In the history of custom choppers as soon as the Japanese inline four motor was on the market people were pulling them and putting them in custom projects. Companies like Amen made this even more accessible in the early 70's and with the introduction of the Kawasaki 750, 900, and 1000cc motors they adapted to include these in their lineup of ready to install chopper frames. However these Kawasaki Amen frames were much harder to come by years later than the CB750 Honda counterpart which dominated the market leaving any KZ chopper out there rolling a real head turner. Flash forward to the 2017 Biltwell El Diablo Run when we had the chance to meet Robbie Hardbarger on his Amen framed Kawasaki Z1 chopper. The bike absolutely screamed down the baja Mexico highways and despite the extreme heat performed amazing. After the run he knew he wanted to change things up and spent several years getting it to the stance he wanted. Just before the 2021 EDR he had it ready to hit the road to San Felipe again and we met up with him once again to relish in this amazing Kawasaki chopper full of awesome road stories. 

So let's start with all the informal introduction stuff. Give us your name and where you hail from.
My name is Robbie Hardbarger, I’m originally from Daytona Beach and am now living in Jacksonville.

So what is the year, make and model of the bike we're about to dive into?
It is a 1974 Kawasaki Z1.

Did you piece it all together originally or was it sort of like already a partial incomplete build from the 70's when you got the bike?
It was stock when I got my hands on it, I rode it that way for a while and slowly pieced together the bike you saw me on in 2017.

Now we know the bike has went through a couple changes and had some serious downtime since we first met you at the 2017 El Diablo Run. Is the motor in the bike now the same one or different and if so give us a little more back story on why.
Partially, I pulled the jugs one day to find some play in a connecting rod, so I swapped out the bottom end for another 74 I had laying around. I bought every clapped out kz I could find, and have always found it easier to swap than to start splitting cases on these things.

Have you done any special work to the motor or is it completely stock?
Nothing special, all stock parts. I always wanted it to be a reliable long distance bike. They are basically bullet proof from the factory and are plenty fast, so I’ve always resisted the urge to seek more performance for no reason.


So when it comes to inline four choppers surprisingly there aren't near as many KZ750 - 900 or 1000 choppers out there as there are Honda CB750's. Why did you choose to go the Kawasaki route?
To my understanding in the 70s most people saw the kz’s as a better candidate for the drag strip, and cb’s as a better candidate for a chopper. KZ’s have become more valuable so most of what you see today are the guys who restore them and the guys who race them. I always liked the kz’s better because I grew up racing and wanted to go fast, and didn’t mind significantly decreasing the value by chopping it.

It's no secret to you that I've been pretty enamored with the girder front end you have on this bike for years. Enough so to even search out and find one myself for my upcoming CB750 chopper. I really believe it just solidifies the stance of any bike perfectly. Was that already on the bike originally or did you luck out and find one and put it on?
I lucked out, found it on Craigslist in 2016 and slapped it on. It was way too long for the stock amen frame I was running, but at the time I didn’t care haha. I eventually got tired of the grasshopper look and stretched the frame up and out to fit the girder.


So we talked a bit one day about how weird the original shock is for these girders. It actually has an adjustment for soft and firm ride what did you have to do to get yours to ride right?
Super weird, yes it does have a dial that says soft on one side and firm on the other. It also has some grooves and a toothed washer for adjusting the spring. Mine was adjusted all the way out, and I just assumed it was blown and rode it rigid for years. I just recently realized it just wasn’t compressed enough. I compressed the spring and moved the washer up and now I have suspension lol.

The front tire you have been running for quite some time is a really cool vintage tread pattern where did you find that and what is the brand?
It was a Metzler tire I found on eBay, i loved it but recently blew it coming around a bend at the grundle run, I swapped the wheel and am running a speedmaster now.

The exhaust has been fairly bare bones in its current state for a while, do you have any plans to potentially add onto it or get creative with it in regards to some type of tip or muffler situation?
I always wanted to do an obnoxious 4-4 all upswept on one side, but constantly let myself get talked out of it. I’m currently looking for a 4-1 sidewinder header and I want to put an upswept yoshimura can on there. I was looking at my Fireblade one day and thought that exhaust would probably look rad on the kz. In all reality, it will probably sit just how it is for another year or two.

The frame looks to be a seventies original frame? Who was the original manufacturer of that?
It was originally a 70s Amen rigid catalogue frame, I really dig them but am a little tall for their dimensions. It’s been stretched up 4“ and out 2”, stetched 4” in the rear, and now has a single center seat post. Not much of the original frame is left.


So aside from the EDR of course, what was one of your other funnest trips that you've done on the bike? Maybe somewhere down south where you live?
The funnest trips I’ve done on this bike have to be all the Tarball runs. Tarball 4 was my introduction to the chopper world, and I’ve always loved the collective attitude there.

We really love the hexagon grips you are running and these great pull back handlebars, who made those? 
So from what I understand, the bends were done by silverback moto for a rigid front end built by a good homie who just passed away, Cody Duszynski. We narrowed them a bit to fit my girder. The grips are vintage.


So what is one of your funniest memories with the bike?
Personally my funniest memory is when I realized I was an idiot riding my girder rigid for no reason. I searched for a replacement shock for years, and my buddy Myles suggested I try to compress it more and lock the washer. I was honestly pretty embarrassed that I hadn’t realized that sooner, we’re still laughing about it.

Do you have any memorable breakdown stories?
I could write a coffee table book with all my breakdown stories from the 2017 Manhandle the Panhandle run in Florida. It was my first long ride on that bike and I was not prepared. Basically everything rattled off, i blew a wheel bearing, i was popping fuses every  couple of miles and ended up just ripping out the headlight circuit to get back home. It didn’t stop me from having a good time, and a super cool group of strangers stopped and fed me fuses and beers every single time I stopped. I made some friends for life. I kept telling them they didn’t have to but they just said ‘no chopper left behind.’ Those guys went on to throw the first grundle run the following year.

So on this newest version of the bike what all did you change up before the El Diablo Run? I noticed you were able to get the bike put back together pretty quickly just before the run.
Oh lord, everything. I had a negative experience trying to outsource some framework just after EDR 2017. I didn’t get it back til 2019, and was so bummed with the results that I let the whole bike sit in the corner for another two years while I rode a different kz. I decided to try to fix the frame and slap it together for EDR 2021 a week before I had to leave, only the tank front end and wheels were the same. Lucky for me I have some great friends who dropped everything and helped me make it happen.

Toshi, Myles, Jake, Jared. Also my mother knocked out a killer silver leaf flame job on the tank. Some of it was a little sketchy, but our goal was to make it roll down the road again and make that big dumb sissy bar fit, so I could ride around Baja and put the whole ordeal behind me. We achieved that so I call it a win.

Last question, do you have any plans for doing anything else to the bike or changing anything up?
I already pulled that obnoxious sissy off and swapped the front wheel for something a little more trustworthy. I may change up the exhaust soon, but for now I’m happy with it!

Well we are stoked on the progress and cant wait to see it rolling down the road once again.

Photos and words by Mike Vandegriff