FZ1 swingarm on 91 FJ

[Derek Young]

 It seems to be a tradition for me to rip apart my FJ in the off season and modify something... sometimes a whole lot of things. This year was going to be different... until I came across a swingarm from a 2003 FZ1 on ebay for $20! Delivered to my door with exchange rate and shipping was around $75 Canadian. Here we go again! I had been looking for a swingarm I could polish since I bought my 91 FJ. As it turns out this one is black with a pretty decent finish which I quite like, so no polishing for now.

I didn't want to go with the FZ1 wheel as it has straight spokes which wouldn't match my YZF600 front wheel. The previous owner had already mounted the rear wheel from a Kawasaki ZX7, 1991 I believe. It was a pretty good match with the front so I thought "how hard could it be to just make this one fit?" This wheel used the stock solid FJ axle(17 mm I think), the new swingarm uses a hollow 28 mm axle. I was able to find new bearings that fit the wheel which also fit the new axle! Just had to machine new spacers and the wheel was done! No machining to the wheel!

[aviationfred]

Sounds like a great find. 

We want photos.....

Fred

[Derek Young]

The swingarm itself needed some machining. The pivot was about .35" too wide. Took it to my buddy John's shop and he milled it down to the same width as the original swingarm for me.

The pivot spacer on the two swingams are the same OD but use different size bolts. The end caps/seals are also the same diameter. I was able to swap these parts and the new arm fit on the FJ!

[Derek Young]

Next problem: brakes
Just after I got the wheel done my brother dropped off a tote full of old FJ parts I had left in his basement. There just so happened to be a brake caliper I forgot about from a GSXR 1100 in there. No caliper bracket though. I had some 1/2"aluminum flatbar laying around and picked up some 2 1/2" aluminum round bar. Some careful measuring and a few hours of labour later and I had a new caliper bracket and spacers.


With a little heat, the stock FZ1 brake stay was offset and I welded a new end on to fit the new caliper.

[Derek Young]

I built a set of paddock stands recently and wanted to mount spools on the new arm. I was considering welding aluminum blocks on the bottom but my nephew Paul talked me into bolting them on instead. He is very helpful in the planning of my motorcycle mods as we spend alot of time talking about it before they happen. He frequently talks me into doing way more than I intend to at the start. He is a great fabricator and has a very good mechanical/engineering mind. In my line of work I deal with a lot of fabricators and machinists, some of them are close friends, and I usually discuss my mods with them before I tackle the jobs.

The new arm already had a hole on each side near the dropout. I enlarged these and drilled 2 new holes. These were tapped to M8x1.25. The blocks were made from 1"x2" aluminum flatbar and drilled/ tapped to fit the m10x1.25 bolts that came with the spools.

[Derek Young]

I have seen posted on here that the rear brake switch would not clear the new swingarm. I installed everything on the bike and raised and lowered it a bunch of times but found no place where it contacted this switch or the wires leading to it. when the rear tire was raised about 6" off the ground the swingarm rubbed against the rear master cylinder, but this is moe than the suspension ever travels so it wasn't a concern. The supertrapp exhaust was a clearance issue as was the exhaust mount bolt. The bolt had to be shortened by about 3/16". I cut the mount off the muffler, made a new offset mount from 14 ga ss and welded it back on the muffler. While I had the exhaust in the shop I welded an extension to the header where it mounts to the mid pip/muffler. This exhaust was designed for an 86 and the mount points are different on the 91 leaving very little lap at the connection point.

This pic shows the clearance.

[Derek Young]

The new swingarm is about 1 1/2" longer than the FJ arm. Of course this means the chain and sprockets needed to be replaced.
This was something I was considering anyway as the PO had installed an EK SROZ chain, which is not the strongest chain, but it was still in good usable condition.
I decided to go with what has been recommended here, the EK ZZZ. George had posted a link for a cheap source which looked like a good option. However the shipping to Canada was ridiculous! In the end I decided to order the chain and 38 tooth rear sprocket from my local Yamaha dealer. He gave me a good discount and I like to give them as much of my business as possible. I want them to be there for me when I need them. I don't mind spending a few dollars more for the convenience of having them around. Most times they can have my parts in 2-3 days as opposed to sometimes 2-3 weeks if I order online from the states. They are also a Kawasaki dealer so they carry parts for Donna's ninja also.
For the front sprocket RPM came to my aid and shipped me a shiny new 18 tooth unit. Very reasonable shipping cost and extremely quick service! Thanks you to Randy and sons!

Here's a shot of the chain and sprocket.

[Derek Young]

I've only had a couple rides on the new setup. Overall impressions are good. The problem I have in doing these mods in the off season is its Been 6 months since I rode the bike and its difficult to know how much difference they make in the ride. Mostly I like to have a project to focus on and its cool to see the changes you can make with a little effort.

This project was quite time consuming and took place over a couple months time. It would have been way easier with the stock FZ! rear wheel/brake parts. Of course easier isn't necessarily as much fun!

Here's the completed job. What do you guys think?






Derek

[rktmanfj]

That's a great looking mod and bike (a bit much RED though...      )
Only thing I really don't like is where it says Kawasaki on the wheel 

[Pat Conlon]

Very nice Derek, very nice.

One thing I noticed on my YZF1000 T-Ace swing arm is that the swing arm spool would bash the underside of my Kerker muffler...when the Penske shock was set at its full soft setting. It looks like your Supertrapp muffler is set higher than mine, but you may want to keep a eye on it.

Also, I had the same problem with the muffler bolt rubbing the face of the swing arm. What I did was to put some low profile ss button head bolts on, with the button head facing inside, and a ss acorn nut on the outside.
Shimming out the aluminum side brackets with a couple of washers (between the side bracket and frame) also helped.
Brake light switch needed a bit of Dremel work and the rear master cylinder cleared fine.

Lastly, my brake line would come loose at the banjo fitting on the master cylinder. The constant up and down motion of the swing arm and thus the brake line, would work the m/c banjo fitting and crush washers to loosen.
This problem was solved by ordering a custom line from Spiegler which had a 90* fitting (instead of straight) at the m/c banjo. I installed the line with the 90* fitting facing up, and the problem was solved.

Good job young man, I'll see you and Donna in a couple of weeks... Pat

[Country Joe]

Derek,
Great mod, the only question I have....what did you do for the shock and linkage? Did you use the FZ shock or FJ?
Joe

[Jonfife]

That's a great looking mod and bike (a bit much RED though...      )
Only thing I really don't like is where it says Kawasaki on the wheel 

Wow! Great work

[rktmanfj]

That's a great looking mod and bike (a bit much RED though...      )
Only thing I really don't like is where it says Kawasaki on the wheel 

Wow! Great work

I think Derek knows I'm kidding (though we don't have a stick-poking emoticon handy)

[movenon]

That swing arm looks like it belongs on an FJ for sure. I can't wait to see it at the rally. Your comment about modding and no riding is dead on. Since the last rally I have ridden maybe 3 or 4 times and that was mostly to see what falls off  ..  My skill level is between zero and incompetent.
Your bike sure looks good, it "wintered" well.
George

[rktmanfj]

My skill level is between zero and incompetent.

Unfortunately, we don't have an emoticon waving a bullshit flag, either.