Fork upgrade

Classic Norton Commando Motorcycles.

Fork upgrade

Postby stockie2 » Sat Mar 24, 2012 4:37 am

Well, I am ready to test out the latest handy work tomorrow. I have my fancy new Landsdowne dampers in, but have now made up composite Teflon bushes. I had made my own bronze, extended top bushes, so these were cut back in length and bored out to accept a Teflon bush I spun up myself, I left a seat in the bottom and installed a thin washer at the top over the flanged section of the bush, to locate the bush. I inserted the Teflon into the bronze when it was still solid, then drilled and bored the interior to mate up with the 34.5mm forks. The section is pretty thin, but it is well located in the bush, so we will see how it lives. The sliding effect is very good, even with twisted side load it glides, unlike standard sintered bronze. I performed a similar trick on the bottom bush to locate a thin Teflon outer over the original floating bush. Geez the forks feel like those modern bikes now. Also I did the trick with the Honda fit fork seals, one other Forum member wrote about, they are 35mm internal and very slightly larger in od, about .3 of a mm. I made up a little seal holder out of nylon that allowed me to mount the seal in the lathe, without damaging the seal and skimmed off the od to make a nice fit in the Norton slider. These seals certainly slide nicer than original seals.

Well, report back on riding experience after tomorrow's run

Cheers Richard

stockie2
Posts: 328
Joined: Tue Apr 19, 2011 7:33 pm
Location: Sydney Australia

Re: Fork upgrade

Postby john robert bould » Sat Mar 24, 2012 4:47 am

Richard, Great to see the lads down under are trying differant idea's. I have just had one of your lads reporting back , he's over the moon with the kit..he now steers into ruts just to get the smile!

john robert bould
Posts: 1964
Joined: Sat Sep 26, 2009 12:18 pm

Re: Fork upgrade

Postby 303 fmj » Sat Mar 24, 2012 10:21 am

stockie2 wrote:Well, I am ready to test out the latest handy work tomorrow. I have my fancy new Landsdowne dampers in, but have now made up composite Teflon bushes. I had made my own bronze, extended top bushes, so these were cut back in length and bored out to accept a Teflon bush I spun up myself, I left a seat in the bottom and installed a thin washer at the top over the flanged section of the bush, to locate the bush. I inserted the Teflon into the bronze when it was still solid, then drilled and bored the interior to mate up with the 34.5mm forks. The section is pretty thin, but it is well located in the bush, so we will see how it lives. The sliding effect is very good, even with twisted side load it glides, unlike standard sintered bronze. I performed a similar trick on the bottom bush to locate a thin Teflon outer over the original floating bush. Geez the forks feel like those modern bikes now. Also I did the trick with the Honda fit fork seals, one other Forum member wrote about, they are 35mm internal and very slightly larger in od, about .3 of a mm. I made up a little seal holder out of nylon that allowed me to mount the seal in the lathe, without damaging the seal and skimmed off the od to make a nice fit in the Norton slider. These seals certainly slide nicer than original seals.

Well, report back on riding experience after tomorrow's run

Cheers Richard



Glad to hear you like the Honda seals. i've been using them for a long-long time now since the mid 80's. I just use some 80 grit on the od to get them to fit.
I also pack the recess area of the seal with silicone grease for lubrication---the stuff BMW used on the early K-bike steering head. I have never had a seal problem
with these. I also use gaiters to protect the fork seal swept area.
75 MK3 I/S
68 750 F/B
2008 Thruxton
2004 BMW R1150RS
1974 Ducati 750 GT
plus others

303 fmj
Posts: 147
Joined: Thu Jan 05, 2012 8:02 pm
Location: USA

Re: Fork upgrade

Postby hobot » Sat Mar 24, 2012 10:51 am

Would one of ya send a pn or site with these H--da seals please.
Its an uncanny treat to hunt for ruts and lumps to hardly notice em.
Throw yourself at the ground and miss!
User avatar

hobot
Posts: 15948
Joined: Wed Oct 19, 2005 6:59 pm
Location: Arkansas, Dixieland

Re: Fork upgrade

Postby ludwig » Sat Mar 24, 2012 1:52 pm

I use Ariete seals :
http://www.ariete.com/en/ari_app/

Type : ARI.003T
Also 35 mm and a litlle bit from the rubber coating must be removed .
Seals perfect and less stiction than std seals .

ludwig
Posts: 1647
Joined: Wed Aug 30, 2006 3:57 am

Re: Fork upgrade

Postby 303 fmj » Sat Mar 24, 2012 6:17 pm

hobot wrote:Would one of ya send a pn or site with these H--da seals please.
Its an uncanny treat to hunt for ruts and lumps to hardly notice em.



the Honda part number is 91255-KBH-003------this is the newest part number--so you should be able to find them easily----they fit many models with 35mm tubes.
75 MK3 I/S
68 750 F/B
2008 Thruxton
2004 BMW R1150RS
1974 Ducati 750 GT
plus others

303 fmj
Posts: 147
Joined: Thu Jan 05, 2012 8:02 pm
Location: USA

Re: Fork upgrade

Postby stockie2 » Mon Mar 26, 2012 3:52 am

Yes John, the forks are now fantastic, the slipperyness of the teflon really compliments your fine dampers. The best part of this mod is apart from the cool looking top nuts, nobody can understand why the forks work so well compared to standard RH's. I find I can definitely push the bike harder in twisty's. The rear shocks now feel a little inadequate! (Hagon's) But for now I am very happy with the result. Regarding the Showa fit seals, if you have access to a lathe, a nice way to modify these seals to fit in the Roadholders is to make up a collet to machine them on. I used some scrap nylon rod, and just machined a step @ 36mm so the seal can be eased on and machined with light cuts on the rubber.
I am getting some rattling from somewhere, could be the fork springs? But the action is spot on.

Cheers Richard

stockie2
Posts: 328
Joined: Tue Apr 19, 2011 7:33 pm
Location: Sydney Australia

Re: Fork upgrade

Postby john robert bould » Fri Mar 30, 2012 10:53 am

Richard, Did you find out what the [spring] rattle is?

john robert bould
Posts: 1964
Joined: Sat Sep 26, 2009 12:18 pm

Re: Fork upgrade

Postby stockie2 » Fri Mar 30, 2012 2:06 pm

Dear John, Saturday here, so I will take a peek. I used the progressive springs I had, not sure if that compounds the issue? There is 10 inches of damper rod that is available to make a spacer between spring and the rod, my next experiment was to put some nylon in there?

Cheers Richard

stockie2
Posts: 328
Joined: Tue Apr 19, 2011 7:33 pm
Location: Sydney Australia

Re: Fork upgrade

Postby hobot » Fri Mar 30, 2012 3:51 pm

MIght just be headlight area rattle, but if spring slack, i highly recommend a stiff spring spacer instead of a solid piece.
Throw yourself at the ground and miss!
User avatar

hobot
Posts: 15948
Joined: Wed Oct 19, 2005 6:59 pm
Location: Arkansas, Dixieland


Return to Norton Commando Classic Motorcycles

Who is online

Users browsing this forum: aceaceca, boda, DogT, htown16, mike996, MikeM, OldBalz, worntorn and 1 guest