You are welcome. For future reference there is also SearchByBore if you get stuck. Might have to turn a land or two, but its an option. Easier to phone Deves though.
Latest Project - Norton Manx with Matchless G50 engine
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Yep. Will take some photo's.
Have been busy on other stuff, photos of some below, nice I think.
Spondon FZ - reworking this bike, now with 146 at back.
1986 UK spec Suzuki GSXR1100 full restoration.
Triumph Thruxton T120 1965, full restoration with a proper engine and making a health 57hp at the back.
Progress! Actually the bike is far further on that the photos suggest. For example the magneto is completely rebuilt, top end has been on the engine, gearbox rebuilt, forks and rear suspension sorted. Both wheels are done etc.
I have been fixing lots of little problems which turned out to be a little difficult to resolve. The gearbox output bearing was spinning in the gearbox case so the bearing needed hard Chrome plate and grinding back to take up the slack. There had been a modification to the gearbox mainshaft and clutch centre to move the clutch for primary chain alignment but I needed to reverse this mod as straightening frame and engine plates meant the original alignment no longer worked.
So the engine sprocket to clutch chainring alignment and alignment of the rear wheel sprocket with the gearbox sprocket took a bit of thought. The way the bike was built had everything spaced on a very odd way. So I’ve started again - it was easier.
Hopefully I’ll have the top end on the G50 in s few days. Then sort the controls, then it’s just the exhaust to make,.
I have been fixing lots of little problems which turned out to be a little difficult to resolve. The gearbox output bearing was spinning in the gearbox case so the bearing needed hard Chrome plate and grinding back to take up the slack. There had been a modification to the gearbox mainshaft and clutch centre to move the clutch for primary chain alignment but I needed to reverse this mod as straightening frame and engine plates meant the original alignment no longer worked.
So the engine sprocket to clutch chainring alignment and alignment of the rear wheel sprocket with the gearbox sprocket took a bit of thought. The way the bike was built had everything spaced on a very odd way. So I’ve started again - it was easier.
Hopefully I’ll have the top end on the G50 in s few days. Then sort the controls, then it’s just the exhaust to make,.
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Cases turned out nice! Finding someone over here that is trustworthy to chrome and grind bearing races would be a colossal challenge. Another option is..... brace yourself... using a pressed on sleeve and then turning the bore. Not something for every occasion, but does provide an option. Means some setup time in the mill. The sleeve is about.010 thick, so you could,if necessary correct a line bore issue when using mismatched cases etc. Some folks have a negative reaction to the idea, but it was passed onto be by a fellow who is quite a machinist and has had good success with it. I’m going to give it a go on some beavered up cases and don’t see it being a problem. The sleeve makes for quite a snug fit on the bearing... certainly more so than the “normal” interference fit between the race and case. Figure I’ll use a small tool post grinder to trim the sleeve. The sleeves as far as I know were never intended for this purpose, but why not....
Anyway enough about the sleeve. Nice work you are doing there.
Ps... using C3’s because the sleeves are snug plus the race will also be snug in the case again.
![Auto part Metal]()
Anyway enough about the sleeve. Nice work you are doing there.
Ps... using C3’s because the sleeves are snug plus the race will also be snug in the case again.
Have used sleeves in the past in the AMC gearbox housing. The issue is the amount of material between the layshaft and larger output bearings. There isn’t much and it’s not unusual for the case to crack between these bearings - one spinning bearing becomes two spinning bearings. The Thruxton Bonny had its timing side main repaired with a sleeve - 2 1/2 years Racing from 65 to 67 left the cases very tired.
I am quite lucky to have someone who can hard Chrome bearings and grind to the correct interference about 10miles away. They also metal spray for crank repairs. hard Chrome Forks and grind back to original etc. In fact they can do most things requiring metal and ceramic coating they can even spray plasma magnesium. Expensive but cheaper than the alternatives.
Plating up bearings isn’t cheap as the bearing outer diameter must be ground back then the bearing filled with wax before plating, then plated. The plated surface is then ground to side and the wax removed. About £90 per bearing.
Some of the issues with this bike were hard to understand or rather why the builder went down a particular route. The front wheel for example had a new liner but this had been pressed in over the brake side spoke holes. To remove the spokes meant removing the liner - you want to try removing an interference fit cast iron liner from a 70 year old mag hub without chewing you fingers off in worry as the hub cannot be replaced.
A few more photos hope they make sense
Three gearboxes, left is a lay down manx box from 1953, middle manx AMC gearbox 1962 and right AMC G50 gearbox 1958. I am building 3 manx framed bikes at the moment, a 1953 longstroke manx (joe Potts prepared for George Brown and later Bob Macintyre), a 1962 original but no history and this bike.
The worrying hub!
Alignment of engine and gearbox and rear wheel - I cannot emphasise enough how bent this frame was, the head stock twist radially, pushed down and to one side. The lower frame rails where 3/4 to one ride which meant the frame was like a banana. The swing arm was twisted to and the subframe was also twist so that one shock was being compressed and the other stretched. But it was worth sorting as basis of the bike ie a 500 manx norton was sold to Francis Beart in 1958 and was raced by several notables until the engine was changed.
I am quite lucky to have someone who can hard Chrome bearings and grind to the correct interference about 10miles away. They also metal spray for crank repairs. hard Chrome Forks and grind back to original etc. In fact they can do most things requiring metal and ceramic coating they can even spray plasma magnesium. Expensive but cheaper than the alternatives.
Plating up bearings isn’t cheap as the bearing outer diameter must be ground back then the bearing filled with wax before plating, then plated. The plated surface is then ground to side and the wax removed. About £90 per bearing.
Some of the issues with this bike were hard to understand or rather why the builder went down a particular route. The front wheel for example had a new liner but this had been pressed in over the brake side spoke holes. To remove the spokes meant removing the liner - you want to try removing an interference fit cast iron liner from a 70 year old mag hub without chewing you fingers off in worry as the hub cannot be replaced.
A few more photos hope they make sense
Three gearboxes, left is a lay down manx box from 1953, middle manx AMC gearbox 1962 and right AMC G50 gearbox 1958. I am building 3 manx framed bikes at the moment, a 1953 longstroke manx (joe Potts prepared for George Brown and later Bob Macintyre), a 1962 original but no history and this bike.
The worrying hub!
Alignment of engine and gearbox and rear wheel - I cannot emphasise enough how bent this frame was, the head stock twist radially, pushed down and to one side. The lower frame rails where 3/4 to one ride which meant the frame was like a banana. The swing arm was twisted to and the subframe was also twist so that one shock was being compressed and the other stretched. But it was worth sorting as basis of the bike ie a 500 manx norton was sold to Francis Beart in 1958 and was raced by several notables until the engine was changed.
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I have a minty long stroke featherbed barrel around somewhere, but everything else (except for a double knocker cam box) is pre featherbed. I was sifting through old papers and came across this...
![Text Handwriting Font Writing Line]()
Decided to see if the Manx CR gearbox might have any truth to it.
![Product Auto part Collection Metal Souvenir]()
Turns our the gearbox on the upper left fits the bill. The one below it also has all the correct CR bits, except the end cover may be a modified street version with the K/S blanked off. Happy day.
One of my favourite WTF repairs. This was done in the bush out in the colonies back in the day.
![Bicycle part Auto part Gear Tool accessory Groupset]()
Decided to see if the Manx CR gearbox might have any truth to it.
Turns our the gearbox on the upper left fits the bill. The one below it also has all the correct CR bits, except the end cover may be a modified street version with the K/S blanked off. Happy day.
One of my favourite WTF repairs. This was done in the bush out in the colonies back in the day.
Assuming they both failed at the same time and in use - They look home made, lever arms look overly long increasing leverage and there stress on the plate - all that energy has got to go somewhere, the material looks cast but brittle or just to light in gauge.
That they have shattered in the same way tell you everything you need to know. Poor design and material choice.
I think the design is (more or less....actually a whole lot less) a copy of the original Electron ones that came from Stevenage, but It would seem some folks efforts to copy them hasn’t gone well, also problems with porosity and not machined properly. They are missing the webbing to support the brake arm pivot etc etc. The fellow that sent me the photo said he thought maybe the brake stays let go. Perhaps the fact that the rear scoops were ripped off may suggest he is right?? The shoes are a modern incarnation and may be converted Honda ones, so no more flexing. If they belong to the fellow that I think they do, then I also believe that some newer lininings with a much higher coefficient of friction had been installed. I wondered about the levers as well, and perhaps the length should have been reduced with the stiffer shoes and better linings. There is a set of what appear to be unused cast aluminum ones on EBay for a price that is relatively reasonable, but one of the photos does show porosity, so after seeing the above photo and their unknown origin, I think maybe buyer beware would apply!
After thinking about it and consuming some caffeine, maybe these aren’t off the bike that I thought they were. If the bike had Bramptons or Girdraulics, then it wouldn’t be caused by broken brake stays.
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from a design standpoint the lever arm length wont make any difference to loads put into the cams or dead stops
no m ore loads than a shorter lever arm,unless of course the brake shoes are glazed like glass and the rider simply panic grips the control lever,because the brake wont generate any heat.that is all a friction brake is is a very efficient machine to convert kinectic into heat by the process of friction
if a brake is working efficiently making bookoo heat and if it has decent feel then a longer lever arm simply means less effort at the control lever
now the thickness of the brake plate itself makes no difference either many have been just sheet metal
with the shoe cam journals,axle boss, stay locations and dead stops all inclusive in a bar stock,cast,forged or billet fabrication tying all together to handle the loading with no flex,this is what enables the feel,besides a sturdy control cable lever assembly and correct adjustment which i have outlined in other posts
on the units here the dead stop for the shoes is a seperate bolt in piece ,is it not ?
and bolted in ,in a poor manner as well,to a thin lonely area of cast without any thought of even spreading out the huge bending loads the dead stop sees
see if the dead stop is allowed to bend a bit flexing the casting it is attached to
well then it will also attempt to pursuade the shoe into less than full contact ,which then requires more lever pull from the rider and the "cure" was longer actuation levers down below
poor dumb bastards lol
so in conclusion its the dead stops
major flexing there because the mfg does not understand design ,it what cause the cast material which cannot for all practical purposes ,withstand continous flexing,to fail in the same way
all a rider can hope for is to be thrown clear lol
Finished.
I reused 95% of the original bike including the fairing. The tank fitted was scrap so I repaired the bikes spare tank which is alloy.
Rebuilt to exactly as it was raced in the manx gp in 1962 (except for the tank), race numbers are crap and will be replaced.
Got to say I love the bike, it’s one I don’t want to give back. The engine is now perfect and everything is the best end of tolerance and she starts easily and sounds utterly fantastic.
I reused 95% of the original bike including the fairing. The tank fitted was scrap so I repaired the bikes spare tank which is alloy.
Rebuilt to exactly as it was raced in the manx gp in 1962 (except for the tank), race numbers are crap and will be replaced.
Got to say I love the bike, it’s one I don’t want to give back. The engine is now perfect and everything is the best end of tolerance and she starts easily and sounds utterly fantastic.
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2,037 Posts
Always love your work, Steve!
Thank you.
I've rebuilt the bike as a race bike, not over polished, tried to maintain or recreate original finishes etc..... The gold engine paint will dull a little with a few more heat cycles. The rims are blasted with crushed nut shells to give an original satin look without making the surface rough.
I have also managed to dig up a little more history too which is a little different to that posted above. 1958 was a come back to motorcycles for Francis Beart as he had spent a few years preparing engines for formula 3 cars (Cooper Manx). His rider for 1958 was Peter Middleton and Mr Beart provided him with two bikes a 350 Manx (I believe this was a Bitsa brought up to date) and a 500 which was purchased new (and the basis of the subject bike of this thread). Beart really wanted 4 bikes 2x 350 and 2x 500 but finances meant he needed to wait until 1959. Using the new 500 Norton Middleton / Beart entered numerous races in 1958 and 59 winning numerous races including the North West 200 finishing 2nd and the Manx GP finishing 6th.
Sometime during 1959 the 500 Manx engine was removed (I don't know why) and a Matchless g50 engine fitted. But this wasn't the 1st Beart Manx using an AMC Matchless or 7R engine. Beart had prepared a road wideline frame (much modified) fitted with a 7R engine for Mike Hailwood. Hailwood rode that bike and complained about the handling probably caused by insufficient weight over the front end probably as a result of the engine positioned higher than a manx and off centre (so the timing chest misses the top right frame tube) add to this that the 7r engine is much lighter than a Manx! Learning from this and using the 58 Manx chassis Beart fitted a heavier G50 engine lower and forward this put the bike more on the forehand and the handling was much improved. Again this bike was intended for and ridden by Hailwood (still trying to get documented evidence of this).
The bike was sold later in 1959 probably to finance new bikes for Beart/riders for the following season. The purchaser was Chris Williams who race the bike in 1960 with some success and set a new lap record at Crystal Palace whih stood for quite a few years. There is a debate to be had regarding what Chris Williams purchased from Beart, either a complete bike or a kit of parts made up from both 7r and g50 manx versions. In December 1960 the bike was sold to Clive Brown, Chris Williams race career changing direction. Clive used the bike all over the UK winning the newcomers trophy at the Manx in 1963. Wins were to follow. Clive also rode for Ray Petty and Francis Beart in period earning Beart his last Manx GP win in 1970 riding 350 Aermacchi. He also rode works BSA winning the thruxton 500 in 1970. He also road endurance racers for Meade and Tomkinson specifically the later Laverda 3C engined Nessie.
Hailwood with the 1st version of the Beart 7R, still looking for a photo of the second version.
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