Author Topic: Steering damper system  (Read 1944 times)

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Offline Endeavor

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Steering damper system
« on: 28 Sep 2009 at 03:26 »
Hello

On most old motorcycles I have worked on they have a rod the passes through the center of the steering stem to apply pressure to the fiber damper, however on my Endeavour the bottom threaded boss appears to be a permanent part of the steering stem It seems strange. Can any one advise as to why mine might be like this.

Cheers Alastair

« Last Edit: 30 Sep 2009 at 20:23 by Dave »

Offline eddie

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Re: Steering damper system
« Reply #1 on: 28 Sep 2009 at 07:21 »
Alastair,
              From the photo, your fork stem looks to be the same as that on the 'Druid' forks that I have on my sprinter. Unfortunately, from the photo, it is not easy to make out whether the cross pivot is in line with, or fore or aft of the centre column. On mine, it is in line and the bottom of the stem has a machined face for the friction disc. This face also has 2 locating pegs - in line with the cross tube - to locate the bottom damper plate. The order of assembly (from the centre column, down) is: 1 friction plate, 1 steel plate that anchors to the frame (shown in photo), a second friction disc, a second steel plate (with 2 holes for locating pegs and a tongue to locate on the centre plug), and a 'star' spring. All this is mounted on a headed centre plug which is a sliding fit in the bottom of the column. Now this plug has to have a slot machined through it to accommodate the bottom fork pivot pin, and a keyway for the tongue on the bottom plate - and the top is threaded for a stud to connect it to the damper knob. The biggest drawback with this setup is that the forks have to be dismantled to remove the bottom pivot if the damper needs any attention.
         From your photo, it looks as if the centre plug my have been modified to have a removable nut instead of the head - in which case, it would then be possible to dismantle the damper without pulling the forks apart.
       Hope this makes some sense!! - get back to me if you need any more details.
                                 Regards,
                                          Eddie.

Offline Endeavor

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Re: Steering damper system
« Reply #2 on: 29 Sep 2009 at 01:32 »
Thanks Eddie

I will hunt the missing pieces up. Mine must of had 73 years of rust holding the boss in the stem as it took a lot of pressure to push it out in a hydraulic press. It was in that tight that I thought it was one piece.

Cheers Alastair

Offline Doug

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Re: Steering damper system
« Reply #3 on: 29 Sep 2009 at 10:01 »
Here is a picture of the lower portion of the steering damper rod for a 1936 600cc Aero;  same setup as used on the Endeavour I would imagine.



The friction disks appear to have been cut out with snips. Original so far as I know (the rest of the bike was very original an unaltered) and likely reflects the austerity at Douglas prevalent at the time!

-Doug

 

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