Sprocket won't fit rear hub

Thanks. Ed

That's an awesome rear mag wheel - I'm one who thinks any & all 16" wheels are uber cool - IMHO the best thing that I'D wanna do with it, is lace up two ROTORS to that tiny little center hub, and use it for a FRONT wheel, fit some 16" wheels front and rear.

Might be a bit crazy on a big heavy four, but I'm guessing the 750 twin might get away with it.

Right now I'm building 16" rims for my "KZ440LOL" project, with a 4LS drum hub in Borrani 3.00x16" alloy rim - Buchanan's has already returned this wheel to me, loose-laced. Looks AWESOME - but yeah I've got it apart to spin out the drum as that particular hub was sent direct from eBay to Buchanan's - the one I actually wanna use has some ventilation slots cut into the centerline circumference, like vanes to blow air out as the wheel spins. Leaning toward building a 2nd identical wheel with the 2nd hub, for tire changes. But then I've got spare cams and linkage, shoes etc - just need to whip up some DIY shoe plates, sans speedo drive 'cause I'm running a magnetic pickup through the original speedo anyway, for electronic speedo etc - but yeah a bit of machine shop time on a couple of lumps of billet and that's two complete brakes. So it's still up in the air.

Either way, the 16" rims are pretty damn cool. I'm fitting 'em up with MAXI-SCOOTER tires, low profile radials in 110/70-16 & 140/70-16 - with all NOS belt-drive bringing up the rear on a KZ400 rear hub - got both types 36 hole and 40 hole with matching rims for each, plus both versions of the belt-drive which should allow some playing around. Ideally with the longer belt for a stretched swing-arm.

The bike is for my teenaged Ex-Daughter, as a first "proper" bike upgrading from scooters. Hence the scooter-ish wheels.

Speaking of the belt drive though, that's another really cool part for the KZ750B twin. Or at least, the KZ750LTD version from a few years later.

Now THAT would be some awesome kit for a Morris Mag wheel!

I dunno whether you'd be into BOTH wheels being 16", but a front rim in 16" and a rear in 18" is really cool too. Got some of that for my CB900K0 Bol Bomber, 3.50x16" NOS Super-Akront is looking like the better option than a 3.00x18" front rim, paired up with a 4.25x18" Akront rear - of which I've scored two, for the Honda rear hub or the Honda FRONT hub in a rim drilled for Harley.

Either way, the hub which I had INTENDED to use on the Honda was the wire-spoke conical rear disc hub from the....

You guessed it! The KZ750B original model! I've scored TWO such hubs, one of which I polished to a perfect mirrored finish inside and out - literally finger-banging the gap in the center of the wheel, polishing around the wholes where the bolts run through. INSANE - but it looked so good! I had that hub in the freezer, for a suck bearing, when the house burnt down to the ground back in 2013 - So at least THE HUB didn't melt. However the steel spoke flange from the right side disengaged when I was scrubbing off the crispy remnants of frozen mixed vegetables - from the blackened carbonaceous remnants left between the two parts - as opposed to indications of a copper or lead compound signifying a BRAZED joint, I suspect the flange is held on with EPOXY. And no, the rotor bolts don't run through that flange, it's just one big center hole stuck together with a slip joint full of glue.

Even SO - it's a super duper light-weight rear hub, it would compare very favourably to a front hub with a cush-drive bolted up to it. The only reason I can't use it is I bought pre-drilled rims which had been intended for other folks' unfinished projects. Or rather, which took off in another direction. Now if one were to dig up a non-drilled rim, the Conical KZ750B rear hub would be AWESOME.

If I had my druthers, I'd like to weld up an alloy replica of the original right-side flange, to the hub which I polished, which I had to soak in molasses-water for more than a year to remove that stuck bearing once it had been torched then soaked by fire hoses and left standing in water for several days - I risked my life recovering that hub, never mind the many hours spent polishing it - somehow it's survival indicates it's a "LUCKY" part to have on the bike. Ha-ha. But yeah, a flange like that might be tricky to replicate, as the spoke holes in it are rather weird. Not quite like the old figure-8 spoke holes from old racing drums, but more like one center larger hole with a slot cut across it where the spokes pull towards, so two spokes are poked through that center hole rather than just one. I wonder whether a figure-8 spoke hole would work better, or if it would be too crowded. But yeah I'd feel better about the whole thing if it were WELDED together. Not too certain whether a brazed joint to the original steel flange would be as good as the original epoxy, but in which case I've already scored a replacement hub so WTF.

I just wish to heck I were using it - even though I'm stuck on using Honda parts everywhere else on the bike, this hub is so much superior to the Honda CB750F1 BOAT ANCHOR of a rear hub, that I'd waive it's Kawasaki status altogether.

In truth, it would've made a great hub for the KZ440 project if I were fitting discs to the thing. It's that light weight. The KZ750 belt pulley should probably fit no problem - SHOULD - I emphasize, fit to the same belt as the 440 front pulley - the wider of the two versions at least. Or perhaps, cut down thin it could also work with the thinner 1" belt. That would be pretty cool, Ah but I'm more of a fan of drum brakes,

If my Honda had come with a rear drum, I'd never have bothered with fitting a rear disc. And what rear disc WAS fitted to my Honda 900, I'm down-sizing the thing as far as I can go. From 296mm to 276mm maximum diameter. Meanwhile the 296mm rear type discs are moving up front. Swapping out the carriers.

Given present beliefs about rear disc brakes, with 220mm being the standard for most modern hyper-bikes, I should think it behooves us ALL to shed some rear wheel weight from the rotor, wherever possible.

Same deal with that Morris Mag wheel's cush-drive. That's one HECK of a way to shed some weight from the rim.

Though I'd hasten to add that the original Morris cush-drive seems woefully inadequate. There's a Honda RCB rebuild on FACEBOOK of all places, "Team Caillou Bedier Racing" even you Kawasaki folks should look it up - 'cause it's got a good example of a period-correct CHAMPIONSHIP WINNING cush-drive, as bolted up to the very first COMSTAR wheels ever built. 1976 RCB racer, 750cc's at that point IIRC.

Anyway yeah the cush is a lot bigger than that Morris Mag wheel unit. I wouldn't focus on the metallic parts so much though, and I should probably get a better look INSIDE of that original Comstar cush. IMHO the original Honda cush-drives were probably waaaaaay over-built back in the day.

And they've probably got more to do with the CHAINS of that era, than protecting the transmission from shock loading. The early CB750 SOHC models had that nagging problem with broken chains flying through the crank-cases. Well then again, they already HAD the enormous huge cush-drive on 'em by that time. Still, I feel like by the time they got around to fitting a rear disc hub, whether that's on the '75 CB750F1 Supersport or the '75 GL1000 Goldwing, there really wasn't so much need for that enormous a diameter in the rear hub! The GL1000 Goldwing proves the point in that IT'S cush elements boil down to six tiny little rubber grommets -

Just like you see in the Morris Mag system!

As for whether the KZ fours, let alone the KZ twin, NEEDS as big of a cush-drive as they originally had fitted - remembering that they had an even bigger cush than the Honda version, with six rubber elements to the Honda's four, and a larger diameter at that - YEAH there were plenty of racers around back in the day, especially DRAG racers, which utilized "the front hub trick" - just like I intend to use on a bunch of rims for my Honda project (I've got 4.25x18", 4.25x17", and 5.00x18" all drilled for a Harley rear hub and hence suitable for a 40-hole FRONT hub) - By the same token, they were race bikes. Intended to be torn down and rebuilt very frequently, to be fitted with new chains as often as was possible.

Apparently the modern chains don't stretch nearly as much as the original non- o-ring type chains they used to have. A good friend of mine who used to race Triumphs over in England in the '60s (R.I.P., Frank "Tatcho" Godfrey) spoke of having to replace his chain every time somebody challenged him, it's on of the principal reasons why he bet money on every race, was needing to replace the stretched out chain! And keep in mind, that's a bike which the Kawasaki & Honda superbikes kicked BUTT on.

So maybe you need a better cush-drive than that, maybe you don't!

There are some pretty decent grommets available through Motocicli Veloci Milano in Italy, which I guess were intended for smaller Italian models. But perhaps they'd fit?
www.motocicliveloci.it/inglese/catalogue/ruoteparts_uk.htm
Beyond that I'd look to any of the replacement grommets from all of the SHAFT-DRIVE bikes, be they GL1000/CB900F or KZ1100 Spectre, what have you. There have got to be some decent grommets which were intended for these exact degrees of horse-power and torque AND which would fit that type of cush-drive no problem. Maybe you'd have to machine up a pair of new plates? Maybe ream out the holes for larger grommets? I dunno - but at least you'd know that the rubber elements themselves were intended for those same forces and those same sizes of wheels on those same bikes etc.

PERSONALLY I'd love to experiment with the polyurethane materials used on SKATEBOARDS - there were the wheels in varying "Durometer" yes, but there were also grommets made for the "TRUCKS" of the skateboard, in the same ranges of stiffness. If one were to build a cush-drive centered around THOSE things, one could pop out different coloured grommets for more or less degree of ... "cush"! That would be pretty damn cool. I'd bet the same materials are available as blocks. Ideally as a pour-in liquid, which one could mould straight into the hub. But yeah it might even be worth making little triangular blocks of the stuff to fit into a regular wheel's cush-drive. It's like how you look at the standard cush elements of a six-lug KZ1000 rear hub, those elements integral to accelerating the bike are larger, whereas the elements integral to using the engine for a brake, for down-shifting the bike to slow down etc - that side has a smaller element. So obviously they played around with what the cush was needed for and to what degree. But they were all made from the same material. it would even be interesting to cross-drill a hole or two into the OEM cush rubbers, to restore some of the original pliability.

'Cause let's not forget - those of use who are still using the original cush rubbers which came with the bike thirty-forty odd years ago - well we'd never consider using the original TIRES. Strangely enough the primary drives have rubber dampers between the primary chain and the clutch, and THOSE rarely get replaced. Only the most extensive engine rebuilds even address that question.

I'd be REAL curious to take some close-up photos of those old racing-drum cush-drives and Mag wheel cush-drives, to see how much they DEFLECT under full load. Would the rubber be squished right out of the way, and the captive bolts riding directly on the metal? 'Cause a lot of 'em use nothing but a slightly larger hole around that pin, where if even so much as half of the rubber had squished to the sides, the pin would contact the outside rim of that outer hole, in the outer plate of the whole assembly.

I'm VERY interested in 'em nevertheless, as I'm trying to design a good cush to bolt up to the wheels built around smaller FRONT hubs, with the Harley pattern spoke hole drilling etc. My thinking is that a regular cheapo DRUM hub could be cut down to just the cush, with one bearing left in that section - cut thin from both the right side AND the left, with the sprocket carrier - "COUPLING ASSEMBLY" in official Kawasaki-Speak - "KAWASAKEZE" if you will. Ha-ha. Just cut down ALL of those dimensions to create as thin a cush element as is possible, with whatever is left between the chain-line and the hub proper. In fact, the KZ's six cush elements would work well with the Honda front hub's six bolts, while a Honda cush-drive with it's four elements would be more suitable for those Kawasaki front hubs which utilize the four rotor bolts. OR for the Honda 36-spoke hubs which use four rotor bolts - for another version there were 36-hole Suzuki front hubs from early disc-brake GT750 & GT550 front wheels, and I suppose they could use a Kawasaki or Suzuki six-lug cush-drive. Sadly, my DOHC Honda situation doesn't look so good with it's five-bolt rotors, 'cause the five-bolt DUAL disc wire-spoke front hubs are some of the most rare Unobtainium of all Honda stuff from the era. Seems they were only on a few SOHC era POLICE bikes marketed to Canada. Basically a wire-spoke wheel in the SOHC CB750F2 '77 front end, five-bolt rotors etc. I've SEEN some wheels built around the DOHC five-bolt parts, with a CB750Fz type front hub in an Akront 5.75"x18" gargantuan rim. Beautiful set-up. No cush-drive though. Between that and the huge 180-spec 18" diameter TIRE I can't see that working out so well on the CB1100F it was hooked up to. So I'M shooting for the six-bolt hubs instead, even though they're that much heavier. Not just one more bolt, but bolts that run straight through the hub. A hub with a thicker mid-section. No it ain't gonna save any weight, but I think it will WORK a whole lot better. Sad to think I'll probably have to sacrifice a Kawasaki hub to do it though. If I can figure out a way, I'll TRY and build it with all original HONDA parts.

IDEALLY it would be carved out of as small of a drum hub as possible. Within the range of wheels which can fit to the 20mm rear axle. Maybe something with a 17mm stock axle such as the KZ400/KZ440 drums - which themselves have four cush elements, maybe THAT could take a new bearing with a 20mm center bore.

After all, there are a few 15mm rear disc hubs which can stretch out to a 17mm rear axle. Too bad there isn't much selection of disc hubs suitable for the 20mm axle, but with "the front hub trick" a person could MAKE one.

Plenty of kits out there for Yamaha dirt-tracker wheel swaps, for the 19" wheel out back - but those XS650 rear hubs don't HAVE any cush-drives. Not even on the drums! The basic HUB itself, not the shoe plate necessarily but the hub proper, makes for a really cool race-replica wheel, 'cause it can have huge air holes cut in around the tiny sprocket bolt circle.

But I don't think any of the Yamaha dirt-track hub kits is necessarily gonna work for such purposes. They're really just a sprocket spacer, aren't they?

Sorry for blabbing but - I'm just trying to offer alternatives for IF a person were unable to find all needed parts to use an original Mag wheel such as this.

Picture it though - a 3.00x16" 7-spoke mag wheel up FRONT - presumably a matching 18" 7-spoke would then have to be weld-widened, to at least a size of 3.50x18" preferably 4.00x18" or even better still 4.50x18" - OR it could work just fine with another 3.00x16" wheel in the rear. Keeping in mind I'm not suggesting a cruiser type of deal with fat BALLOON tires per se. Though that could potentially be pretty cool as well. But yeah I'm suggesting something a lot sportier like the GPZ900RR NINJA, or the Yamaha FJ1100 - THAT type of 16" rims!!! Of course there are several examples of Honda models with 16" front and 18" rear, but many versions from all of the "big four" rolling on 16" front 16" rear, or 16" front 17" rear, etc.

Either which way, it's cool to visualize that same stance of those mid-'80s Sports-Bikes, but on an earlier mid'-70s SUPER-bike racer.

IMHO.

-Sigh.