|ZX6 swingarms in general
The 86 is different from the 88-89 models. They can be distinguished by looking at the ends: the 86 has a radiused section between the top surface of end plate and the rear surface, it's kind of rounded-looking; while the 88-89 model has three flat sides on the end-section and is very angular. They are both designed to use 17mm axles and traditional external adjusters.
|One amusing (sort of) thing I noticed while playing with two ZX6 swingarms in my office was that one of them made swishing sounds when I moved it around. At first I thought I must be dreaming, but no. There's water inside one of them. It doesn't leak out, and I don't see a hole, so I'm not sure how it got in there, but in there it is. Upon further inspection I noticed that the sides of this one were bowed out slightly, in contrast to the very flat sides on the non-swishing swingarm. I'm guessing it sat in a puddle, filled with water through a very small leak, and was frozen solid at some point. (This is New Hampshire, after all).|
|[UPDATE 27JAN00: I wrote this section before I took an '86 swingarm off a bike myself. I was surprised to find a set of end-caps at the pivot area that were NOT present on any of the other three early ZX6 swingarms which had graced my garage. These endcaps had center holes just large enough to accomodate the axle, so the collar pins them against the inside of the frame, and the swingarm pivots *inside* them, which explains the marks on the early-model ZX swingarms in this area. The endcaps have lips which wrap around the pivot area's outer diameter, acting as a dust seal for the bearings, thus replacing the inner-diameter dust seal found on the later model (shown below). Including these endcaps in the installation would be a good idea, but will require significant additional grinding of the frame bosses (less desirable), or cutting of the swinger pivot tube area, as described below for the 89 model, which was a modest p.i.t.a. This new discovery leads me to say that this swap is only marginally better than the '89 by virtue of the collar diameter]|
|I'd suggest that you start by cutting the pivot bolt collar so that it just barely fits in place in the frame. You want a good tight fit here. You may have to buy a new collar (for about $37). I was able to salvage one of the two I had by cutting the rusty-nasty end off in this process. I had to take about 8 or 10mm off the overall length.|
|Now cut the pivot area of the swingarm down equally on both sides so that you can fit it into the frame. The '88-'89 pivot area is much longer than the '86's, and so requires the removal of about 9mm of material (as opposed to the little filing job required for the 86's). The proper length for the pivot area will be about 1mm shorter than the collar, in order to fit the bearing-seals on the ends.|
|INSTALLING THE F2 WHEEL|
The salvage yard where I bought the swingers and stuff had a box full of unlabelled axles which had come from bikes being disassembled. I was allowed to paw around and take from it what I wanted. I took several axles to try out, and several spacers. I used some of these spacers as raw material to fabricate the captive spacers in my F2 rear wheel. They fill the wheel's 20mm centerhole, and allow the use of a 17mm axle, which is what the ZX6 swingarms are designed to hold (so I didn't have to bore out the notches to 20mm, though I've heard lots of people do just that, and have no problem). I borrowed heavily from Todd Bates' spacer design (below) but I had to modify them to suit my funky brake caliper carrier, which I fabricated out of 1/4" aluminum plate. I originally used a front EX-500 caliper, and the stock ZX6 caliper-brace, and drilled a 43/64" hole for the 17mm axle I used.
|Later, I acquired a front caliper off a DR350 (?) dirt bike in the junk yard, which I cleaned up enough to make work. I had to mill off some of the friction material to fit it around the F2 rear disk, but it works. I mocked up the caliper carrier with 1/4" thick panelling, then transfered that design to aluminum plate. Currently, an ugly bar made of flat-stock acts as the caliper brace, since I couldn't make the nice aluminum ZX part line up properly.|
WRITTEN BY TODD BATES, WERA #192(n)
I will keep this basic, for all different experience levels of responders. I am just completing my f-2/zx600 conversion and do not claim to be the source for higher moto-knowledge, so use your own judgement for this. This is what worked good for me.
'87 EX500 racebike
'94 f-2 front end
'85 or '86 ninja 600 swingarm, axle, and adjusters
f-2 rear wheel and brake caliper
I think the best material to make them out of is stainless steel. Most small time machine shops (myself included) do not have this on hand, so I used "stress-proof" steel, c.r.s. would also work fine. I would not recommend aluminum because the thin wall would be weak.[recall though, that this component should be trapped between a fixed axle and a fixed center tube, with no rotating contact points. It shouldn't need to be very strong...Just strong enough to prevent it from mushing out under the compression of torquing the axle nut...My point being that I think aluminum might work, but watch it carefully if you try it.-Wade] [JULY2000 NOTE: I used aluminum for my bike, and after 3 hours of race-pace over three weekends, there is no visible spacer deformation. I will use aluminum for this application on my bike from now on. -W] Good stainless will not rust, but stress proof and c.r.s. will. If everything is coated with grease at assembly this should not be a problem
If you are going to hire this out, the prints should be easily understood by any competent machinist/toolmaker. They will thank you if you take the axle in so they can be sure of the size. What we want is a "slip-fit." Our Japanese friends build awesome bikes, but their reputation for exacting tolerances is kind of over-rated [I concur with this.-W] I've seen a fair amount of variance in parts. The bearings in the wheels do not vary much at all, so this is not a problem. What we want here is a "snug slip-fit." Meaning you can slide it in my hand, but without excessive "slop." [NOTE: I'd suggest bringing the whole wheel in to the machine shop, so that they can test assemble it. -W]
|FIXING THE CUSH DRIVE|
In order to get the F2-rear wheel sprocket lined up with the EX500 motor output (countershaft) sprocket, one must machine down the sprocket-mounting face on the F2 cush-drive. Before you can do that, you have to remove the studs. These are held in place with some modest threadlocker. I'd suggest torch-er-ing the studs one at a time for 3 to 5 minutes with a propane torch. As an aside, I simply love my electric-lighting torch head!
|Then hold the cush stationary (I used a pry bar between the cush-drive lugs) and twist the stud *real* hard. I found that Sears "robo-grip" and vice-grips were not suited for the job, as a result of interference in their rotation by portions of the cush drive. A set of medium channel locks did the trick. I mangled the studs getting them out, but since I don't plan to reuse them, it's not an issue. I have heard that if one uses a narrow set of vice-grips they can be removed without damaging the threads. Remember, everything is *real* hot now!|
|With some advice from Andre, I was able to mount the cush on my lathe and mill the face down the 7mm it seems is necessary to get the sprockets lined up. Very cool. I love making chips. Various sources have suggested that as little as 4mm might be necessary. YMMV, check your installation yourself, ok? The bolts required to replace the studs are M12-1.25 x 25mm.|
Last modified on 30JULY2000