Zephyr 550 cafe-racer kit (reversible).

I started this project in March, 2021. It hasn't been shown here because time was pressing so I had little time to photo-document every little step of the project, so I fixed only the main stages. Time gaps between such benchmarks of the project were irregular and at one occasion it was like two months (because my subcontractor in fiberglass wasn't able to do the job for me faster). Then I was too busy fulfilling the first two orders on kits. And so on and so forth. So every time when I've got a thought like "It would be good to show this project on KZRider" there was something bashing me over the head and throwing that thought far away.  To simplify things I just repost articles from my website here with dates of their original posting on my side to clarify chronology of the project.

May 15, 2021

I have been working on this project for some time. Now came time to announce it.

During the years of Zephyr 750 cafe-racer kits making I was regularly asked if my kit is compatible with Kawasaki Zephyr 550 and Zephyr 1100. Well, the answer was simple: 550, 750 and 1100 Zephyr frames are different, so the 750 kit couldn’t be installed bolt-on on 550 and 1100 bikes.  In case of Zephyr 1100 my kit could be installed with some minor modification of Zephyr frame and kit seat base, however in case of Zephyr 400/550 differences are less subtle so there is no chance  to install 750 kit on 400/550 models.

To make the situation with Zephyr 400/550 even more complicated, Kawasaki redesigned these models in around 1993. The most visible changes were made to the rear brake system and dashboard. Less visible from the first sight were changes that Kawasaki made to the seat and rear fender. In early 400 and 550 models, the place for OEM tool kit was organized similarly to one of the 750 model : its position was under the rear cowl and it had to be strapped to the rear part of the rear fender by rubber.  In later models of Zephyr 400 and 550 Kawasaki integrated a special tool kit compartment into the front part of the rear fender. This caused quite a change of a seat design, so seats from early Zephyr 400-550 couldn’t be installed on later Zephyr 400-550.   I’ll show the difference between seats in one of the next posts.

Position of tail mounting points for Zephyr 400/550 does not fit those of Zephyr 750. Therefore, in a situation like this the only way to get the cafe-racer kit for Zephyr 400 and 550 similar to those for Zephyr 750 is to… design the new kit.

Some time ago we got a later model of Zephyr 550 in our workshop. Actually, it’s Zephyr 400 – version of 550 bikes for the internal Japanese market, with 400ccm engine and built –in speed limiter.  A frame, a seat, a tank tail and other exterior parts of 400 and 550 models are identical.  I was so eager to start working on the kit that I found no time to shoot motorcycle photos.  Therefore, I could do it only recently, when I gave the initial parts of the kit into the paint-shop, where they will be prepared for molds making.

The goal of the project is the same as it was in case of 750 Zephyr: to make a completely bolt-on  cafe-racer kit for Zephyr 400 and 550 compatible with both earlier and later models (including their original seat locking systems).  Similarly to 750 kits, 550 kits will have E-approved tail light and two optional types of license plate holder with E-approved license plate light.

At the moment the 400/550 kits project is moving under full steam and I hope to post an update soon. Meanwhile, here are photos of Zephyr 400/550 which was the start of this project.
 

May 31, 2021

At last, models of the tail and the seat base for the Kawasaki Zephyr 550 cafe-racer kit are ready. I already handed them to my contractor in fiberglass works so the next step of the project is molds’ and first real parts making.



And here is a bit of a story about how I made models of parts. Since frames of 750 and 550 Zephyrs are different, the only parts from Zephyr 750 kit that fit Zephyr 550 are license plate holder and tail light. This means I had to modify the tail pretty much and make a new seat base for a kit of Zephyr 550.

As I already mentioned, front mount points of Zephyr 550 tail are positioned 30mm further and for around 30mm wider than those of Zephyr 750. Thus I have reconfigured the front part of the tail  mostly completely. With keeping symmetry it was quite a job. Once I finished what one may call sculpturing, I gave the tail to a paintshop, where it was primed, painted and clear coated. In the course of these actions I found flaws, and made sure they were  consequently eliminated. Clear coating is necessary not only for finding flaws but also for mold making:  the better the surface of the model, the better the surface of the real part will be. Here is how tail looked after I received it from the paintshop:




 

What I don’t like about the look of the original Zephyr 550 tail is the design of its front ends: they are angular, and their angularity doesn’t fit at all the design of side covers. They also positioned tad too close to rear shocks. For Zephyr 550 I designed new front ends of rear tail, different in design to both:  original 550 tail and 750 kit tail ends. Here they are:

 

 

 

And, again, as I’ve already mentioned, there are two modifications of Zephyr 550: the early and more recent . Their seats look mostly identical from the top side, but from the side of the frame the difference is significant.

 

 

 

My goal was to design the seat base which will fit both modifications of Zephyr 550 and cafe-racer kit tail. I based my work on an early type of seat base, but even with such a base it was closer to making a seat from scratch than for modification. For one thing, the length of my seat is 52cm, so it is significantly shorter than the original seat.

 

Its rear part is narrower and is of completely different configuration.

 

In addition, both types of original Zephyr 550 seats have a “soft” front “hood”. It means that the front upper protrusion has no hard base. And as the elevated front end of the seat is a significant part of seat design I had to design and make a hard “hood” for it.

 

And on top of all this I had to make the seat base acceptable for manufacturing from fiberglass, which also means scores of modifications. After I finished with the seat base, as it was with a tail, I handed it  to the paintshop for priming, painting and clear coating. I hope to get the first parts ready in two weeks.

 

 

 

 

Reading about my hopes to get first parts in two weeks makes me smile now. There and then every week beyond that term made me mad. Properly made fibreglass moulds are  quite expensive things and I was ready to pay the price. However, I wasn't ready to get the first  ready parts not in two weeks but in two months. And there was nothing I could do to speed up things.  

It's mostly midnight here, so I'll continue the story next time.

Top quality work Gazzz, very rare in the aftermarket world

Nicely done Gazzz!

Thank you!


Next entry dated July 23, 2021.


And here we go: moulds for  Kawasaki Zephyr 400-550 cafe-racer kit are ready, as well as the first two sets of real fibreglass parts.  And even if it took longer than I was expecting (and much longer than I  dreaded to imagine), results are quite impressive. Here is mould for fibreglass seat base.


 

 

Its likeness to broad-brim hat is caused by the reason that seat bases have to be vacuum moulded, therefore mould was optimized for such manufacturing.

Mould for tail may look less impressive, but in fact its two-piece mould for a  part of a quite complicated form, therefore, both its parts have to fit neatly.


 

 

First two sets of parts (pre-ordered) are also ready. In fact these two seat bases are already in the upholstery shop and their cushioning is finished. I hope to get both seats ready next week.  My aim is to keep the same seat (and therefore kit) design even as seat bases of 550 and 750 Zephyrs have surprisingly different structures.