This is awesome stuff - I dig this model of bike a LOT. I'd want to swap the tank though, if one were to do a full-on café treatment perhaps a tank from Kawi H2 triple? I'm putting an H1 tank on a KZ440 which requires a tunnel swap or at least some really heavy modifications to the stock tunnel on this here H1 tank.
I've been working on a crazy KZ440LTD café for my ex-daughter that's been up against ridiculous odds - burning down to the frame type of shit it's unreal but I'm still moving forward - and it's pics like these that remind me what it's all about. These bikes are a great basis for a small café the tube frame and air cooled motor, the late year of production just so much going for 'em I'm considering substituting the 305 for the 440 in my project here - though there are alternatives as well - I've noticed the engine sprocket for EN305/KZ305/GPZ305 seems to match - don't quote me on this - the GPZ600R Ninja. Now wouldn't THAT make a great basis for a wire-wheeled belt-drive conversion?
Or even better how about a SIDE-CAR conversion? I've just bought a spare T500 Titan 2LS front hub and another 3.00x16" Borrani NOS alloy rim -
((((to go with the 3.00x16 on GT750 4LS & 3.50x16 Akront on KZ400 with all NOS belt-drive both versions 22:60 & 22:65 for alternate - maxi-scooter radials in 110/70 & 140/70 spec set these wheels apart from most retro 16" chopper/bobber type rims - well the whole combination as a whole is odd you've got to admit))))
So YEAH as I was saying, now that I've got this spare matching front rim with appropriate hub, I am very seriously considering a three-wheeler simply because these 3x16 Alloy Borrani rims are sooo appropriate for classic racing side-car wheels - But only after the bike's coming together complete or going into final paint etc, so as not to slow down the completion of the damned bike itself (I figure I'll have to weld-on some lugs in appropriate mounting locations before the frame gets consigned to the powder-coater's, that way it's a straightforward add-on further down the line - What I'm visualizing is at least the 440 but more like the KZ550 option - I've heard the GPZ600R engine swaps straight into the KZ550 frame - really it boils down to a round-tube frame with an adequate motor that's got the splines to mount a belt-drive pulley - I'm not giving up on the belt-drive no matter what (though the KZ440LTD rear wheel is kicked over to the right in stock form, and it would need to be moved to the center-line, in which case I'll have to sacrifice the 140 tire for a 140 or even 120 spec) What I'm VISUALIZING is a leaning side-car frame but really petite (as close as possible to a secondary side-ways swing-arm as one could go without the side-car body falling straight off the thing) -with one of those shells that they use on scooter side-cars only with the proper bigger tire and some suspension of course - so rather than something utilitarian just a small support frame with articulations and suspension on that wheel - or perhaps if the frame is light enough it could have suspension between the frame and body shell ... but yeah a petite lightweight frame that could accept a platform with a small bubble fairing for a racing side-car set-up, and a basket from a shopping-cart for future zombie survivalism and hardware store slash grocery shopping purposes ... oooh it could use one of those coin-slot chain locks for anti-theft ha-ha - and a scooter-sized body shell for passenger/dog hauling.....
Or if it costs about the same I'll get a second matching bike, maybe the two of THEM could be bolted together for a stable platform. Ha-ha. Like a Catamaran sailboat - Was it Death-Klok who had the four side-cars on the one chopper? It all comes down to whether I can get a cheap sidecar shell or a cheaper bike or a volume discount on four complete side-cars....
Either way, now that I've got $$$ on rims and hubs - I've got to build SOMETHING around a belt-drive and this unusual hub-rim-tire combination - I figure the GPZ600 would be a good motor donor but I don't like the frame for much else but a racing side-car. KZ250 & KZ305 or KZ400/KZ440 are all on the table of course - But damn it would be nice to fit this onto the any old bike off the top of my head and just get the drive pulley machined for the splines of my choosing! KZ550 would be one possibility, though the tires and the belt strength at 30yrs of shelf life - that adds up to a sub-500 TWIN in my mind at least -
ANYWAY yeah these lil' GPZ bikes are cool I see waaaay more potential in this thing than say, the KZ305CSR -even with it's wire rims 'cause a wire rim swap sort of opens your mind to what hubs you SHOULD be using - It drives me nuts when folks re-spoke a set of wheels and they don't upgrade the drum, you know? To a bigger drum I mean. Disc is an option too of course, but a bigger drum is such a simple simple thing to do when you're getting new rims and spokes - I just feel like messaging folks and saying "WTF?" -
Anyway these GPZ bikes in particular they've got the five-spoke mags which are far far cooler than typical Kawasaki seven-spoke mags. Gotta be a lot lighter for one thing, and the matched diameters is awesome too - I'm not sure of the widths but they seem adequate for this size of bike maybe even something a lot bigger even - but the main thing about the five-spoke mags is they're reminiscent of a lot of Unobtainium-Magnesium rims from Italy such as Campagnolo etc - the earlier KZ type are much like Lesters and Lesters just aren't my cup of tea. Campagnolo rims aren't quite three-spoke DYMAGS by any stretch - it's sort of like how Comstars are reminiscent of Astralites they're not the same damned thing but the style is essentially the same - but yeah like I say they're cool mag rims ... for mag rims - It would be neato to give 'em a spray of gold/bronze paint to imitate the Italian aftermarket stuff. You know, there were some of those five-spoked Campy rims with drums in both fore and aft - conical drums from what I've heard - really neat things with hydraulic actuation and loads of cooling vents in 'em. Probably 'cause of the hydraulics overheating. But yeah, the five-spoked drum rear is VERY reminiscent of those wheels I think they'd lend themselves to a replica styled vent hole pattern etc. Dunno how one would stick a drum into the front one though - a rear rim up front with custom covers on it perhaps - Too weak of a brake IIMHO - still it would have the right look. Those Campagnolo front drums were something really special. - As are these Kawi rims - not many other bikes sporting rims like 'em.
Of course, I'm also of the opinion that these smaller bikes can get away with skinny 17" and 16" WIRE SPOKE rims too, rather than just a swap to wire rims in the same sizes which doesn't do much for you - I guess I should cut and paste my standard treatise on odd-ball rim and tire combination - leaving out the 12x3.50" Borrani CAR rims with 72 holes that I'd like to put on an actual Maxi-scooter such as Suzuki Bergman some day - maybe with some Zundapp/Cezeta-esque imitation bodywork instead of the butt-fugly modern crap....) But yeah - Odd-ball rim swaps:
SNIP:
It doesn't have to be outrageously costly either 'cause alloy rims can be re-drilled for different hubs if you upgrade the diameters of spokes and nipples - most hubs will take bigger spoke no problem especially non-butted so only the nipple end goes up in size, though the threads would still be fatter than the wire itself so that's your limit, this way you can definitely get the required nipples for the re-drilled holes - even if the threads have to be spun to get 'em through the hub flanges - there are TONS of 17" MX rear rims out there, typically 2.15 & 2.5" widths and almost always 36-hole which is great for drum hubs. There are also a lot of sixteen inchers - I don't necessarily mean the mid-width 16's I'm using (3 & 3.5 ie chopper rear rims which are not only extremely common but more often as not they're also unwanted & hence they're as cheap as borcht too - yet they're hard to find in alloy & even more scarce in 36-hole which is practically a pre-requisite for drums, unless we're talking KZ400S and Kawi H1 triple front drums - 36-hole disc-brake REAR hubs being the truly odd-ball hubs but there are lesser known less expensive than Yamaha TZ hubs in up to 17mm axles possible with cush-drive and a classic looking design etc...) - there are also 5" FAT rear rims in 16 (40-hole) but there are also 2.50" and 2.15, 1.85 etc alloy rims that were used on '50s-'60s vintage racers, and they often go for as cheap as equivalent 18" rims (or cheaper, being that hardly anybody knows what to do with 'em) There are the huge fat modern chopper 16s and standard fare 3-3.5, oh and 4"-4.25-4.5" widths too lately - but there are ALSO sixteen inch alloy rims in all the concievable widths, including 2.00 (WM2.5 or WM2&1/2 as stamped) going all the way down to 1.60 and 1.4 or 1.2 moped rims in 16 - I'm thinking 1.6 and 1.85 would be as small as I'd go and I'd only do it for an ultralight project - but WM2/1.85 & WM3/2.15 would be dead on, and of course as wide as one would care to go if it's all about the contact patch into the corners. MY rim selection opens up options with radial tires, 170/55 or 160/60 max widths for maxi-scooter tires, though there are pretty much ANY size and type of tire you can think of in sixteens also - I think a 120/70-16 or 110/80-16 rear is about as small as those would go but those are probably the Bias-Ply versions - I do know there are radials for 3 & 3.5" rims in 110/70 & 140/70 there was even a dual-compound mini version of Pilot Power, from Michelin - but it's discontinued. All the same - perhaps it's overkill anyway to go with mid-'90s sportbike bias tires on WM3-16 front and WM4 rear, and several skinny 17" sizes for those '90s 125-250cc racers besides. Surely radials are over-kill on ultralight bikes anyway - I've picked a set matched to the WEIGHT of the bike as a first priority before even looking at widths etc. There's gotta be some possibility of running heavier tires with lower pressure for greater contact and higher temperatures as a by-product - but there's no way I'll put THAT onto a bike for my own KID. But yeah, the wider bias stuff is already huge over-kill on lightweight SOHC twins with rockers and tappets on the valves. Those '90s 125-250cc sportbikes some of 'em can kick ass on the superbikes of the prior two decades, so they're perfectly justified having fat 16" & 17" rims - that's not to say they wouldn't be even better with wire rims though. Drum brakes are probably a no-no. Unless the 260mm drum could squeeze into a 16" - bolted straight through the drum lining to the rim with zero tolerance MAYBE - They're still probably hopelessly under-rated. I guess one could try one of those CBX550F internal disc conversions with the rings around the comstar hub. That thing is like a drum-hub on steroids - it's a dead give-away as soon as you look at the thing, though surely some new side-plate covers could be fabricated that cover over the twin-pot calipers rendering the look of a hydraulic actuated drum, or internally cabled - like the '50s Guzzi "Bicylindrica" V-twin, the Proto-Ducati what an awesome bike - very plain-sided drums, the cables just plug through to the insides - the CBX550F internal disc brake hubs are designed to show off the disc system - sort of a dead-end of a certain type of technology - in a sense they're the dead end of DRUM technology. And comstars at the same time. You'd think they would've done a wire-spoked version, surely it must've been on their drawing board.... Really though, it could be better disguised and blend right in with an earlier '60s era style. Something between a pie plate or pizza tray (seen em used to disguise comstars a CRIMINAL ACT to DOHC fans like myself) and the round hub covers from Guzzi Ambassador/Eldorado 2LS front hubs, late era Harley big-twin single-disc front hub etc - plain rounded domes of a sort - Maybe even something reminiscent of the late-'80s early '90s GL1500-GL1800 Gold-Wing Kuryakyn disc covers with all of their LED light bars and fiber-optics etc. Okay maybe those look too modern - but they're a great way to hide some discs, I'd like to stick some on some wire rims heck if I can pick up a pair for cheap who knows.... I think for the 550 internal dual-disc, or the VTR250 single-sided version (in a solid wheel so harder to play around with) on internal disc comtar hubs I'd just add on some bigger vents fore and aft, a rear one straight over the caliper....
I wonder what those discs compare too - obviously the caliper is inside the disc but I'd like to know what the outer diameter of the disc swept area is.... Probably right around the size of '77-'78 model SOHC CB750F front rotors from the comstar rims. Much smaller than the later slotted rotors on the DOHC which are still pretty small rotors - Motorcross brake discs by today's standards....
Those same diameters of rotors are on CBX750F and early VFR etc, both of them running on 16" front rims (with odd-ball rears in 18x 2.75-3.5 with 140/80-18 tires which are so lovely on the SOHC/DOHC CB750K/F etc - (plenty of good donor rims too, Dymag looking stuff - especially lovely was the CBX750F 3.5x18 rear boomerang comstar as a donor to the CB1100F/R I've got a matching 18x2.5" silver front boomie just waiting to pair up with that one, I've even got the 300mm vaned/vented Aspencade rotors on it. On the DOHC CB's this is one SWEET set of rims.) AHEM yes - those early '80s sportbikes show that it IS possible to have an outer/conventional caliper on a conventional disc on that small of a rim! Modern 300mm-330mm floating rotors are probably too much. Put spokes behind that and you wouldn't even see 'em.
But damn I mean that stuff is appropriate for the LATE model 250cc twins, the '90s era sports-bikes. Not street-bikes. and the GPZ may have sporty styling but it's essentially tarted-up KZ305CSR it's no NSR250 race-replica. So I figure, just as with my KZ440 plans with the 4LS drums - (uprated with filed-down T500 shoes to maximize shoe to drum contact etc - I'd like to find some other unrelated shoes with more diameter of shoe contact more so than the width, but the T500 stuff is more or less a straight swap with an afternoon's work on a bastard-file, plus they're as cheap if not cheaper than GT 4LS shoes)
AHEM - yeah as I was saying, I figure a 200mm 2LS drum on the front end of a KZ305CSR/GPZ305 would probably lock up the tire and put the bike into an endo or a dive either way over-kill on the brakes. The GPZ rotors would probably fit up to the 'CSR disc type hub no problem, or a Z650 dual-disc hub alternatively. And the rear drum well obviously the KZ400 early, larger diameter rear hub, the late KZ400/KZ440 hubs, the KZ305CSR and probably even the KZ250 hubs are all a straight swap back there - not accounting for chain-line mind you, but most of those are fixable with a swap of a carrier from the other hubs - Point being, thee bikes which came in alternate lines with wire rims these are the easiest to swap rims and hubs on - but what makes the GPZ305 superior above so many others is it's later production run meaning younger bikes, hopefully lower mileage etc. And the bolt-up rear-sets on these bikes that's a no-brainer too, one could adapt any other bolt-up rear-sets to the original bolt holes, or cut down the stockers, all sorts of options there. Not a lot of round-tube frame bikes from this era they're mostly square tubes and delta-box etc. It's a huge deal so far as aesthetics are concerned - which is the distinction between a sport-bike or muscle-bike and a café racer in the first place, so yeah a big deal from the DTT perspective. You just can't do the same stuff with a 250 NINJA it would be butt-fugly. Well, it would probably be cool too - they were neat little bikes those earlier 250 Ninjas. The new ones make for great café bikes actually, it's the early '90s version that sticks in my mind's eye as an odd-ball. I had a CB100/SL100 hybrid I'd built back in those days, and a friend's 250 Ninja just looked like a friggin Go-Bot/Transformer toy or something. I'd LOVE to see a decent café made from one. Just not so much as I'd like to see the GPZ305 café.
When it comes to one's teenaged daughters, don't mistake the importance of looking cool. Ha-ha - Mine would have been fine with the KZ440LTD in crusty old patina paint - I'm just sayin' - it's just that much better to stick 'em on a café. That way the bad boys that come along don't seem quite so cool. If she meets some young loser with a cooler bike you might just be able to stand his company. Then again he might beak off about bikes and café racers etc and it could be worse. All the more reason to perch your daughter on a pedestal on top of the type of café racer that you would put on a pedestal. This is why I'm building my kid's project from the ground up. The side-car option would be sturdy in that sense too. Oh and then if she gives some dude a ride home he's not on the back seat of the bike ha-ha. Thing is I'll have to start over on the bike's pedestal, make it at least double the width....
-S.
She's also very good about taking care of her car at school, checks the tires, does her own oil, knows to always check the fuses first if there is a problem. And has had to show the guys how to properly jump start a car on several occasions.
