72 Combat project swapping "front burner" spot

This followed me home from my Daytona trip-




Nifty Norvil 13" full floater up front, lots of go-fast bits inside, new ARD mag in the box, etc., etc.

I was planning on building one of the two Norton projects I had sitting on the shelf, in a side-by-side build with Chip's combat; it looks like this one is much further along, and the engine is a known quantity versus the other 2 that I have which were unopened and sitting for lots of years.

Look for it to have the black Dunstall bodywork (deep GP tank) with rearsets & clip-ons.

The fun never stops on Planet Paul...

GrandPaul,

What kind of caliper and mastercylinder are you planning to use with that full floater?

I already have the parts that are sold as a Norvil "kit", including the mounting adapter from Fair Spares. I'll check the box for the caliper & master cylinder manufacturer's names.

Had a bit of time on my hands so I mocked up the GP tank & seat; I'm not sure how much I like the look, also don't know about the depth of the tank disturbing the bikini fairing lowers (still need to fit it up and see) It will all make more sense after I fit up the clip-ons & rearsets.


I fitted up the Novil brake caliper adapter and AP racing caliper, and test fitted the brake hose and master cylinder. The latter parts will come off again when the clip-ons go on.


Note added breather at upper left, also rubber faced camchain adjuster. nice touches.


After digging all over for the mounting hardware, I installed the ARD magneto and timing cover. The internal clutch actuator arm had slipped it's moorings, necessitating reoval and replacement of the tranny cover which resulted in draining and re-filling the already serviced assembly. That ARD mag is a REAL piece of work; super-simple to time - slip the pin in the slot, mount everything, remove pin!


Some more digging to find the proper alternator rotor spacer, then installed a like-new 3-phase Sparx unit I had sitting on the shelf. Primary side also done, just need to clean off the niggly surface rust on the clutch spring & hub, then pop the cover on.


Ahhhh.... Progress!

Lookin' good, GrandPaul!

I'm not too familiar with the ARD unit. As I understand this is a capacitive discharge system? The unit supplies current to the coil in a timed manner? What advantages can you expect from such a system?

I know CDI's were popular in the early to mid seventies, but I guess I slept through that class.

Ron - the ARD doesn't rely on power input, it generates it's own electrical impulse with permanent magnets. It's better than the old style magneto because it uses no points that can wear out or fail.

It's a hybrid CDI, with a pulse delivery timing signal that is interpreted by the brain module to trigger the circuit delivering the induced pulse from the rotor. That's if I understand it correctly just from studying it; there is no wiring diagram per se.

No battery, no alternator, no capacitor, NO PROBLEM.

Only possible point of failure would be vibration-induced failure of the black box; I've mounted it semi-rigidly with good isolation.

No battery, no alternator, no capacitor, NO PROBLEM.

Click to expand...

Paul,
If I made a statement like that I'd have a major disaster the first time I started the bike! :roll:

Is ARD still in business? I found instructions on the British Cycle Supply website, but they indicate the units are no longer available.

Not sure if they are still around, I believe so. Either way, this unit is brand new.

Got a bit more work done just before Easter, then again yesterday & today.

Nipped up all the front brake caliper parts, fabricated a coil mounting bracket and mounted it, removed the headlight ears & mounted the adjustable clip-ons and instrument cups, installed clutch lever quadrant and cable, fiddled with the front axle and spacer, modified the fairing to properly clear the forks at full turning radius, fabricated a lower stabilising bracket for it and mounted it all up. Re-adjusted the clip-ons, then stuck the tank and seat on it for a photo-


After I was done for the day, UPS showed up with the chain, battery, more cables, rear shocks and throttle twistgrip.


More stuff including all the proper front axle bits and z-plate mounting spacers should be here tomorrow. Then I'll install the rearset pegs and new carbs-

Paul,
I like the adjustable Tomaselli clip-ons! Good looking rearsets too. Who made them? Since you are going to run a reversed shift lever are you doing the reverse camplate also? What are your plans for a rear brake light switch? I always thought the factory Production Racer bracket on the backing plate with a little arm from the brake arm pivot actuating a stock Commando switch was a clever design.

The shape of the fairing (at least from this picture) looks more like the Ducati 750/900 SS bevel than Production Racer or Dunstall. Did you have to fab mounts for it?

Got the clip-ons off e-bay along with a frame and an empty set of cases. The clip-ons got all scratched and gouged by the newbie who couldn't figure them out without making a mess.

The rearsets are Clubman (I believe), I got them used from a buddy who decided he wanted to go "bobber" instead of cafe racer.

I'm flipping the shifter over and using the standard shift pattern like all my other Brit bikes (what an elegant solution).

I'm using an in-line brake light switch (it's all the rage, and oh-so-simple).

The fairing is a Clubman reproduction of the Ducati SS, it works PERFECTLY with the 6 gallon Dunstall GP tank for width and depth. I was concerned about that when I did the first mock-up using Chip's genuine Dunstall fairing, it was too narrow and too high up to fit right (see earlier photo a few posts up). Clubman sells a complete front mounting bracket (a bit on the spendy side) that also mounts the headlight, I fabbed the bottom/side brackets.

It looks like a fun project!

So, what's an in-line brake light switch?

Is it simply a micro switch mounted to the frame that connects to the brake rod with a small spring?

Nope, it's a module built in between a 2-piece cable sheath that has an internal switch, much like late 60s and early 70s Triumphs use on the front brake cable.

No springs, no adjustments, no lumps dangling off the brake pedal or chainguard, etc.

Rearsets, shocks, head steady and miscellaneous parts installed.

Right side pipe (original stamped "Norton" installed for mockup photo-



It's going to be cutting it close for April 12th...

Pulled the head and corrected the previous owner's mis-assembly; the pushrods were jamming (thankfully, just scarred, not bent or cracked tips).



I managed to pull it off and put it back on without a second set of hands by using this nifty trick (just pull the cloth strips out after the head is lowered on the studs:



So, I'm ready to pop the carbs on, wire it up and get her lit next week!

Paul,
Did you check the pushrod length? Typically Combat motors did not have the pushrods shortened .040" when the head was milled. Unless the previous owner cut the pushrods down during the rebuild, the geometry will still be off. This leads to or at least aggravates the tendency to wear a groove in the valve stem on Combat motors.

At least it has been my observation that valve stem end wear is worse on Combat motors than others. Perhaps it is due to the increased lash, but I think the geometry problem is also a big contributor.

I did not measure them, I trust the previous owner implicitly on his description of what was done. The inside of the engine is brilliant.

Pushrods set properly, head re-torqued, valves set, all is well. Fantastic compression.

Dug through the boxes of bits again, found proper manifold isloators & hardware, mounted up the carbs with cables and K&N air filter. Choke cable is wrong, need to re-order; throttle twistgrip is wierd, has a big gap between the 2 halves, might swap for an original Norton unit even though this one works. Also installed oil line manifold and braided stainless rocker feed pipe setup. Hard to make out, but I also mounted the sparx 3 phase regulator ahead of the battery box.



Fitted up a nice chrome set of pillion peg / exhaust mount brackets and install the exhaust system after chopping about 1-1/2" off each header pipe so they'd fit with the mounting hardware.



Installed front brake line, topped off the fluid and bled the system; NICE. Still need to sort one spacer for proper front brake alignment without the floating rivets scratching the right fork leg, but I've got a washer in there for the moment (none of this shown at the moment).

Popped the guages in the cups, nipped 'em up and connected the cables at both ends. I might swap these out for a pair of "solid blob" units I have, not sure at the moment.

Success!
Completed all the connections for the magneto harness, installed a set of plug caps, set the small High Rider tank on it for test-runing purposes along with a pair of good used petcocks from the parts bins, then I fit, cut, installed & adjusted the chain.

It took 4 kicks for it to fire, I'm not sure what I was doing wrong as it surely had fuel in the carbs? Anyway, it blubbered and sputtered a bit, but sounds great. As soon as I had a good show of return oil flow, I twiddled the idle and it settled into a nice steady 1,000 RPM tickover.
The maiden voyage was a bit inauspicious, as the tranny doesn't seem to want to select gears without serious persuasion. Also, there's a clickety sound in the rear hub that I know shouldn't be there.

Still a lot to do, but it's running, and that's a milestone.

Shifter: sorted. The overly fat new rubber was jamming against the kickstarter. re-oriented both, no more issues.

Binding front forks: sorted: replaced left side upper bushing which was a too-tight fit for the new stanchions; wierd that the right bushing was perfect...

Front axle & spacers: sorted. Located correct left side spacer and nipped it all up.

The engine will be stone cold for tomorrow's check of what's what up in the rockerbox area, still making more tapping than a well-behaved Norton ought to be doing.

Once I get that sorted, I'll investigate the rear hub & stub axle clickety-clunk noises.

It's looking pretty good to have it running right by tomorrow evening, then fit & mount the bodywork Thursday with some electrical wiring both days.

As this is a mag ignition, with 3-phase alternator & regulator kit, I'm going to pull the new wiring harness off and wire it myself with a very simple schematic. I'll save the new harness for the other '70 Commando project that will be nearly all original.

Sorry lads, no more pix today.