Re: 79 CB750K RCB Clone-ish GOT MY RCB FAIRING!!!
Hey, I really like what you're doing. I'm doing something similar on my '82 'F. Goldwing wire front wheel, KZ wire rear wheel, etc etc etc. I've been fiddling around with the idea of what fairing would fit with my other bodywork, and I've decided just to make all of my own bodywork for the bike. So far I've adapted some chrome fenders and old school signals to it, made my own seat pan out of bondo, and I wanna go with fork and shock covers sort of like an old CB350F four, stuff like that. But all home-made.
What I was gonna suggest, was if you're gonna modify the tank, cut it open and bang it into the shape you want. I got myself a set of peening hammers and body dollies for forty bucks at Princess Auto. I've just gotta get the thing welded back together. I used an old rusted, dented up spare tank, and I found that they already have a good half inch of filler on them as stock, well down at the front near the welds they sure do. Also, I found that a few of the really bad crash dents split when I tried to shape them back flat too quickly. But now that they're shaped, they overlap where the cracks were, so they're gonna weld up just fine as soon as I can get my hands on a welder. I figure my MAPP Brazing kit won't be up to the job. Or maybe it's ME that won't be up to it.... Ha ha. Anyway, other than using a fibreglas cover like you'd see on an old Bimota HB2/HB3, (and I personally like the real tank underneath a hell of a lot better anyway) the best way to make the tank look how you want it to is to bang it into shape. You'd be surprised how easy it is with the peening hammers. It's a good way to remove every last vestige of rust in there while you're at it. Ha ha. Of course, by the time it's welded back together you'd better coat it pretty quick nevertheless. I know there are a lot of great fibreglas tanks out there, but I wouldn't use one on the street. Been in too many crashes and seen far too many more to trust the damned cagers not to set me on fire this time! Anyway, for the same kind of money, I've seen a couple of small shops online that will build any tank you want out of alloy, one guy was whipping them up for about five hundred bucks. If I had my druthers. But the stock steel tank isn't a throwaway item just because it's shaped this way and that. The tunnel is already shaped right, though you could theoretically tighten it up in there for more volume ... the top can be stretched and bent into a very pleasing shape. And you've got the K tank, I've had to start with the damned F tank!
My own tank, I've banged the boring flat sides of the F tank a little bit round, smoothed out the ridge on the top, and overall sought out a rounder, more of a "sand-cast" look to the tank. One other thing, is that I've hammered up the rear corner of the tank, this probably took more time than the rest of it, and stretched that back corner into more of a square profile. And the "ears" where the side-covers hook up have been clipped off, and I've tried to make a straight lower edge to the tank, as I've been shooting for that SOHC look to it and I wanna put a chrome trim down there maybe.... I might just grab my other SS tank and do the same with it, being that it doesn't have the big dents to start with, and I won't have to worry about those cracks as a result. But maybe I'll just finish this one. We'll see. Right now I'm focused on putting on some fatter rims, the GL front wheel has an alloy rim, but it's a skinny 19", so I cut out the rear rim from my SS comstar wheel, thinking of using that up front 'cause it's a 2.50" by 18", and I wanna throw a 4.50 out back for a 160/60-18. I've dicked around a lot with making rear-sets and clip-ons for my bike, but will likely go with clubmans on the top clamp which I polished just like yours, and plain bar clamps with relocated fuses. The SS fuse location is ugly as shit.
That blue tank you mocked up at first was a really cool one. Some of the guys doing RCB replicas have gone to the trouble of welding, and in some case simply bolting on, perimeter frame members, and then fitting up modern alloy tanks with the "correct" profile where the underside is angled and all of that.
What else I wanted to suggest about your bike, is that if you look at the stance of a typical RCB, and here's a good place to look at a few great Spencer replicas (I mean, other than the 1100f.net site) where they're doing this kind of thing on a whole other level. I'm sure you've got most of these pics already but I can't view what pics you linked to this thread, so here you go anyway:
http://neu.teamdor.com/index.php?show_1=86,71
On many RCBs they have a much taller clearance, despite the 4-1 pipe underneath, they have almost a dirt-bike stance to them with their tall forks and shocks. Now, I dunno if you wanna go with new shocks out back but it's easy enough to do the PVC insert method which is repeated many times over on the cb1100f.net forum, to raise the stance of the front end. I know a lot of folks like to lower the stance, but if you want that RCB look and you want the bodywork to scream "RCB!" rather than remind people of a weird old British cafe bike, then there are many other elements to look at. Personally, I love wire wheels. But the '79 SS silver comstars are another element of the RCB as well. And with that, you might want to go with a twin disc front end. But then again, the wire wheels look really hot. I've got a pic somewhere of a Bol D'Or classic racing RCB with wire wheels, and it was super cool.
But I envision my own bike, and yours as well, looking more like an interim version between the CR750 and the RCB. Fact is, the typical RCB replicas ignore all of the myriad versions of the bike that were fielded, as there were a few later versions that had a radically different frame. I'm sure that, seeing as you're calling the project "RCB-ish", you don't care about making it perfectly accurate. Which is a healthy attitude. I shudder to think of putting all of that effort into a project such as this without getting creative. Hell, I've mucked around with my engine covers a whole bunch, I'm carving away at everything. Prolly 'cause I don't have everything I need to start putting it all back together just yet, so for the time being I've just kept taking shit apart. Even though I'd already taken the bike down completely. It's like "Well, I'll just cut everything in half then.... Ha ha.
Anyway, yeah. The bodywork looks great on the bike, (and I'm really impressed that you managed to get them, it's "poly 21" right? Heard they're impossible to order through, unless you speak the lingo.) It just seems a bit odd given the bike's stance. Heck, all of it looks weird. It's certainly set me straight about the pipes I wanted. I kept thinking about a 4-4, 'cause I like the look of the old ones. And I hate the pipe-less side of bikes with a 4-1. But when it comes down to it, the 4-1 is where the power AND the weight reduction is at. Maybe a 4-4 with straight pipes or with really small mufflers on them, but the 4-1 is the no brainer replacement for ME. And if I don't like the look, then one of those face second pipes which they used to sell, which were basically smuggling cans, that's the way to go.
I'll definitely be keeping an eye on your project. I love the 'K style frame, I wish I had those little metal tabs on the frame instead of these stupid assed alloy peg brackets. In fact, now that I have my rear-sets I just wanna weld up a tube triangle onto the frame and chuck the things. I've got lot's of spare parts for the 'F, I've got a whole engine in parts here. I've got cam bolts too, yanno. Maybe there's somebody closer to you, but I've got 'em if nobody else does. No three week wait, at least.
I hate that "two to five weeks" bullshit. I still remember when my bubble was first popped so far as that shit goes. I was a pretty trusting kid, and I got a job as a stock-boy for a retail outfit. The orientation speech, where I was told that everybody who wanted anything was told "two to five weeks", their names stuck in a book and then that book was thrown under the counter to wait until enough orders were piled up, or the sales-rep came around, or the annual inventory replenishment was due, crap like that; what a shitty way of doing business. A lot of the time, it made more sense to deal with magazine advertizers than with retail dealers, and cut out the middle-man. After all, they were dealing with the same people themselves. All of that way of doing business made sense once upon a time, when shipping was different. I wonder if we'll return to a similar way of doing business someday when energy isn't cheap enough to ship everybody's little do-dad via air courier.... But once direct sales were available telling people "two to five weeks" became pure bull-shit. Any which way you slice it, I advocate the recycling option whenever possible. Funny, something else I remember from magazine classifieds: "Send SASE to...."
-Sigh.