This may be an old topic, but I wanna weigh in on it anyway - There's a lot of discussion here about whether or not the 16" rear wheels are "acceptable" with little discussion of the TRULY ridiculous tire on most of these bikes, which is the 19" front - This is true whether you're running Lesters or WIRE SPOKE (ideal best most beautiful wheel IMHO) or even Comstars - I come from a DOHC perspective/background so I absolutely LOVE/HATE the Comstar wheels - if they're done RIGHT which is to say the right sizes and the right selection of what's available out there then they can be the most awesome thing you can put on these bikes - take for example the GL1100 reverse/black five-spoke comstar in 18x2.50 and the CBX pro-link matching 18x2.75" rear, or the 18x2.50 boomerang comstar (CB1100F versions are gold but there are also CB750F-CB900F Euro models with silver rims) combined with the '85 CBX750F Euro model nighthawk's 3.50X18 in black - those are some wonderful pairs of Comstars with rim widths you're not gonna FIND in any other CB750 rims bar none....
Above all, for ME it's about the weight. Which is why I've gone with alloy rims on wire hubs. Though I've got TWO specimens of the SOHC supersport rear hub with the disc etc, I've gone ahead with the Kawasaki KZ1000A/KZ750B-twin rear hub 'cause it's a heck of a lot lighter and it will run a smaller disc 'cause it's so tight on that side - pain in the ass to covert, compared to the SOHC to DOHC way to do it, but still - The GL1000 front hub bolts up to one of the three versions of CBR900RR rotors - I don't recall which. Though, when they bolt up it behooves one to use the '78 CB750K hub with the star cross-section rather than the grooves on the standard type hubs, the grooves typical of a DRUM hub, they're meant for cooling - still I think they look nice and I prefer the look of converted drums with aftermarket discs to the Supersport rear hub which looks to me like the '70s Battlestar Galactica Cylon motherships.... I mean, WTF is with them making the hub so damned HUGE when they could've cut down the spoke flanges and run longer spokes? They wanted to use the same spoke sets? Stupid, especially when they went to a 17" on the Automatic and the Gold-Wing, the '78 CB750K etc etc.
In looking at all of the "Bike PRON" I look at all day long, I found the one consistent factor among my favourite bikes was that their rims matched in diameter, front to back. Doesn't matter whether they're 16" rims or 17" or 19" - heck even the smaller rims on scooters, especially max-scooters (oh but I'll get to that in a bit!) So when I was looking at putting wire rims on my DOHC CB750F - hopefully to be a "7-eleven" soon - I chose the widest Borrani profile in 3.00X18 and a middle-width 4.25" x18, 'cause 17" sportbike rims just look screwed up on a DOHC, and I've seen a lot of that lately - so I wanted to make something in between the two forms, the "Fat wheel" and the "skinny rim" look. I wind up with tires for a mid-'90s BMW sport-touring type of rig, with a 110/80ZR18 (now superceded by 120/70) and 160/60ZR18 - both sizes I can have in RADIAL and BIAS if I so choose - plenty of back-up options if the tire sizes are discontinued.
Now, I also had a KZ440LTD to fix up for my lil' GRRRL, who at 11 or 12 said she was intimidated by the Honda - though she'd picked an '82 CB900F with full fairing and luggage as her fave from out of a two-foot stack of classic bike magazines, without even seeing my 750 at that age she picked a silver one even - for a long time I thought she was teasing me for tearing apart my perfect stock 750 to change it's look ... ANYWAY, while looking for tires for the kid's scooter one day, along with the scooter I got for her MOTHER -by then my EX, and yet I got her a VINO 125 just so the kid could ride it "When the cat's away" - still, as soon as she realized her mom would be able to follow her around all of the new brownie points I'd just won went straight down the toilet! Still, it motivated her to become the fastest scooter jockey she could be, reading up on technical riding skills with every library book she could find and a few thick texts she bought at Chapters with her babysitting money - just goes to show what the proper motivation can do - I wish I could take credit for planning that but it was a fluke! Ha ha. ANYWAY yeah, while looking up tires for scooters AND tires for my DOHC project, I came across the section of new tire designs for the then-new MAXI-SCOOTER segment! Meaning 16" sizes, with recommended rim widths right there in the 3.00x16 category - at the same time I was shopping hubs etc, and I was seeing a lot of 16" take-off rims. You can imagine the lightbulbs going off in my head. Which is to say, the KZ400 rear drum fitting up to a 16' rim drilled for CB750K, the front hub lacing to the Harley version there-of, being that the Harley rear hub is so small. SO YEAH - I was kicking around how to do this, I was also contemplating the KZ400S front drum, which is one of very few drum brakes with 40 spokes - also the Kawi H1 drum though I'm not sure whether it's any bigger....
So that was my PLAN - to go with cheap throw-away steel rims and re-coating them whether with chrome or powder or paint whatever - but I had a bit of a guilt trip about the kid's safety, especially after considering running the same front end and brakes as on my DOHC bike (the CBR 300mm+ rotors work with CBX pro-link caliper hangers so you don't even need to make caliper hanger blocks! they bolt straight up to the DOHC Supersport forks whether the 750 or the 900, or the GL1100 for that matter) ANYWAY yeah after this conversation with the kid's mom about the relative merits of drum brakes vs discs, which is to say - as I put it then "Not quite AS safe yet absolutely dripping with nostalgia...." - and the long blank stare she gave me, I came up with a different set-up in the same sizes.
NOS Borrani 3.00x16" alloy rim with 36 holes to match it's GT750J 4LS drum hub, 3.50x16 super-Akront alloy rear rim in KZ400 rear and all NOS belt-drive parts. Now, keeping in mind that I lost everything in a house-fire this past March and that I've bought all of the parts I've described here TWICE now, this becomes quite a ridiculous project especially now that it's glaringly obvious that the kid should be riding a DOHC CB750K and I don't even HAVE a KZ440LTD to fix up anymore ha ha - STILL I wanna build these wheels and the KZ would make a great school commuter bike, and heck after all the effort I just wanna see it finished even if nobody even RIDES the #$%*er.... (I've also grabbed a T500 Suzuki 200mm drum 'cause I wanna lace one of them up to some wheels for my Honda Cub project some distant day. In the mean-time I just wanna look at the thing 'cause they're so pretty! Just make your own jokes, go ahead and picture me at the Disco with freckles & roller skates on: Drum-Member -"I love DRUUUMSSS!!!")
But the clincher in the whole 16" rim thing is the MAXI-SCOOTER tires I was talking about. The 3.00x16 & 3.50x16 will suit a 110/70-16 & 140/70-16 which are basically a 90% sized version of sportbike tires in 17" - I was turned off by a lot of the 17" tires I've seen fitted to smaller twins from the '70s etc - overkill if you will - and I'd seen a few 16" sportbike tires from small-bore modern bikes, EX250 Ninja for example, they're 16" but narrow compared to MY selection - This works a hell of a lot better, aesthetically speaking, proportionally - than the supermoto rims and sportbike rims people keep using on builds these days.
Of course, I'm not really GOING FOR the typical modern retro café sort of look. The kid was really hard-core into her scooter and always talking about a bigger scooter, a MAXI-SCOOTER etc - so in trying to ease her into the life-long love of motorcycles I wish to engender I figured this 1st "proper" bike should be somewhat of a "Scooterish" or "Scooter-esque" style of bike. It's gonna be a real odd-ball. And hell, on my own DOHC project, much as the PLAN has been to make the DOHC into a kind of Sand-Cast tribute, or send-up to the original DOHC Honda the CB450 Black-Bomber, I'm also leaning towards using a bunch of GL1200-GL1500-Kuryakyn brake disc COVERS - you know those chromed covers they fitted over the whole wheel and fork and #$%* so the GL1500 looks sorta like the VTR250 or the CBX550F? Yeah, hell maybe somehow that won't be Butt-FUGLY when it's adapted to the DOHC, who's to say....
So yeah, that's MY rim & hub selection, I dunno what you'd prefer - I've got the spare hubs on hand for my next DOHC bike but I'm keen on doing a DOHC 'K model and retaining the rear drum, only I wanna go to fat Supermoto rims on the thing with their 36 spokes, as such I grabbed a Suzuki GT550 disc hub, which has the 36 spokes - and I'm thinking I'll grab a matching rear drum too, so I can lace it up to a supermoto rim in 17x4.25, then all three bikes will have odd-ball wheels but in matched pairs for that ideal aesthetic which I love in all my Bike-PRON. I've got a 3.50x18" super-Akront that would lace straight up to the 'K rear hub, but I'd rather keep the 17" rear and fatten it up. The DOHC Honda can take a much much wider tire than most other bikes. With the Pro-Link CBX's drive sprocket in place it's no issue to fit 6" wide sportbike rims and 180/55ZR17 rear tires. Front tires are okay too, it's a great bike that way. As for the KZ440LTD, I'm not sure yet whether I can use the belt-drive, which is the sole remaining reason to go with a KZ of any sort let alone the 440 - It would sure be cool to use the KZ750B twin's version of the belt-drive on a KZ four but I'm not sure which of them fits the twin's sprocket. Either way, it's an old belt and if I were gonna run a belt on a superbike I'd go with the GATES INDUSTRIES POLY-CHAIN GT CARBON belt, which is as strong as chain in like widths - meaning a smaller chain width belt would work okay but also meaning the standard width of most belt-drive systems would be 4-5 times the strength of a chain! Oh yeah. And the DOHC has a sprocket spline the same as the aftermarket Titanium output shaft they make for the HAYABUSA - the main issue with running a belt on a 'Busa with aftermarket hot-rod engine parts is they always wanna use those stretched swing-arms. But still if a person could figure it out I'd bet the kits would sell like hot-cakes! I'm sure it would work on pretty much any bike so long as you're willing to stretch a swinger an inch or two AND play around a bit with the final-drive ratio, maybe with a bigger pulley up front than would fit under the stock sprocket cover - Minor considerations IMHO - Still for a long time I was OBSESSED with putting a belt-drive onto my DOHC Honda, I just wanted the advantages of not having to run a rear hub with a cush-drive (a major deal when you're searching around for wire-spoked rear hubs with a disc brake!) and at the same time the boost in power due to the losses being eliminated - SO this is another reason why I'm so keen to finish this KZ440LTD build, to get the belt-drive obsession out of my system!
BUT YEAH - I just wanted to say, ya'll are waaay off the mark when you're talking about wheels here. First and fore-most, if you're doing LEGITIMATE performance mods to your bike's wheels, you should be looking at wider rims, lighter wheels, and dropping the front end steering to quicken things up- AND aesthetically speaking pairing up the same diameter of rims is just too cool.
(((I suppose I can stand an '80s sportbike with the 16" front and 18" rear in the vein of VFR750F or CBX750F etc - but don't talk to me about the 21" chopper front rims etc -Please? - Even the MX bikes I love, my very 1st bike was a '70 SL100 and I got a '69 CB100 for parts, wound up building a CB100 with it's rear rim up front and the SL rear rim with CB rear hub - meaning both rims were 17" whaddya know! - I love vintage scramblers with both rims the same size, minibikes, scooters - what have you I love all types of bikes - and yet this one factor is consistent. Even vintage V-twin American bikes, gimme the 16" rims front and rear or else 18" like the rear on a '78 Sportster, just put another 18" on it please - or 16" better still, front and rear. I've got big ideas about setting up wire rims on a later-'80s sportbike, such as VFR etc - with the 16" front and 18" rear intact, just to see how that turns out - though really those bikes would benefit best from a swap to 17" rims for best tire selection.....)))
But yeah, much as Lester rims WERE considered performance wheels back in the day, that's only 'cause there weren't very much wider rims available in alloy - they were out there but few & far between, and probably "race only" spec and what with people being so paranoid about law-suits etc - they probably didn't do anything that wasn't approved by the local DMV. Anyway yeah, tubeless tires were new technology - and more to the point nobody had figured out how to SEAL wire-spoke rims up for tubeless tires.....
(((There are SEVERAL ways of doing this, I plan on using the aquarium-silicone method on my own wheels, being that I apprenticed to a master aquarium builder for more than 5 years - but mostly 'cause of what I heard about the "TEAM INCOMPLETE" Beemer Boxer, how they sealed their rims on advice from Buchanan's spoke & rim and they lasted through more than five seasons of racing without any indicated wear and tear - thing is I KNOW which silicones are best for high strength joints, from building tanks big enough to park your truck in 'em - and I plan on using acid-etching techniques just as I'd have done in any other Aluminum to silicone joint, so I have confidence in it. The way most folks would make a mess of such a project I think I might be worried about riding on wheels like that myself!)))
But yeah - tubeless tires no longer require the use of cast Aluminum heavy-assed mag wheels!!! IF and I do mean "IF" there was any advantage to using a Lester mag wheel, or a Shelby-Dowd or what have you - it was compared to running a heavy-duty inner-tube on a chromed-steel rim. And even then, I'd have to wonder - what with the thickness of the walls in those CAST alloy rims, and how they all had smaller lighter looking hubs, center sections what have you - their weight must have been disproportionally heavier towards their perimeters. I know there's the whole question of the suspension and keeping un-sprung weight down, but the rolling inertia has gotta be the big deal here, ennit? Yeah. Well take a look at the wall thickness of a proper wire-spoked alloy rim, especially a super-Akront (as opposed to the regular akronts) like the 3.50x16" NOS specimen I lost in that fire - WOW what a light-weight rim! Far lighter than the 3.00x16 Borrani, and that would mean waaaaaaay lighter than the thick-walled D.I.D. rim I had from some KZ1000CSR/KZ650CSR wheels I had. The cast mags have a gap between the spokes of one-fifth the circumference - compared to one-fortieth or one-thirtysixth, that's a huge deal. In order to make up for it, they've gotta be waaay thicker in cross-section. Ergo, HEAVIER!
Add to that, how the mags only came in skinny widths anyhow - if you're not gonna have 'em welded up wider by the likes of Kosman industries, then they're gonna be useless rims and above all a STYLE-based modification. At least the Lesters had a bolt-up cush-drive so something could be done with that.....
But something even greater can be accomplished with the COMSTAR WHEELS. IMHO. They're a perfect compromise between the two types, they're a composite construction which allows such a light weight, plus they're all Aluminum & tubeless which was the main advantage of the cast mags in the first place - People #$%*-can them and say they're loose, but I've had high-mile specimens that you couldn't bend if you parked a truck on top of 'em. - I think if you had a really poorly balanced wheel/tire situation and ran it that way for a long time, maybe THAT would shake one of these things apart over many thousands of miles - All I know is I've had several sets and never seen a problem with loose rivets etc. There are several styles, of which I like the non-reverse silver version, the 1st version - the best. Plenty of folks have disassembled them and re-assembled with bolts etc - I'd really like to find a silver non-reverse front wheel in 18" - there had to be one on the smaller bikes, one would think - and then bolt 'em up to the wider rims from the black wheels, that would truly kick ass. AND if one could use the black/reverse type front wheel from the GL1100 in a 2.50"x18" size - as a REAR wheel, just as was done with front-to-rear conversions back in the day only with a comstar instead of a wire hub - then a bolt-up cush-drive like that on the Lester or from a later Ducati (plenty of five-bolt cush-drives from single-sided Ducati wheels, that with a weee-bit of machine work should bolt up nicely to the comstars) THIS WAY the main problem with all Honda rear wheels could be dealt with, by cutting out the rear hub which was always such a friggin' BOAT ANCHOR. AND, - even better still, if a person were as brave as those on these forums who've disassembled and re-assembled Comstar rims using high-strength bolts & lock-nuts etc - Then some of those wider rims could be fitted to such a converted front wheel and this would make for one hell of a light-weight wheel that matches nicely with the front - OR, conversely you could get a pair of ASTRALITES since they're being manufactured again! Comstars are just as awesome as Astralites, they're the best, lightest, most hi-tech and best-looking performance wheels any manufacturer USED on their bikes through that entire era right up to today. Even the modern cast stuff is just a cop-out. They're managing to make 'em a bit lighter, but they've got a long way to go. I'd hazard a guess that using extra-heavy-duty spokes, maybe a higher spoke count - watching what type and how heavy of a hub one used (TZ750 rather than CB750F SOHC for instance) That a well-thought-out wire-spoked wheel would perform just as well if not better than all of the stuff they're running out there on the track today - with the possible exception of the carbon-fiber stuff. But then again, I'm sure the carbon could be used for wire rims and hubs too, as they're used with embedded metal components already - Now THAT would be an awesome set of wheels. But yeah, I figure they use three-spoke mags to keep the costs down, just as they did with cast seven-spoke mags back in the day - and they put 'em on the high-performance machines so they'll look just like the stuff on the salesroom floor. Which is to say, the wire-spoked wheel was an engineering marvel that hasn't been surpassed - and the friggin' WAGON WHEELS that supplanted them in the '70s and '80s don't have a place on one of MY bikes in this day and age, whether or not it's a classic bike or not!
As I mentioned before, the big problem is finding a rear hub with a disc brake and wire spokes.
-There are the Suzuki GS1000 rear hubs, not all that different than the Honda SOHC Supersport hubs.
-AND there are the Kawasaki versions in KZ1000A/KZ750B-twin which are conical
- then there's the KZ1000LTD with 40-spokes and the 'CSR version with 48 spokes, both of which use a light-weight rear rotor with 7 bolts that matches perfectly with the VN1500 Vulcan classic rear disc which is cross-drilled and very new, especially given that so many Vulcan guys go for a wheel swap of their own, seeking out ridiculous Performance-Machine style mags etc - there are loads of nice rotors for those hubs.
All the same, the earlier CONICAL hub is much lighter. Though it IS of a composite construction, with a chromed-steel flange on one side. I had one that was stuck in the freezer while the rest of the house burned down around it, and though it didn't melt at all the joint came apart - I suspect it's an "INTERFERENCE FIT" with epoxy or maybe even BRAZE in there. But it's much much lighter, and when the wheel is laced up it shouldn't be any different than say, the bolt-up rear hubs from the likes of Norton and Triumph
-The triumph rear hub doesn't have a cush-drive IIRC but it's got great potential
- either way it's a 40-spoke hub, which limits rim selection, and if you're keen on using 17" rims especially the 36-spoke hubs are a $$$ saver 'cause you can use the knock-off supermoto rims which are of decent enough quality to use on our bikes so long as we're not riding as hard as those super-moto nuts are doing.... And the quality of alloy is supposed to be a lot better now - no more "Monkey Metal".
-TZ Yamaha hubs - 36 spoke but have no cush-drive. And you've gotta watch which one you're buying. I bought a cheap one, turned out to be for the 125 I think I can use it on a Honda Cub or some such! Hmmm- a triple-disc conversion of a ... CB100 maybe. Sounds cool. Though I'd much rather use drums on that one anyway....
-Yamaha TDR250, though this only has a 15mm axle and bearings are available up to 17mm meaning fine for an SRX600 but not suitable for the CB750 family or other superbikes in general as they've all got 20mm axles! Still, it's a classic looking hub with a disc and a cush-drive. Goes to show how the axle is a big factor, when bearings to adapt this hub are difficult to source and maybe even counter-indicated due to some load-bearing index or speed rating or other considerations....
-Harley hubs - probably the cheapest option, but again you'd need to figure out a cush-drive. I guess this is vitally important on the SOHC Hondas and even the later Hondas, just 'cause of the way their transmissions were built. No cush and you could ruin your tranny. But yeah, Harley wheels are available soooo much cheaper - whether it's spokes or hubs but especially rims. Half the price of building authentic Japanese wheels. And you can buy 'em sealed up as tubeless right off the shelf. Talking about a lot of steel rims rather than alloy, but a huge range of sizes in steel rims, 17", fat 18" what have you. Chromed-steel tubeless rims with those tiny hubs I'd bet that's a very light wheel compared to a Japanese hub laced up the best way you can.
Now - much has been said and done as to comstar wheels, especially the CBX550F dual internal disc-brake front hub, and the internal rear disc with twin-pot calipers - I couldn't think of a way to make a drum work as strong, certainly not in that same diameter - they really look awesome when laced up to wire rims - Lots of pics out there. The first time I heard of the method it was for rear hubs for shaft-drive Hondas, like the CX650 etc - the method was to construct two plates for the sides, they'd bolt up just as the comstar elements did and then the spokes would go through holes in the plates. Usually you see this done in steel.
But I've seen something much much more elegant - a dude on the CB750C Customs forum did this for a shaft-drive CB900C - he took the existing hub and had it spun down on a lathe, then a drum-brake rear hub was lathed out and the "plug" was welded into the drum. Now, it occurred to me that this wasn't just for shaft-drive wheels, or for that matter converting to a rear disc - or even for comstar wheels for that matter - It could ASO be used for just about ANY wheel you like!
For instance, any modern CBR/GSXR/ZX wheel set could be converted to wire-spokes this way. An expensive hassle for a front hub to be sure, especially when you can just use any old dual-disc wheel from a classic superbike - but then again keeping the original spacing for the discs and the axle/bearings etc - this might all be worth it compared to converting an old hub to different bearings and having spacers made for the discs etc etc -so MAYBE it's worth doing both wheels - definitely worth it for the rear wheel however, what with what little selection there is.
For a long time I was really keen on using a smaller front drum, a single-sided hub, for a single-sided-swingarm conversion. But I just saw it done, at long last - on some European guy's Jawa 500 conversion. Beautiful build. But I'd still rather have seen it on a V4 like a VFR - in a tribute to the CZ type 860.... You'd want a tubular steel frame but a chain drive so it would be some weird assembly using the Magna frame and the interceptor motor.... Either way, it would've been a better tribute to classic Czechoslovakian machinery!
Still, what with all of the hassle involved in a wheel swap, and the poor selection of hubs and their prohibitive weight factor - this is something to be considered. Being that you can tailor the width of the flanges, the diameter overall and hence the weight - and give the bike just the look you wanted - plus line up the chain-line right there in the hub rather than dealing with off-set sprockets or a milled-down carrier etc -It just makes sense.
Of course, there ARE thousands of modern MX wheels out there with a 20mm axle size, but they're BUTT-FUGLY so I won't even dconsider it. Same goes for all of the Grimeca hubs used on Guzzi/Ducati etc, or the modern Billet monstrosities that are used on modern conversions, such as the Ducati Sport Classic - overall not that great of a set of wheels compared to what you CAN build - but the hubs especially, just fugly friggin' things. On a classic Japanese bike, I would argue it makes a lot more sense to stick with the aesthetic theme and use proper period-correct hubs. And that can be retained even with a weld-up composite hub as the part you're retaining is the bearing/axle shaft and the bolt circle from the rotor. The rest of the hub is an open question, and there are many smaller drums so cheap one might wanna take two ... say, KZ305 hubs - and build a wider hub with more grooves in the center yet a smaller overall diameter - within a cube proportion that would still look like a classic bike part - go too wide, too cylindrical and it would look a little modern, as the old stuff was more of a pancake in practice. I guess the cush-drive is a consideration too - one could either use the original cush from their own bike and that becomes the diameter to stick with, or go conical and drop the other side's diameter down - Or there's the question of whether the KZ305 cush-drive is adequate for a superbike and maybe you'd wanna stuff the cush with a different rubber - I was thinking along the lines of skateboard wheels in all that colourful urethane/varethane - in different durometers - the typical classic bike cush-drive rubbers were a normal vulcanized tire rubber - probably a known value for it's ... what's the term, its coefficient of elasticity - And one could find some numbers on the durometers of the urethane and the vulcanized rubber, maybe come up with something similar or - more to the point, SOFTER - that way one could use a smaller cush-drive so long as the cush is smaller - you'd get the same degree of "cush" just in a smaller package. Gotta be a way this can be done without screwing up the transmission. I mean, a worn-out cush-drive probably allows for a lot of slack, which might seem like it would work softer but when the rubber is hardened from all of those years sitting in junkyards, heat-freeze cycles etc - we're probably talking about something more like a slight slip with no contact followed by a quick SMACK - so possibly even worse than not having a cush in there at all! There are methods of treating smaller rubber components to bring some life back to 'em, I wonder if there's something similar can be done with big thick cush-drive rubbers. I'd bet the show circuit guys even use the stuff on their TIRES....
I mean, that's a consideration no matter WHAT type of wheels you're using. Lester mags have gotta be hard to find rubbers for, hey? I'd bet there's even some kind of goop you could pour into the damn thing, just fill it up like a bunt pan or a Jell-O mould and assemble the wheel, hopefully it doesn't pour out the bottom while the bike's parked - you get my point - some kind of mouldable rubber that would work in the cush-drive. Otherwise, maybe cut into triangular blocks. Just a whole friggin' skateboard wheel stuffed into each hole. I dunno. But there's gotta be a way to use non-standard wheels and hubs, and yet tune the cush rubbers' coefficient of elasticity such that the thing's not woefully inappropriate for your transmission!
Well, at least when you're talking about the modern crotch-rocket type of #$%*, the smaller drum hubs have a cush approximately the right size - and the superbikes of the '60s-'70s-'80s all have right around exactly the same size of cush-drive anyway. Whether four, five - six elements, they're all around the same diameter. It's probably got a lot more to do with the rectangular contact surfaces on the side of the cush-lugs, where they meet the rubbers - and the angle of the rubbers too, as they don't seem to fully meet face to face but rather gradually under compression, with a certain degree of contact under slight compression already.... Still what with how they're probably waay way overbuilt, plus the wear and tear they see over a service interval - PLUS the way you see the same components fitted to a KZ550 and a KZ1100 a CB750 and a CB1100R, a GS550 & a GSX1400 etc etc - I'd just draw the line at using something like ... the little grommets from the GL1000-1200 Goldwing series, or from Aermacchi - Harley 250-350 with the little grommets fitting around the sprocket bolts with washers to cover 'em - So long as there's something a little more substantial than that, well okay then. But then there are the modern Ducati type cush-drives with the five-or-six grommets that fit into rings that look like a circular brass knuckle, with sprocket carrier lugs that are little plugs into the grommets - this is something midway between the two types and yet it's adequate for modern crotch rockets and all the HP they pump out.
Thinking about it, one has to wonder whether the whole thing is superstition, that you don't really NEED the cush-drive in there in the first place. Me, I'd rather err on the side of caution.
AH, BUT I DIGRESS.
You guys shouldn't be so DOWN on using 16" rims. Though I'd have to agree about using a 19-16 combination. Still, one could have 16" rims front and rear and still carry off a cool vintage racer look to your bike. Hell, maybe even MORE of a classic racer depending on the period you're shooting for, in that 16" rims were de rigour for stuff like Bimota HB2 etc, most track bikes of the '70s Bol D'Or circuit I'd bet you'd see at least one example of each species sporting 16" rims on a given track day. And I'm not even talking about early '80s superbike stuff, I'm thinking as far back as Honda Black Bombers, Triumph twins, etc etc - the 116" rims were the first rims available as wide as 3", probably even the first 2.5" aka WM4 - so you'd figure anybody looking for more rubber on the road would've jumped at the chance. If they had the scratch that is.
Put it this way - the rims I sought out for my little GRRRL's KZ440"LOL" project, the vintage NOS Borrani 3.00x16" rim - or the 3.50"x16 Super-Akront - in looking for replacements for my NOS specimens in the months after the fire, MONTHS that it took me to find more NOS stuff - I found a few of 'em on hubs that I considered using but which the sellers thought were worth more than the NOS stuff - I paid $99 for that Borrani yet not long after I found some more around $300ea and a story that most of the stock had gone for $500 ea to some chopper builder schmuck - hopefully not a TV
