Roadholder forks length differences

While doing some maintenance on the Commando with the front wheel off I noticed that the free length of the left hand fork leg is maybe a half inch longer than the right hand side. In order to get the front axle installed I must compress the left hand leg upwards to get the axle holes lined-up. At first I thought the damper rod might have unscrewed from the fork cap but this wasn't the case.
Here's a pic of the resting fork length. The axle obviously isn't centered in the hole but you get the idea:



I rebuilt the forks a couple years ago with new stock AN springs and seals. I was hoping someone might immediately recognize the problem here so I don't have to tear everything apart. Fork tubes are pulled up tight into the top yoke. Is it possible the forks have different length damper rods? The LH fork leg will compress upwards fairly easily while the RH leg spring tension is very strong. This bike has always pulled to the right slightly but I was never able to find any bent frame tubes or fork yokes. I recall that Atlas forks are slightly shorter. Perhaps there is an Atlas fork component mixed-in somewhere. It never occurred to me to compare the 2 fork tubes for length.

Here's a pic from the fork rebuild several years ago:



Thanks.

Atlas/short roadholder forks are about 2 inches shorter than Commando.
So that is unlikely to be your immediate problem.

Drained the oil yet, to see what comes out.
(And, ultimately, replaced with the correct quantity of oil).

1 inch is not normal, you need to strip out the dampers and measure the parts,
I cannot see the damper rod being screwed into one top nut further than the other side..more than 1 inch!
1/16 difference would be normal,and that can be adjusted out via the amount the 3/8 unf rod is screwed into the top nut.
Sounds like one rod is longer,due to the compression difference . Good time to change the oil anyway.

OK, I found part of the problem. The spring retainer nut on the LH damper rod had backed-off around half way.
So the rod was not fully seated into the fork top nut. I think this accounts for around 3/8".
After checking both and tightening everything it's much better, but there is still maybe 1/16" difference.

Did ya put two thick gaskets/washers under the longer leg damper tube? Valve at ends of rods may be that much off? You've got it down to insignificant anyway.

hobot said:

Did ya put two thick gaskets/washers under the longer leg damper tube? Valve at ends of rods may be that much off? You've got it down to insignificant anyway.

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I don't think so but I guess it's possible. During the last rebuild I had polished the fork legs and rinsed them out thoroughly with hot soapy water and WD-40. I know they are hard to see down in the bottom of fork leg. I seem to remember having a leaky fork oil drain screw afterwards so I had to pop the fork nut off to refill it and probably didn't secure the damper rod properly.

Mark all I can say is thanx for sharing some vigor to steal time to dive back in again and again with hopes ya didn't screw something else up finishing off something else wrong not even your fault. Damper cap stops extension so possible one damper rod screws itself a bit deeper when nipping down the top cap bolts. At least ya got it into mere academic worry range now.

3/8 + 1/16 = 1 inch?

mschmitz57 said:

OK, I found part of the problem. The spring retainer nut on the LH damper rod had backed-off around half way.
So the rod was not fully seated into the fork top nut. I think this accounts for around 3/8".
After checking both and tightening everything it's much better, but there is still maybe 1/16" difference.

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john robert bould said:

3/8 + 1/16 = 1 inch?

mschmitz57 said:

OK, I found part of the problem. The spring retainer nut on the LH damper rod had backed-off around half way.
So the rod was not fully seated into the fork top nut. I think this accounts for around 3/8".
After checking both and tightening everything it's much better, but there is still maybe 1/16" difference.

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Poetic Licence. its obvious from the first picture. Its like the 1/2 hour wait when your in a hurray, really only 4 minutes.
Dereck

Dereck

mschmitz57 said:

OK, I found part of the problem. The spring retainer nut on the LH damper rod had backed-off around half way.
So the rod was not fully seated into the fork top nut. I think this accounts for around 3/8".
After checking both and tightening everything it's much better, but there is still maybe 1/16" difference.

Click to expand...

Can you account for fiber washers on the bottom. They're about a 1/16" They can and will hide down there. Unkmowingly adding an extra or leaving one out would do it.

I have known where a fiber washer as been folded over double ,producing different lengths . glue them on to the damper base with a little sealant, they carn't fall off on assembly.