1974 CB750 Built from Parts w CBR600 Front & Rear

[Frankenfe]

More pics...Odds & Ends...

*Rear Master Cylinder Mount, Notice the Alloy Cap, Turns out a stock Early CB750 Cap from front Master Cylinder, fit the CBR600 Rear Resrvoir. I will probably cut a band of aluminum and wrap the reservoir as well.

*New Fork Stops (CB750 use one in front center, CBR600 uses one on each side)

 

[surffly]

im thinking about running F2, mechanical speedo, set up on an F i have.
Any pictures of how the brake stay set up with the DOHC swinger?

Ive been reading alot of the DOHC guys swap these wheels but only seen a few on the SOHC bikes

 

[Frankenfe]

I havent worked out the caliper stay yet, I dont see it as a big problem, just close to everything and want proper clearance. Regarding a speedo If I really need one I will design a mount for top of the upper triple tree to hold my smart phone and run one of the 2 free GPS Based Speedo apps I have on my phone. I tested in my car and amazingly accurate.

im thinking about running F2, mechanical speedo, set up on an F i have.
Any pictures of how the brake stay set up with the DOHC swinger?

Ive been reading alot of the DOHC guys swap these wheels but only seen a few on the SOHC bikes

 

[zimm]

nice work in the oil tank cool build

 

[Frankenfe]

I was trying to figuire out what to do with the ignition switch hole in the upper triple. I did not an ignition in the triple and had mounted the ignition switch and a starter button in one of under seat trays, easily accessed with my left hand. I decided cutting it the excess of the hole off and smoothing would have looked stupid and been a poor decision structuraly. One of those Nice Billet Triples is not in my budget.

That left me with what to do with the hole in the upper triple. It begged for a starter button. So I made a custom fit piece to mount a starter button only in hole. I Cut and ground it out of 1/4" aluminum, the same material I made the gauge trim ring out of. It is in ruogh form in these pics and needs a little more fitting, finishing and polishing. I also need to figuire out a way to mount it.....then what do I do with the starter button below the seat ? .. 2 starter Buttons?

 

[Tim]

Looks great! I'm going to have the same decision on my GSXR tree (going on my XS650). No starter button on my bike so maybe one of those hula-dancer girls people put on their dashboards

 

[Frankenfe]

I'm going to have the same decision ...... No starter button on my bike so maybe one of those hula-dancer girls people put on their dashboards

Or a plastic Jesus

 

[Frankenfe]

Well I was talking with my son about the build, he said it was a like a big puzzle that I was making the pieces fit together for, I think a name was born....Jigsaw

 

[dcmspikes]

signed up. this is cool. why not one of the idiot lights in the ignition hole in the triple? or your smart phone mount?

 

[Frankenfe]

signed up. this is cool. why not one of the idiot lights in the ignition hole in the triple? or your smart phone mount?

Spikes, I thought about both things, But.....
I probably will only be using one idiot light, a blue one for High Beam, It is currently mounted in the Headlight where I will also mount a rotary On/Off/On switch with a Chicken Head knob for the lights. I may use a second green one for Neutral, if I do it will probably be mounted in an aluminum "saddle" shaped piece I plan to make to bridge/cover the gap between the stem and the tank tunnel. I have more frame exposed there than I would like, due to moving the tank back to provide clearance between the tank and the fork tubes (the CBR600 Forks have much less "offset"?).

As far as the Smart Phone holder, it is not something I will use alot, and don't want the upper triple looking like something is missing or remnants of a high tech holder when removed and parked.

But thanks for throwing suggestions out there.

 

[Frankenfe]

I mentioned before I bought (I kid you not) a $100 Truck load of parts, among the more notables..

a Chopper Frame, I gave to my buddy to help me unload the truck.
2 Crap engines, I gutted one & made a much lighter weight "Mock Up" engine.
A Smoked Plastic Points Cover
An Oil Preassure Gauge Adapter
A 1975 CB750F0 missing the rear tire tank seat bars....

The '75 Super Sport yielded me an engine and alot of Bolts & Nuts I needed including Engine Mount Brackets.

Here is the engine cleaned up and mounted with the bits I have picked up, the Oil Cooler Adapter, The Oil Preasure Gauge Adapter (with new Gauge I got) and Smoked Points Cover. Not sure about using the Smoked Cover, I saw a cast "Honda" Logo'd Points cover for SOHC on ebay but too much $. Sure was nice having it on the stand and able to rotate.

I do have to sort out something in the engine mecahanically, I hope not so serious I need to split the case. This sure would make a great donor engine - Perfect Fins, Solid Mounts, Didn't appear to have any leaks, so clean up was relatively easy. I also understand that these F engines had a slightly greater offset to the engine sprocket, that will help my eventual Sprockets / Chain alignment need.

 

[Frankenfe]

I also saved a Shifter Cover from one of the crap engines and cut it away like on a CR, may just have as an option to use without the sprocket cover. (Seen laying at rear of engine in pic above).

 

[kevweez]

really cool build. The oil tank gas tank execution was fantastic. I like the CBR front end. I was thinking of doing something similar, probably later down the road.

 

[Frankenfe]

So I have had the enginee on a stand cleaned up for awhile now and decided to start digging into thr "issue" with it. It is not "Frozen" but can only be turned 540 dgrees (1 &1/2 Rotations) and locks either direction. I know something is up with the kick start because it does not seem to operate properly. I pulled the valve cover off and things look relatively good in there, no real sludge a little browning from running to long between oil changes I suspect.

Checked TDC to confirm had not skipped a tooth on the cam but looks like it lines up. So next is to dig into the kicker.. I have pretty much assumed that it is going to take splitting of the case to repair (Best Guess - Kick Start Sprocket) (Hope - kick return spring jamming things up).

 

[Frankenfe]

I spend alot of time just staring at the bike which results in changing probably 30% of what I originally have made. Sometimes I go througj multiple changes bepre ariving at what I like.

That said I am not "feeling" the Front Fender. So Ihave started a poll. I am think about cutting the fender even further, down to it's simple fender shape without any verticle components. I would also slightly rotate it back in the it's position. Very Crude Pic below to give you an idea.

No Fender
Cut Down Further Fender & Roll Back
As Is

 

[dcmspikes]

i think the smaller fender looks good cut back with no verticals. the vertical components give it a more modern look to it. not sure what else you will have going on. to me its a choice between modern or classic.

 

[Bozz]

Something to consider for your fender is a virago fender. (circa 1985)


I snagged one at a junkyard and plan to use it on my KZ900 with a more modern front end.


What makes it work for me is that it is designed to mount to a fork brace and not the fork leg.


So you can mount a chrome, vintage looking fender to a modern front end simply by modifying a fork brace.


And if you can't find a brace for your front end, they are pretty simple to make...

 

[Frankenfe]

i think the smaller fender looks good cut back with no verticals. the vertical components give it a more modern look to it. not sure what else you will have going on. to me its a choice between modern or classic.

I agree with ..Verticle / Modern - Cut / Classic. Since I am going for a more Simple & classic look probably gonna cut the fender down further. Damnit, all that time wasted making brackets.

 

[Frankenfe]

Something to consider for your fender is a virago fender. (circa 1985)

I snagged one at a junkyard and plan to use it on my KZ900 with a more modern front end.


What makes it work for me is that it is designed to mount to a fork brace and not the fork leg.


So you can mount a chrome, vintage looking fender to a modern front end simply by modifying a fork brace.


And if you can't find a brace for your front end, they are pretty simple to make...

The problem I found using a more Vintage / Chrome type fender is the wheel size Since Most Vintage bikes had 18" or 19" front fenders there is an issue. IMO, unless the fender was designed for a 17" wheel the arc is off and looks funny, So a simple fender designed for a 17" wheel is what I need. It may work cutting down a vintage fender to the point the difference in arc isn't noticable. I will look into the Virago fender too.

Since every fender is designed for the specific mounts on the lower tube, just about everything requires custom brackets I have no problem doing that. If I cu it down, I may do very simple rod type stays / brackets

 

[bluesmoke69]

Great work on the bike. I have have a 1997 cbr front end in my basement doing the same thing. I am going to run a waterproof gps for my speedo. Keep up the great work.