A few questions

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I've searched the site for info on the rear wheel offset for 1973 Commando. I've got a thick head, most everything I've seen here concerning wheel offsets is very confusing to me. Can anyone give me the measurement between the edge of the rim and a straight edge held against the right side of the hub as shown in this picture. This would be the most accurate way to get the offset correct.

A few questions


Next, the parts manual shows this spacer going on the underside of the fender, it makes more sense to me for it to go here but the bracket doesn't seem to hold tight enough to the fender to keep it from moving side to side. Is this the correct placement of the spacer?

A few questions


Lastly, the service manual shows the ignition wires going on the outside of the frame, like this:

A few questions


I tried threading the wires between the air filter back plate and the frame but it was very tight and I thought vibration would eventually short them out.

A few questions


Any other suggestions on how to place the wires?

Thanks for your help.

Art

Coming down the home stretch
A few questions


A few questions
 
bentrod said:
I've search the site for info on the rear wheel offset for 1973 Commando. I've got a thick head, most everything I've seen here concerning wheel offsets is very confusing to me. Can anyone give me the measurement between the edge of the rim and a straight edge held against the right side of the hub as shown in this picture. This would be the most accurate way to get the offset correct.

The primary objective is to set the wheel rim on, or as close as possible to, the frame centre line (not swing arm). The correct amount of offset will be whatever takes to do so.



bentrod said:
Next, the parts manual shows this spacer going on the underside of the fender, it makes more sense to me for it to go here but the bracket doesn't seem to hold tight enough to the fender to keep it from moving side to side. Is this the correct placement of the spacer?

I think the spacer actually goes between "Clip bracket" [22] and the head of the "Special screw" [18] so above the bracket, not below it.
 
Thanks L.A.B. I don't think the spacer goes where you suggested, not enough meat on the bolt to make it through the fender.

A few questions


These are the original nut & bolt setup I believe. I take pictures of everything when I refurb a bike, unfortunately, the fender and tail light assembly were taken apart when I purchased the bike. Here's the bolt assembly.

A few questions


Art
 
bentrod said:
Thanks L.A.B. I don't think the spacer goes where you suggested, not enough meat on the bolt to make it through the fender.

My MkIII has washers in place of the spacer, there is enough thread to fit the thin nut and washer below the mudguard. I can't see how it would work with the spacer between the bracket and mudguard and certainly not with the spacer below the 'guard as the special screw would not be in the correct position to fit the tail lamp fairing.
norton-taillight-assembly-t17274.html
A few questions
 
L.A.B. said:
bentrod said:
Next, the parts manual shows this spacer going on the underside of the fender, it makes more sense to me for it to go here but the bracket doesn't seem to hold tight enough to the fender to keep it from moving side to side. Is this the correct placement of the spacer?

I think the spacer actually goes between "Clip bracket" [22] and the head of the "Special screw" [18] so above the bracket, not below it.

No, the spacer goes under the fender as illustrated.
If it were fitted between the "Special screw" and the bracket, the fairing would not fit correctly. It would sit too high at the front, and be incorrectly angled at the rear where it mates with the tail-light.

The support bracket, #25, sits on top of #22, and not underneath as it is in the photo. When fitted as per the photo, it somewhat negates the clamping of the bracket, #22.
 
Thanks, bad assumption on my part that a Norton parts book or service manual could be wrong :lol:

Art
 
NorComCycles said:
No, the spacer goes under the fender as illustrated.

If it were fitted between the "Special screw" and the bracket, the fairing would not fit correctly. It would sit too high at the front, and be incorrectly angled at the rear where it mates with the tail-light.

Without those packing washers (in place of the spacer) shown in my photo, the front of the lamp fairing would distort and be crushed by the retaining screw when tightened and it doesn't result in it being incorrectly angled.

mudguard-clip-spacer-t11730.html
 
L.A.B. said:
NorComCycles said:
No, the spacer goes under the fender as illustrated.

If it were fitted between the "Special screw" and the bracket, the fairing would not fit correctly. It would sit too high at the front, and be incorrectly angled at the rear where it mates with the tail-light.

Without those packing washers (in place of the spacer) shown in my photo, the front of the lamp fairing would distort and be crushed by the retaining screw when tightened and it doesn't result in it being incorrectly angled.

mudguard-clip-spacer-t11730.html


The "packing washers" you are using are not the spacer. I only commented on the spacer. There can always be variations in what fits best between machines. I never said otherwise. If you feel on your particular machine having some washers there makes for a better fit, obviously you are entitled to fit as many washers there as you choose/can.
Given that there are no washers shown in that location in the parts book, and that I do not recall having ever seen any extra washers there on a bike, nor the need for any (I have personally owned more than 20 Mk 3 commandos), I think there is a possibility/likelihood that something is amiss with your bike. But it may just be the way it is, as we know can happen. I really do not mind either way.


The spacer in question goes under the fender from the factory. I do not understand what your comment regarding the washers you are using has to do with that.
To say that the spacer is correctly fitted when located in any position above the fender, is simply wrong. And that was what the OP wanted to know. You gave him incorrect information, and though I rarely post, I felt a little sorry for him, and wanted to see him set straight.
 
To answer your first question:
The datum I use is the machined face on the left hand (drive side) of the hub; this (to me at least) seems to be the only viable point of reference.
If you're using the standard WM2 rim, the straight-edge should sit against the hub and rim with zero offset.

The ignition switch wires only seem to make sense if they're routed outside the frame, as you've already concluded - My MkIIA with the plastic air box wouldn't permit anything else. Great on an Interstate where it's all hidden, but a right pig's @rse for a Roadster :cry:

I don't recall using a spacer on the mudguard/tail light fixings, a couple of washers sufficed below the bolt head. As has already been suggested - I'd agree that it's to prevent stressing the fibreglass trim, as all non-fastback Commandos use the same Mickey-Mouse clip setup - the pre-73 models had a captive nut moulded into the tail-light fairing, with a bolt up from underneath the mudguard through the clip to clamp the whole sorry mess together!
I guess the thickness & pliability of the rubber packing will be the controlling factor
Apart from that it's a fine example of British Engineering at its best... :roll:

Incidentally, your build looks great so far- how long before it's tearing up the roads?
 
NorComCycles said:
The "packing washers" you are using are not the spacer. I only commented on the spacer. There can always be variations in what fits best between machines. I never said otherwise. If you feel on your particular machine having some washers there makes for a better fit, obviously you are entitled to fit as many washers there as you choose/can.
Given that there are no washers shown in that location in the parts book, and that I do not recall having ever seen any extra washers there on a bike, nor the need for any (I have personally owned more than 20 Mk 3 commandos), I think there is a possibility/likelihood that something is amiss with your bike. But it may just be the way it is, as we know can happen. I really do not mind either way.


The spacer in question goes under the fender from the factory. I do not understand what your comment regarding the washers you are using has to do with that.
To say that the spacer is correctly fitted when located in any position above the fender, is simply wrong. And that was what the OP wanted to know. You gave him incorrect information, and though I rarely post, I felt a little sorry for him, and wanted to see him set straight.

I'm aware the stack of washers are not what's shown in the parts books. I may be wrong but personally I cannot see any logical need for a spacer below the mudguard/fender when there is a need for one above it, and in any case the special screw would not long be enough to take the stack of washers and the spacer.
 
Apparently the PO had it placed wrong and this was the result, as L.A.B. suggested would happen. I'll come up with an arrangement that will make everything work. I really shouldn't be so anal about little things like this but the rivet counters would certainly point out the fact that I have the spacer in the wrong location. :lol:

A few questions


But the spacer placed under the fender appears to work out well. The 'special screw' is in the right position to accept the screw that hold the fiberglass cover and the fender is nice and tight on the frame rail.
 
B+Bogus said:
To answer your first question:
The datum I use is the machined face on the left hand (drive side) of the hub; this (to me at least) seems to be the only viable point of reference.
If you're using the standard WM2 rim, the straight-edge should sit against the hub and rim with zero offset.

The ignition switch wires only seem to make sense if they're routed outside the frame, as you've already concluded - My MkIIA with the plastic air box wouldn't permit anything else. Great on an Interstate where it's all hidden, but a right pig's @rse for a Roadster :cry:

I don't recall using a spacer on the mudguard/tail light fixings, a couple of washers sufficed below the bolt head. As has already been suggested - I'd agree that it's to prevent stressing the fibreglass trim, as all non-fastback Commandos use the same Mickey-Mouse clip setup - the pre-73 models had a captive nut moulded into the tail-light fairing, with a bolt up from underneath the mudguard through the clip to clamp the whole sorry mess together!
I guess the thickness & pliability of the rubber packing will be the controlling factor
Apart from that it's a fine example of British Engineering at its best... :roll:

Incidentally, your build looks great so far- how long before it's tearing up the roads?

As it happened, after truing up the WM2 rim, the result was zero offset on the drive side of the hub. The straight edge lays across the hub and edge of the rim just as you say. The wheel is not centered in the swing arm but slightly left of what would be the center. I'll come up with a way to make sure the wheel is really in the center of the frame and lined up with the front wheel.

Thanks for your complement, I should have it on the road within a week or so. No to steal my own thread but here's a question I've worried about. I'm pushing 69 years old, my legs aren't what they used to be. How hard can I expect it to be to kick over a Commando? I never had a problem with my Atlas so I'm hoping the Commando won't be any different.
Thanks for your help everyone.
Art
 
On kicking over: I have found it easier to put bike on center stand and kick with LEFT foot, seems to get more (all) of my weight onto the kicker pedal
Doug
 
bentrod said:
Next, the parts manual shows this spacer going on the underside of the fender, it makes more sense to me for it to go here but the bracket doesn't seem to hold tight enough to the fender to keep it from moving side to side. Is this the correct placement of the spacer?

The parts book correctly shows where the spacer goes on the underside of the fender. The bolt itself is special in that it is machined from hex bar stock and drilled and tapped for a 10-32 screw. The spacer is there because there aren't that many threads on the bolt and without the spacer the nut would run up against the unthreaded part of the bolt. The reason why the bolt doesn't have that many threads is because they didn't want to weaken the bolt by having the threads cut in the portion of the bolt that is drilled for the 10-32 screw.

bentrod said:
I tried threading the wires between the air filter back plate and the frame but it was very tight and I thought vibration would eventually short them out.
As far as the wires go, I have seen various factory photos of the wires going on the inside or on the outside of the frame tube. I was able to route mine on the inboard side of the frame tube by running the wires first down parallel in front of the frame tube about 2 1/4 inches from the end of the switch boot and then tucking the wires on the inboard side of the frame tube. I have plenty of clearance that way.
 
I agree with L.A.B, the rear wheel centre line needs to be on the frame centreline. This could have been established using a surface table when the frame was stripped and before assembly started. Re alignment in current state, you can fix the rear wheel approxiamately square to the swing arm spindle with equal turns of the adjuster bolts. Place a straight edge between front and rear wheels, the gap, after allowing for any difference in tyre width, will give you an idea of how much your frame is out of alignment. If there's no gap then your very lucky or your frames been blueprinted.
 
I made a mark in the web at the end of the large frame tube right in the center. I take a straight edge, or carpenters square and with the tires and shocks off, you can pull the rear wheel up between the rear hoop and make sure the rim is centered on the tube (equal distances to the center mark) and also parallel to the tube with a longer straight edge. If you can get a straight edge all the way to the headstock, that really lines it up. You can do this with the tire on and the shocks too, it's just a bit easier without that stuff in the way. Rear mudguard has to come off though.

Dave
 
I've used string tapped at stem then laid down spine and to dangle off rear loop with a weight. Also check swing arm leg square to vertical and can be expected. Rear loops can get saggy to ruin the sleek line with the seat.
 
The problem with DogT and hobot's methods is the assumption that the spine is the centre of the frame. The frame centre is from the steering head axis to the midway point between the rear isolastic brackets. The rear iso. bracket stud holes need to be checked they are square in two planes to the steering head to stand any chance of getting the swing arm spindle square.
 
Oh DogT and me got the geometrical frame center tied down, so you are confusing factors on center of gravity and power unit off centering issues. Which issues here are cosmetic appearance balancing only vs operational mechanical balance ...
Swing arm legs has a skewed clue on this. A perfectly made all true and square Cdo will be easier to assemble and better isolation sense in all conditions but will not affect its slightly biased CoG handling nor delay onset of dangerous wobbley Hinge. Other famous successful sold cycles have been made off centered in tires and mass too.
 
No Hobot, I'm not confused at all. C of G is determined by mass distribution. Centrifugal force created by the turning wheels will cancel the slight C of G bias that may exist. If I read you right, I don't no why any designer would build a bike with the rear wheel offset from the frame centre line i.e wheels out of line from each other. Rear wheel can be offset in the swingarm, but not offset from the frame centre line. From experience a Commando built with swingarm axis and wheel spindles perpendicular in two planes to steering head axis and front and rear wheels in line with the frame, holds it's line on the straight and through corners. It no longer exhibits the wobbly hinge you mention, this is a symptom of wheel misalignment. Working from a surface table datum beats string any day.
 
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