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Roadholders

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Roadholders

Posted by robert_dixon at July 06. 2018

Can someone please advise me on the bushes and seals for Roadholders, are all roadholder bushes and seals the same. I wish to replace the ones in my 1949 500T.

Thank you.

Re: Roadholders

Posted by ian_macdougall at July 10. 2018

Hi Robert, as far as I know the bushes and seals are common to all Roadholders. Someone please correct if I've got that wrong.

Ian McD

Re: Roadholders

Posted by philip_hannam at July 10. 2018

Ian is quite correct.  All the Roadholder forks used the same seals and bushes. The difference between Short Roadholder and Long lies in the way these parts are held in position.  In the Short versions the bottom steel bushes have large circlips holding them to the stanchions. On Long forks there is a large hexagon sleeve nut and washer.

The Phosphor Bronze bushes and oil seals are generally held in place by the Lower Chrome Shroud on the Short Forks, whereas on the Long version or any Forks with exteral springs there are shouldered inserts that thread into the top of each boot.

Attachment may help if enlarged......a lot!!!

Attachments

Re: Roadholders

Posted by ian_macdougall at July 12. 2018

After 40+ years of Norton ownership I should really know the answer to this, but I have to confess I am not sure. Which way up should the Roadholder seal be fitted? I think that usually the open side of a seal should face the oil, so in this case open side down, facing the bush. But there is a paper washer between bush and seal. If the paper washer sits against the open side I can't see it doing anything useful, more logical for the washer to sit between the closed side of the seal and the bush. There must be a right way round for this, does anyone have the definitive answer?

Cheers, Ian McD

Re: Roadholders

Posted by barry_carson at July 12. 2018

i was looking at the diagram in the link on the short roadholders is there something a miss with the way it shows the seal holder it should be above the seal washer ect. mind you wheres the seal.   unless i am looking at it wrong

Re: Roadholders

Posted by ian_macdougall at July 12. 2018

I have spoken to RGM about the seal direction - open side down.

Cheers, Ian McD

Re: Roadholders

Posted by philip_hannam at July 12. 2018

The golden rule of almost every oil seal is OPEN faces OIL. Or OPEN side faces the oncoming OIL.  On a Norton this rule applies to the forks, crankshaft, timing cover and gearbox seals. The awkward one for this rule is the timing cover. In this case the open side faces the oncoming oil flow which is sent through the case via the oil pump.

With regard to the paper washer inside the forks. Many of the bush and seal replacements kits do not contain such any more. Its original purpose was to sit on top of the oil seal and act as a buffer against the seal holder. I guess the idea being to prevent the top of the oil seal being torn by the base of the seal holder, when it was screwed down in place. Like with  modern car and bike oil filters a dab of oil or grease will do the same job.

Re: Roadholders

Posted by ian_macdougall at July 12. 2018

Hi Philip, I'm happy with the seal principle Open side facing Oil. Less convinced by the paper washer thoughts. The exploded diagram for Long Roadholders in the '56 Model maintenance manual clearly shows the components in ascending order as Bush/Paper Washer/Seal/Retaining Ring/Leather Washer/External Spring. The paper washer is sandwiched between bush and seal so not protecting the seal from the retaining ring. The only part of the seal that will be in firm contact with the paper washer will be the outer edge. It must have some purpose but it's not obvious; I'm not going to lose any sleep over it! Forks reassembled with new seals (right way up) and paper washers. Hopefully it will be a while before they start leaking again.

Ian McD

Re: Roadholders

Posted by philip_hannam at July 13. 2018

Ian.....I agree with you.  All of my Commando Fork drawings/diagrams show the paper seal between the top bush and the oil seal. Perhaps it acts as a barrier to keep some oil inside the seal and any metal debris away from it.

This link is worth checking out. It shows Mick Hemmings in action refurbushing a set of forks. Spot any mention of a paper washer!!!

http://archives.jampot.dk/Technical/Suspension/Norton_Roadholder_Stripdown.pdf

Re: Roadholders

Posted by ian_macdougall at July 13. 2018

Thanks Philip. I will file that for future reference.

Ian McD

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