English French German Italian Spanish

Roadholder forks overextend - Part 2

Submitted by jim_algar on Sun, 21/04/2013
Forums
Heavy Twins

Have worked on my Roadholder forks, which when fully extended left a gap between the seal holder chrome top and the shrouds (see original thread for photo.) Partially disassembled, everything looks right. Stanchions measure 23.3, correct for "long" Roadholders. Bushings are correct and in place, as is oil seal. First question; is there a "right side up" for the oil seal? Open or closed end? Second question; what stops the forks at full extension is the two bushing -- upper and lower -- meeting, yes? I haven't pulled the damper tubes our of the legs yet; anything I should be looking for there? When fully extended, distance between top surface of upper yolk and center of axle was 29 inches, which people here should be 28. So where is the extra inch coming from? Photo attached.

Attachments Fork1.jpg

Submitted by martin_rowe on Sun, 21/04/2013

Permalink

Hi Jim, don't know if you've done a typo, and have no idea of the dimensions of stanchions myself, but I think you'll find that your bike has short, not long roadholders, the latter I think having their springs on the outside. I stand to be corrected of course.

Submitted by jim_algar on Mon, 22/04/2013

Permalink

I've done some research which suggests (if I'm understanding it) that "long" Roadholders (23.3-inch stanchions) are pre-featherbed, and that with the featherbed models (like mine) came the "short" Roadholders (21.8-inch stanchions). I've just re-measured my stanchions and they are most definitely 23.3. Has my 1956 99 been fitted with the wrong stanchions at some point, creating a hybrid with (correct) inner springs but wrong (long) stanchions?

Submitted by martin_rowe on Mon, 22/04/2013

Permalink

I've just measured my old stanchions that were replaced last year, and they come out at 21 7/8"('58 Model 99). Personally I would say your stanchions are not correct for your bike, and this might explain the gap. Seems odd that all seemed well before taken apart though. Is it possible to force the sliders up when fitted on the bike so that they look right fully compressed (might be easier to do this without the springs)? Does the gap disappear with the wheel on the ground?

Submitted by martin_rowe on Mon, 22/04/2013

Permalink

Just to respond to your other questions Jim, the length of travel is determined by how far the damper rod can go up and down in the damper tube as far as I know, I don't believe the top and bottom bushes come into contact with each other in normal use. The damper rods are held in the tubes by ally screw-on caps (prone to wear and bloody expensive). You fit the seals sealed-side up - in other words, if you can see the seal spring once you've fitted them they're the wrong way round.

Submitted by michael_sullivan on Mon, 22/04/2013

Permalink

Jim:

Here's a silly question:

In your original posting you state that you rebuilt the forks.

The question is: were they correct before you rebuilt them or were they the way they are now?

Submitted by jim_algar on Mon, 22/04/2013

Permalink

When I bought the bike there was no apparent gap underneath the lower fork shrouds, but that was with weight on the front wheel. It's been so long (years) since I started the rebuild of the bike that I cannot remember if the gap appeared when the bike was up on the centerstand.. I have scoured the Internet for pictures of featherbed Dominators and have not seen a single one showing such a gap as mine exhibits, even when on the centerstand with air under the front wheel. Therefore, all evidence points to the fact of my bike having had the proper ("short" 21.8-inch) stanchions replaced at some point with incorrect ("long" 23.3-inch, i.e. pre-featherbed or Commando) stanchions. So I'm on the hunt for the proper parts.

Thanks for the help and suggestions, all.

 


Norton Owners Club Website by 2Toucans