Building the P38 Racer

[Hannibal Smith]

1974 CB550 going cafe style.

Got to the rear drum today. Programmed two vents on a 2.5" radius to clear the internal webbing and spice up the back end a bit. I will install perforated stainless steel sheet after the drum gets polished.

Machined the vents from the backside and cut a shelf so that the stainless screen sits nice and tight against the outer plate, it will be epoxied once I cut the screen.

Wheel is filthy, but the vents add some "racer" to it.

The machining was straightforward, I just machined a precision pillar that went into a CNC mill, and then secured the plate. I cut from the inside, and the program follows the drum radius, and I also keep the rib in the casting.

Triple clamp and clip-ons are to be machined next.

 

[troybilt]

Real nice! got the 'before' pics of the bike? And what else is planned?

 

[Hannibal Smith]

So, this is how it started...
I was fixing to drive about 80 miles to Pismo Beach California to get a CB750 that was partially dismantled (carbs off etc.) and needed to confirm the phone number on Craigslist...I check Craigslist and there is a CB550 right in town that just got posted, I e-mail in rapid fashion, as my buddy Ian is waiting in the truck for our Pismo trek...

The "Pismo Clam" is how the bike is now referred to, was waiting, but there was a catch- The bike was not titled, and once I got to Pismo, the guy's uncle would take over, and give me a handwritten bill of sale as the bike was from Ohio....I called some local crooks (always nice to know some) and they told me it was possible, but tricky.

So we are pulling out of the drive, and my cell rings.......................the local CB550 is waiting.

Long story short, I buy the bitch ( the local CB550) with 500 dollars American and load her up on the truck. We get back, and I realize that I forgot to get the key! For all you US Military folks, a P38 is the standard can opener, my buddy Ian(also an ex-Army vet) says, "wouldn't it be cool if it started with a P38?" I laughed.

I go back, get the key, and no shit..........................the key is stamped "P38"!!!

 

[BigSherm]

Hell yeah! I carried a P-38 on my dog tag chain for years.

Sherm

 

[ridesolo]

Hell yeah! I carried a P-38 on my dog tag chain for years.

Sherm

Yup, I did, too. Cory

 

[sabres7th]

p38 lol! go navy. ;D nice vents are you gonna weld some wire screen on the inside?

 

[Hannibal Smith]

p38 lol! go navy. ;D nice vents are you gonna weld some wire screen on the inside?

Yes, definitely needs a screen!

 

[overdraft]

ummm...

I will install perforated stainless steel sheet after the drum gets polished.
Machined the vents from the backside and cut a shelf so that the stainless screen sits nice and tight against the outer plate, it will be epoxied once I cut the screen.

 

[sabres7th]

my bad post officer. their is no blood in my alcohol 8)

 

[Hannibal Smith]

Here is the key.

Build vision- The bike will be built as I would build a track bike, lacing wire etc. The lights will be almost an afterthought, for example, the tail light needs to be seperate from the cowl on a bracket, as if I wanted to run my racebike on the street, I would just get a tail light and secure it anyway I can, so the wiring must also be independent with a toggle and seperate fuse etc.

The headlight will be secured via the lower tripleclamp (more than likely) with the wiring seperate as will be the tail light. Most people won't notice. It will be done in a planned and clean fashion, but to the trained eye, will appear that I made some brackets, ran some wires, and slapped lights on my track bike so the cops won't give me shit.

 

[sabres7th]

is that parachute cord? ;D

 

[hurricane7]

Great story Hannibal!

Don't know what you've got planned for the paint, but here's an idea for ya. (I painted this on an old Indian) I know it's not a can opener, but the rear section of a P38 lightning kinda looks like it could be used as a bottle opener. ;-)

 

[laidout]

is that parachute cord? ;D

looks like 550 cord to me!

 

[Hannibal Smith]

Designed and made my triple clamps this weekend. Tried to keep it 70's style without going too nuts with a modern "CNC look". Kept it simple and plausible for the era.
Started with 2 chunks of 6061-T6 aluminum.

Precision bored the 35mm allocations for a perfect fit, when forks fit perfect, you will hear a "hiss" when you slide them in.

Another shot of the process in the mill.

I incorporated fork stops into the lower clam, for a street bike, fork stops are a must if you use a sidestand etc. They will be polished, what you are seeing is the clamps pulled from the tumbler after being machined.

I will machine matching clip-ons this week.

 

[tWistedWheelz]

^ If this work is any indicator of how the entire build will be, this could be one of the best builds I have seen. Great work!

 

[BCBarker]

Who has two thumbs and is completely jealous of the triple clamps??? THIS KID!

 

[Hannibal Smith]

Stainless screen now is in the cooling vents, I also machined a brake torque arm.

Ground off all the brake bosses on the right fork, as I will just be using a single front disc, these will be polished when done.

 

[Skyeye]

Hannibal,

Very cool stuff. Would you mind showing us the back side of the brake cover to see how you fastened the screens? Please?

Scott

 

[JRK5892]

very cool! you made those trees with a mill! wow man you have more patience than me... that is CNC work righ there! nice work bud very nice!!!

 

[dcmspikes]

some great work going on here. i was going to do vents in my hubs then i decided against it. after seeing yours with screens i might just do it after all. when you made your triples, did you use the same spacing as the original trees? im referring to the space between the forks and the relation of the steering stem. one of my next steps is machining triples and was thinking of pulling the forks closer to the steering stem a little.