project carbon cb

so this originally was going to be a modern spin on a cafe bike, but as I do my research my vision of it has changed, itll prolly fall into the streetfighter catagory now, but only in some peoples points of view. everything still swathed in lots of carbon, still a steel cradled air cooled 1975 736 but im swapping in a single sided swingarm and going the modern route. my plan is to create a bike that the untrained eye will think is a brand new factory special. im dulling down the paint scheme to reflect a more muted factory choice, and reworking the intended graffic to look more factory as well. this will probably drag the build out longer, but if youre building it to be something special it shouldnt be rushed.

Sounds like a great project! What bike are you starting off with I'm a little confused. I assume it is a 4cylinder 4stroke of some description.

sorry, didnt factor in this being a new thread. Its a 75 cb 750 that was given to me by my little brother. It had been leaning against a barn for many many years. i ran a thread for it in the cafe build section for a while.
Stock forks with lowers wrapped in carbon, triple tree top carbon as well.
modern milled aluminum clipons with modern controls.
no guages (heads up in helmet)
hid headlight in handmade shroud (carbon...duh)
handmade tank and seat (to look like a ducati 1098, obviously)
single sided swingarm with 17 inch mags and modern brakes
carbon side covers and valve covers
kick only (maybe, i am getting a little old for kickstart....i may get lazy)
oil tank hidden in the seat (or tank, havent decided)
many small trick one off parts, like an auto style turn signal switch setup with flash time modulator, concealed idiot lights and switches, remote on (no key) with an angel eyes halo to indicate an one condition. through swingarm underseat stainless exhaust, front fender from a cbrr with rear fender tire hugger mounted to the swinger, thinking about a neon tail light.....with everything left bare carbon, bare aluminum or powdered maybe a slate or steel gray. I know its a huge project with me doing almost every part, and most of which Ive never done before but I do love a challenge and dont mind the time.
I do mind the dollars though thats what will take me at least a year.
I am looking for parts. I need nt650 (hawk gt) parts, swingarm, wheels, brakes......if anyone happens to have them just laying around.

im hoping to get in to some carbon stuff soon. any worries about gas, oil, or electrical current when working with these parts. im thinking valve covers (oil) carb covers (gas) ignition cover (electrical)
also, what about the bolt holes in covers? do you cast them solid and drill them out for the bolt to pass through? should you add a sleeve in them to take the load of the tightened bolt? can it be threaded? if you make a 1/8" thick panel can it be easily cut with a bandsaw?

cant wait to see some progress on this

a lot of the parts will be simply wrapped in carbon, ill cut away as much mass as i can, leaving the bearing surfaces such as bolt holes and such in place, fill the cuttaways with foam for structure, wrap in carbon then remove the foam structures. this will give me the appearance of a carbon part, the strength and tollerances of the factory covers with only a negligable weight gain. the tank, seat, side panels and heel plates will be custom molded from kevlar with carbon fiber as the last two layers.

the tank and seat i plan to do in the same way that the gulf oil 550 was done (the stunning lemans special) utilizing the belly of the pan with a foam mold. that bike is one of my inspirations. loved the gulf oil paint scheme and the vintage racer look.....but he did such an amazing job that I would just be doing a poor copy so im going a whole different route instead

I may end up lining the oil contact parts with tank liner if it comes to that, as i will the tank. this swingarm oil tank will solve a few placement problems (i originally was going to reduce the fuel capacity and put the oil tank in the gas tank, or the seat. but I have a lot of electronics, the main electrical, starter soleniod, brain etc, then a reciever for the remote on, the brakelight modulator and turn signal timer, the starters for the hid headlight, the transmitter for the heads up helmet etc......so i need the seat for that, and hate pulling over every 50 miles for gas......so woohoo for fortuitous accidental design changes. im still debating wrapping the swingarm in carbon like everything else or leaving it cast aluminum with the elf tag in place.......im swaying towards bare at this point.

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Looks like an ambitious and fun project. Can't wait to see what you come up with, and thanks for the props mate!

As far as chemical resistance, if you use an epoxy resin, I believe the only worry you'll have is with ethanol. And the use of Caswell liner will take care of that. Oil should be no problem for epoxy resin. I'm making a carbon belly pan for the gulf and anticipate a little oil leakage on it. No biggie.

from what ive seen as for bolt holes if you are casting a part yourself i personally would cast a sleeve in place to take the crush load, and if you leave it extra long you can use the sleeves as clamp points for secondary work then trim to final when everything else is done. cast carbon can be easily cut with bandsaw, leave it a little proud then trim down with a dremel or grinder to avoid splintering, all of which should be done before the final coat of resin or clearcoat.

are you thinking of making a negative mold and casting? or a lostmold style with a foam mold, laying the fabric, then mechanically of chemically removing the mold?

hey ringo....absolutely love that lemans special, well done. ill be doing a belly pan as well, be sure and take many photos so us lowly beginners can see how its done. I was thinking of just putting the completed bike, with exhaust up on the bench and making the lost mold foam right on the bike, so that I can be sure to leave ample clearance for the pipes. are you going to wrap the headpipes to keep the heat down until its past the pan?

Hey I'm right there with you man. This was basically my first foray too. As for the pipes, I don't think I'll wrap them. I should have at a bare minimum 1/4" clearance between the pipes and any composite part, probably more like 1/2". If MotoGP bikes can have less clearance between even hotter pipes and carbon, I (we) should be ok I'd think.

ill be making my exhaust from stainless at some increased expense and hassle and reeeealy dont want to wrap them up. im all hyped up to get back in the shop and get some work done.....unfortunatelly we have two birthdays within a few weeks of christmas so im broker than broke...and chomping at the bit to get back to it. im at a point where i can do very little without more parts. and its killing me!

Ill try to get some pics up soon

im planning on making negative molds and casting. then hopefully vacuum bagging the parts. might have to drill some holes for pins to set up the sleeves for the bolts. great tip on leaving the last clear coat after everything is shaped/ground. thanks for info. really looking forward to seeing what you do.

so i was planning to get the shop straightened up and the frame bolted to the bench for some frame mod work, but ya see I was making stew for my dogs, and the damn potato and my thumb seemed to share the same time and space (they told me that wasnt possible in physics....they lied) so I tried to cut off the last quarter inch or so....but the pesky bone got in the way about halfway through...a few stitches and some medical grade superglue later Im all better.....I wish they would listen when I tell them Im immune to lidocain....ITS IN MY MEDICAL RECORDS PEOPLE! but instead they did what they always do....try try again, stab! oh you can feel that? thats wierd, six more shot later...stab, oh you can feel that thats wierd....six more shots..........so probably not to much getting done this weekend but ill try a little......the only part that hurts is the joint they did the nerve block injections on (twice) until i hit it on something....so work will be slow for a week or two..

got the bitch strapped to the bench this weekend, did some mockup work on the front end. I originally was going to have to replace the fork tubes due to the normal cb rust issues but since I have decidded to run the clipons in a comfortable ribing position ie on top of the triple tree it actually conceals ALL the rust....175 bucks saved right there! (ill probably still replace them....cuz im an obsesive jackass but its a nice thought) so, air shock setup and all will look nice with the machines clipons and new controls...still dont want any guages up there tho so im going to relocate that airshock guage somewhere else. has anyone used the oil line plate and hoses from summers? they look decent and would give me what I need to relocate the oil tank to the swingarm.

so, when locating the rear shock mount bracket what is the best way to find the proper location?. I dont want to have to relocate the thing three times to get it right. and I dont want to have to track down the doner bike and measure the shock compression with 250 pounds on it.....any suggestions?

i was doing some research...im a mental designer you know. and stumbled across some info that would be waaaay cool on a show bike, i wont do it on this one, but cool to design and consider for the future. so I was already planning a simple heads up display for speed and with my idiot lights mounted just out of my optical field (when it lights youll see it by reflection.....the low oil light only) but its possible to do way more, voice activated turn signals being the coolest. helmet mounted (and hidden) brake light...turn signals. all you guages displayed "floating" in your optical field.....so much stuff you could do to "wire" your helmet using a cable or even bluetooth.......i think i am going to do the voice activated signals some day tho. you could even "secure bluetooth" the starter button (with a controller that would read neutral and engine condition) to a voice control, although i would hide an "enable" button on the helmet. how cool would it be at a show to walk up to your bike and tell it to start?

Have you ever noticed how, when youre looking for something on egay you cant find any good ones, then when you change your mind they come out of the woodwork?. Im doing a monoshock rear now. when I looked i couldnt find any cheap remote res oem rear shocks....there are hundreds now. is it just me?

Im seriously thinking about welding up an alloy fuel tank, oil tank and seat cowl. then sculpting the covers around then. The covers would be removable. If i dont like how it comes out....or lay it down. I redo them. no real metal forming needed it doesnt have to be curvy...itll be covered. has anyone done this? part of the reason is I need to use a negative mold for the carbon fiber....to get the surface I want it has to be vacuum bagged to a negative. I could over lay it...then overcoat and polish but I like the thin glass finish that comes from a negative bag.....

Creating a cover for an alloy tank is actually a fairly common practice. Great way to not worry too much about that precious composite work.