1981 CB750K Project Superleggera

generalyen said:

Put the race in the freezer over night and quickly install it the next morning.

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That's what we did. The lower race went in without issue. The replacement bearing was supposed to be here yesterday but was never delivered. So at least I get my money back for the worthless overnight shipping. I've got some dry ice waiting for the upper race, if it hasn't all sublimated yet. Gonna really get that sucker cold.

Since the bearing didn't come in all I managed yesterday was the start of a rudimentary pin out guide for mating the R6 controls with the CB harness. This morning I'm trying to decide on a color combo and decide what connectors I want to go with when I re-build the harness from scratch.

Well boys and girls USPS finally got their heads out of their...you know.

The replacement bearing arrived!

I plopped the race immediately into the dry ice I bought for this occasion a couple days ago. Thankfully enough survived.


After some smacking with a punch, she was seated! I lubed the bearings and installed the lower triple! Progress!


With the assistance of my roommate I was able to slide the forks into the trees without flipping the bike off the center stand.


Then it was a simple matter of sorting out the clipons and doing some temporary wiring for the controls (which will be readdressed at a later date when the entire harness gets a makeover). Slap the wheel on and we're good to go.


After wiring the ignition, starter and brake lights I slapped the tank and seat back on and took her for a shakedown.


Nothing fell off! And holy crap the brakes were 10,000 times better. I can lock the front tire with two fingers now, I couldn't do that with two hands on the original setup. Also my low speed turning radius is severely decreased. As I Austin Powers'd my way out of my driveway I saw in a new light the draw of tank dents on bikes with clipons.

Tomorrow will be a lot more wiring and a couple more test runs to see if I remembered to tighten all the important bits.

As a note, is there a quick and easy way to shorten the kickstand? On the old setup she barely leaned, and with the lowered front the side stand is basically useless. I meant to take a look at it tonight but it's still 82 degrees out and I sought the AC instead.

are you sure the front tyre is backwards? I mean, you should for an indicator arrow on the sidewalls instead of looking at the pattern of the thread. Because the direction of the pattern seems okay.
(The pattern at the front is made for braking, while the pattern at the back is made for acceleration)

Yeah I mounted the wheel with the directional arrow pointing the proper way and the brakes didn't fit. It's a very small offset on the R6, but it's definitely noticeable when you're trying to bolt stuff back on.

omgwtfbbq! said:

Yeah I mounted the wheel with the directional arrow pointing the proper way and the brakes didn't fit. It's a very small offset on the R6, but it's definitely noticeable when you're trying to bolt stuff back on.

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strange, always thought those dual disc front wheels were symmetrical.
Good to know for following projects

I was also under that impression, I don't see any real reason why the wheel would be asymmetric, except the spoke design.

Tiny updates:

Rear suspension is at the lowest setting, still getting the nasty decel headshake. Gonna wait on the rear suspension and new rubber before taking further steps to correct this issue.

I mentioned earlier that I cobbled together the stock throttle cables, but it was atrocious. Today I got in a motion pro cable set, OE length for the 2009 Yamaha R6 donor bike. It fits. BARELY. Well, half fits. The pull cable is on, obviously. It's adjusted all the way out and it is barely long enough. I had to adjust the mount of the throttle assembly to get it to fit, which meant a quick hole drilled in the clipon for positioning.



The push cable...

The push cable isn't long enough. So that's a minor issue. But my thought process is if the throttles hang open and I fail to either pull the clutch in or hit the kill switch, that's a failure on my part. I ain't gonna go blaming Tesla for crashing me into a wall.

On a better note my LEDs are due to arrive tomorrow, so the bike will again be road legal soon. I apologize in advance if anyone on the board ends up on the wrong end of my high beams (unless you're driving with your high beams on, then it was on purpose). 8)

Got bored last night and tried again to get the horn to work. I don't know why it doesn't. If I run 12V directly to the horn and ground the other lead it works just fine. But from what I can see none of the switch logic in the R6 control accomplishes this. I may have to pull the wire wrap and see if something is broken between the switch and the horn. Though that's only an 8" run and it seems on that everything else works fine on that side (clutch switch, headlight switch, blinkers).

Anyway, while troubleshooting I misidentified a wire and shorted the horn power to ground. I've blown my share of fuses, but I've never blown one in half before. Thankfully Honda provided a spare.

Those throttle cables are way too short - they need to go around the fork leg and out beside the headlight. Otherwise, they will kink up when you steer to full lock on the right.

hillsy said:

Those throttle cables are way too short - they need to go around the fork leg and out beside the headlight. Otherwise, they will kink up when you steer to full lock on the right.

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This will be an issue when I change the tank profile and actually get some steering back. Unfortunately no one $&^@ing lists the lengths of the cables anywhere so I had no idea how long these were till they showed up at my door. For future reference, 2009 Yamaha R6 throttle cables are just about 24" long. The OE cables were over 36" long. When I was using those they stuck out from the front of the bike rather comically, the clipon throttle being much closer to the steering head than the OE control was.

For now though, my steering angle is so severely limited by the clipons hitting the tank that the cables don't kink at all in this configuration. I'm gonna be talking to my parts guys next week about longer alternatives. Thankfully cables are cheap and easy to change. I haven't done any real riding yet anyway, since my headlights don't come in till this afternoon and I don't yet have a mounting solution for them finalized. For little shakedown runs through the neighborhood this setup is working well.

You can use bicycle brake cables for MC throttles if you can either solder / buy screw on ends. Keep all the hardware off the R6 cables and just replace the sheathing / inner cable and cut them to whatever length you need.

I've done custom cables on other applications and they're a pain. Mainly because I lack the equipment to do proper soldering. If I can't find an easy OE set that works I'll probably go that route though.

A lot of auto shops will have the screw on cable ends which makes it a lot easier to make up custom cables.

I don't like the screw on ends. They destroy the cable and have a habit of coming off in my experience.

I agree - I solder all mine.


However, my brother used one on the carb end of the throttle cable on his z1300 (which I now have) and it was on there for quite a few years without any issues. I've soldered on another end now, though....

Also not a fan of screw on bits

I also solder them.
I make the end piece out of the part of steel screws where there is no thread. I use the saw to cut of the desired length, drill a hole, and chamfer the hole at one end. (the end where you will cut of the cable).
When you pull the cable through the self fabricated peice, disentwine the cable.
The solder, and grind off the excess wires.
(Attached a small drawing if I couldn't make myself clear )

I also stopped using the soldering iron to solder the parts. The soldering iron seemed to have a too low heat output to proper melt the solder in between the cable string.
I use the oxy-acy burner on his lowest possible heat output, and heat the parts with that. I guess it's perfectly feasible to use a small propane torch.

I use this: Lee Precision Melter (Grey) https://www.amazon.com/dp/B00162UONY/ref=cm_sw_r_cp_api_hADxxbZX4RR71

To make all my cables, along with a 50/50 lead/tin bar. I preheat the ferrule and cable end after fluxing on the top of the pot. You will want to use the lowest temp possible that the solder flows to avoid overheating and damaging the cable. One the flux has burnt off, I submerge the cable end upside down into the pot. Super simple and a great investment. Takes a lot of the guess work out of cable making.

Also check out http://www.flanderscables.com for cable stock and ferrules.


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Thanks for the resources lads. I'll probably have to resort to making my own, I've been looking for an excuse to buy a torch anyway.

Made a bit more progress on the bike today.

These little guys showed up saturday:


They're Black Oak 6" LED light bars, 12 5W Osram diodes putting out a combined 6600 lumens for a total of 13,200 for the pair. One is a flood light, that's going to be the low beam. The other, a spot light. That'll be the high beam.

I did a quick test mount with zipties since the actual mounts don't come in until tomorrow.


And after more faffing about with the wiring I got them working properly with the R6 switches.



Unfortunately I work late nights the first half of the week, so I won't be able to properly aim them until late tonight. I'll be sure to post some comparison pictures tomorrow.

Now all I'm waiting on is my new gauge cluster and she'll be back out on the road. Until I get my rear suspension setup that is.

Looking great, I was tearing off the front of my bike also. Gold too, looking sharp. Great write up so far and helps me for what is to come. Thank you.


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No worries boss, if you have any questions about the process let me know. It's pretty straightforward till you start wiring up new shit to the old harness.