Fork Length

Now this is something new to me...

On reassembling the forks, I find that the left fork stantion is about 1/16" longer than the other. This makes passing the axle through the lower legs impossible without slightly compressing the left fork.

I have rechecked to see that the left upper bushing is fully seated and it is. The top bushing nuts appear to be set equally into the fork legs on both forks.

This inequity in fork length would certainly be improper in a modern fork assembly with adjustable fork length in the triples.

Is this normal, or am I missing something?

BrianG said:

On reassembling the forks, I find that the left fork stantion is about 1/16" longer than the other. This makes passing the axle through the lower legs impossible without slightly compressing the left fork.

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In that case are you absolutely sure it's the stanchions that are different lengths and not the complete fork assemblies?

BrianG said:

I have rechecked to see that the left upper bushing is fully seated and it is. The top bushing nuts appear to be set equally into the fork legs on both forks.

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Are the damper assemblies the same length?
If one damper assembly is slightly longer or set lower than the other then the fork assembly on that side will extend further.

Are you sure the lower ends of both damper tubes are fully seated in the sliders?

Both damper rods equally threaded into the fork caps?

If not obtaining perfect .ooX" tube length match, then will get no respect here, but fact of the matter is it don't matter a whitworht as long as can still clamp down - yokes to axle squarely. Can't trim lower end d/t bushing clip-age, maybe can the top, but I do not know, d/t taper seating issues. This implies must buy a new pair of stanchions to please forum reputation or don't tell if going down dirty practical. If ya didn't notice fork issues before dis-assembly, logic implies won't again as is.

Of course too late now, its public knowledge that you have asymmetric stanchions, so only newbie strangers would now pay more than half what ya got in it. Should consider digital age permanent records in decision, on top of forum reputation. Must be a newbie not to know this before asking, but how else ya going get past tender foot stage but facing contrary conflicts all with logic seeming to fully support both views and making a decision on your own.

As the others have said or implied, the length of the stanchion is irrelevant with regards to the positions of the sliders at full extension. It's the damper rods and the damper tube/slider assemblies that determine where the sliders stop.
I have experienced a similar thing when fitting the axle. 1/16" sounds pretty good to me. The Norton forks aren't exactly precision instruments.

If the stanchions ARE different lengths, it would affect the positions at which each slider reaches its stop at full compression, but again I wouldn't be too concerned about that, provided the difference is no more than about 2" (joking).

If my memory serves me correctly, I recall reading in "Norton - the Complete Story", that Norton once advertised that they now had two-way damping in their front suspension when in fact they had none at all. This was before the Commando.

Thank you all for the information and the answer to my problem.

While refitting the front end to the newly painted frame I did not want to risk the instruments so I used a pair of old bearings I had laying around. Perhaps by now you can guess that the bearings were not identical, one being 1/16" wider than the other.

Not knowing that it was the damper that limited fork extension, I did not consider the fork cap spacing as a possible cause.

The wisdom here is an amazing resource. Thanks again.

HAHAHA, EUREKA, I told ya so, all our guessing had no relation to what you found!

Ok will add wrong size stem bearing to list of fork faults. At one time, maybe Manix fame era, Roadholders had effective hydro stop soft reversals up or dn via the cone shape closure and stanchion hole blocking with good dampening with just the plunger like 'valve's making various holes/gaps do their springing dampening thing, - to earn permanent reputation as UN-Apporachable.

While apart cheapest easy/quick way to desire less fork fluid viscosity would be JBW cap hole then drill out to barely allow rod to pass w/o restriction, then diddle rod dia. a few 1000'th less an inch or so in sag length engaged with pilot on. I've experience the adjustable modern forks, on track and off road wildness, so even though modern adustable damper forks are all the rage to put on race Commandos, to say they ain't in same league as cleverly slightly
modified corrected Roadholders - so their only bragging rights is - they beat the shit out of factory ruined Roadholders, BFD - ain't faced or tried hobot/Fault kit forks. JMS bushes are just icing on the cake but good to follow his and lugwig wisdom to not think of damper 'valve's as valves but simply good sealing syringe plungers.

I have performed the JMS damper mod, closing off the lower damper holes and leaving only one 1/16" hole, and flairing the damper piston.

Combined with new stantion tubes and bushings and new springs. We shall see.

hobot said:

HAHAHA, EUREKA, I told ya so, all our guessing had no relation to what you found!

Ok will add wrong size stem bearing to list of fork faults. At one time, maybe Manix fame era, Roadholders had effective hydro stop soft reversals up or dn via the cone shape closure and stanchion hole blocking with good dampening with just the plunger like 'valve's making various holes/gaps do their springing dampening thing, - to earn permanent reputation as UN-Apporachable.

While apart cheapest easy/quick way to desire less fork fluid viscosity would be JBW cap hole then drill out to barely allow rod to pass w/o restriction, then diddle rod dia. a few 1000'th less an inch or so in sag length engaged with pilot on. I've experience the adjustable modern forks, on track and off road wildness, so even though modern adustable damper forks are all the rage to put on race Commandos, to say they ain't in same league as cleverly slightly
modified corrected Roadholders - so their only bragging rights is - they beat the shit out of factory ruined Roadholders, BFD - ain't faced or tried hobot/Fault kit forks. JMS bushes are just icing on the cake but good to follow his and lugwig wisdom to not think of damper 'valve's as valves but simply good sealing syringe plungers.

Click to expand...

Ok but ya ain't mentioned most important dampening element, new caps &or rods that fit tighter on damper rod clearances. Skipping this factor is what makes Landsdowne or Shawa dampers braggarts seem to be the best there is, and are, ugh - compared to ruined Commando issued non functional Roadholders, which are not like early fully functional un-approachable Roadholers. To suggest this directly confronts/offends expensive fork option experts/machinist/vendors - that ain't tired Fault-hobot kit to know for sure. Realize less than 10% of Commando owners are online and there are 100's 1000's 8N Ford red belly tractors but supply of their valves world wide essentially depleted by volume of Fault kits sold, he told em about 5 yr ago. Accessnorton as good as it is does not cover the scope of most the world of Commando owners. Spring rates are even more important but not covered/mentioned by the hi end grades.

In my situation the OEM damper end caps were well inside, on the right side, the JMS spec, so that shouldn't be an issue with this build.

Alrighty BrainG, see how it feels but Ms Peel with tighter alloy caps and 10 mm bigger dia alu rods with damper 'valves' made to be plunger seals more than valves, had almost scrapping close fit, so much so before I even put on road, took sand paper by guess/by golly educated relief at 'neutral' inch in sag area to be so flabbergassingly pleased, can only hope any one else attempts are half as effective pleasing. If ya quiz Fualth kit users which only a couple online here, they all say they seek out hitting deepest pot hole edges and curbs at oblique angles trying to feel any sense of upset, time and time again as so addictive uncannty absorbing. Sane people avoid obvious high impact edges but hobot-Faulth users make a hobby out of it as can't believe how good it feels to feel nothing. I would not believe hobot either so can't bad month the Landsdowne or Shawa devotees as they know not what they are missing out on and not part of bigger Commando world to know better.

Current best there is Landownes/Shawa vendors/machinists only compare to factory forks of financial stressed short cut stop gap ruined non functional obnoxious Roadholders but there's a reason they were called unapproachable road holders, once upon a prior time. hobot has forgotten more on Roadholders history details than all's ya all's put together, as accessnorton, good as it is, is rather recent and limited compared to what's gone on before and outside its posters.

To put in hobot pecking order reality perspective, good forks only mater on sane public roads thrills and best vintage race powered rigid mounts - that ain't capable of tri-linked handling hook up acceleration that fully extends lengthened forks, for farther leans, to top out silent indefinte unfelt then lift off slight wheelies leaving apexes, so mention this as no fork can handle the actual turning power of rear patch when gets down to it. Won't cost much to try hobot advice & reversal but bet ya never go back, if ya got any riding thrilling spirit left.