Author Topic: Vintage Speed Part Mashup - 1976 CB750F  (Read 15934 times)

Offline slikwilli420

  • Posts: 193
Vintage Speed Part Mashup - 1976 CB750F
« on: Nov 03, 2015, 11:33:59 »
Hi all, I have been documenting my build over on the SOHC 4 Honda forum for the last year and a half or so and had been meaning to post it over here as well. There are a ton of great projects that have high attention to detail and I have really enjoyed lurking over here but its time to post.

I will essentially be posting all the content from there to here so you will get it will seem like a lot at once but its almost 2 years of work.

Offline slikwilli420

  • Posts: 193
Re: Vintage Speed Part Mashup - 1976 CB750F
« Reply #1 on: Nov 03, 2015, 11:36:27 »
I have finally decided it is time to start my project thread. I have been doing a lot of reading on certain topics to get a decent knowledge base before I dive in. I don't have a ton of pics but am really trying to make sure I document everything both for me and for others to reference. There are things I am doing that I don't think have been done before but then again, I have not seen everything quite yet. I have tried to assemble a great collection of vintage speed parts to create something that has a really old school feel. Here is a rundown of my intentions.

1976 Honda CB750F Super Sport
Front end components:
     Betor 35mm forks with Race Tech springs/emulators
     Ceriani-type 17mm axle
     Lester mag wheels
     Thinned and drilled rotors (thanks Godffrey!) assembled with ARP 12pt bolts/nuts
     Betor upper/lower aluminum triple clamps
     AP Lockheed CP2696 calipers bolted to custom brackets with SS brake lines
     Manx-style fiberglass fender with aluminum stays
     Speedhut 10K RPM/140MPH GPS Speedo/Tach combo
     0-100PSI Speedhut oil pressure gauge - signal fed from oil galley hole
     Tomaselli adjustable clipons
     Ceriani style headlight ears
     Stock hand controls
     Rearsets - undecided
     Rickman steel inner tank with fiberglass cover - being converted to oil/gas tank combo
     Rickman tail piece with battery tray underneath
Rear end:
     Dresda-style swingarm (thanks Voxonda!)
     Lester 18" disc rear wheel
     Thinned and drilled rotor (same as fronts)
     Original AP Lockheed CP2195 caliper with custom aluminum mount
     Frame splice kits to remove top rails for head removal
     Gussets at key corners and X bracing over swingarm
     Finish all welds
     Relocate electronics from left side to a cover tucked under seat frame
     Stock oil tank - GONE!
     ??? - Anywhere from stock to totally insane
     CB900 oil cooler with custom plumbing to new oil tank
     Weber 40DCOE sidedraft carbs with custom manifold/linkage/mounts

That is the rough plan for now. This has been an ongoing project for about 10 years and has taken many forms but I think I have the vision and finances to make this happen.

Here are a couple of pics including the bike as it sits now, the oil/gas tank combo, the front brakes, and the Weber manifold.

Offline slikwilli420

  • Posts: 193
Re: Vintage Speed Part Mashup - 1976 CB750F
« Reply #2 on: Nov 03, 2015, 11:37:31 »
I was playing with my new Hobart Handler 190 MIG welder today and got some gussets made up and welded in. I just need to clean up the welds a bit and they will be a done deal. The frame splice kit was basically finished as well.

Offline slikwilli420

  • Posts: 193
Re: Vintage Speed Part Mashup - 1976 CB750F
« Reply #3 on: Nov 03, 2015, 11:39:07 »
I did some additional work on the gas/oil tank combo last night. I wanted something different and this also gave me the opportunity to open up the triangle to lighten the look of the bike. The tank was cut in half and I also removed a 1/2" strip so there is air gap between the two to keep heat transfer at bay. I will probably have some thermal tiles between them as well. The two halves will be be finished up then have tabs of some sort to connect them back together so the cover will fit properly.

The oil tank will be plumbed with -10AN lines feeding through an oil thermostat and to an oil cooler and return on the other side of the tank. The filler cap will also come up through the cover and I will make a gas cap that is similar in style.

A few goodies arrived today, including my Dresda swingarm copy from Voxonda, my SpeedHut gauges (speedo/tach combo and oil pressure), and the linkage kit for my 40DCOE Weber carbs.

Offline slikwilli420

  • Posts: 193
Re: Vintage Speed Part Mashup - 1976 CB750F
« Reply #4 on: Nov 03, 2015, 11:39:52 »
I recieved the Race Tech emulators and springs for the Betor forks I will be using. This was another great learning experience this project has given me. I had never even replaced fork seals before, and now I have done a whole set of forks. They are buttoned up and I have guesstimated on preload spacers based on the RT instructions. Now all that is left is to clean up the lower legs and decide on anodizing/powdercoat/polish/paint.

The rear axle on the new Dresda swing arm is too short and Voxonda suggested the axle from a DOHC 900F model which I found basically NOS on eBay.

I also added a few other things to mix it up a bit. There was an NOS Tommaselli Super Pratic throttle on eBay that needed to be on my bike. I will either just remove the throttle tube and keep the right hand control or find a new control altogether. If I go hydraulic clutch I will have to change both.

As to mounting the Weber carbs, I will have the manifold plate waterjetted this week and then start mounting the linkage. Here is a pic of it mocked up.

Offline slikwilli420

  • Posts: 193
Re: Vintage Speed Part Mashup - 1976 CB750F
« Reply #5 on: Nov 03, 2015, 11:41:22 »
I'm working on relocating the electronics to under the seat. My idea uses the threaded holes already in the frame for the battery/tool tray. The new plate in the pictures will have four posts that will raise the panel up higher under the seat so less is visible in the triangle. I will also make a cover that has perforated/screen/louvers for look and air flow. The reason I mounted them facing down instead of up as others do is so it's easy to access the fuse block in the event of a blown fuse. The battery will go into a tray under the tail hump.

The last thing is adding baffles and the appropriate breather attachments to the oil tank, which I will need some help with. Im thinking 1 or 2 baffles that span across the whole tank vertically separating the feed and return sides and have 6-8 holes around 1" each. As for breathers, I need one for the crank and one for the valve cover.

Offline slikwilli420

  • Posts: 193
Re: Vintage Speed Part Mashup - 1976 CB750F
« Reply #6 on: Nov 03, 2015, 11:43:13 »
For the electrical relocation project, I wanted to share what I came up with. You can see that I wanted to raise the panel as far up as I could without interfering with the seat subframe (Im 6'1" so I need legroom) that will be there shortly so as little of it hangs into the triangle as possible. For a guy who has all of a month of welding skill I think it will look great after some powedercoat and some finish work.

Offline slikwilli420

  • Posts: 193
Re: Vintage Speed Part Mashup - 1976 CB750F
« Reply #7 on: Nov 03, 2015, 11:43:39 »
Just finished getting the manifold plates cut for the Weber's at a local waterjet place. As soon as I can get the spigots machined they will be laser welded on and then the holes tapped for 8mm studs.

Offline slikwilli420

  • Posts: 193
Re: Vintage Speed Part Mashup - 1976 CB750F
« Reply #8 on: Nov 03, 2015, 11:45:23 »
On the rear end, I am still waiting to get the Marzocchi Strada bodies powdercoated, then they can go back together. I picked up a VFR axle in great shape that will work with the wider swingarm. I also have the caliper bracket for the rear that I just got back from the waterjet shop.

The front is coming along well too. The waterjet shop made the brackets for the front calipers in two pieces so I can play with spacing to the rotor. If you find pictures of Dholda CB750 endurance bikes, you will see my inspiration for the front.

Im also working on rearset brackets, which cam from the waterjet as well. These are similar in style to the ones brandEn has on his bike that FunJimmy made. I still need to cut the passenger triangles so they fit flush. I have also picked up some 1045 TGP shaft to make longer bolts for the brackets to bolt to.

Last update is the triple trees. I have been staring at the originals for a while and am really put off by the porosity of the aluminum and I thought that since Im trying my hand at CAD, I would draw some up. The pics are the two designs I like the best.

Offline slikwilli420

  • Posts: 193
Re: Vintage Speed Part Mashup - 1976 CB750F
« Reply #9 on: Nov 03, 2015, 11:47:45 »
The Weber DCOE carbs have finally been mated to the engine! Its been a long road of designing, machining, welding, and fitting to get them to work. I still need to rig up a plate to support them from the top so the boots don’t need to do any work. I picked up Venhill clutch and throttle cable kits so I could build cables to the length I need for my bars. I also need to get some additional hardware for the throttle linkage as well as some nicer stainless clamps for the boots.

Swingarm pivot and lower engine bolts have been made from 1045 TGP shaft, threaded on each end for SS nuts. One end has the nut threaded on then pinned with a roll pin to create a bolt. The additional length will allow me to have plenty of space to mount the rearset brackets correctly and solidly, finished off with Tarrozzi pegs/levers.

Instead of the RC header, Im going to run the Kerker for the time being. I picked up a 2” comp baffle for it off Amazon for $112 shipped which should sound great.

Im going with a 7-row Earl’s cooler. I know there have been complaints but it seems well made to me and Im going to give it a shot. The cooler will be routed through the relocated oil tank that is under the gas tank cover.

I finally have a design for my triple trees that I love, after designing about 15 different iterations. I will have a 1.25” top and 1.5” bottom, tapered bearings and an NOS Ceriani stem, with dampening knob. The only thing that might change is the pinch for the stem, since the Ceriani is notched on the bottom to take a bolt that captures it instead of pinching it. The top will also end up without a pinch and simply be a close fit to the stem.