R. Plunkett PTFE

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john robert bould

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Who the hell's R Plunkett ?
Well in 1938 Roy discovered PTFE. by pure chance, he was working for a U.S.A company producing cfc gas for our common fridge's.
He discovered a slippy white substance that Dupont later called Teflon, now whats this got to do with nortons?
Well as a retired engineer i now have time to "Mess about" with my love of progress and Motorbikes
I made up some Polytetrafluoroethylene [PTFE] bush's for the use in Roadholder forks, The material is soapy and the cof is about as low as you can get..0.5-0.1 which ranks it as "LOW" friction...But test proved the bush's crept under load.
So i have tried Oilon, tricky to machine unless the tools are super sharp, and the swarf ribbons ..BUt what a fantastic result, friction factor allmost 0.1 and strong.
So good old Roy plunkett, frying pans to Norton Forks, Oilon is twenty five times more resistant to wear than bronze and wont wear out your sliders, unlike the silly iron ones installed...Norton where old "die hards" i am now looking at Oilon swing arm bushs, as the material require's no Lube. I hope this thread was a refreshing change from the repeats.
happy rideing
http://www.lansdowne-engineering.com
 
"Oilon is twenty five times more resistant to wear than bronze and wont wear out your sliders, unlike the silly iron ones installed...Norton where old "die hards" i am now looking at Oilon swing arm bushs, as the material require's no Lube. I hope this thread was a refreshing change from the repeats.
happy rideing "

Sales hype!
All these plastics so called more wear resistant than bronze is tosh.
Time & time again our designers at work try these plastics, because they read or listen to the sales hype, & always find they cannot replace bronze. They are too soft & wear like crazy under load.
Fork bushes may be OK as there is not too much load on them, but they will not last that long.
Wouldn't try it on swinging arm bushes though, would be oval in no time.
This is my personal opinion, having been in engineering for too long, please prove me wrong.
 
My Yamaha uses a type of plastic bushing in the swingarm, thay do not last and the replacments are bronze or needle bearings. I have my reservations about plastics in high load areas.
 
I tend to agree with the last two posts, John. Although Oilon is no doubt very good for fork bushes, and I think your fork bush conversion is well worth trying, I fail to see the advantage in using this material for swinging arm pivot bearings.
 
daveh said:
I tend to agree with the last two posts, John. Although Oilon is no doubt very good for fork bushes, and I think your fork bush conversion is well worth trying, I fail to see the advantage in using this material for swinging arm pivot bearings.
Click to expand...

I recall Ludwig made some plastic bushes for the forks.
 
Flo said:
"Oilon is twenty five times more resistant to wear than bronze and wont wear out your sliders, unlike the silly iron ones installed...Norton where old "die hards" i am now looking at Oilon swing arm bushs, as the material require's no Lube. I hope this thread was a refreshing change from the repeats.
happy rideing "

Sales hype!
All these plastics so called more wear resistant than bronze is tosh.
Time & time again our designers at work try these plastics, because they read or listen to the sales hype, & always find they cannot replace bronze. They are too soft & wear like crazy under load.
Fork bushes may be OK as there is not too much load on them, but they will not last that long.
Wouldn't try it on swinging arm bushes though, would be oval in no time.
This is my personal opinion, having been in engineering for too long, please prove me wrong.
Click to expand...

I had Nylon [standard] bush's on the brake arms on my truck, lots of pressure and they lasted well, You may be right about the small swing arm size, but Matchess forks used plastic, i have seen them 50 years old and still in good order. as engineering goes only the faint hearted stay still, many chain guide's on brick transporters use oilon..it out lasts steel!
 
Yes, Matchies use plastic fork bushes. If I remember right, they are black. I bought a G80 a couple of months ago, as I had one 35 years ago & fancied another one. Didn't realise how gutless they were, but fun.
Plastic works well on chain guides. The links soon wear a groove in them, then the rollers roll themselves on the rubber or plastic.
 
Plastic doesnt tend to have a long life if its used for fork bushes. Far superior is the DU bush, which has been used for many years by fork manufacturers such as Marzocchi: http://selflubricating.devprecisionengi ... dry_du.htm

Here in the UK older forks are often fitted with DU bushes, as they reduce stiction as well as provided a much smoother action. They can often be found in sizes to replace existing fork bushes, and are well worth fitting as a cost effective upgrade.
 
Carbonfibre said:
Plastic doesnt tend to have a long life if its used for fork bushes. Far superior is the DU bush, which has been used for many years by fork manufacturers such as Marzocchi: http://selflubricating.devprecisionengi ... dry_du.htm

Here in the UK older forks are often fitted with DU bushes, as they reduce stiction as well as provided a much smoother action. They can often be found in sizes to replace existing fork bushes, and are well worth fitting as a cost effective upgrade.
Click to expand...

Interesting, thanks. Which older forks use these bushings? Is there a size suitable for Roadholders?
 
Well done JRB, for putting this up,
I seem to recall some Japanese dirt bikes, way back, useing a Nylon type material as swinging arm bushes.
They worked well and were easy to replace but were replaced far more often than the Brass ones on Euro bikes.
As chain tensioners or guides or swinging arm protectors, they worked fine. Of course I have no idea what material they actually were.
Well done every body else for constructive criticism.
We live and learn on the Norton Commando Forum.
 
Carbonfibre said:
Plastic doesnt tend to have a long life if its used for fork bushes. Far superior is the DU bush, which has been used for many years by fork manufacturers such as Marzocchi: http://selflubricating.devprecisionengi ... dry_du.htm

Here in the UK older forks are often fitted with DU bushes, as they reduce stiction as well as provided a much smoother action. They can often be found in sizes to replace existing fork bushes, and are well worth fitting as a cost effective upgrade.
Click to expand...

Carbofibre, Excellent link! Yes the DU are far better But i would guess the manufacture's would require quite a few to make up an order, which would be expensive,
Marzocchi would have ordered thousands, Oilon may feel loose with time, it's not due to wear..but distortion PTFE soon loose's it's roundness..i have fitted a good firm set into a norton leg and "Belted" the leg with a heavy mallet...the bushs spread , Oilon with stood the test quit well, i think extream testing is sometimes far in excess than "real Time" use, and if the distort in 5 years ..well the alloy slider is getting an easy life, There is a few New materials on the market with good qualitie's Graphite filled nylon being another. I will do some tests on differant "plastic" bushs...but mayby to old to see if they out-last the Matchless 50 year old ones !
 
What makes you think it won't wear out the sliders ?, once it impregnates with particles it will be even more abrasive than steel.
 
John,

Why not give Maxton a call, they use "plastic" bushes in their upgrades which work really well (not sure exactly what type, as they've only been apart once in 15 seasons to change an oil seal!)
 
john robert bould said:
Carbonfibre said:
Plastic doesnt tend to have a long life if its used for fork bushes. Far superior is the DU bush, which has been used for many years by fork manufacturers such as Marzocchi: http://selflubricating.devprecisionengi ... dry_du.htm

Here in the UK older forks are often fitted with DU bushes, as they reduce stiction as well as provided a much smoother action. They can often be found in sizes to replace existing fork bushes, and are well worth fitting as a cost effective upgrade.
Click to expand...

Carbofibre, Excellent link! Yes the DU are far better But i would guess the manufacture's would require quite a few to make up an order, which would be expensive,
Marzocchi would have ordered thousands, Oilon may feel loose with time, it's not due to wear..but distortion PTFE soon loose's it's roundness..i have fitted a good firm set into a norton leg and "Belted" the leg with a heavy mallet...the bushs spread , Oilon with stood the test quit well, i think extream testing is sometimes far in excess than "real Time" use, and if the distort in 5 years ..well the alloy slider is getting an easy life, There is a few New materials on the market with good qualitie's Graphite filled nylon being another. I will do some tests on differant "plastic" bushs...but mayby to old to see if they out-last the Matchless 50 year old ones !
Click to expand...


Here in the UK you can buy DU bushes in very small numbers, and as they are commonly used industrially I would imagine they can be found easily pretty much anywhere. Most plastic fork bushes, tend to wear pretty rapidly, which means slop between the slider and stanchion, leaking seals, and poor suspension performance. Its quite possible to upgrade old style forks to work almost as well as modern, but cartridge internals are pretty costly, and for proper suspension performance modern rear units will also be required.
 
Seeley920 said:
John,

Why not give Maxton a call, they use "plastic" bushes in their upgrades which work really well (not sure exactly what type, as they've only been apart once in 15 seasons to change an oil seal!)
Click to expand...
Seeley, who is right here, Carbonfibre is saying "no good " you are saying 15 seasons and still good?.....
 
john robert bould said:
Seeley920 said:
John,

Why not give Maxton a call, they use "plastic" bushes in their upgrades which work really well (not sure exactly what type, as they've only been apart once in 15 seasons to change an oil seal!)
Click to expand...
Seeley, who is right here, Carbonfibre is saying "no good " you are saying 15 seasons and still good?.....
Click to expand...

Carbonfibre is always right, just ask him. :mrgreen:
 
john robert bould said:
Seeley, who is right here, Carbonfibre is saying "no good " you are saying 15 seasons and still good?.....
Click to expand...

John — the proof of the pudding is in the eating. Seeley 920 has knowledge based on first hand experience and I will go with that. Maxton Suspension have a good reputation which they have earned and I doubt very much that they would put that in jeopardy by fitting plastic bushings that didn't last p***ing time! Many racers in these islands with Maxton suspension speak highly of them. Just look around any race paddock.

Ideally, you could fit your Oilon bushes to a 'test mule' to look at wear rates, distortion, etc. Jim Schmidt uses Turkite for his upper fork bushings and teflon impregnated bronze for the bottom bushings. He mentioned it in a thread on this forum:

not-caferacer-t9368-15.html?hilit=turkite

He also mentioned that it was expensive.
 
john robert bould said:
Seeley920 said:
John,

Why not give Maxton a call, they use "plastic" bushes in their upgrades which work really well (not sure exactly what type, as they've only been apart once in 15 seasons to change an oil seal!)
Click to expand...
Seeley, who is right here, Carbonfibre is saying "no good " you are saying 15 seasons and still good?.....
Click to expand...


Hi John,

all I can say is that mine feel as good as they did when they were originally fitted! If you get to Darley Moor next month there will be plenty of people who you can chat to about them as well as seeing a commando with a 90 degree crank!!!
 
Seeley920 said:
john robert bould said:
Seeley920 said:
John,

Why not give Maxton a call, they use "plastic" bushes in their upgrades which work really well (not sure exactly what type, as they've only been apart once in 15 seasons to change an oil seal!)
Click to expand...
Seeley, who is right here, Carbonfibre is saying "no good " you are saying 15 seasons and still good?.....
Click to expand...


Hi John,

all I can say is that mine feel as good as they did when they were originally fitted! If you get to Darley Moor next month there will be plenty of people who you can chat to about them as well as seeing a commando with a 90 degree crank!!!
Click to expand...
I will do my best to be there..its only 12 miles away!
 
john robert bould said:
Hi John,

all I can say is that mine feel as good as they did when they were originally fitted! If you get to Darley Moor next month there will be plenty of people who you can chat to about them as well as seeing a commando with a 90 degree crank!!!
Click to expand...
I will do my best to be there..its only 12 miles away![/quote]


Lucky bugger :-)
 
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