Okay so if I am to understand this correctly - let's look at the three major types of Honda hubs!
The biggest hubs such as CB750K, CB750F1, CB900F etc (and oddly enough the smallest of Honda hubs too, like the 90mm-100mm drum hub on the rear of my C70 Passport for instance, or that of my old '69 CB100K0 when I was a teenager) have two bearings in the hub proper, then a third bearing in the sprocket carrier with the top-hat spacer in the middle of that bearing, which gives the whole assembly the correct side-to-side/axial alignment, preventing the bearings from getting crushed apart, etc etc.
Then there are the OTHER ones, with the little GROMMET type cush-drives. The CB350K twin has one like that (as did the '70 SL100 I also had when I was 16, despite it being an almost identical drum brake to the cush-type version in my CB100K0) - there are grommets in the hub, the sprocket connects with "Captive bolts" which project blank unthreaded nubs into the grommets, and the whole assembly as such is retained against the hub proper with an enormous CIRCLIP - correct?
Oddly enough, the GL1000 and the CX series also had hubs with a cush-drive consisting of tiny little grommets sunk into the hub, with a ring-gear attached via little pegs. If you compare this to the cush-drive of "comparable" shaft-drive models such as Moto Guzzi V-twins or the KZ1000/KZ1100 shaft-drive models it's far far simpler of a design and yet the actual "CUSH FACTOR" is vastly reduced!
Incidentally - I was reading up on Guzzi cush-drives just last night, and found CONFIRMATION FOR A THEORY OF MINE, that it's recommended by the Guzzi Gurus to drill holes into your old cush-drive rubbers, to restore some of that spring factor. 'Cause the rubber is hardened. It's kinda ridiculous when you realize how simple of a structure are the Guzzi cush-drive rubber elements! They're nothing but little flat pie slices, compared to the complex shapes used in comparable Japanese hubs! OH - and they recommend using a product called "RUBBER GREASE" -
(((Yeah, watch what store you BUY that from, you might get something completely different than intended. Ha-ha. Then again, they might BOTH be different thicknesses of silicone-based lubricant. Ha-ha. Even if they ARE, don't stick the wheel lube up your ass. It will probably make you very sick. Stick to the grape jelly or Crisco, they're cheaper no doubt.)))
But it's interesting to note, the bikes which have so much care and attention to their thoroughbred healthcare (just to keep 'em up with our Hondas, BARELY) with their wrought-over manuals and assiduous restorations and museum collector's value - yet without replacement parts for their cush-drives - THEY have well worked out procedures that even extend to the point where they're keeping up with MY brain-storm sessions.
DRILLING HOLES! Who knew? ... Yeah okay probably a whole bunch of you. But I found the rubber-grease thing surprising. Here I had just learned about "slide pin grease" for calipers - Aha, well do you think that's why my DOHC caliper boots keep stiffening up? DUH.
I'm gonna head in to the auto parts outlet and buy every damn type of grease they HAVE. It won't be as fun now that I'm a single dude. Used to be a blast renovating that old 1907 death-trap (I literally wound up crippled for life after fixing that house) COUGH - shopping for supplies at the hardware store we always played a game, discovered back when I first started building aquariums actually - Walk up to the counter and ask the clerks - SHE: "Do you know where I can find the really big caulk?" ME: "It doesn't have to be that big of a caulk, I'm sure we really only need *this* much" SHE: "I've got a lot of cracks to fill I figure we need the jumbo size. And does it come in any other colours?" ME: "That's really not necessary! Just a standard sized package, the simple generic white caulk please." Ad nauseum. Somehow I think it won't be nearly as much fun going in alone, shopping for "rubber grease" and "slide shaft grease" and "pin hole grease", "ball & shaft grease" whatever the hell else. Worse case scenario the shop clerk follows you home ha-ha. I'll have to dig through the closet, see if I can find a trench-coat while I'm at it, wear it with shorts underneath, walk past a few playgrounds on the way to and from the auto parts store. Get arrested with a big tub full of "rubber grease" in my pocket, with a deep hole in the center of it where I've been repeatedly dipping big wedges of rubber deep into the bucket. And if I've got one of the rubber do-hickeys with me at the time it probably wouldn't help one's case either....
COUGH. Yes. ANYWAY there's yet a THIRD type of Honda rear hub cush-drive:
In THIS case, we're talking about a sort of hybrid between the two - there's a larger indented area in the hub with triangular rubber blocks, there's the cast Aluminum sprocket carrier which bolts to the sprocket itself rather than mere captive-bolts - HOWEVER there is no third sealed bearing nor is there a top-hat spacer between the two cast Aluminum parts. Instead of a ball bearing and top-hat spacer, the two cast parts seat against one another concentrically - they have cast-in steel rings integral to their structures not unlike the drum lining of the brake portion itself - very interesting, but then again many of the larger hubs have cast-in steel cores anyway, or at the very least tougher grades of alloy in the cores with lighter casting alloy making up the outer main body of the hub - for weight savings of course.
(((Here you read so much about the larger racing type 4LS drum hubs and how impossible it is to forge cast THEM with the pre-heated drum linings integral to the casting, meanwhile Japanese bike makers were doing that and a lot more in every one of these "mid-grade" street-bike drum hubs!)))
The sprocket carrier in this case is held in axial alignment (left to right on the bike) by that steel bearing surface and/or the cast Aluminum lugs between the rubber dampers themselves, OR a lip on the left face of that steel bearing, which keeps the carrier from moving to the right.
Meanwhile a threaded retaining collar attaches to the hub proper, through the large opening in the sprocket carrier, keeping the carrier from moving to the left, away from the hub and wheel.
One would THINK that this design is equivalent to the larger version with the third bearing and the top-hat spacer. And for the first set of bearings it's probably even superior! It's just that the bearing surfaces are WEAR PARTS, but they're not replaceable at least not as easily as off-the-shelf sealed bearings, or steel top-hat spacers for that matter (which are only "wear parts" if you abuse them terribly) -
So MY question is whether Honda made provisions for these wear parts to be REPLACED???
If not, I'd suggest that the hub and the carrier be machined out to some small extent, and a sintered bronze SLEEVE BUSHING be inserted in their place. OR, if only a small amount of material can be removed from either or both parts, that a steel sleeve make up the difference. 'Cause the sintered bronze might not be up to the loads involved. It's better on the lube retention, but I'd worry that it might crack. Heck I'd be worried that ANY of this stuff might crack!
Another angle might be to cut down some portion of the threads for the retainer, maybe have a groove cut for a circlip IF the retainer is also important to holding the hub's two bearings in place - and carve out enough material to stuff a third BEARING in place. It needn't have a top-hat spacer at all, just a thin washer to keep the bearings properly aligned in the center and keep the carrier and hub from contacting and pressing together in the outer diameter where the rubbers are, so yeah a really thin spacer or washer should be enough - the main thing being that the bearing be sufficient to support the sprocket and force from the chain etc.
There's gotta be an equivalent three-bearing top-hat type hub, with a third bearing smaller than the standard SOHC/DOHC 750/900/1100 bearings -
Speaking of which, keep in mind the same bearings in the wheels of the 750 handle loads from 140HP 1123cc CB1100R type of stuff, or a GL1500 with two passengers plus all of their livingroom furniture and 1970s audiophile spec stereo system with 18" woofers etc. As such you needn't look at the 750 size wheel bearings as necessary for the 750 and thus scale that down by 2/3rds to come up with a bearing for the 500/550 - 'Cause the standard 500/550 hub has proven to be a decent high-performance hub for 1000cc bored-out Japauto CB750K's - Therefore it's gotta be possible to incorporate something from say, a CB250 rear hub, or an equivalent hub like....
I'm working on my CB900K0 Bol Bomber, but also concurrently on a "KZ440LOL" for my kid. So the DRUM hubs which I'm mainly familiar with right now, aside from some KZ650CSR type of stuff I'd bought for it's rim back when the 440 was a much lower budget project. Ridiculous idea, and those rims were heavy as #$%* - steel firestone rims would be better! But yeah - I'm pretty familiar with the cush-drive bearings of the KZ400, KZ440LTD, KZ440G/KZ305CSR - some of which are a larger diameter 40-hole and others a smaller slightly wider 36-hole version. Interestingly enough, though they're used on a 400 twin there's a much lesser known KZ400 FOUR cylinder which was basically the earliest version, Japanese market, KZ550 - but built a lot more ... SVELTE, than the later KZ550 & KZ650 etc. Compared to the KZ650 rear drum that KZ440 drum is CLOSE to the same diameter but much thinner - It's really surprising how much WEIGHT is saved. But yeah the bearings themselves are a lot thinner in the axial dimension. I dunno whether I'd mess around with a KZ400 hub on a KZ650.... I guess it depends on whether the 650 were tuned up at all or simply stripped down for weight with stock carbs & pipe etc.
I try and think of an equivalent HONDA hub and not a lot comes to mind other than the CB250 - IIRC most of the later XL hubs are a conical type without any cush-drive what-so-ever.
I'd suggest a rear disc conversion using a Yamaha TDR250 rear hub with upsized 17mm wheel bearings in it. Or does the CB550 use the same 20mm rear axle as the 750?
I was really shocked to learn that my CB900F had the same 15mm axle as the KZ440LTD, or the GT750J 4LS drum - it made it simple to fit the 4LS drum into the 900 fork, though fitting the fork to the KZ is less simple. But yeah, it strikes me that any period Endurance Racer upgraded to at least a 17mm front axle usually a 20mm one and that's one major reason why I wanna stuff the GL1500 fork onto my bike. Meanwhile a lot of modern crotch-rockets use 17mm rear axles, so a lot of DOHC customs with one-off swing-arm conversions can manage to use different hubs. ME I've got the Cal-Fab swingarm, period-correct aftermarket Unobtainium "bling" (gotta dull it down with some paint!) So I'm stuck with the 20mm rear axle and the limited selection of rear disc-brake hubs available in this spec.
Just sayin' - I hope for YOUR sake that the CB550 used a smaller rear axle than 20mm - though I'd hasten to add that a 20mm front axle mod would be a good idea. I figure a hollow axle with the same diameter as the fork's axle clamp area but running straight the whole way through, could work well with an axle clamp nut on the OUTSIDE of the fork's clamps. Ideally a castellated nut with an R-clip or whatchamacallit. It's actually part of the provincial code here for motorcycle safety inspections, that the check-list includes cotter-pins on the axles as important as signal lights and brake lights. They accept it if your fork isn't intended to have one, but I was told the rear MUST have a cotter pin. Odd. There have got to be bikes which don't come with one. Can't think of 'em off-hand. But yeah - an upgraded front axle with a full-diameter rod from clamp to clamp would REALLY improve the front end. Supposedly as much as a fork brace. Put it together with a fork brace and it's like you've got a bigger class of fork on the bike. There was a bunch of stuff about it on some old Laverda racer build threads that I think were linked from the "Euro-Spares" library. Brilliant stuff in there.
I dunno how you guys feel about the CB550 rear drum, whether you feel it's adequate. If I were to swap to a smaller lighter hub, I'd still stick with the proper cush-drive type. The question is whether the CB250 drum is an adequate BRAKE to work with the 550 - especially a tuned-up 550 making 650 class power. The CB350K design DOES seem like it would save some weight. But yeah, I'm actually really impressed with that 40-spoke KZ400 rear drum, just that it emphasizes diameter over width, yet retains that super light weight construction of the smaller drums. I've got hubs AND Borrani 3.00x16" alloy rims for my KZ440LOL project, and I figure I'll probably build 'em both. It will be interesting to see which of 'em is heavier in the end. I've decided to build the 40-hole version mainly for aesthetic reasons, to match the tight fit and short spokes of the 4LS drum in the same 3.00x16" rim up front - well there's also a couple of Akront 3.50x16" rims to play around with. For a wider tire. In case I wanted to stick a CHAIN on the bike at any point. Hardly worth losing the extra horses transmitted by the belt, but you never know. If and when we add a side-car to the thing, it would be cool to have that fatter rear tire off-set toward the center of the outfit....
ANYWAY yeah, I like that KZ400 40-hole rear drum. It's as good of a design as could be achieved under the circumstances.
If I were building a drum hub for my 900, I'd probably just use a CB750K DOHC rear hub, and IF I were to attempt one for an 1123cc 140HP version of the bike, I figure I'd try the 200mm drum from the XS650 with a 2LS actuation, wider shoes - maybe attempt to mill the thing out to a full 8"/203mm for the thinner lining and wider automotive type shoes, albeit from crazy old fashioned cars at that. Bah - I dunno WHAT I'd wanna use for a rear drum on a CB1123F "Super-'F" that's just a crazy idea.
But yeah, there's gotta be some room in the CB500/CB550 design.
I guess ONE thing to consider, is that if you've got to replace the CB550 rear drum but you don't wanna grab new spokes & rim etc (I think like - ANY excuse to swap to Aluminum rims is a good one - twist my rubber arm! Alloy rims have gotta be the smartest of all possible performance upgrades!) Well one possibility is that the original CB500 and some early 550 drum have the thinner material in the center core, that they're supposedly ever so slightly LIGHTER than the later version. So I figure THAT would be one good reason to replace the hub with another used eBay hub! Paired with a few other mods it could be made really light, plus push a whole bunch of air through the thing.
A really cool part I wanna use on the KZ, but which would only fit properly with the smaller diameter 36-hole hub, is the belt pulley carrier from the later water-cooled KZ454LTD - it's a belt-pulley center body (ie sprocket) cast integral to the sprocket carrier itself. The pulley is simply a steel ring bolted to it's circumference. HUGE weight savings there. Even over the 60-tooth pulley with the alloy center carrier (which is a huge savings over the one-piece cast steel pulley) But what's REALLY cool about it is how the whole center section is like an empty pocket with big ribs inside. Like a hub with the cush-drive removed. What I wanna do with the thing, is drill holes in it such that the whole structure works as a huge air extraction vane, pulling air from out of the drum on the other side of the wheel! Now THAT would be awesome for a drum with a nice big air scoop on it. Instead of exiting via the back end of the plate in the typical through and through air flow pattern of a normal ventilated modded drum - it would go from one side of the bike all the way to the other. I've modded one of these two 4LS center hubs, well I'll get around to doing the other later on, as it's plenty of hassle - with little ducts cut in the CENTER of the hub. Not from one drum to the other, but out through the space between the spoke flanges, at the outer circumference of the drums. I opened 'em up like half-moons on the inside, but the better designs like the Yamaha 260mm 4LS drum or the Guzzi 220mm 2LS drums, they have just a flat opening, such that all of the air is drawn only from that area just across the skin of the drum linings themselves. Emphasizing where the air is coming FROM, over how much air is moving overall. Maybe I'll try that on the other center hub.
There's some really neat stuff I've been reading about cross-drilling drum linings. It's mostly done on vintage automotive HOT-ROD drum brakes, of the NON-"Al-Fin" types for the most part - but the same principal applies nevertheless. I'm thinking that this should be tried on a REAR drum if at all, 'cause a front drum could really screw things up for a front hub! I picture just a very few pin-diameter holes. The entire purpose of which would be for WATER exfiltration more so than air. And they'd give some bite too, supposedly. At least, the old Hot-Rod dudes report that they're equivalent improvement to upgrading to a rear DISC system, that's how much more bite they had!
I dunno though - maybe I've gotta rebuild the fire-damaged KZ440, build a 2nd copy of this project. I'd need to rebuild the motor, but yeah. Extra rims, etra 4LS center hub, extra NOS belt-drive - I wouldn't need to do THAT much more shopping ha-ha. It's either that, or I give the 900 to the kid and keep the 440 for my SELF - she's already suggested it. Ha-ha.
'Cause when you TRY a mod like that, the life you risk should really be your OWN. Bad enough, the mods I've already done! 'Nuff said.
Repairing/modifying the damaged hub would be expensive, and a hassle - but the end product could be far superior and long-lasting compared to a replacement 500 hub. PLUS it would add weight to the hub. Whereas the replacement 500 hub is still a hassle, having to rebuild the entire wheel. But it would save some weight.
Now - as for purchasing an entire separate WHEEL, I've bought whole wheels for my initial version of my own wheel swap - only to find that the same size of given TIRE of a bike model doesn't equate to the same widths of RIM - I was disappointed to find that both the GL1000 front and the KZ750B rear rims were narrower than the stock Comstars on my '82 CB750F - whereupon I set about figuring out how to swap the Comstar rims over to the new hubs. Drill 'em out and lace 'em. Would actually be kinda neat looking. Actually, the Comstar rims would be cool for a larger rim on wire-spoke wheels which have the nipples in the hub. Trying to think of which models I'm thinking of. One of the Honda REBEL V-twins IIRC. An XL250R or something like that. Drum hubs on 'em, but yeah they'd make for some REALLY cool tube-less wire wheels on the likes of a CB550 heck I didn't even think of that ha-ha. The 2.50x18" rear Comstar outer rim, usually saved for a FRONT wheel widened from a CB400T or CM400 front Comstar, normally 1.85x18" or 2.15x18" - for a replica RCB style front wheel, basically a CB750F2 style non-reverse Comstar but with 2.50x18" just like the GL1100A or CB1100F/CB1100R etc. Meanwhile the REAR wheel is widened by a weld-up method, though I'D suggest using an Akront "Nervi" rim if the blades would hold tight to it, and use a rear wheel with a smaller drum hub replaced with a block of billet rather than the enormous boat anchor of a standard CB900F rear disc hub - Rebuilt Comstars are AWESOME. It would be cool to use 2.50x18" & 3.00X18" Boomerangs re-riveted to the hubs & blades of an XBR500 now THAT would be a crazy wheel set for a smaller SOHC-four. I wouldn't stuff 'em full of the widest possible tires though, I'd rather keep the same tires on 'em but keep the side-walls straighter. They'd still be Comstar rims, but they'd be a lot lighter than standard Comstars at least. Of course the best of all possible Comstars would be build from two identical FRONT wheels in 18", preferably still with the wider rear rim - I guess even a 2.15x18" & 2.50x18" pair is pretty damn good for a smaller SOHC where 1.60x18" & 1.85x18" sizes are normally used. Of course wire-spoke wheels achieve all this and a lot more besides, which is why I'm going with wire-spokes on my "CB900K0 Bol Bomber", well that AND their importance to the whole, '65 CB450K0 Black Bomber "homage".
ANYWAY what I was gonna say about shipping whole WHEELS from eBay purchases, I've come to see that as "spending good money after bad" - whereas the hubs themselves are an essential component, the used spokes and crusty old steel rims don't JUSTIFY all of those shipping expenses!!! Hubs can fit into flat-rate boxes. I've shipped 'em across the Canada/US border for twenty bucks - which is saying a LOT compared to shipping whole wheels. If you're gonna spend ridiculous $$$ on this stuff spend it SMART.
One thing I've figured out, which hasn't always saved me any $$$ due to the ridiculous odd-ball rims I've sought out, but HAS at times been ridiculously cheap - is seeking out USED alloy rims from eBay. IF you can find 'em solo, or get the seller to cut the spokes. They don't have to fit EXACTLY, as Buchanan's can modify the spoke holes to suit Within reason. The wheel in my avatar, the 4LS drum in the fat 3.00x16" Borrani, was a rather special set of spokes, and I did have to pay the "loose lace" fee just to ensure that it would be possible to assemble the wheel given the short spokes and tight space. But yeah, the NORMAL wheel sizes can be done with nothing but the regular rim re-drilling fee. They charged ME twenty bucks to do it on this wheel. Yeah, they're special spokes, yeah there were ancillary fees due to it being an odd-ball wheel. But a $20 re-drilling fee could apply to some of the really cool Akront rims out there sitting on late '70s early '80s Competition Motorcross wheels, rendering a period-correct high-performance race spec wheel-set based around CB550 hubs.
Speaking of the MX hubs though, some of those old conical Husquevarna hubs, or other European competition spec MX-ers - some of 'em had MAGNESIUM HUBS - and seeing as few of these bikes seem to be getting fixed up, compared to the Honda SOHC fours, it leaves a lot of very nice MX wheels for decent prices. Just a regular search for Akront shows the tip of the iceberg of what's available out there. A 2.50x18" rear rim with a Magnesium hub and 2LS actuation - some of 'em would be awesome on a CB550.
But if a person were to build their own cush-drive, and were looking for a "front hub trick" type rear disc conversion, I've got a very odd hub that I bought quite by accident. I thought it was gonna be a TZ750 or even RD250 rear disc hub, but it turned out to be something like a TZ125 late model or far more likely Honda MT125 rear hub. It's got it's disc, and I've got pics of it when it was still in it's rim. Bit of a goof up purchase. I'd keep it for a C70 Passport or S90 type of rebuild some day, but in truth I'm far more interested in over-sized DRUM brakes than I am in disc conversions. However it does occur to me what an ideal hub it would be for a triple disc mod on a smaller SOHC four. Though, if and when I get around to building one, MY version of a SOHC bike would be a smaller model with a CA72 Dream leading-link fork and 4LS drum hub, or something similar. I guess I could visualize a high performance 650 or even 750 SOHC café, but my tastes run far more toward the DOHC end of the spectrum and even the next 750 I'm planning I wanna stick drums on THAT thing too.
(((My membership here is predicated upon the PARTS of my bike which come from the earlier models!)))
But yeah, this lil' MT125 rear disc would hardly be sufficient for a bigger SOHC - I picture it on a CB350K twin or CB350F SOHC-four TOPS. It's a very compact hub and disc. 36-spoke, decent flanges but asymmetrical and thus not suited for a front wheel. It's a four-bolt pattern sprocket (which I've got a specimen of, and it's appropriate for a 125cc machine, seems identical to C70 Passport stuff) So I could see a four-bolt sprocket from the SOHC bikes adapting to it. Especially with one of the three-plate and grommet type DIY cush-drives. Maybe even a small C70/CUB type hub carved down to just the cush elements and then bolt THAT up. It could wind up being a really cool rear disc swap, but it's by no means as direct a bolt-up swap as say, a Yamaha TDR250 rear wheel. THAT would be far more direct of a swap.
What the heck is so superior about a rear disc brake though? Drum brakes are lighter, simpler, more reliable in the wet, and far lovelier besides. If I wasn't this far into my project, I'd swap back to a drum on my 900. At some point when I get the GL1500 fork & PC800 "hub" cut out for a fake 4LS drum, I think I WILL swap out the rear disc for a 190mm drum. If only because a spoke conversion of a CB550F rear internal disc hub is soooooo damned heavy. For only a 230mm rear disc. Far better to fit up a 276mm disc to the CB750F1 rear hub and fabricate some type of tin-pot SHROUD to make the damn thing look just like the regular drum hub. Far better a Hurst Air-heart style plug-in disc conversion on a regular rear drum, for the cooling fins between the spoke flanges, and a tight shroud over the rotor and under-slung compact caliper - It's doable IMHO given the enormous diameter of the CB750F1 rear hub. The GL1500/PC800 trick, fake 4LS idea revolves around creating a wire hub with as large of an outer diameter as possible. 'Cause there were rotor shrouds, aftermarket items from chromed sheet-metal (tin?) built to fit the GL1000 and GL1100, GL1200, the Yamaha XVZ1200 has the most interesting version of which. Anyway, all of those rotor shrouds could bolt up with a regular SOHC wheel, GL1000 dual-disc etc. It's the CENTER section which is most important to the fake 4LS design. However rotor shrouds on a standard dual-disc front hub would appear something like the vintage Harley dual-drum front end, or the Vincent Black Shadow dual-drum, etc. Still, not quite the same thing. Even so - when it comes to the rear disc hub from the SOHC CB750F1, the diameter is already THERE - the shroud which is needed would be for the hollow "yo-yo" shape of the center hub, a shroud which would be equally welcome on a GL1000 rear wheel, which would also benefit greatly from a dress-up shroud.
Possibly the most beautiful rear hub swap I've seen done was a wire-spoke conversion of a CB900C Custom shaft-drive rear hub - instead of the bolt-up plates method, he put the Comstar hub on a lathe spooled it down to a plug and welded it into a hollowed out CB750K drum. GORGEOUS, to see the rear wheel with the cooling fins between the spokes. This is why pre-1975 CB750K's with the plug-in rear disc conversion with Hurst Air-Heart disc & caliper etc, are so much more beautiful than the CB750F1 - not to mention a lot of their rear-sets mods were far lovelier as well.
Thing is, this weld-up HUB method can be done on ANYTHING. CBR900RR if you wanted to. It's far less welding than a Kosman style Weld-widened RIM and needn't be as accurate besides. The hub conversion is the whole wheel swap once it's laced to spokes there's no need to convert sprocket alignment/chain-line OR the rear disc brake. Obviously the greatest benefit is to the shaft-drive models. I'd love to see it done on a GL1200 or GL1500 - done up as a replica of the sole Bol D'Or endurance racing entry of ANY Goldwing EVER, a '75 GL1000 with Aluminum monocoque frame, in the '76 season. ALSO the same year the DOHC-on-SOHC CB750-based RCB started out, and won the whole show straight through to 1980 - Unfairly many would say, being that Endurance Racing was mostly a PRIVATE TEAMS venture. Honda threw a lot of $$$ at it and swept the deck clean.
Sure that gave us the DOHC models, but IMHO the real tragedy is what all Goldwing development we might have seen, had the GL1000 run Endurance races for the next several years. Maybe an alternative like that, Honda wouldn't have let CRAIG &$%#@*&# VETTER screw with the 'Wing!!! Might've stayed as a sporty model instead of a land-yacht, might have turned into the ST1100/ST1300 Pan European ages before. Bit of a toss up for me, 'cause I love the DOHC and the 'Wing both - perhaps not in equal measure, but it's unfair to have to choose one or the other!
Okay so I've figured out what I'd like to do with all of MY hubs ha-ha. As for the 550 drum well, I still think it's a pretty awesome upgrade part for the SOHC 750 so let's not count it out quite yet!
Most of you guys would probably just replace it with another OEM hub, wouldn't you? Bah. SOOOO much potential in there for a better, lighter, more awesome rear drum. I'd sure be interested in the Magnesium drums from the MX-ers. Or at least, a 2LS plate from one at the bare minimum. If the whole thing were hooked up to an alloy rim in a size I could use (((I'm picturing 2.15x18" front and 2.50x18" Non-shouldered Akront for best weight savings and the closest appearance to stock rims, with standard tire sizes just stood up straighter in the side-walls. Well, maybe ONE size wider?))) it would be a total no-brainer. Well, if the hub were an extreme conical type, with a rather screwy butt-fugly look to one side, maybe I'd feel compelled to fit some type of high pipe on that side - picturing the type with sprocket and drum both on the left, so it would work - Maybe pipes bent up high & tight in the front converging under the seat, maybe a simple 4-2-1 with a high turned-up tip in the rear - Perhaps even some type of number plates back there, or some light hard luggage in a chrome rack? SOMETHING to hide the fugly smaller side of the hub. But you never know, SOME of 'em don't look half bad. It might even be possible to add some type shroud to that side of the wheel which scoops up air and pushes it through the drum. I dunno. OR it might be nice to cut a bunch of ventilation holes in through the back side of the drum hub and make it COOL, like a Brit-Bike hub the legendary "Comical" drum?
Thing is, those particular hubs don't HAVE any cush-drive bits. Just a sprocket bolted around the circumference of the open drum "bell" - no room for one.
But I'm pretty sure there were some decent Magnesium MX rear drums which HAD some small, CB350 class of cush-drive. I'm not sure whether they're on the cheap end of the spectrum, but they do exist.
Either way, it's cool to find a thread with so many pictures explaining what the 550 cush-drive is all about. It's an important element that a lot of folks ignore. Very likely to their own bikes' detriment!
-S.
