Norton Commando Remove Fork Tubes
Although the most common reason for front fork removal is to replace leaking seals, the fork tubes on this 1974 Commando were badly pitted from years of sitting and needed to be replaced.
This article covers fork tube removal on 1972 and later Commando models.
To read about how to disassemble forks click here.
To read about how to assemble forks click here.
Getting Started
For those of you with paint on your tank, you'll want to remove it to prevent accidental scratching.
Removing the gas tank will also give you more room to work.
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Brake Caliper and Master Cylinder
Disconnect the steel brake line, then remove caliper from fork leg.
This caliper was bone dry, so I didn't need to worry about leaking brake fluid!
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Headlamp Removal
On each side of the headlamp is a bolt, washer, and spacer, which go through the left and right brackets.
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Prop Up The Front End
The bike needs to be propped up just enough so the front wheel may be removed.
There are several options here, most common being a small floor jack under the engine.
Seeing as this bike was already half-stripped, it was light enough for me to lift up by the forks and rest on top of a piece of 2x4 on a cinder block.
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Checking For Neck Play
With the front wheel off the ground, now's a good time to check if the steering bearings need replacement. In a crouching position over the front wheel, grab the forks and push/pull forward and back. Even the slightest amount of play should be looked into. Also check side to side movement for any binding.
If you're going to be replacing neck bearings, the master cylinder and handlebars will need to come off.
A 7/32" Allen key is required to remove the handlebars.
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Front Wheel Removal
On the bottom of the right-side fork, remove the 5/16 x 1-1/4" pinch bolt. Then remove the right-side axle nut with a 15/16" socket. The axle can be tapped through from the right side with a soft mallet.
An alternative way is to slip a large screwdriver through the left-side axle, grab the screwdriver with both hands, then twist and pull the axle out.
Front Axle Removal
Front Fender
Although you can remove it at any point, it's easier to remove the fender with the front wheel off.
There are four nuts (3/16 Whitworth), two on each side, that hold the fender onto the sliders. The two bolts that hold the fender stays to the fork sliders are 1/4 Whitworth.
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Pinch Bolts
On each side of the lower fork bracket are recessed Allen bolts. You'll need an 8mm or 5/16" Allen key to remove them.
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Fork Tube Removal
The fork top nuts have internal and external threads. They are screwed onto the damper rods, and also screw into the top of the stanchions.
With a 33mm or a 3/4 Whitworth socket, unscrew the big top nuts. The fork damper rod screws into the bottom of the big nut.
Separate Damper Rod From Top Nut
With the fork springs exposed, unscrew and remove the top nut from the damper rod. A thin open-end wrench is needed for this.
This will allow for gauge cup removal.
These final steps are often the hardest. How easy or how difficult the fork tubes come out often depends on how long the bike was sitting and how rusted they have become to the triple trees.
Re-install the top nut back into the stanchion. With a rubber mallet, smack the top of the big nut and hopefully the fork tubes will move.
If they don't move (many won't at first), try spraying with WD40, and letting them soak for a while.
If they still don't move, try a few more manly whacks with the mallet. If there's no movement - stop. Spray it with more penetrating fluid, let it soak overnight and try again tomorrow.
While removing the forks, they may get hung up on the rubber O-rings on the top and bottom of the headlamp brackets, which detach once the forks slide out of the triple trees.
Left and right headlamp brackets before cleaning.
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Drain Fork Oil
One of the oil drain screws was difficult getting out. Rather than take a chance of stripping out the original 50 year-old screw, I waited until the fork was removed and laying horizontal on the workbench, which gave an easier vantage point. A fibre washer should come off with each drain screw.
The old fork oil was drained out into a pan, and can be recycled with old engine oil.
Read: Front Fork Disassembly
Read: Front Forks Overhaul
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