75 Mark III refurb/mod project

Beauty shots & additional test ride results:









Got the front brakes bled and topped off. Since the bike doesn't have a plate, and the city has been working overtime issuing tickets to slow thier budget deficit, I figured I'd better keep the test riding close to home. Still, the bike feels great; typical Norton bottom end torque that just sets your eyeballs back in thier sockets and accelleration that keeps them there (and we're talking moderate throttle use during run-in). The difference between a stock cam & springs and Megacycle cam with Precision Machine spring kit is DEFINITELY noticeable.

Suspension is decidedly stiff, but not jarring (then again, I only weigh 140). There's still some available tweaking, but I'm thinking of letting the owner fine-tune it to his preference.

I really need to get some miles on it, so I'll probably stick my Interstate plate on it and take it with me to the Texas Mile this weekend...

I like that light... prob 90% of the ones I see are crooked and pointing up. Looks nice to see it parallel to the ground for once lol.

U gonna put a v.stack on the amals?

It was easy, didn't even use a level. Hand-cut the notches for the rear frame loop, too; touched up with a rat-tail file.

Carbs on this one, and the 74 "mule" are getting UNI dirt bike type socks, the only thing that will fit in the available space.

Hi Paul. So I guess as there's no remarks about the handling (other than it being a bit stiff) that the monoshock is just that - unremarkable? By this I mean that it's just doing what it's supposed to do - and no reflection on the design or implementation.

I'm just back from the "Texas Mile" land speed event, it was PACKED, record attendance, and SPEED was shooting some Paul Tracy thing with a Camaro vs mustng (just goofing off for the cameras, they were doing 190+ MPH runs).

The bottom line on this bike and the Silver one is that I have simply not yet had the time to properly sort the brakes to the point where I have full braking capabilities, and nominal operational lights where I can take them out on the street and run them through any significant paces.

Now that I have the planning, preparation and "unwinding" done from the TxMile event, I can concentrate this week on nailing these two down and reporting back with a significant preliminary analysis of my swingarm design. I probably won't get to have either of them on the TRACK any time soon, so a comprehensive, "edge-of-the-envelope" analysis is still going to have to wait.

As far as BASIC low-speed observations: totally unremarkable.

The front & top steadies arrived from Windy Eads (BillT), through Greg Fauth (norbsa).





That completes the engine mounting picture. They'll be installed next, and not much left to do besides a bit of electrical wiring and battery mounting...

Dunstall rearsets arrived (kit was for a Kawasaki triple, no Norton MkIII kits available), thanx, swooshdave.



Here's my plan to adapt them; parts are already at the welder's-



Should have them on the bike by tonight...

I can't believe how nasty the original rear master cylinder was on that thing. The one I removed and sold off my MKIII looked NOS compared to the one you had.

grandpaul said:

Dunstall rearsets arrived (kit was for a Kawasaki triple, no Norton MkIII kits available), thanx, swooshdave.

Here's my plan to adapt them; parts are already at the welder's-

Should have them on the bike by tonight...

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That's a crazy setup on the brake side (the wrong side). If you had more time would you have figured out how to adapt another master cylinder?

grandpaul said:

The front & top steadies arrived from Windy Eads (BillT), through Greg Fauth (norbsa).

That completes the engine mounting picture. They'll be installed next, and not much left to do besides a bit of electrical wiring and battery mounting...

Click to expand...

You mean you you rode the bike with no headsteady and the thing didn't collapse upon itself? Inconceivable! :mrgreen:

The Mark III rearset brake linkage is very much typical of what you'll find on Dunstall and others. That's simply the way it's done.

Yes, I rode without a top steady OF ANY KIND, and no, it didn't get me killed or even hurt bad. In fact, I didn't notice anything extraordinary about the ride AT ALL. (Of course it was kept under 100, and not pushed hard in switchback twisties)

Top head steady fitted up (thanx for the spiffy polish job, Greg)...



Front steady fitted up (thanx for the powdercoat, Greg)...



Rearsets are ready to install, I might get 'em done tonight...

grandpaul said:

Top head steady fitted up (thanx for the spiffy polish job, Greg)...

Front steady fitted up (thanx for the powdercoat, Greg)...

Rearsets are ready to install, I might get 'em done tonight...

Click to expand...

That's right, install everyone else's parts but not mine.

Long day, but got a lot done. Welder did exactly as I instructed, results were not exactly what I anticipated.

Not a lot was needed to make the shifter work, I simply cut a spare shifter, drilled the arm and rotated it 90 degrees, re-shaped the actuator arm a bit and...



The brake side took considerably more work. I tried to trim and hollow out the OEM footpeg spacer block, but ended up having to completely cuto off the lower 2/3 of the block leaving only the upper two mounting holes and the new rearset mounting lug. I then trimmed the cut-off section to retain only the section that the mounting bolt runs through, to use as a spacer/support for the third bolt. The reason for all this was the spacing needed for the brake pedal to clear the kickstarter, required flipping the aluminum mount spacer "inside out"-



My plans to use the brake pedal as-is were foiled, as the curvature around the master cylinder is perfect, but the arc needed to allow the proper range of motion needs to be reworked with another 3" section added.

Also, the Kawasaki kit left only a very short section of threaded shaft, and a much-too-small yoke for the brake pivot clevis. That will all be replaced with a new assembly similar to the one mocked up in the photo, but made with a spare OEM pivot clevis that I had on the shelf.

There, dave; are you satisfied?

but the arc needed to allow the proper range of motion needs to be reworked with another 3" section added.

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Do you have room for your foot in between the kick start arm and the gearbox? Looks tight. Or are you going around the kicker with another bend?

Yes, I rode without a top steady OF ANY KIND, and no, it didn't get me killed or even hurt bad. In fact, I didn't notice anything extraordinary about the ride AT ALL. (Of course it was kept under 100, and not pushed hard in switchback twisties)

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.......and there was me worrying a bit about cornering stresses on the 3/8" bolts and Ludwig asking me if I was 'hoping' they'd be OK. Still wouldn't have taken the risk but I guess those small dia. ISO buffers resist a lot of rotary movement.

ludwig said:

Just when I tought I had seen everything!

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"You ain't seen nothing yet"

...as the kids like to say...

ludwig said:

Just when I tought I had seen everything ..:
I think I'll set this one for desktop background for a while !

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Really because it's a hella lot more elegant than the Hyde solution.



Stare at that for a while... It's an E-start, just take the damn kickstarter off!

Dave that's the new lay down kick start, You just lay down beside the bike and kick start it. LOL. :roll:

Hortons Norton said:

Dave that's the new lay down kick start, You just lay down beside the bike and kick start it. LOL. :roll:

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People often say how nice Hyde stuff is. They must have just had Dunstall crap to compare it to. :roll: