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British Bikes / Re: Information about a Norman Rambler?
« on: March 21, 2024, 02:38:55 AM »
Norman fork’s range from the sublime to the gorblimey, but all present unusual problems to the modern restorer.
Norman first discarded girders to make their own forks in the late 40’s. This was the period when Britain had cleaned up after WWII and everything had to be new and fresh. Girders were out and télés were in except few designers actually had any idea of how they worked.
The Norman concept had a quantity of oil held in the top of the teles above the seals where it would magically provide some sort of damping action. They further provided a balance tube on the top yoke connecting each leg so oil could move itself from leg to leg to balance out the action. The Owners Manual carefully advises that a quarter pint of engine oil only needs to be poured in one leg for successful operation. Further to this they fitted grease nipples to lubricate the bushes and advised they should be oiled (not greased)every 200 miles.
In service the oil soon found its way past the seals to fill up the void below. Needless to say no drain plug was provided so the oil just accumulated and steadily reduced the fork action as it did so. The only way you find out why your forks don’t work is to pull them apart and find the accumulated mess. Luckily, having a fairly extensive library I found various illustrations in Show magazines of the day that helped a lot.
To be fair Norman realised this quite quickly removing the balance tube and revising the Owners Manual to just providing enough oil to lubricate the internals and no more. Problem solved——-not.
Unfortunately the most easily available Owners Manual is the early version without the fork revisions and you don’t even know the revisions exist until a friend chances on a later copy in an op shop. Needless to say Norman didn’t reprint the Manual but merely printed the revised instructions on a slip of paper and glued it over the top of the original. Using a minute blob of glue of course so you can flip back and forth to see both.
After a few years Norman dropped their own make forks and fitted early undamped MP (Metal Precision) forks. Neither better nor worse than their own I think it was just cheaper and easier to buy in forks than develop their own.
Early MP forks are what current riders call “upside down ‘ forks with the slider working up and down inside a bushed outer shroud. When the fork bushes are worn out the sliders will have twice the wear and also need replacing. Essentially rather than being the wearing part the bushes act as laps. Road grit and the like embeds itself in the bushes then wears away the sliders much more effectively than it does the bushes. As there are no spare’s available rebuilding early MP forks requires pretty good machine shop facilities. And I’m not even mentioning the basic design that makes disassembly without damage a nightmare.
Finally Norman fitted Armstrong leading link forks. Bang up to date and as good a lightweight fork as you could get at the time. Pity Armstrong disappeared from the game. Rebuilding a set of Armstrong’s will lead down many rabbit holes and expenditure. Even worse if they are bent. But a late model Norman twin is a very pretty bike and rides as well as it looks.
So there you are, get yourself a classic Norman and you will have a bike where the front end restoration may take as much effort as the rest of the bike.
Norman first discarded girders to make their own forks in the late 40’s. This was the period when Britain had cleaned up after WWII and everything had to be new and fresh. Girders were out and télés were in except few designers actually had any idea of how they worked.
The Norman concept had a quantity of oil held in the top of the teles above the seals where it would magically provide some sort of damping action. They further provided a balance tube on the top yoke connecting each leg so oil could move itself from leg to leg to balance out the action. The Owners Manual carefully advises that a quarter pint of engine oil only needs to be poured in one leg for successful operation. Further to this they fitted grease nipples to lubricate the bushes and advised they should be oiled (not greased)every 200 miles.
In service the oil soon found its way past the seals to fill up the void below. Needless to say no drain plug was provided so the oil just accumulated and steadily reduced the fork action as it did so. The only way you find out why your forks don’t work is to pull them apart and find the accumulated mess. Luckily, having a fairly extensive library I found various illustrations in Show magazines of the day that helped a lot.
To be fair Norman realised this quite quickly removing the balance tube and revising the Owners Manual to just providing enough oil to lubricate the internals and no more. Problem solved——-not.
Unfortunately the most easily available Owners Manual is the early version without the fork revisions and you don’t even know the revisions exist until a friend chances on a later copy in an op shop. Needless to say Norman didn’t reprint the Manual but merely printed the revised instructions on a slip of paper and glued it over the top of the original. Using a minute blob of glue of course so you can flip back and forth to see both.
After a few years Norman dropped their own make forks and fitted early undamped MP (Metal Precision) forks. Neither better nor worse than their own I think it was just cheaper and easier to buy in forks than develop their own.
Early MP forks are what current riders call “upside down ‘ forks with the slider working up and down inside a bushed outer shroud. When the fork bushes are worn out the sliders will have twice the wear and also need replacing. Essentially rather than being the wearing part the bushes act as laps. Road grit and the like embeds itself in the bushes then wears away the sliders much more effectively than it does the bushes. As there are no spare’s available rebuilding early MP forks requires pretty good machine shop facilities. And I’m not even mentioning the basic design that makes disassembly without damage a nightmare.
Finally Norman fitted Armstrong leading link forks. Bang up to date and as good a lightweight fork as you could get at the time. Pity Armstrong disappeared from the game. Rebuilding a set of Armstrong’s will lead down many rabbit holes and expenditure. Even worse if they are bent. But a late model Norman twin is a very pretty bike and rides as well as it looks.
So there you are, get yourself a classic Norman and you will have a bike where the front end restoration may take as much effort as the rest of the bike.