubing for the frame, but in the new bike’s case that frame’s been designed using computers instead of men with slide rules, and welded together by robots instead of yet other humans.

Exhibit A, a slide rule.

You’d definitely be able to tell the difference between the old engine and the new one from the saddle, but those differences wouldn’t be as fundamental as the ones you’d feel between old and new chassis. In addition to its stiffer frame, the new bike’s inverted fork, “horizontal back link” rear suspension, and modern radial tires all work together to make those under age 40 feel like something fundamental is wrong when they climb on a bike like an old Z1. Did somebody forget to tighten something? Did somebody forget to tighten several things? People get used to imperfections when they love old things, though. Take my wife, please.

Horizontal Back Link Rear end, read all about it here.

As for the brakes, there’s no comparison between the old Z1’s single disc and flimsy caliper to the new bike’s dual discs and monoblock calipers; both power and feel are way better, also the front tire. Nobody knew from stoppies in 1972, not on big street bikes anyway. And nothing but maybe the Space Shuttle had ABS in 1972 – and it hadn’t even been invented yet.

Can you tell which is which? But for a small LCD panel between the clocks (and an anachronistic aircraft style filler cap), it would be tough from this angle. Old engine redlines at 9000 rpm, new one at 10k.

All those things are going to increase the bike’s overall stability, while letting it exploit its steeper rake angle, shorter trail (only 0.25-inch shorter, or 6mm) and inch-shorter wheelbase to turn and burn much quicker than the old one. Its biggest performance advantage, though, will be its 13.5% weight reduction, the product of a 46-year diet program. Compared to the increases in accel and decel, that’s less than you might expect. Lightness is the most expensive thing: We’re still using steel, aluminum and rubber just like in 1972, albeit less of it.

I dug the new Z900, so I’m sure I’ll like the Z900 RS fine. But I’m still holding out for the 350-pound carbon-fiber and polymer-composite two-stroke Triple replica of the real H2. I hope I’ll still be able to lift at least one leg 32 inches when it gets here.



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  • Rocky Stonepebble

    I’ve still got three slide rules. One of which is circular. And quite a few (proper) calipers. Not those digital ones, for the dummies.

    • Alaskan18724

      One day I’m gonna get one. And learn to use it. My calculus is in the rapidly dwindling past….

      • Rocky Stonepebble

        I loved linear algebra.

        Now, I like gin and tonic. And naps.

        • Alaskan18724

          And Xena, Warrior Princess.

          • Rocky Stonepebble

            No. Just naps.

          • Alaskan18724

            Wonder Woman? Linda or Gal?

          • Rocky Stonepebble

            Hockey. One, maybe two beers, and a nap. Then, wake up after the game is over, check the score on-line, and go to bed.

            It’s a wild crazy life I lead.

          • michael32853hutson@yahoo.com

            Lynda hands down-then and now

          • Rocky Stonepebble

            Hands down what?

          • michael32853hutson@yahoo.com

            LOL i just got a mental image…

    • Joe Boro

      Yeah, I used to call those old calipers verynears as it get’s you kinda close.

  • Alaskan18724

    Lean on ‘em for the Cafe’. Lean hard.

    • Rocky Stonepebble

      Come to Canada, loser.

      • Alaskan18724

        Isn’t that, “hoser”?

        • Alaskan18724

          I’ll meet you in Montana.

          • Rocky Stonepebble

            Too far west.

          • Alaskan18724


      • dbwindhorst

        Any interest in adopting a retired couple from South Carolina?

        I’ll throw in a questionably maintained first-gen KTM Duke.

        • Rocky Stonepebble

          Always have a welcome for Americans. Now, those miserable fat Belgian bastards on the other hand …

    • Ruth

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      • Douglas

        We can tell yr a lifesaver….by the hole in yr head.

      • Blake Newton

        Showing your naughty bits on the web isn’t a “job”.

        • Rocky Stonepebble

          It is for me!

  • Gruf Rude

    That rootbeer & red NAILS the original look. I remember uncrating the original Z-1 at our shop in ’72 and just being awed. . . Code name ‘New York Steak’ and over-the-top for the era.

  • john phyyt

    Big ass alternator hanging on the end of the crank waiting to be ground off or smashed off when skinny cross ply tires let go after being unable to slow down enough for blind corner , ( single piston front disc ; ineffective in wet) yet motor produced so much more power than everything. …

    “feel like something fundamental is wrong when they climb on a bike like an old Z1. Did somebody forget to tighten something? ” .. Nailed it brilliantly. Thank you Mr Burns

  • Starmag

    My friend’s older brother bought a brand new striped ’75 in blue. At 14 I thought it was the most beautiful thing,( not just motorcycle ), I’d ever seen, ( besides Michelle down the street ). I still do.

    Nice comparo John. There’s a few tests out there already on Euro sites. Why do they usually get bikes first? ( H2 SX excepted of course). America’s market is the largest(?) and we’re closer to Japan. Especially MCN, which has become a very lame publication.

    • Jason

      The EU combined buys quite a few more bikes than the USA.

      • michael32853hutson@yahoo.com

        then we have to catch up!

    • Ronnie

      I bought an brand new 1975 kz 1000, was an awesome fast bike.

      • Rocky Stonepebble

        You have a time machine?

  • Tanner

    damn shame the XSR900 looks so goofy.

    this kawa looks so good. wish it was a triple, though

  • 12er

    The Cafe Version is giving me a tingly sensation again. If I fit, its going to be tough to pass up.

  • michael32853hutson@yahoo.com

    i have the same mental $5K limitatation-but i sure like this new retro-bike!

  • LightenUp

    Another fine article, Burns. Now, about that old love of yours, do you mean your soon-to-be-estranged wife?

    • michael32853hutson@yahoo.com

      quoting Rodney Dangerfield shouldn’t be grounds for divorce-on the othre hand congressmen are resigning over conversations about surrogacy!

      • Jim Beaux

        It was Henny Youngman, not Rodney.

        • michael32853hutson@yahoo.com

          yep-you are right! i sit corrected

        • Rocky Stonepebble

          Wait! Burns and Henny Youngman are married?

          • Jim Beaux

            It seems that Henny is not so picky after all.

          • Rocky Stonepebble

            Maybe Burns has an inner beauty?

            And the cheque is in the mail! A-hahahahaha!

    • john burns

      any similarity between persons living or dead is purely coincidental

  • Butch Schultz

    They should’ve gone with 18″ hoops like Honda did on the CB1100.
    Maybe next year.

  • Mr. Canoehead

    “And nothing but maybe the Space Shuttle had ABS in 1972 – and it hadn’t even been invented yet”…The Dunlop Maxaret ABS system was developed for airplanes in the 1950’s and was adapted to the Jensen FF in the late 1960’s – the first automotive ABS.

    • Blake Newton

      I did not know that. Excellent to know. Particularly with Benz claining it invented it in 1978. Oh hey…did you hear? Led Zepplin invented rock music in 1972? 😉

      • Rocky Stonepebble

        Chrysler, together with the Bendix Corporation, introduced a computerized, three-channel, four-sensor all-wheel ABS called “Sure Brake” for its 1971 Imperial. It was available for several years thereafter, functioned as intended, and proved reliable.

        Blah, blah, blah … many other car companies blah …

        1978: Mercedes-Benz W116 became the first production car to use an electronic four-wheel multi-channel anti-lock braking system (ABS) from Bosch as an option from 1978 on.

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  • Bill Gore

    In ’75 I purchased a KZ-900 which was my first foray into Japanese motorcycles, having ridden Brit bikes for several years. The fit and finish of the Z-bike was amazing, and the acceleration was initially almost scary. Of course there were issues. It was great in a straight line but squirrely in corners. After substantial modifications, including increasing the braking, and stiffening the frame, I ended up with a bike that could outrun just about anything that tried to challenge us. Certainly it wouldn’t compare to what is currently available but, at the time, it was exemplary. In fact, a friend of mine, who had always been a die-hard Harley-Davidson advocate called the Z’s engine a “300 pound” watch. He had never seen a motorcycle engine come from the factory blue-printed!

  • Dave Brumley

    I miss the kicker.

  • dtrides

    Interesting how similar the pricing is on your comparison .
    As far as I can see , everything has gone up by a factor of 5 since I bought my first liter bike in the late 70’s….except wages ..didn’t know how good we had it back then. 🙁

  • Jon Smith

    I had a Z1 I rode from Alabama to California to my new station.
    Racer Brown cam, Hooker cross over TT headers. That thing would haul ass.
    Not much good though since it had high speed head shake issues. Nothing will scare you worse than a tank slapper at 135 mph…

    • Rocky Stonepebble

      Ever been in a Turkish prison?

  • Jay Vee

    I remember walking into Linden Kawasaki at 18 and thinking about trading my ’72 purple H2 in on a Z1, which was very impressive, but instead I was seduced by a yellow Ducati 750 Sport instead. While I would miss the smell of 2 stroke that saturated my riding gear, I wanted something by then that could at least get around a corner and figured the Duc was my ticket so I missed out on the Z1. Wish I had all three today….

    • James Marshall

      Purple `72 ??? I remember the classic first Blue Mach IV in `72, and the Purple people eater in `74.

      • Jay Vee

        You are so right! I just looked at me photo album and it is blue! Being old and color blind doesn’t help…..

  • James Edward Zeiser

    Yes, the new bike goes faster but can you hang a Windjammer fairing, Krauser bags and put your wife on the back comfortably and ride from New York to LA? In specializing motorcycles, as has been done, riders have been forced to decide what they want a bike for ALWAYS, not just spontaneously ride. A lot has been lost for what has been gained.

    • Rocky Stonepebble

      “Yes, the new bike goes faster but can you hang a Windjammer fairing, Krauser bags and put your wife on the back comfortably and ride from New York to LA?”

      WTF are you doing with my wife, and why are you taking her to L.A.?

  • DuckyRider

    I’m in love with that bike. I think I’d moved from a Honda 750 KO of 1969 to a BMW toaster 750, but that Kawi was a sweet looking machine, and would devour any four stroke I knew of. This just tells me it’s going to sell to us old guys who have a few more rides left in them.

    • mike no

      Us ole guys? I bought the 71 750 Norton Commando new off the show room floor in 71. Now umpteen bikes later I guess you are right. I ride a 09 Road King today, the bike of ole men.

  • James Sullivan

    I was an H2 man back then and I eagerly await the 21st century version. It will be incredible!

  • Bmwclay

    I’ve seen and ridden the Z1’s back in the day but I really did not care for them. A little too coarse and raspy feeling. The handling with those little 38mm twisty forks did not impress. Then my best friend got a Norton Roadster and let me ride it. Don’t know if was the bike or the Georgie girls in the ads, but I was in love. The Combat engine had almost as much power as the Z1 but weighed 100 lbs less and handled like it was on rails. Just check the day the bike was made, you didn’t want one made on Wednesday or Friday.

    • mike no

      I had the Norton Commando and you are right, the Nortons were very nice bikes.

  • Rapier51

    Here’s a good video of what is essentially an out the showroom floor 84. I doubt many kept the stock pipes which was too bad because that sewing machine sort of whine, which I learned later was those roller main bearings, was the thing that above all really ‘got’ me about the big gals. You can hear it here a bit.


    • Jim Beaux

      She’s a real beauty. Whatever happened to the old girl?

      • Rocky Stonepebble

        She left him when he bought the bike.

  • michael folk

    got a the duck tail fender trim and 2 side covers for a 1974 zi 900 for sale 775 513 9504 in nevada call for price

  • Blake Newton

    Wrong. ABS had been invented! Chrysler called it Sure-Brake on the big Imperial luxo-barges in exactly that year. I know because as well as being a motorcyclist, I am a Mopar man.

  • Mitch

    Fuel Injected 2 Strokes NOW!

    • Rocky Stonepebble

      I’m not a g​ay man, but if I was, I’d be all over you!

      (I’ve only ever owned one four-stroke)

  • Craig Hoffman

    If we could transport the current Z back to 1974, aside from the technology causing people to believe it is the product of space aliens, the performance would blow everyone away. Now it is commonplace.

    The article lends perspective. Just because this bike’s performance level is commonplace does not mean it is not extraordinary. Having to hang on while rapid fire shifting and manic acceleration with a screaming wail and the scenery blurring by never really gets old. All this from what is considered in modern terms to be a “mild” bike. This is a great time to be riding motorcycles.

    • mike no

      The 900 back in 72, or 74, blew everybody away! I had the 750 Norton and the 900 was unbelievably fast to me.

      • Craig Hoffman

        My brain was permanently warped in 1976 by an ill advised ride as a 14 year old in a grassy field behind my house on a neighbor’s TM400 Cyclone dirt bike. I had a wee little Honda 100, and begged him to ride the 400. He said OK, “but only if you can start it”

        Put my High Point boots on, kicked that evil machine with all I could muster and off I went, and have never been quite the same. It was like I felt the hand of God 🙂

  • FacticalWeapon

    I had a 75′ Z1. I have had many bikes since. None made my heart pound like my first Z1.

  • Kevin Bottorff

    I had fun beating them in the drags way back in 75 with my 750 Honda. Of course I was 50 lbs lighter than any of the other riders. And we learned you never let them come out of the red line when racing. THATS how ya got power from them. Then we would trade and I would beat them with there own bike. I don`t know how they never figured it out HP per lb people if all else was equal.