Road holder forks on a jubilee

Should be relatively straightforward, of course the Navigator/Electra use the same frame as the Jubilee and have Roadholder forks.

You will need to get a couple of ball races (One top, one lower) and 2 sets of ball bearings. This assumes the front frame tube already has races in place.

I expect Peter Holland or Andy S will be along soon to correct me!

Yes you'll need a set of races and possibly a steering stop, also a front wheel - just about any Norton full width front wheel will fit.  I have roadholders on my jubilee, at least until I get the Navi running! I'll try and remember and take a picture tomorrow 
Dan

Gary, I'm assuming these are "Short" (ie featherbed) Roadholders? And are they the earlier 7" centres? (not 7 3/8")
Last century and in my Norton infancy, being blissfully ignorant of that point, I struggled with a mismatch of sliders, hubs and yokes. 

Mike and Dan have got it all covered. 

7 ins Roadholders plus the pre-64 Navigator lock stop is easiest. 

Your Roadholders won't accept Jubilee:- Front wheel, front brake, brake cable, mudguard and stays. A lot of parts to source.

PS.  The gap between top and bottom yokes on Roadholders is enough to grip the RH fork ears nicely. The steering head bearings are spaced on a heavyweight to match the fork ear heights. On Navigator special spacers are inserted on the upper steering stem to make up for the lesser steering head. You will need all the Navigator parts that fit on the stem. 

I have a sneaky feeling you have the later roadholders with the 7 3/8" centres (ie as measured at the top nuts, the giveaway is what looks to be a mounting for a key- type steering lock, next to the r/h handlebar clamp.
A photo looking down on  the top yoke would help confirm either way.
Not that it matters in the grand scheme of things, so long as the bits all came off the same bike they should match. I think the change was made around 1964ish, with the introduction of the 650ss/Atlas models, and allowed for a wider front tyre to be fitted.
Also, check the bottom of the L/H slider: this has a pinch bolt to secure the front spindle in position, and is a well-known weak spot: it cracks/breaks very easily from overtightening. After all, it is metal not plastic! The result is often seen welded up- or worse!. 

Looking at your sliders I think you'll need a 7 3/8 bottom yoke, but its difficult to be sure without measuring. The brake side slider is a bit wider to centralise the wheel on the wider forks. This a pic of mine on 7" forks. 
If you buy new stanchions and bushes, i recommend Andover, the quality of some of the other suppliers hasn't been so good lately, with bushes having to be reamed and machining marks visible on the stanchions. I recently bought a set from Andover's and they fitted perfectly. 

This type of mudguard bracket works well, if you don't mind it not being all original. https://www.tga.co.uk/products/y-brackets/

Hi Gary
The stanchions are the same diameter, from long roadholders to the commando, but the bottom yokes can get over tightened and be a tight fit. A suitable wedge can loosen things a bit.  The difference between the 7" and 7 3/8 wide forks (apart from the obvious yokes) is the width of the built in wheel spacer at the bottom of the brake side slider.

A jubilee is very much improved by fitting roadholders - but it's up to you what you want. I'm just about to put new bushes in my jubilee forks (currently off the bike) and see if I can make the front brake work well, which is its weak point, the 8" full width front brake you have is a very good brake when properly set up. 

Dan 

...are all the same diameter, however there are I think 4 different lengths: "Long" Road holder ie pre- featherbed, "Short" RH ie f/bed, Manx and Commando.
I'm guessing, but I expect the Navigator/Electra stanchions are "short" R/h. 
Just to confuse you even more, the spring rates vary, to account for different machine weights. But again, in the grand scheme of things, so long as they are both the same (system of 3 coloured dots near the top of the springs) you're probably going to be OK on a relatively low powered machine. 
Welcome to the wonderful world of Nortons! 

Chrome stanchions in the picture? Commando....
Pre-Commando forks have chrome extensions that screw in to the sliders to retain the top seals. 
Have a look at the illustrated parts lists on RGM or Andover Norton, you will see what I mean. 

Good luck Gary. Keep posting, keep sending photos. 
Everybody on here is only too happy to help out. 
As mentioned in other forum topics, try and get along to your nearest branch. 

Parts look a good match, the brake plate notch looks fully engaged with the slot in the slider, and the boss lines up without a gap.
Given that the forks are possibly a Woolworths mix'n'match, and probably just the angle of the picture, but the rim doesn't look centrered in the forks. Maybe worth checking before everything else gets assembled!

Hmm, If it is a 7 3/8 brake slider and you have 7" bottom yokes that would explain why your wheel isn't centred. You could always machine the brake slider down to 7" size. I think i have one off the bike somewhere I could measure if it helps. 
Dan 

Gary I'll send you a message so you can call me if you like. There should be no need for a wheel spacer, just matching parts.