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Japanese Bikes / Re: clutch slave number two.
« Last post by toglhot on March 27, 2024, 06:04:25 AM »
More pics
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Japanese Bikes / clutch slave number two.
« Last post by toglhot on March 27, 2024, 06:00:20 AM »
Previously I made a clutch slave with a 25mm piston. I bought a 9.5mm master cylinder and hooked it up. No go, the master only moved the slave piston a little under 1mm, not enough to separate the plates, so, back on the lathe.

I had a couple of 20mm hydraulic ram seals so turned up a slave from 6061, recessed the top to take the seal and turned up a 20mm stainless piston.

The slave sits inside the cover near the sprocket and chain, so, its a rather dirty environment. There was imsuficient space to add a dust seal. Instead I turned up a 3mm cover which also doubles as a seal stopper, stopping the seal from popping out.
To mount the slave I shaved 3mm off the side to miss the wall separating the area from the alternator. Then mounted the cover on the mill and bored the mounting hole out from 26 to 29mm, making a neat fit for the slave. To hold the slave in place, I drilled the M5 threaded holes through and recessed the outside of the cover to fit the Allen heads.

Hooked up the master to test it out and discovered the piston had jammed. I managed to get it apart only to find the seals had expanded, now too big for the bore. The add for the master said it was mineral oil friendly, so taking the sellers word, that's what I used. As we all know, introduce petrolium based products to brake seals and they expand, so the ad was obviously wrong, the slave is brake fluid friendly.

I can't get any seals for this master, so it went in the useless parts drawer and I set about modifying the cover to take the original screw type actuator again. Two stainless T nuts were turned up to fit in the 6mm hole, threaded internally M5 and then pressed into place. A Delrin ring 26mm ID, 29mm OD was then turned up and pressed over the screw actuator and the lot assembled.

To ease the clutch pull for my fused arthritic fingers I made an extended lever for an old actuator by 5mm, turned up a seal keeper and welded everything together. So, back to cable operation.

If I ever manage to find seals for the master I simply have to press the stainless T nut out of the case and install the 20mm slave.
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Autojumble / 1937 J A P 500cc bearing cage wanted
« Last post by D.R on March 23, 2024, 10:05:00 AM »
I’m looking for the main bearing cage on the drive side on a 1937 500cc J A P engine it has 2 rows of 5/16” x 1/4” rollers,if anyone might have one, thanks David
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British Bikes / Re: Information about a Norman Rambler?
« Last post by Rex on March 22, 2024, 09:56:27 AM »
The past is truly a foreign country, as the old cliche goes.
Take Scott, postwar. Presumably they started with a blank sheet of paper with a sports bike for the new era of post-war enlightenment.

"Righto Smithers, take down the following model requirements-
1) oil injection, no premix here
2) double-sided front brake, huge back brake for max braking efficiency
3) Oleo-pneumatic Dowty forks developed from WW2 aircraft landing gear and giving a wonderfully supple and compliant ride
4) Water cooled engine for max power and efficiency."

"Very good boss, but how about the number of gears and rear suspension?"

"A three speed gearbox and a rigid rear is good enough for any chap and that's what we'll fit".
And so they did, and duly went under three years later.
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British Bikes / Re: Information about a Norman Rambler?
« Last post by cardan on March 22, 2024, 09:21:17 AM »
It's the same photo! I've not figured out where it was taken - the photo is part of a collection attributed to British Tube Mills, and presumably it was in Adelaide, and now we knoe it was c1954 I will take another look.

Leon
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British Bikes / Re: Information about a Norman Rambler?
« Last post by cardan on March 22, 2024, 05:57:19 AM »
Wow.

I'd love to be a fly on the wall when management and designers were talking over new models and future directions. We think of 2-stroke lightweights as being pretty utilitarian, but there were obviously people in the companies who had aspirations to build a better mousetrap. I have to admit I don't know (or didn't know!) much about Normans, but I'll think better of their efforts from now on.

I recently researched Tilbrook in South Australia, and like some of the more interesting UK brands (DOT, DMW, Greeves...) it was a good reminder that there were some very interesting Villiers-engined bikes built in the 1950s.

Re the swing-arm Roamer in the photo above, I'd say 33d6 is spot on with 1954 (see attached). In 1951 and 1952 Super Elliott seem to have sold autocycles and Villiers engined "Super Elliotts", but I could find no photo or survivor... I assume they were just re-branded Norman/Roamer/Rambler. Yell if you've seen one!

Cheers

Leon

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British Bikes / Re: Information about a Norman Rambler?
« Last post by R on March 21, 2024, 10:55:16 PM »
Oddly enough, you can almost substitute the word Norman with Norton here, and get almost the same story !!

Almost - the technicalities vary a little.  But spread over many decades.
Damping was almost a foreign concept back in those days !
And were often a case of one step forward, one backwards and 2 sideways. ?
We diverge, so the details can wait ...
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British Bikes / Re: Information about a Norman Rambler?
« Last post by 33d6 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.
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British Bikes / Re: Tiger T100s 500cc engine knock
« Last post by Rex on March 20, 2024, 03:55:49 PM »
So, how did the 500S engine knock turn out, or even the Villiers spark plug? ;)
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