BUMP! A BUMP and a HUMP!
Very sexy and/or yummy period-correct WHEEL-PORN ~ so juicy ~ and some relative "Unobtainium" SFAIK. Pretty choice for a Honda at least, given that D.I.D. was the OEM house-brand for wheels throughout the '70s & early '80s? I could really get behind using these things on say, '75-'77 GL1000, for a "DLF-1000" Endurance-Racer replica? OR a CR750 replica of course.
But how much do they WEIGH? That's the pertinent question.
Either way, this archive thread is still a good find, if only for bike-porn purposes. But mainly, to ME, it's about filling in the blanks in the TIME-LINE of period-correctness. And how refreshing, to hear that somebody else is interested in the DATE of manufacture! I mean, that's what it's all about, ennit? All well and good to have compatible parts, but they can't serve MY/OUR purposes, or not ALL of 'em at least, if they spoil one's bike's own "TIME TRAVEL" abilities. (Of course without decent period-correct replica TIRES, this effect might stretch down as far as in inch or two from the road, but never quite touch it....)
I've FINALLY found some evidence in print, AND a time reference, on period-correct vintage alloy rims! I've been looking all over for this type of thing for a while now.
I've got "Super-Akront" in 3.50x18" and 3.50x16" with the high domed drop-center profile like a soft curve or pyramid & larger dimples I think, and a very early looking Akront 2.50x16" non-shouldered, plus a couple of 4.25x18" Akront (regular flat profile) as well as plenty of 3.00x16" Borrani record aka "rinforzatto" which don't have the bead-retention ridges necessary for running tube-less (sealed with shoe-goo or aquarium silicone etc - look it up!) Neither do the "Super-Akront" for that matter. Meanwhile, I've got some 2.50x18" un-marked Borrani from the rear of AMF-era Harley Sportster etc, which DO have the bead ridges. Plus some modern production 40-hole Super-Moto rims in 4.25x17" & 5.00x17" & Morad 3.00x18" as per the current eBay listings "Italian style" etc - and some later (regular old, like '90s era) Akront brand 3.50x16" and GAWD knows what else in my wheel hub & rim collection/museum here!
So what I'm curious about, is what year each size in each brand was first available. So as to really pin down the period-correctness of these current & future projects. I intend to try and build each and every pair, should I live so long, and try 'em out with successive tire changes perhaps so as to get a feel for all of the possibly geometries & the like - Sets for my "CB900K0 Bol Bomber" start with 3.50x16" Super-Akront with 4.25x18" Akront (for a Freddie Spencer '82 Superbike vibe aka Interceptor Superbike vibe, only in wire laced rather than 3-spoke Dymags) then 3.00x18" with the other 4.25x18" Akront, and then another DOHC-4 project beginning to take shape a "Featherweight 750 for Ever" with parts from the 900 etc, using the Harley 2.50x18" with the Super-Akront 3.50x18" - I'd like to build this one as a '79 style DOHC-4 or even more retro-fried this is why I'm curious about a date stamp on that pair, same with the 4.25x18" on the '82 bike 'cause it strikes me - This wider size might have been more of a late '80s early '90s issue? The Borrani 3.00x16" all go on the "KZ440LOL" with Suzuki 4LS & low-profile Maxi-Scooter tires, NOS belt-drive, an odd-ball Proto-Super-Moto twist wherein we're planning on painting the rims half-&-half just like the modern Super-Moto kids have been doing. Then I figure there's a place for a pairing of 2.50x18" with 4.25x17" for a GL1000 or thereabouts (maybe a GL1200-based DLF-1000 replica? Would like to do that with the 4.25x18" rear but the swing-arm on these presents some snug limits) as well as a 3.50x16" with 5.00x17" pairing, and some pretty boring 3.00x16" with 3.50x16" and 2.50x16" with 3.00x16" AND/OR 2.50x16" with 3.50x16"....
And heck I'm also hunting for stuff for a pair of C70 Passport scooter frames & two complete KZ440LTD forks, for my two complete twin 9yr-old Nephews. So that's where I was thinking the recent acquisition of 2.50x16" Akront 36-hole would be useful - I'm thinking I'd like to snap up some 2.15x16" to pair with 'em, and Mike's XS650 has great prices on that size of rim and drilled for nice big 180mm/200mm (XS rear hub?) 36-spoke patterns. With or without shoulders no less. plus he sells the 2.50x16" in the exact same lacing/drilling. I really like the thought of hugely over-sized drum hubs being massively ventilated, then either skimmed out oversize like 200mm to 203mm for 8" shoes & side-plates from Brit-bikes etc - OR better still if they're only gonna be used on the light-weight lil' Passport bikes it might even be possible to CROSS-DRILL their linings, now THAT'S one reason why I can see myself putting XS650-spec drums onto a little Cub-Clone bike! If I wind up with 40-spoke rims I'll use KZ400S front & rear drums, which are something like 180mm but lace up well to CB750 pattern rims etc. Just sayin' - they're about the most appropriate of all these alternate hubs for Passport use, IMHO - AND that's about the only 40-spoke front drum from Japan, at least in this size range. But yeah, this makes for some interesting re-use re-cycle wheel parts,, IMHO - and some interesting Passport builds, even in spite of the telescopic forks. The idea being to build everything on par with the biggest Cub-Clone motors we'll be able to lay hands on.
-Sigh.
POST-SCRIPT:
Some other pairings would be useful too though. Like a 2.50x16" and 3.00x18" and/or 3.00x16" with 3.50x18", for a wire-spoke conversion of MVX250F aka Bill Ivy JAWA Type 673 replica. Or perhaps even 2.50x18" AMF-Harley with the Morad 3.00x18" - not the biggest sizes available, and heavier than their non-shouldered counterparts (such as Super-Akront 3.50x16" being a good 3rd lighter than the Borrani 3.00x16") HOWEVER, they're both drop-center shouldered style, so they'd be really ideal for a PAINT SCHEME, wherein I'd like to do 'em up painted in contrasting black & silver, to look like later DOHC era COMSTAR rims of the black aka "Reverse" pattern. This is also why I'm hunting for alternative cross-sectional profiles in 2.50x18", rather than the AMF-Harley type, to make a better pairing with the Super-Akront 3.50x18" rear. AND I'm digging around to find a non-shouldered 3.00x18" to pair with the 4.25x18" Akront rear. 'Cause once you've got 'em together in matching STYLES it begins to seem like they're all that much better than the pairings which you'd previously though of as matching SIZES. If I can pull off BOTH matching characteristics of styles AND sizes, well THEN one could really say that the bike is a "SHOULD'VE" or "COULD"VE", which is to say an OEM model built in an alternate dimension/time-line etc. Plus - the WEIGHTS of the non-shouldered rims are truly impressive. This way, I can build the really wonderful "track-bike" wheel pairs in both "SKINNY" (2.5 & 3.5 - same sizes as the Boomerang Comstar wheels from works-spec CB1100R racers from Donington park "Transatlantic Challenge" etc) and "WIDE" (3.0 & 4.25 - same sizes as 2010+ CB1100) in as lightweight a version as was humanly feasible - AND then the slightly less wide but still ample sized "Comstar Painted" shouldered/drop-center rims - (in 2.50x18" & 3.00x18" aka the correct sizes for CB900F2 and/or CB1100R street-bikes) AND the odd-ball 16/18 pairing is a very good match for the AMA Superbike at Daytona, AHM '82 "CB750F" which had DYMAG rims in 3.00x16" & 4.00x18", so mine will be slightly wider. So too with 3.50x16" & 5.00x17" these are sizes appropriate for either the early CBR900RR or CB600F Hornet etc, and good alternates for the 6-point Comstar wheels from VF1000R for instance which were something like 2.50x16" & 3.50x17" ETC ETC ETC.
Everything I'll make in wire-spoke will be extra wide yet still a good match for a given model of bike, so that they'll still fit the OEM swing-arms and brakes, chain-lines or shaft-drive, fenders etc etc - so that it would be a basic straight-up swap to wire-spokes, rather than too ridiculous of an upgrade which won't seem at all period-correct. Well, except for the "KZ440LOL" which is more like an adult-sized MINI-BIKE straight out of the CIRCUS.....
But yeah I guess my POINT here, is that with any & all of these pairs which I'm either building now for my CURRENT projects, and/or the pairs which I'd like to build for the next couple of projects (whatever 2nd-hand Honda bikes that come up on the local market, which I'm planning to work on just as soon as these ones are finished!) I would like for them ALL to be as close as possible to "PERIOD-CORRECT" (-ish) So that they'll come off as something of a "Should've", "Could've" etc.
I like the TIME MACHINE factor of all this stuff. Whatever weird stuff I do to a bike, I'd still like to be able to get out the old instamatic film cameras, some 2nd-hand vintage clothes and safety gear etc, grow out the ol' PORN-'STACHE (as opposed to the porn STASH which is another thing entirely!) and shoot some TIME TRAVEL photos and/or movies. Just for fun, of course. But yeah, it's nice to have proper period-correct vintage EVERYTHING, (maybe even hairy bush?) so as to be able to let one's imagination run wild!
But for all of that, I need the CONTEXT - I need to know whether anybody else has any vintage catalogues or cycle 'zines, brochures or adverts of any kinds - Anything which relates to just the alloy wire-spoke wheel rims only. Specifically the AKRONT, BORRANI, and/or SUPER-AKRONT brands.
I'd ALSO be very curious about the WEIGHTS on those D.I.D. brand rims! I've never even SEEN the things before. I've only heard of 'em referenced on threads about OEM Honda wheels, and I'd assumed they might be from something like a CR750 kit, or an early pre-production GOLD WING let's say.
I wasn't aware of 'em being available as aftermarket items at all!
It's not like I've ever heard of aftermarket racing cast/mag wheels from the likes of ENKEI - Have you?
But SFAIK, it doesn't LOOK all that good! In my own experience thus far, with only the OEM rims from GL1000 Goldwing (1.85x19" & 2.50x17" - square profile with a hollow sealed-in shoulder which sometimes makes tinkling sounds), plus KZ650CSR & KZ1000CSR (3.00x16" rear, 48-spoke, seemingly made twice as thick so as to avoid splitting around the air-valve hole?) as well as plenty of D.I.D. brand center-flange rims from various COMSTAR wheels (both hollow shoulder from 5-point types and extra thick solid type from Boomerang wheels), but with zero encounters with the aforementioned (in the thread, up above, by other posters) 2.50x19" & 3.50x18" sizes - I've only ever found the D.I.D. brand rims to be hugely over-weight relative to the other marques. With 3.00x16" D.I.D. from KZ-CSR weighing probably DOUBLE that of the 3.50x16" Super-Akront.. And the 3.00x16" Borrani shouldered/valanced/flanged drop-center type "Record" aka "Rinforzatto, coming in somewhere midway between the two. I've got 2.50x18" D.I.D. from COMSTAR rear wheels (Hollow-Shoulder types, the 5-point version) which weighs up the same as an Akront 4.25x18" - I don't have an analogous sized Akront 2.50x18" for comparison, but I think THIS comparison already says a lot! From this, one might interpolate that the 2.50x18" wire-spoke Akront rim, might weigh as much as 40%-50% less than the D.I.D. Comstar -
AND furthermore, that the Akront "NERVI" center-flange type rims, appropriate for re-building a COMSTAR wheel, might be the same proportion of around 40%-50% less than the OEM rims from Honda Comstar wheels!
So yeah, IF any of those D.I.D. brand rims pictured above are still kicking around, disassembled? OR if somebody took their stats sometime in the past - I'd really love to hear some figures. Gotta get me a better scale so I can state the same for each and every wheel rim I've bought - Maybe THEN it'd be worth an all-in wheel building thread? I'd hate to repeat the wheel sizes AND weights each time I mention 'em! Ha-ha.
IMHO there are plenty of BRAND NAMES being thrown around here, but we sure don't hear much about the actual WEIGHTS of alternative wheels on our bike builds. Whereas you read about a BICYCLE build and there are all sorts of figures thrown around! So we get a lot of folks spending big $$$'s and not knowing how much if any improvement they're gonna get from their investment. Which SUCKS!
POST-POST-SCRIPT:
I'd really like to see more stats & figures in all of our build threads. We certainly see the same when people talk about ENGINE modifications. And when we talk about BRAKE upgrades, there's plenty about drum & rotor diameter, the surface areas of various caliper pistons or master-cylinders - the lengths & ratios of various pedals & cam armatures. And when it comes to wheels, folks are beginning to speak about widths and tires that will fit with them, along with their origins and the vintage of the bike they're from. But when we're talking about lightening a chassis, nobody speaks about what sort of weights we're shaving off. They'll speak to whether or not it feels like an improvement, but there's little to no means of ascertaining which is the better of two options!
IF we can get some figures on this type of thing, where at least SOMEWHERE on these FOUR-UMS, we could get all available info on a given type of wheel, or fork, or swing-arm - Not only the dimensions such as where folks really getting into a swing-arm swap will speak about width at the axle, length from pivot to axle etc, but WEIGHT would also be nice to know. And let's say tunnel dimensions, fuel capacity AND the weight of a given gas-tank for instance. Fork swaps, people talk about not only tube-diameter or steering bearing sizes, plus crown off-sets, axle to crown length, suspension travel and sag rate under a given load, etc etc - It would be nice to figure in the WEIGHT of an all-in front end. Either as a whole including the wheel etc, but also just a basic triple-tree with legs and an axle let's just say.
With info like that, we could help future project planners to save $$$, as well as get the most bang FOR their buck. To plan out not only the ideal suspension up-grades without going into the over-kill zone, but also how to plan out the best possible bang-for-buck LIGHTWEIGHT chassis, weight shaving without sacrificing the basic specifications and/or stats which are assumed to underpin the chassis' abilities. So let's say, folks would know how to put together a lighter front end without having to ... say, scale down from a GL1000 front end with 37mm tubes to the 35mm tubes of CB750K or even 33mm of the CB400F etc - and/or 296mm rotors down-sized to 276mm or 260mm, by knowing about the dished one-piece rotors for instance, for Comstar bolt-patterns the FT500 Ascot 296mm front rotor is one possibility, or the '81-only CB1100RB-only 296mm dished front 5-spoke discs (Metalgear Australia makes a perfect replica disc - AND replacement 9-rivet outer discs for SOHC-era rotors) It's good to know about the dished discs weighing a good 50% less than the 9-rivet types (in 276mm at least, I've verified this, but it's probably even better in the 296mm scale 'cause that extra 20mm diameter is all the thick heavy part on the heavy version, but mostly open air in the middle on the "dished" one-piece version!) But looking at it from another angle, builders might be interested in greater HEAT-SINK factor, and seek out 296mm 5-bolt discs from CB750A Hondamatic - OR greatest surface-area AND weight, so they'd want the double-thick VENTED discs from GL1100A Aspencade, CB1100Rc/d, CBX pro-link, and GL1200 - PLUS one might be looking to upgrade their discs from 276mm to 296mm or perhaps the opposite to shrink 'em down 'cause they're using an alternative HUB style from a bigger bike, on the smaller model? It's a pity there aren't more OEM options for 6-bolt discs, which is why it's good to know about the AFTERMARKET versions such as the 24-carat Unobtainium KIMTAB discs from thee Magnesium wheels of the same name - However given how EXPENSIVE these discs can be, it's important to know exactly how MUCH lighter than OEM they might be, as one could alternatively drill 6-bolt patterns into the 5-bolt dished versions, or even better still to cut out the centers of the FT500 ASCOT discs for instance, to stick 'em on the SOHC-era 9-rivet center carriers. See, the weights and other dimensions are ALL relevant here, as the builder might want to compare absolute WEIGHTS vs a comparison of COSTS so as to come up with the 9-rivet carrier together with the thinner outer discs cut from FT500 Asct rotors, OR perhaps even with some far later era FLOATING discs, from CBR/VFR etc, it might even be feasible to swap 'em without doing any cutting at the machine-shop - or minimal cutting even? THAT one would be something of a "holy grail" of SOHC upgrades, I should think! What I'D like to find, is something to fit the later DOHC or VF-series era 9-rivet center carriers, with the bigger rivet-circles, to match 'em to a 310mm-316mm-320mm disc, to suit a later era fork & calipers! But THAT type of thing would be a whole other order of magnitude over & above what I'm talking about here.
The best I've found thus far, was the Metalgear Australia "Compare Discs By...." which can be used to cross-reference several different ways.
But imagine something like that not only for the brake DISCS, but also for the wheels, to offer up choices of wheels with compatible rotors (perhaps even with alternate rotors of their own fitted) which would offer either a weight savings, or an alternative tire size, diameter or width that is - And then a table of forks with the same length & axle diameter & tube diameter, which could swap out and shave weight - The best example I could think of would be the 36mm tubes of the Yamaha XS750 forks, which have these huge castings on the lower sliders where the caliper hanger is integral to the leg and saves weight by eliminating the two huge bolts. So these might be eliminated/replaced through use of some later era 36mm fork legs which used bolted-up caliper hangers whereupon you go down the stream of caliper selection and discs which leads you to wheels, OR possibly mill out the triples for 37mm Honda legs perhaps 38mm Marzocchi - From another perspective, these XS750/TX750 forks might just be useful either as a lighter alternative to the version with bolt-up calipers OR as a donor fork where you'd cut down those original castings to fashion NEW lug spacing, for hanging whatever calipers you see fit!
Surely somewhere in the distant future, all of this mix-&-match stuff could be laid out as a huge stack of reference materials, perhaps a couple of photos per item and a few columns of figures per item per class of items. And then the whole mess could be cross referenced?
Well THAT'S a whole lot of work, to be sure. But if there were a couple of stickies on the Four-um and 'F-orum and other forums, which just as with steering stem bearing catalogues and wheel bearing catalogues which led a few enterprising and intelli' GENTS some years back to compile the front and rear AXLE diameter charts - the fork tube diameter charts from the SEAL catalogues, etc etc. I've been using the Galfer wave-rotor specs to SEARCH for a given handful of compatible rotors for only a these FOUR different wheels here (Honda COMSTAR front and rear hubs as well as the SOHC CB750F1 '75-'76 wire-spoke disc-brake hubs, front and rear) But - if there were a way to compile any & all specs from such sources for brake rotors, we'd have specs for both brake rotors AND some of the specs useful toward compiling the info for the WHEEL off of that bike. Of course, those commercial lists are useful every now and again - but it's the parts which each of use have actually found USEFUL which are best applicable to a data compilation. Ergo, each of use who's DOING any mix-&-match work, could enter said data into a few short columns just as with a CLYMER guide "specifications" section.
And so too, sites like "Motorcycle Specs" are sometimes useful for tire information, heck somewhere down the line if such sites are to survive the next 10yrs on the 'net they could possibly even expand their own range of figures to include a lot more useful info than just the basics. In doing a wheel-swap, I ran into some problems when I attempted to use TIRE SIZE figures from said sites, for wheel-swap guide-line. At the time, eBay listings NEVER included close-up photos of wheel rims or detailed zoom-able images of each side - with which one may ascertain the diameter and width of the WHEEL ITSELF - As such, when I bought GL1000 front and KZ750B rear wheels (both from 1977) for my '82 CB750F - I may have been giving the bike the same sizes of TIRES - However I was replacing a front rim of 2.15x19" with 1.85x19" - and a 2.50x18" rear with 2.15x18" - And what stuck in my craw at the time was that KAWASAKI was pairing up an OEM tire with a rim in combinations which were outside of the range of "Manufacturer's Recommended Rim Width" specs from the tire manufacturer's own web-site - let alone the basic guide-line "Tire To Rim" compatibility charts. Going off the premise that these were hard-&-fast rules, I didn't keep these wheels on the bike for very long at all!
Perhaps if that KZ750B/KZ1000A rear wheel had an ALLOY rim, of a type that could be sealed up as tube-less, one which was or could be construed as, less heavy than the OEM Comstar wheels? Maybe THEN I'd have clapped my hands with glee!
Instead, I began to search for replacement rims, which might have been a quick process if not for the conical rear hub of the KZ750B/KZ1000A - If only I'd have found a decent rim for it! The only other 40-spoke conical rear hub I can even think of would be the vintage TRIUMPH rear DRUM hubs. And those seldom if ever pair up with a rim any wider than 2.15" wide, for racing class rules for period-correct components only. OR if it were a matter of TIMING - 'Cause just a short time ago, I passed over an eBay listing for a KZ1000A rear hub in a Super-Akront 3.50x18" rim!!! Just about the most ideal combination of featherweight rim and light-weight hub that you could come UP with for this application. I ALMOST bought the damn thing, but I've since come to a more critical view of the KZ750B conical disc hub itself. (((It's still simply the most brilliantly light-weight rear hub of it's class. However my 2013 house-fire showed the chromed-steel right-hand-side spoke flange to be stuck there with nothing but EPOXY. Perhaps with a SOLDERED joint, or an Aluminum replacement flange welded up? THEN I'd be all over the damn thing! But instead, I'm going with a bolt-up cush on a "FRONT HUB TRICK" rear wheel, so as to take advantage of the cheaper more readily available and mass-produced HARLEY pattern drilled rear rims! I've found 'em in 2.50x18", 3.00x16"-3.50x16", 4.25x17"-5.00x17" and even 4.25x18" - obviously THIS could be the truly intelligent cost-shaving option! Adaptations however, include a bearing swap possibly even with machined-out pockets for a better grade of wheel-bearing, plus the bolt-up CUSH will have to be machined from another donor hub [in my case, the damaged KZ750B conical, and I've even purchased a couple more of 'em!] And that cush is gonna have to be really carefully attached 'cause we don't IT to turn out just as flimsy as the KZ750B chromed-steel spoke flange! Perhaps a STEEL cush-drive "box" or "pan" would be suitable? IF the weight could still be kept down! It's gonna be a really good hub, but "DEVELOPMENT COSTS" are worrisome enough that I'm still moving forward with a heavy-assed CB750F1 rear disc hub, if only because it's already on hand. THAT copy of 4.25x18" Akront rim, being drilled for such a huge rear hub, is gonna be swapped over to something like a GL1000, where the SHAFT-DRIVE makes such hubs a prerequisite. Ideally, a weld-up converted GL1200, or VF1100C Magna / VF1100S Sabre, or other such rear hub "core" would be welded into a DRUM that's been hollowed out side-to-side. So again - some pretty involved construction going on back there, but with a huge pay-off in the end. Especially if the hub could STILL be scaled down? GL1100/GL1200/CB900C rear shaft hubs require the CB750K/CB650 size of rear drum. But perhaps V65 Magna/Sabre would only require CB500/CB550? IF that V65 wire-spoke hub winds up weighing substantially less than the GL1000 version of which? Well then I'll consider that a "Win/Win"....)))
So back to the alternate hubs on the CHAIN-DRIVE DOHC-4 for a minute, I suppose if a puny 3-bolt disc and down-sized cush, narrower 17mm (from 20mm) rear axle were suitable? As with a swinger swap from some later era crotch-rocket "middle-weight" (possibly an anachronistic term for 600cc class)? AND that a 36-spoke rim? THEN one might have selected a Yam TZR250 rear hub, a good alternative to semi-Unobtainium RD250 etc rear hubs. But I've held to the "hard & fast" rule that MY particular bike needed to keep that 20mm rear axle, that ample dinner-plate-sized CUSH, and the solid mounted 11"-ish diameter rear disc. (SOME of which I've revised in my new perspective on it all!) And as such, I've found that one might as well ignore the 36-spoke rear hubs 'cause the only DISC types are either disqualified by not having a cush-drive (TZ750, Harley, etc) and/or lacking the 20mm axle (TZR250 is 15mm upgrade-able to 17mm max - good for a smaller bike!) OR by having a more slightly built rotor with seemingly flimsy rotor bolts (TZR250 with it's 3 bolts and disc of substantially smaller diameter!) I've even snapped up a rear hub BELIEVING it to be a TZ750 hub (listing was "TZ, Honda MT etc" or words to that effect) which turned out to be Honda MT125R the Elsinore-based too-smoke Road-Racer. Which is to say, VERY petite to where it might as well be a Honda FRONT hub, and with an axle diameter of only 12mm - Which is to say, suitable for a CUB or a PASSPORT! (((I'm happy to say I've found a HOME for it! But since it was my own mistake to purchase it, and since I asked the seller to discard the spokes and the lovely D.I.D. 2.50x18" square-shouldered (GL1000 style) RIM, yet paid full price for it - How can I estimate a price? So I've asked for a SWAP instead.)))
YES, I could very easily have followed the "Go-To Formula" for wheel swaps. But then I'd have been disappointed, as the CB750F1 rear hub is actually a little bit HEAVIER than the COMSTAR rear hub - And depending on the brand & type of RIM selected, I would've very likely wound up with a RIM that's just as heavy if not heavier than the OEM D.I.D. rim on the Comstar, especially when up-sizing AND so many classic wheel builders recommend the shouldered type rims ('cause they're stiffer and hold up to bumpy roads etc) And especially if I'd selected a type without the bead-retention ridges, as with say - the vintage style reproduction Borrani 3.00x18" 'Record'/'Rinforzatto' which doesn't have bead ridges AND it's a very heavy type! Following THAT type of recommendation, I'd have wound up with an even heavier wheel than the OEM Comstar!
POST-POST-POST-SCRIPT (Never even done one of these!) aka "PPPS":
AND, when you consider that the 3.00x18" size doesn't give you that much of a TIRE advantage over the 2.50x18"
(More like the wider tire's just gonna sit with a slightly straighter side-wall.) As a wheel-swap, THAT choice could really suck donkey balls!
If alternatively, one were to use the lightweight hub, and a lighter rim which CAN be sealed up tube-less? Just look at how the 4.25x18" weighs the same as 2.50x18" Comstar's D.I.D. rim, well then how about the 3.50x18" Akront? The NON "Super-Akront" type, not quite as light-weight, not nearly as beautiful IMHO, but it DOES have the bead ridges! Surely IT'S gonna weigh a fair chunk less? However much a full hoop of 1.25" width weighs, albeit that's not directly proportional 'cause the 'drop-center' side-walls and the walls of the rim itself, will still remain and in equal dimensions to the 4.25" version's. Still, THAT'S gonna be a decent improvement! Probably equivalent to sticking the Comstar wheel itself on a big chuck and lathing out any "extraneous" material, to whit right to the point of falling apart?
(((What's even more awesome in the Comstar sense, are the Akront "NERVI" rims which have identical profiles to the wire-spoke Akront rims, with only the addition of a central spine flange for "spoke" blade attachment. Which probably puts the most of 'em at around 10%-15% heavier than the wire-spoke equivalent. Ergo, if the Comstar D.I.D. rim's around double, the "NERVI" has got to be around 40% less, 60% the weight of the OEM. Of course, that's a couple of degrees of best-guess extrapolations/interpolations. But I'M betting that it's pretty damn close to the mark. Go ahead and try to remove some 40% of the mass from your Comstar rims ha-ha. [NO - that would be sarcasm! So please DON'T?] Even if it's less, perhaps "ONLY" 25% mass reduction, yet the wider sizes are available? Combined with some HUB weight reduction, either a bolt-up cush-drive for a FRONT Comstar wheel, OR a plug-insert type pre-1975 style rear disc-brake conversion of a smaller drum type rear Comstar hub [CB250N, XBR500, etc) OR direct cutting/drilling to the OEM hub, OR perhaps even a hub substitution using a lump of billet OR better still a "hub"/CORE, cut from a later-era 5-spoke/6-spoke Cast/Mag wheel? THERE'S the method for constructing a truly impressive COMSTAR wheel-set! It's almost a more simple process than selecting best components for the WIRE-spoked versions of which!)))
Now, as I was saying vis-a-vis 3.00x18" vs 3.50x18" vs 4.25x18" rear rim sizes: the 4.25x18" will give you 160/60-18 Bias or 160/60ZR18 Radial. But both that width AND the 4.25x18" are going to give you the 150/70-16 which is practically the same thing in Bias-Ply being that SOME 150/70's are 160/60 in actual dimensions, while so too certain 160/60's are actually - So if you're NOT gonna go with radials then I'm betting that the 3.50x18" is the smarter choice, IF you're happy with bias, AND if the weight is more important to you than that little smidge of (possible) extra weight!
Now "OFFICIALLY" (and for practical reasons it's probably a hard-&-fast rule) the 4.25x18" is the entry point for the RADIAL tires, (usually Sport-Touring Radials but still Radials all the same - 160/60ZR18 to pair with 110/80ZR18 aka 120/70ZR18 up front on a 2.50x18"-2.75x18"-3.00x18" up front - the ONLY size of 18" FRONT Radial SFAIK - the other rear 18" radial would be 180/55ZR18 which is a recent development for which you'd need 5.75x18" a size which Akront had made for a while now, even back in the day they made Akront "NERVI" type in this size and OH how I wish I hadn't passed over the one rim I'd seen, which would at the time of manufacture been intended for some horrid Harley DRAG racer with 200mm wide DRAG SLICK type of rubber - Like I say, the 180/55 is a new development so it's important to keep up on what they're making as of NOW.
(((Witness the MAXI-SCOOTER radial sizes with 140/70-16 rear which a few years ago came out in DUAL-COMPOUND Michelin and rather high-speed types no less, just like a scaled-down PILOT POWER - if ya'll can fathom what all that could do for your "BOBBER" style 3.0x16" & 3.5x16" wheel-swap???)))
I'm wondering myself, whether we're likely to see a new class of skinnier radial tires, suitable for 3.50x18", perhaps either a 160/60 which would squeeze onto the 3.50" width, OR perhaps even a 140/70 spec in 18" diameter? It would open up new possibilities for owners of - for instance, the GIXXER "Slab-Side" and "Sling-Shot" earliest '85-'86 models. Or several other models from practically any other marque. The 2010 CB1100 has 18" rims, so too with the embiggened Guzzi V50 Monza known as the V65 Lario which was embiggened yet again and badged as a "V7" (Not to be confused with the ORIGINAL Guzzi V7 mind you.....) There are SEVERAL IN-PRODUCTION models which have brought the 18" "skinny" wheels back into vogue. Weren't the very first 2010 CB1100 rear wheels only 3.50" wide? The point being, there's a substantial market out there for improved tires of 18" diameter, It's a big maybe, but there'd be huge pay-offs for that particular rim size -
It's pure CONJECTURE, but perhaps we'll even see radial tires for 2.50x18" rims but they'd probably be a lot narrower than the Bias-Ply sizes we're used to today.
I'm actually far more hopeful that we'll see a return of classic '70s spec racing tires WITH the classic grid-pattern sipes etc. Reproductions of the most classy high-spec vintage rubber from the mid-late '70s, which would've been suitable for these 3.00x18" & 3.50x18" rim sizes. Now for those of us who are far FAR more interested in the "REAL, NOT RETRO", the actual CLASSIC bikes not "Modern Classic" facsimiles - THAT would be the best of all possible developments!
WELL - TO SUMMARIZE:
I'm delighted to finally dig up an archive thread with info about origin dates for a particular size and brand of aftermarket alloy wire-spoke rim. OF the size range and period with which I'm primarily interested, no less. Albeit, not precisely the thing I was looking for. It gives me hope of finding THAT, at least.
But we need to gather more info, all possible info whether we think it's relevant to us right at this moment - to create a "data-base" of aftermarket parts and/or alternative swapping components from later models. Within reason - I could really give a damn about the USD forks and mono-shock conversions, given that they tend to RUIN a good classic bike's whole aesthetic ethos not only in it's congruity but more to the point some of this crap just makes the whole bike look fugly as all get out, 'cause they're just that CHACHI that they undermine anything else that still remains.... So I'm talking mainly about "slightly later than original" upgrades where a fork or a wheel or gas tank, an engine swap even - would still resemble the originals closely enough that they'd pass a cursory examination without jumping out at you. And perhaps some degree of leeway on that, for the stuff that look close enough to the WORKS-spec upgrade parts, from the period-correct RACERS of that era. There's plenty more leeway for the DOHC series than the SOHC stuff - But the whole "Hand-Me-Down" system could still apply equally across the SOHC/DOHC divide (or "Astrological CUSP" as the people of the SOHC era might have put it at that time?) And of course there'd still be methods of DE-FUGLIFYING some of the newer more CHACHI looking crap - By stripping off their lurid pink anodizing etc. For instance, some OHLINS shocks could be stripped of their gold foil or electroplate, Titanium-Nitride coatings or whatever the #$%* - They could then be polished or chromed, and their springs stripped of the hideous YELLOW coatings and then dipped in RED - WHY? 'Cause they might pass for the original CB1100R piggy-back shocks. (Which SEEM like the very first piggy-back shocks which had the bottle at the top! Can you think of an earlier version? What better way to retro-fry modern aftermarket piggy-back shocks then, than to make 'em look like the CB1100Rc/d version?
There's even a possibility which might work out really well for the SOHC crowd - What if there's a way to fit the original SOHC calipers or later 'F2 & early DOHC floating calipers even, to a later era caliper hanger from VF series or some such, so that a thicker beefier fork which yet resembles the Magnesium 35mm CR750 works forks, could pair up with 296mm dual rotors rather than mere 37mm GL1000 front end with 276mm discs or the DOHC 39mm with twin-pot calipers etc - But an actual reasonable facsimile which upgrades many or all of the basic specs (perhaps also 20mm axle, integral fork-brace, and 310mm-316mm-320mm discs?) Yet which passes that cursory examination AS a real works-spec CR750 fork. Methinks this would be the holy grail of SOHC mix-&-match chassis parts. Well that and maybe a CR style over-sized under-seat alloy oil tank which originated as some cheap wine-&-beer-making equipment? Or an alternative FRAME which more closely resembles the CR frame than the CB chassis itself? OR, a 200mm drum hub which could double as a CR type Magnesium rear 2LS drum? (I'm thinking perhaps a Harley 8" front full-width drum, or CB450 drum skimmed to 203mm, and improved bearing pockets, with a modified British 8"/203mm 2LS shoe plate or the OEM CB450 version, perhaps CB72/CB77 rear 2LS with it's cams & pivot pins removed & replaced with alternates so as to work with 8" shoes (IF & WHEN a database of DRUM mechanicals is constructed?) and a compact bolt-up/weld-on cush-drive? Just a brain-fart! IF that's at all remotely possible - More than likely limited to a 17mm axle upgraded from the original 15mm, using a later era swing-arm where 17mm rear axle is standard - Much more likely to find one in box-section, too!
It would all begin with collecting the MATH on all of this stuff. Just think for instance, of how changing out to alternative CAM pivots in a drum's actuators, perhaps also with a thinned-down or bushed-up pivot pin, or alternatively the shoes themselves could have their pivot points modified with a scooped-out half-moon at the pivot end, or another wrap of steel over the cam/lever end so as to meet with a cam that's slightly off-kilter - WITH a decent geometric modelling program, it's feasible that substitutes COULD be construed, such that a really decent 200mm 40-spoke 2LS drum could be built from junk-yard parts. Which could be lighter than stock due to it's liner being skimmed out that extra 1.5mm's for the full 8" diameter. Plus a little bit of ventilation here & there, maybe even some grooved relief cuts in the drum lining? I mean, you wouldn't get it down to the weight of a Magnesium original, but no biggie 'cause if you care that much you CAN still purchase the replicas. And if the weight's more important than the appearance, there are some incredible light-weight rear drums from period Motocross models, some of which were even magnesium themselves. Albeit conical drums with the chain and brake on the same side (WHICH would allow one to use the CB72/CB77 2LS rear shoe plate! Assuming you can't already find a 2LS plate on these Magnesium hubs? There are a number of really decent conical rear drums out there, which are already laced to Akront 2.15x18" & 2.50x18" - sometimes even 2.75x18" if you expand your search to later stuff like Honda's own "Montesa Cota" - IF any of these drums is up to the chore of rear wheel braking, then that's a really smart high-perf rear wheel, especially when it's correct to the SOHC era as with the case with some of the MX wheels I've got in mind.
POST-POST-POST-POST-SCRIPT:
I guess I'm a lil' more hung up on the OEM appearances though, so even where I AM planning to use a rear drum on my next 750 (DOHC-4) project, I'm looking at full-width drum hubs. Likely the early KZ400 drum, 'cause it's got a better cush-drive than the CB500/CB550, with less messing about with cush-retainer circlips etc. I guess it'll depend on what all is possible with the aftermarket DISHED rear sprockets - Whether the CB750K pattern bolt circle could be adapted to the KZ cush carrier. But even if NOT, there's always the chance of using a KZ454LTD rear cush element, which is normally a combination "coupling assembly" AND a belt pulley, but the outer belt pulley is only a thin skin bolted to this large casting which would be equally capable of taking on a thin outer ring of 530 sprocket. Which would also add up to substantial weight savings. AND it could be milled out as a sort of extractor fan, in the sense which Laverda SF750 front and rear drums had, only on a much larger diameter such that the vent holes could be cut a lot closer to the drum lining itself, the working surface where the flow of cooling air is most needed. Kinda like the way I cut the 6 huge vent slots in the Suzuki 4LS drum for the "KZ440LOL" project. That stuff's all gonna add up to a really decent rear drum, adequate for the DOHC 750 yet far lighter than OEM, and able to quickly recover from any heat fade due to ventilation and cooling rather than the ample heat-sink factors of the heavy-weight OEM drum lining. In this instance, I've got the 3.50x18" Super-Akront - Again, there are no bead retention ridges here. As such I'm stuck with using a light-weight INNER-TUBE, which will bump the final weight up to that of the next-best option. Worth it for the period-correct vibes though. It's a beautiful rim. So given that compromise, I'll be making concessions in tire selection probably with a 130 rather than 140-spec tire. (Depending on whether there's still any life left in this here Pirelli 140/70-18, currently pinched onto a 2.50" Comstar rim!) AND the hub weight reduction, sprocket weight, and the shoe-plate will have to be adapted also. (((Perhaps there's a chance at a 2LS set-up, given that the KZ400 early 40-spoke rear drum's SLS side-plate has two parallel pivot pins, one for each shoe and spaced such that these shoes are of a correct geometry for a 2LS set-up, even WITH separate pivots and cams, rather than just the two items, combination pivot/cams, as with the "Victory Library" method of Harley SLS to 2LS conversion.))) I'll likely cross-drill and ventilate the shoes themselves, drill out the pivot pins and/or cams, play around with the splined armature whether that's a replacement of the bent-double sheet-metal type (Suzuki 4LS arms vs those of the T500 Titan, more like the front arms from smaller Honda 2LS drums, CB350K etc, as opposed to the rear CB750K armature. KZ400 lever arms are of the heavy cast-steel variety. Perhaps cross-drilling 'em? Typical matched-size bent-double sheet-metal type levers are at least 50% less than cast-steel. So sheet-metal AND cross-drilled? Shoe plates minimalized to just the core section where strength is needed, then thin pie-plate sheets over the rest of the drum's opening. Lightening holes drilled between the spoke holes, then any & all such vent/weight holes are tapped for threads to maximize surface-area. Opening the inner wall of the drum, which in the KZ400 early hub is identical to the earlier S3 (too-smoke triple) drum, except that the earlier version had each cush-segment open in the middle, not venting air in that instance but rather just to lighten the structure. I guess the question is - if the KZ400 early drum is considered adequate, well does that also apply to the S3 version as well? Surely it's adequate for KZ400 use. Gotta wonder why Kawasaki stopped cutting out those sections. On the 750cc FOUR-cyl, it might be the straw which breaks the camel's ... ass off. On the speeding tarmac. When the camel's bike's rear wheel hub cracks in half....
-Sigh.
