79 CB750K RCB Clone-ish. On the road.

Re: 79 CB750K RCB Clone-ish GOT MY RCB FAIRING!!!


Welded my good mufflers on to my old pipes. By good, I mean the mufflers weren't disintegrated like my old ones.

I also bit the bullet and cut up my fuel tank to aesthetically stretch it. I wanted to actually stretch the tank, but I know that particular metal work is beyond my skill set right now. I may attempt it later. I need to go to work to cut off the rest of the botto that was too tight to use my grinder.


I was also working on my seat pan (7075 T6) but I cracked it when working it. I may need to find some T4. Also thinking about glassing my seat pan too...
Re: 79 CB750K RCB Clone-ish GOT MY RCB FAIRING!!!

You know, the late 70's/ early 80's CB's are big bikes. They are tall, have a long wheel base and of all the sporty ones out there, they feel like they fit best. After seeing this pic I took, I think my next project should be an old wing.

Re: 79 CB750K RCB Clone-ish GOT MY RCB FAIRING!!!

C'mon, man...at least pump up the tire! You're right, though, you wouldn't fit the Duc.

Fairing looks good.
Re: 79 CB750K RCB Clone-ish GOT MY RCB FAIRING!!!

Who can tell me how much filler I can use after welding this before I have to worry about it falling off?




On second thought, It may be better to move the tank rear and up a little and just add to the front where it wont be seen as much...

Still, if I welded this close to as is with the little extra height and blended the line with filler, what would the thresh hold be for falling off in chunks?
Re: 79 CB750K RCB Clone-ish GOT MY RCB FAIRING!!!

Like plastic body filler? Not much, especially on a tank, they flex and vibrate quite a bit.
You might try leading it, that'll stick better...but it's lead.
Re: 79 CB750K RCB Clone-ish GOT MY RCB FAIRING!!!

Def lead it. Eastwood has this Lead-free Body Solder. Way better for you to work with and apparently does the job just as well.
Re: 79 CB750K RCB Clone-ish GOT MY RCB FAIRING!!!

I'm still playing with the panels for a more natural look that will when parked beside another will make you scratch your head and wonder whats up.

How hard is the eastwood kit to work with?
Re: 79 CB750K RCB Clone-ish GOT MY RCB FAIRING!!!

It looks insanely easy. It gives you the solder, paddles and tinning solution and then a DVD to get you started. From what I gather, leading is really easy to start but difficult to master. I think I would be good with it b/c the only thing I want to do is fill some seams, not rock some sweet hot rodder lines.

Check it out : http://www.eastwood.com/ew-basic-lead-free-body-solder-kit-with-dvd.html
Re: 79 CB750K RCB Clone-ish GOT MY RCB FAIRING!!!

It's not bad at all, I prefer it to bondo. It's easy to apply once you get the basics. The difference between a noob and an experienced guy is the amount of cleanup and finish work. You'll have a fair amount of body filing to do, the kat that's been leading for 30 years will have much less shaping to do. Meh...go to it
Re: 79 CB750K RCB Clone-ish GOT MY RCB FAIRING!!!

ya, exactly. Not to mention he will be a little whacky from playing with lead for the past 30 years ;)
Re: 79 CB750K RCB Clone-ish GOT MY RCB FAIRING!!!

Son of a god damn it! I'm getting to hate living in the middle of freaking no where!


I got my valve shims way the hell back, got all but two of my valves shimmed but had to exchange two valves for ones I needed but lacked. Three weeks for order and shipping in the first place, four to send back and get new again!

I got them last week, installed and while torquing my cam caps I break a bolt! Got it out in one piece but if I cant find my spares from my other engine (don't like that idea much but...) it will be another three weeks to get another bolt with $5 in shipping so I can button up my valve cover!

Tired after two christmas dinners. I might hold the couch from floating away for the rest of the night instead.
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:
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...."

Re: 79 CB750K RCB Clone-ish GOT MY RCB FAIRING!!!


The engine is done!!!!! Lets hope she don't grenade when I fire it up for the first time!

The fairing and tail I widened are from RW Super bike http://www.rw-shop.de/rw/de/index.php?seite=first If they are Poly 21, I don't know. I tried getting Poly 21 first but couldn't get a hold of them and Roman (from RW) was VERY helpful and patient! He speeks/ writes well enough english to get the point across. I did have to send him a labeled picture of that I wanted to be 100% sure he knew what I wanted.

The pipes! you don't need to tell me about the weight savings! These bastards are heavy! That being said, I still love the looks and the balance of each side (Always thought Harleys are weird for having both pipes on the right side... for pedestrians to hear how awesome you are???). 4 to 1, while lighter and better performing just looks like everyone else. Besides good, 4 to 4's are rare as hens teeth, a new set costs over 1k!

As you noticed, its not a dead to rights copy, I wouldn't want that ether. Wheres the fun in tracing a pin up drawing if you cant add your own style (bigger boobs) to it?

I think I've found a point where the skins on the tank need minimal manipulation to fit and look good with use of very little filler and yes, trimming the tab on the skin for the side panel.

Yea, its on a piece of wood to make the rear a little taller, I want to get some shocks about 1" longer if I can. I just prefer a little more aggressive stance.

You think the "originals" are taller?

Soy, can you add a few pics of what you've done?



Re: 79 CB750K RCB Clone-ish. Engine done!

If you haven't followed my build thread, I also have an issue with the dohc stance. This is what I did with mine, ala Pistol's awesome dohc cb750.

Had my machinist modify the pivot area by fitting roller bearings.
Welded up a new shock mount.
Re-powder coat the whole swing arm.


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Re: 79 CB750K RCB Clone-ish. Engine done!

Awesome! The stance looks great! I have a similar mod planned for my swingarm.
Re: 79 CB750K RCB Clone-ish. Engine done!

I have mixed feelings about the pivot mod as it was expensive for a machine shop to do. I just didn't like the idea of a plastic bushing and the reputation of the early dohc's for producing the "death wobble". I have a cb900 swing arm with roller bearings that is almost a bolt on, but my frame was already finished. I would've had to drill out the hole where the pivot bolt goes through and sleeve those points. 20/20 hindsight, eh? Anyway, the new shock mount is a cheap and easy mod. Thanks again to Pistol for doing it first! Sorry I stole his idea, but the ends justify the means. :)
Re: 79 CB750K RCB Clone-ish. Engine done!

I'll call that shock mod a last resort, I am saving up for some Hagons right now that I can hopefully get in the length I want. I'm also in my spare spare time working on a swing arm jig...

What do I have left?

Tank, head lights LED/ Halogen, dash, seat mounted, fairing mounted, seat pan, electronics, GSXR 750 carbs..... Ummmmmmm Gettin down there I guess...
Re: 79 CB750K RCB Clone-ish. Engine done!

You gonna build your own swing arm? Cool! This summer, I plan on taking a welding class (non-certification) at IVY Tech. I so want my own set-up. Anyway, love where your project is going. I've never seen an RCB, race or race rep.

Oh yeah, I've not had any luck finding '86 gixxer carbs, have you? The last set I saw on flea bay had a crazy ass price of $800. Seriously?!? ::)
Re: 79 CB750K RCB Clone-ish. Engine done!

Garage Rat said:
I'll call that shock mod a last resort, I am saving up for some Hagons right now that I can hopefully get in the length I want. I'm also in my spare spare time working on a swing arm jig...

What do I have left?

Tank, head lights LED/ Halogen, dash, seat mounted, fairing mounted, seat pan, electronics, GSXR 750 carbs..... Ummmmmmm Gettin down there I guess...

I got the Hagon's an inch over and they look good. I haven't sorted my front forks yet, so I don't know how much of an effect they had on the stance.
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