Date: Thu, 14 Apr 94 08:24:10 BST
While away in the snowy north in my quest for
120 Shilling ale, I had time to read a number of books on the old industry.
I hope you find the following, an amalgum of articles and my own notes
and views, interesting.
In 1966 AMC, which at that time included Norton,
was acquired by Manganese Bronze Holdings. The chairman of MBH, a group
of engineering and metal firms was Dennis Poore.
Apparently he had been planning this move since
1962, and by completing it just after the receiver had been appointed,
avoided negotiations with the long-suffering AMC shareholders.
Dennis Poore chaired a meeting in late 1966, getting
together executives from both the Wolverhampton Villiers plant and Norton-Matchless
at Plumstead. The purpose of the meeting was to come up with a new flagship
for the new concern, a big bike primarily aimed at the US market, to replace
the Atlas.
They decided to resurrect a five year old design
produced at Plumstead by Charles Udall, a unit construction 800cc dohc
parallel twin with a four-speed gearbox. This heavy engine was housed,
inclined forward, in a modified featherbed frame decked out with many AMC
cycle parts topped by a tank bearing the traditional Norton name. The project
was dubbed P10.
Bernard Hooper, who had been with Villiers from
1958 to 1965, was designated the project's cheef designer. Hooper was an
experienced development engineer who, while at BSA, had already been responsible,
with Herman Meier, for taking the 125cc Bantam to 150cc, and for the experimental
Sunbeam S10. Then, as a freelance, he had worked on the racing 344cc Scott,
and with John Favill at Villiers had developed their all-original 25bhp
250cc twin-carb two stroke single, the Starmaker, which was to become the
basis of some quite successful road racers. He left late in 1965 to go
independant, rejoining Norton Villiers late in 1966. (Later Hooper and
Favill were to collaborate again, at first for Norton Villiers Triumph,
on an idea they started when freelancing in 1965, the revolutionary two
stroke stepped piston SPX Wulf Design.)
Hooper was quickly disillusioned with the P10.
One of the engines main features was the long, single row, cam chain, at
88 to 90 links it was as long as a conventinal final drive chain. It ran
through a series of teflon coated steel tubes, outboard of the engine,
which gave the superficial appearance of inclined pushrod tubes and made
the bike resemble a stubby Vincent Comet. The engine suffered from vibration
and a lack of power, a consequence of the long cam chain and the traditional
if outdated paralel twin design. The team's attempts to continue develolment
on the engine and cylinder head were undercut by the knowlage that Wally
Wyatt, the seasoned Plumstead, (Norton) based development engineer, had
already modified the Atlas engine to produce more power than the P10 looked
capable of.
Early in 1967, the now late Dr Stefan Bauer joined
the
team as Director of Enginnering. He came from Rolls Royce, and before that,
the atomic energy industry. He was not a motor cyclist, which may have
contributed to his approach which was perceved as abrubt and high handed.
Bauer was emphatic from the start that vibration
would not be tolerated. He also endorced Poore in insisting that, come
what may, the new flagship had to be ready quickly. in time for the Earl's
Court Motorcycle show in September 1967.
It was apparently Poore himself that finally put
a stop the the P10 project after a test ride, a bike that would have become
the 800SS. The unit construction twin, with double overhead cams that the
British bike industry needed to evolve, to challange the rising sun from
the east. This underfunded, underdeveloped and therefore misformed new
hope, was killed at birth by its stepfather. There is a surviving example
at the National Motorcycle Museum in Birmingham.
There was three months to go to the show, and
Hooper came up with the idea, of using the Atlas engine in something like
the new type frame that Bauer was had been developing for the P10. The
new frame would be used despite the reputation of the fetherbed, which
is I suppose an indication of the authority and attitute of Bauer.
The new frame would eliminate Vibration by hanging
the engine, gearbox and rear swinging arm from rubber bushes, isolated
from the main frame and the rider, hence the name 'isolastic'. The new
frame would not just have a single top tube, but a 2.25 Inch diameter main
spine, twin front downtubes and a triangulated rear section. The new frame
was also light, at 24lbs some 11lbs lighter than its predecessor, the fetherbed.
Bauer was also responsible for the new oil bearing
Triumph frames, to be used on the new range of Triumphs for 1971. Dr Bauer
had temporarily joined BSA-Triumph from Norton, from where he would return.
This new Triumph frame would benifit from computer stress analysis, however
there were still several broken frames to sort out as they were tested
at MIRA, and the design would be changed accordingly.
THE COMMANDO ISOLASTIC ENGINE
MOUNTS: Dr Bauer designed a frame with engine mounts carrying rubber bumpers
to isolate the rider from the vibrations of the large parallel twin Atlas
engine. The unique thing about the bike and frame, was that the swinging
arm was connected directly to the engine plates, and therefore the engine
unit. While this arrangements gets round the problem of transmission snatch
and windup from the rubber mounted engine with chain drive, it also creates
its own problem, a 'rubber' mounted rear wheel. (That is, the rear wheel
is rubber mounted through the rubber engine mounts to the frame).
All this from the company that brought you the
featherbed. So, unlike other rubber mounted engines, like the BMW and Sunbeam,
(both of which with rubber mounted engines but shaft drive and conventionally
mounted swinging arm) the Commando engine mounts had to be something special.
Allowing up and down movement, but limiting sideways movement to the smallest
possible clearance to allow the mountings to work and provide a stiff ride.
There are three engine mounting points on the
Commando. The first at the front of the engine is a large diameter tube
with two cresent shaped pieces welded to one side. The cresent shaped pieces
bolt to the front of the engine, and a smaller tube goes inside the larger,
the gap between stuffed with the rubber mounts. These are rings of rubber
and on later models the rubber 'rings' are fixed with circlips, the early
ones moved about a bit. The inner or smaller tube is bolted to two lugs
welded to the frame. This is a special bolt with a reduced head to allow
it to be removed and clear the exaust. The bolt is secured with washers
and a locking nut.
Side to side movement, or end float, in the front
mount is controlled with either shims or, on later bikes, (standard on
the MKIII), a screw or vernier adjustment. The moving parts are seperated
with a teflon washer.
In my experiance, movement in the front mounting
is the most critical to the handling of the bike, the rear mount tends
to act as a pivot. This is also the mount that needs adjusting most frequently.
This mount cannot be converted from Shim to Vernier without the help of
a machine shop, although there are a number of places that will sell you
the vernier type engine mount. The difference between the two is that on
the shim type, the centre tube protudes from the cresent engine mounting
plates by different amounts. The one sticking out more needs to be turned
down so that both sides are the same, it also needs to be turned down 'square'
with the tube, (so you can't do it with a hacksaw).
Converting to the vernier or MKIII type, you will
still need some bits from the old shim mount, even with the conversion
kit. Its also a good idea to replace the teflon washers, which will also
be missing from the kit. The vernier type is essentially the same as the
shim type, however the center tube is thredded at one end, to allow the
end cap to be adjusted for clearance. The threded end cap has a series
of holes to allow adjustment.
To adjust the vernier type simply loosen the main
bolt that passes through the middle, then using the 'tool' (Which is a
thin rod of metal about the same diameter as a thick spoke) tignten to
take out all play, then backoff by one of the series of adjuster holes
in the head. This gives 5 thou clearance.
The rear engine mount is a large diameter tube
again, but this time as part of the engine plates. The plates secure the
gearbox to the engine and have a mounting point for the chaincase centre
bolt. The large tube is located directly above the swinging arm pivot.
This is the inaccesable mount, adjustment with the shims is possible but
difficult, the vernier is easier. The internal tube is again fixed to the
frame through two lugs welded onto the frame, a stud replaces the bolt
and is secured with washers and two locking nuts outside the two 'Z' plates
and spacers.
Converting the rear mount requires no machining,
however, you will need to remove the engine, gearbox and swinging arm to
get it out. (It may actually be possible to convert with the engine and
stuff in situ, but you ought to replace the internal rubbers at the same
time, which can only be done with the mounting off the bike.
Adjusting the rear vernier type is the same as
the front, its the same thing really. I believe it to be a bit of a false
economy to upgrade the mounts to MkIII vernier and not use Stainless parts.
Its also worth noting that deep dome head nuts are available for the rear
engine mounting stud, to hide all the non stainess standard parts, however
these nuts are not locking nuts.
If you are replacing the internal Isolastic rubbers,
there is a service tool for the front mount, I assume you use the same
for the rear. The rubbers come in different sizes for each mount, reducing
different types of vibration I guess.
The third and final engine mount is the one that
fixes the head and prevents the engine and thereby the swinging arm twisting.
This is much simpiler that the other two engine mounts in that there is
no end float to adjust. On earlier models it consisted of a flat piece
of metal bent into an 'S' shape, this was intended to allow the engine
to move around its vertical axis, (up and down) but prevent any side to
side movement (This would result in the rear wheel twisting). The early
'S' shaped top engine mount failed and broke so often I find it hard to
believe there are any left. It was replaced with two simple rubber mounts,
the same as the ones for the exaust mounting plates. These screw directly
into the smaller frame tube above the engine. There are two triangular
plates, studs and a bracket which complete the arrangement, securing to
the head with three socket screws.
The only conversion worth noting here is with
the Norvil head steady, apparently it goes under all types of tank and
improves handling, (stops the rear wheel from twisting as mentioned earlier).
The only company producing genuine Norvil stuff is good ol' Fair Spairs.
NOTES:
Captain, Great article. I haven't read Classic
bike in a few years but wouldn't Mick Hemmings still take exception to
Fair Spares being the only supplier of Norvil Parts?
About ten years ago I purchased a Norvil "type"
headsteady from a Florida outfit called Britannia. It is a crude copy but
I have used it with no problems. It is basically a modified front isolastic
mount and uses the same washers, etc.
At the time I had made many changes to my bike
including a new swingarm spindle and pinning of the spindle so I am not
sure how much the headsteady mod made to the improved handling. I also
noticed back then that the isolastic tubes were not centered on the engine
plates which meant the rear wheel cannot be centered to the frame and front
wheel. I never understood how Norton got away with this.
Date: Thu, 14 Apr 94 09:55:08 PDT
Peter's piece on isolastics was very nice. Only
two comments I'd like to add to it.
The final form of the heady steady (the third
mounting point for the isolated engine/transmission/swingarm) was also
a plate, albeit of welded-up construction, attached to the main frame spine
by an interesting bolt-and-spring apparatus.
While less likely to break than the earlier version,
it still cracks.
Without a doubt, the Norvil headsteady is far
superior. It's main advantage is that it, too, is an isolastic mount like
the other two, not a simple bolt-up affair.
The original Commando frame had a potentially
fatal design flaw which was, fortunately, very quickly discovered and corrected.
In the original design, there were gusset plates to keep the fork attached
in the correct orientation to the frame spine. Unfortunately, these very
quickly cracked at the bottom, causing the fork head to break loose and
swing upwards. The new frame replaced these gusset plates with a small
diameter tube running from the bottom of the fork head to the middle of
the frame spine. Although this corrected the fracturing problem, it created
another problem of its own. That frame spine eventually bends under the
weight of the engine, and the fulcrum of the bend is the point at which
the small tube attaches to it.
A good featherbed frame, bolted up as Rex McCandless
designed it (and not welded up as Norton chose), could have been very interesting.
Hmmmm. This might make a very nice Next Project for me to try.
Date: Thu, 14 Apr 94 12:53:24 PDT
John Kula writes:"
...and SHill torments with
Steven, do people lacerate glaciers?
I've been making so many decisions about my project
that sometimes I go to bed _exhausted_ from the effort of inspiring Colin.
Look at it this way: by the time I'm done, I expect that I won't have to
spend 3 hours per week working to remedy some problem or another. That's
half a day a month, or 6 days a year, or _two months_ in a decade (which
is at least how long I expect to keep it).
Two months up front, all at once, or two months
in dribs and drabs for the next ten years? :-)
8.2 Swinging
Arm, Bearing Maintanance.
Date: Mon, 14 Feb 94 10:25:34 GMT
The swinging arm: Or swinging fork if you prefer.
As most of the manuals state, although a grease nipple is fitted, should
be lubricated with EP120 gear oil.
As one or more previous owners probably put grease
in it, this is an area subject to a lot of abuse. An oversized spindle
is avaiable, but you will need to reem the bushes and mount, (the tube
in the engine plates).
8.4 The Rear
Suspension Units.
Date: Thu, 7 Apr 1994 15:39:11 +0200
Hi, First of all, thanks to all of you who contributed
to how to use the valve lifter and thereby save me from braking my leg!
Great! I think this question mainly goes to (any) British members of brit-iron:
I am looking for new rear suspension units for my Matchless G3, 1965. The
ones fitted at the moment are not the right type, beeing the not shrouded
type with open visible spring.
The original ones were Girling, shrouded type,
with black top, chrome bottom and a plane top and bottom yoke(Similar top
and bottom yoke, not the jampot-type).
I want new ones looking as much as possible like
the original ones and of course they must have the correct length. Who
would you recommend to supply me with new ones. I have seen both Hagon
and Norridge advertise in the magazines. Are there others?
How do I make shure that I get the right ones
By the way, if anyone wonders what my bike looks like, take a look in The
Classic Motor Cycle, January -94, under the title "Authentic and unrestored".
It`s a strange and I guess in many people eyes, ugly bike, put together
from Norton and Matchless parts in an effort so save costs. But as you
know, to no good, because most of the production came to an end the year
after.
Date: Don, 07 Apr 94 15:39:48 MESZ
Why not just buy a set of shrouds for the units
you've got?
They're available in stainless steel, which cuts
down on maintainance.
Date: Mon, 11 Apr 1994 12:51:09 -0500 (EST)
Well I just got the Commando back on the road
after a years absence. A crack in the gearbox lead to pulling it and also
replacing the motor with one I have been building up for about 4 years
now.
I only have about 25 miles on it and am in the
retorqueing and carb jetting process now. I'll have more on that later.
What I was wondering, what can be done to improve the Norton suspension.
I still have the stock front springs using 20w
fork oil. The rear has Koni 76 series shocks (internal damping adjustment)
and the original Girling 126 lb springs.
I have been considering a Koni 7610 series shock
but am told by some it will interfere with the stock chaingaurd. Also considered
is the progressive rear spring from the 7610 for my existing shocks. If
any one knows the hot setup please let me know.
I consider the bike to be a sports tourer (in
the modern parlance) as I still plan a number of 400 mile plus days on
it. My aging bod doesn't absorb the bumps like it once did and exposure
to modern machinery makes the Norton less appealing for a long trip and
the National is 1800 miles away.
8.5 Fixing
a Faulty Sidestand.
Date: Wed, 16 Mar 1994 10:21:16 -0500 (EST)
I'm writing for my friend who has a 68 BSA 650
that has a broken sidestand. It's broken up around the frame. He's a competant
mechanic and a General Fixer of Broken Things. But this one has him mumblin'.
(I watched him fix a broken kick shifter for a 400 Yamahopper with a torch,
two screws and some brazing in about ten minutes.)
Since I don't actually know what's broken (haven't
seen it), could someone give the two dollar lecture titled "How to fix
a broken sidestand" and I'll pass it along to him. Your check is in the
ethernet.
tom root
Date: Wed, 16 Mar 1994 08:44:00 -0800 (PST)
Tom Root writes:
"I'm writing for my friend who has a 68 BSA 650
that has a broken sidestand. It's broken up around the frame. He's a competant
mechanic and a General Fixer of Broken Things. But this one has him mumblin'.
(I watched him fix a broken kick shifter for a 400 Yamahopper with a torch,
two screws and some brazing in about ten minutes.) Since I don't actually
know what's broken (haven't seen it), could someone give the two dollar
lecture titled "How to fix a broken sidestand" and I'll pass it along to
him. Your check is in the ethernet."
The 68 A65 frame is brazed lug consruction, which
means that it is made up of tubing brazed together with cast steel sleeves.
Many of the brackets, such as engine mounts are attached in a similar fashion.
The side stand bracket is a cast steel lug or sleeve with a flat projection
(which the side stand attaches to), and this would have been slid over
the frame tube before the frame was bent and brazed together.
The side stand bracket frequently has a pin through
it and the frame to locate it at the correct angle. It is most likely that
this brazed lug is buggered, and it is not easy to fix.
Some possible fixes, as briefly as possible:
1. If the flat is broken, fabricate a new one
from steel and weld it (arc or tig) to the lug.
2. If the lug is broken, then find an old buggered
frame and section out the lug. Slice the lug in half, and then weld (arc
or tig) both halves together on the frame. Then braze the lug in position.
3. As 2 above, but if you can't find a donor frame,
then fabricate the complete lug from steel stock. This would probably require
the use of a lathe.
4. If the frame tubing is buggered, then you will
need to section in a piece of tubing, with a new lug attached. At least
this avoids splitting the lug in two then welding it back together again.
None of these fixes are easy, and all assume the
engine is removed, and preferably all the junk is off the frame. There
is no easy way to fix a buggered sidestand bracket and have it stand up
to any use/abuse. If you mickey mouse it, you will never trust it, and
never use it.
Date: Wed, 16 Mar 1994 09:57:35 -0800
Be careful, the Unit construction BSA frames were
ALL brazed. Brazing and welding do not mix very well. I carved out a chunk
of steel to replace my broken sidestand lug and brazed it into place.
Date: Thu, 17 Mar 94 09:41:01 CST
On my 68 Lightning the sidestand lug has broken
loose - it seems like a sleeve around the frame tubing. It allows the bike
to wallow over to the left, but not fall completely over.
My short time (read that as the last decade) fix
has been to:
1) Use the centerstand
2) Park it with the left side uphill
3) Prop the sidestand up on a brick I plan to
rebraze the collar when I have the engine pulled out for repair - which
I understand is required every 10 to 15 years on BSAs. har, har. ;-}
Date: Thu, 17 Mar 94 8:11:11 PST
My erstwhile '68 TR6R's sidestand mounting tab
broke off which resulted in a halfmoon rather than a fullmoon. ;-)
Short term solution was to buy an _universal_
dirtbike sidestand which mounted to the frame rail via c-clamps. Worked
nicely although it looked a bit funky. It was either that or a section
of 4x4 to prop the bike up. :-)
Date: Thu, 17 Mar 1994 10:51:27 -0800 (PST)
Graeme sez:
"Short term" eh? What year did you put it on?
:-)
Date: Fri, 15 Apr 94 09:25:07 BST
I recall a converstion I had with Les Emery of
Fair Spairs a year or so ago. He and his wife bought the Norvil Name, and
all the Drawings jigs an tools From Norton. He told me of the Legal action
he was currently taking against Mick Hemmings who was also using the name.
The problem being that Norvil was never registered
as a Tradename. In the U.K. this means that anyone is able to sell parts
and call them Norvil.
Things came to a head when British Classic Bike
Mags, carrying Mick Hemmings adds, were faced with legal action in the
U.S., apparently Les was able to prosecute under Americal Law. This forced
the Mags to drop Mick Hemmings adds for a time, you may have noticed that
the latest adds from him refer to Production Racing parts, not Norvil Parts.
If you are still in doubt, the following notice appears in the front of
every Fair Spairs part price book:
>SPECIAL ANNOUNCEMENT
Date: Fri, 15 Apr 1994 10:23:07 -0500 (EST)
Peter, Thanks for bringing me up to date. As I
said I've been out of touch for a few years. Having met both gentlemen
its a pity that it turned out that way.
Date: Fri, 15 Apr 94 09:12:59 PDT
Well, Les Emery at Fair Spares may own the _rights_
to the name, and all the factory jigs, etc. However, I have to tell you
that Fair Spares' implementation of the Norvil Headsteady looks like it
was put together by a rangytang. I think _I_ could do a better welding
job. Hemming's is much neater.
Date: Fri, 15 Apr 1994 09:51:00 -0700 (PDT)
Peter Aslan AKA etc. passed along the Fair Spares
caveat, as below:
All parts sold by Mick Hemmings are manufactured
without the aid of these jigs tools and fixtures." I am not in a postion
to say how Hemmings stuff compares to Fair Spares stuff. That is, as they
say, an empirical question. But what I do want to comment on is the questionable
value of a claim that insists that using the original jigs, tools, and
fixtures is all that desireable.
Probably a number of you Norton afficionados know
the story better than I do how after Norton moved from Birmingham to London
difficulties were experienced in machining a particular engine part accurately
(Now there is a trivia question: what part was it?).
Turned out they had to phone some old fart who
used to operate the milling machine in the old plant, who explained they
had to use a wooden timber as a brace to prop up the head of machine before
it would do its job properly. In this day and age of CAD and CAM, handcuffing
yourself to the decrepid tools of the past seems unnecessarily limiting.
I would much rather obtain a part that is machined
accurately to 1/10,000 of an inch than on which one which is about an 1/8
out, and needs the judicious application of the biggest file and hammer
I can find. Notice if you will I am differentiating between the tools of
the past versus the bikes of the past. Or am I missing the point?
Maybe technological self-flagellation is an essential
element in owning and appreciating British bike. Any comments from the
disassembly of Luddites?
From: Peter Aslan
A POINT OF INTEREST:
When the Norton Commando was originally
conceved, and still in prototype form, it had the verier, (threded adjuster)
adjustments to the isolastics. For the production models, and I asusme
to reduce production costs, shims were used.
Date: Thu, 14 Apr 1994 12:42:03 -0500 (EST)
From: Pete Serrino
From: "John Kula"
From: "John Kula"
A good featherbed frame, bolted up as Rex McCandless
designed it (and not welded up as Norton chose), could have been very interesting.
Hmmmm. This might make a very nice Next Project for me to try."
> John, At your present rate of progress, your
current project has already become your next project. Or do you think it
possible to go backwards into the future?
Do they bug slugs?
Do they deep-six 286's? Slow is relative.
From: Peter Aslan
From: Olav.Saastad@TF.tele.no
From: tsumner@acorn.co.uk (Tony Sumner)
From: Pete Serrino
From: tom@marie.stat.uga.edu (Tom Root)
From: Stephen Hill 356-9389
From: rdb@strata.com (Robert D. Burget)
From: kichline@devnull.mpd.tandem.com (Chuck
Kichline)
From: Graeme Harrison
From: tim@eskimo.com (Tim Keane)
>My erstwhile '68 TR6R's sidestand mounting tab
broke off which resulted in a
>halfmoon rather than a fullmoon. ;-) Short term
solution was to buy an _universal_
>dirtbike sidestand which mounted to the frame
rail via c-clamps.
From: Peter Azlan
>All Norvil parts are genuine and manufactured
bt the Norvil Motorcycle company
>limited or the Norton Motorcycle company Limited,
who have been manufacturing
>GENUINE NORVIL PARTS SINCE 1968. We have all
the drawings, Jigs, Tools
>and fixtures. Any parts obtained from ANY other
source and sold as genuine are fake
>pattern parts. All parts sold by Mick Hemmings
are manufactured without the aid of
>these jigs tools and fixtures.
>LET THE BUYER BEWARE !
From: Pete Serrino
From: "John Kula"
From: Stephen Hill 356-9389
"All Norvil parts are genuine and manufactured
bt the Norvil Motorcycle Company limited
or the Norton Motorcycle company Limited, who
have been manufacturing
GENUINE NORVIL PARTS SINCE 1968. We have all
the drawings, Jigs,
Tools and fixtures. Any parts obtained from ANY
other source and sold as
genuine are fake pattern parts.