Author Topic: Norton plunger suspension seized.  (Read 16505 times)

Offline Rex

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Re: Norton plunger suspension seized.
« Reply #30 on: March 29, 2018, 04:08:26 PM »
How about cutting the spring vertically? At least that way the cut ends will move in the same plane as the cutting disc.

Offline mini-me

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Re: Norton plunger suspension seized.
« Reply #31 on: March 29, 2018, 05:11:41 PM »
Can you get a new spindle? In that case I'd  just cut right through the damn thing with an angle grinder.

I once dropped one of these bikes  on my foot, hence lost all my interest in plunger Nortons >:(

Offline iansoady

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Re: Norton plunger suspension seized.
« Reply #32 on: March 30, 2018, 10:18:27 AM »
My local Norton dealer seems to be right out of them but I can make one.

I'll have a go at cutting through it today. If I disappear from the forum I'll have cut through my hand as well........
Ian
1952 Norton ES2
1986 Honda XBR500
1958-ish Tre-Greeves

Offline iansoady

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At last some light.....
« Reply #33 on: March 30, 2018, 12:04:36 PM »
Successfully chopped through the bearer bar as the cutting disc just fitted between the spring coils. It was a little fraught getting the remains off as I had to slide the assembly a long way sideways to get my compressor in and I was waiting for the whole lot to take off past my ear.

I now have the remains of the bar starting to move in the slider after a lot of heat and more penetrating oil so am feeling very pleased with myself. As I suspected it's very rusty which is what was seizing it into the slider.

Now all that remains is to get the shroud welded up, get a pair of springs made and to make a new bearer bar. Final photos will follow.

Many thanks to all here for helpful suggestions. Unlike the NOC where I got none.........
Ian
1952 Norton ES2
1986 Honda XBR500
1958-ish Tre-Greeves

Offline 33d6

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Re: Norton plunger suspension seized.
« Reply #34 on: March 30, 2018, 02:02:29 PM »
Now you understand my enthusiasm for wrapping it all up in a bed sheet before removal. No drama. No bits flying about. No waiting for the left ear to be plucked off as a spring whistles past a bit close.

It makes you wonder if the designer ever thought how his design could be put together or pulled apart again for maintenance or just left it to the bods on the shop floor to cobble up something. I suspect the latter.

Offline john.k

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Re: Norton plunger suspension seized.
« Reply #35 on: March 30, 2018, 02:17:11 PM »
John Deere graders are the worst,designed to go together on the assembly line,and be completely inaccesable for field repairs to quite simple parts.

Offline iansoady

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Re: Norton plunger suspension seized.
« Reply #36 on: March 30, 2018, 02:26:23 PM »
The recommended Norton technique actually works quite well (long threaded rod) but I had to move the whole lot much further out as the rod had to go up the middle of the bearer rod, which was thoughtfully provided with a through hole at Bracebridge Street. It meant there was only 1/3 or so of the shroud engaging with the frame. I did consider the bedsheet......

Anyway, I've now successfully got the very rusty remains of the rod out of the slider so can start planning the rebuild. Sadly the bearer rod is a bigger diameter than I can get in my Chinese lathe so will need to find a helpful person to make that for me.

I'm so relieved to have managed to get it all apart however.
Ian
1952 Norton ES2
1986 Honda XBR500
1958-ish Tre-Greeves

Offline iansoady

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Where to get springs?
« Reply #37 on: April 03, 2018, 10:40:59 AM »
I now need a pair of main springs making. In the (fairly) distant past I've used Paul Savage in Redditch but his phone number is now coming up as unobtainable. Probably he's of an age to have packed it in.

Any suggestions - preferably in Redditch, centre of the spring and needle making world?
Ian
1952 Norton ES2
1986 Honda XBR500
1958-ish Tre-Greeves

Offline Rex

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Re: Norton plunger suspension seized.
« Reply #38 on: April 03, 2018, 10:52:27 AM »
Active Springs were always good, but the last time I had some hairpin valve springs made to pattern for an old French bike they took eleven weeks and the Summer was over.
They were quality though, so maybe I was just unlucky.

Offline iansoady

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Re: Norton plunger suspension seized.
« Reply #39 on: April 03, 2018, 12:15:17 PM »
Yes, I think those companies would much prefer manufacturing in large quantities.

Actually, I've looked more closely at my existing springs and have successfully dressed out the minor marks made by my inept angle grinding without thinning the parent metal significantly.
Ian
1952 Norton ES2
1986 Honda XBR500
1958-ish Tre-Greeves

Offline iansoady

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Success at last
« Reply #40 on: April 23, 2018, 02:58:28 PM »
Having chopped the main spindle ("bearer bar" in two, I was hoping I'd be able to make a new one myself but my tiny Chinese lathe doesn't have the capacity.

So I turned to someone who goes by the name "divie" on the Real Classic forum. An ex-toolmaker of many years experience, he has a very well equipped small machine shop in his garage. He very quickly made me a new spindle out of EN16T which fits to perfection and now the back end is all together.

Onwards and upwards!



You can just see the top of the new bearer bar peeking out here:

Ian
1952 Norton ES2
1986 Honda XBR500
1958-ish Tre-Greeves