Lotus Elan

KO spacers

PostPost by: "Andres B. Sta. Mari » Thu Jun 27, 2002 3:29 am

Hello, Jeff,

Sorry, my note to you was half in jest. But partly serious ...

As you know, the Rudge-Whitworth knock-off (I think the British say
"knock-on"?) system, found on MGs, Triumphs, Jaguars, etc., tighten in the
opposite way from the Lotus system. For instance, on an MG, the LH side
tightens CW.

The Lotus system is the reverse, with the LH side tightening CCW (left side
with left-hand thread - more logical and easier to remember).

The difference is based on the fact that in the R-W system, the KO bears
against a taper formed on the outer rim of the wheel center. On the Lotus,
the KO is bears against a taper on the inside of the wheel center. On a
slightly loose KO, the two circles (the wheel center and the KO) are not
concentric and touch at only one point, and accordingly an epicyclical
relationship occurs. The epicyclical movement of the two circles either
loosen or tighten the wheel, depending on which direction it is turning.

I did not invent this. The book Lotus Engineering book devotes a couple of
pages to the topic. Chapman supposedly illustrated the epicyclic movement
to his engineers with a jar cap (representing the K0) inside a masking tape
roll (representing the tapered Elan wheel center). Try it.

I also read somewhere (I recall in Motorsport) that actually it is braking,
not accelerating, that loosens the KO.

Now, the question is - does a wheel spacer between the KO and the wheel
center act like gear and reverse the movement?

Presumably, if the wheel surface is flat as well as the spacer surface that
bears upon it, as on the Spyder wheels that Bob described, there is no
epicyclic movement and all is safe. But if the spacer-wheel interface is
tapered or allows an intervening epicyclical relationship to occur, do we
upset the main epicyclical relationship?

I hope this is very clear to you. To be honest, it isn't to me, and I
haven't had much success with the cap-and tape-roll experiment either.

This is what happens with a very focused, highly specialized interest - one
has all this trivia of interest to no one else. That is why the Elan List
is so busy.

Regards,

Andres
45/8439
"Andres B. Sta. Mari
 

PostPost by: "Robert D. LaMoreaux » Thu Jun 27, 2002 11:24 am

I did not invent this. The book Lotus Engineering book
devotes a couple of
pages to the topic. Chapman supposedly illustrated the
epicyclic movement
to his engineers with a jar cap (representing the K0) inside
a masking tape
roll (representing the tapered Elan wheel center). Try it.


I just put a scan of this page up in the files section. http://groups.yahoo.com/group/lotuselan/files/

To tell you the truth I don't intirely understand it either, especially since I have seen race cars with tapered nuts that are the opposite direction of the Elan.

Sorry about forgetting to remove the digest stuff from the end of my last message. I meant to. really.

Rob LaMoreaux
Ann Arbor, MI USA
(734)-971-5583
***@***.***
Too many Hobbies.... Too Little Time
1969 Lotus Elan....It's not a restoration, it's a never-ending adventure.
"Robert D. LaMoreaux
 

PostPost by: jivers » Thu Jun 27, 2002 5:25 pm

Andres,

Thank you for the wonderful explanation. I now understand what you
were referring to.

On the Compomotive wheels I am using, there is no recess in the
wheel. When I tried to tighten the spinner without a spacer, it
bottomed out without clamping the wheel. Therefore, I grabbed the
spacers that came with my Revolution wheels. These spacers have a
recess on each side, one side being deeper and sharper than the
other. By using these in the reverse of the way used on the
Revolutions, I was able to obtain sufficient clamping and maximize
thread depth without bottoming. Unfortunately, I lack the engineering
knowledge to figure out the implication of the epicyclical idea with
the added variables.

Based on my manual and the thread responses, my hubs are on the
correct side. Based on past experience with wheels coming loose due
to the spinner not being tight enough, I am convinced the pegs were
lost first and this allowed the spinner to unwind. There was close to
a half mile between the first lost peg and where the spinner came off
at substantial cornering loads.

Jeff Ivers
67 Elan S3 FHC

--- In [email protected], "Andres B. Sta. Maria" <[email protected]> wrote:
Hello, Jeff,

Sorry, my note to you was half in jest. But partly serious ...

As you know, the Rudge-Whitworth knock-off (I think the British say
"knock-on"?) system, found on MGs, Triumphs, Jaguars, etc., tighten
in the

opposite way from the Lotus system. For instance, on an MG, the LH
side

tightens CW.

The Lotus system is the reverse, with the LH side tightening CCW
(left side

with left-hand thread - more logical and easier to remember).

The difference is based on the fact that in the R-W system, the KO
bears

against a taper formed on the outer rim of the wheel center. On
the Lotus,

the KO is bears against a taper on the inside of the wheel
center. On a

slightly loose KO, the two circles (the wheel center and the KO)
are not

concentric and touch at only one point, and accordingly an
epicyclical

relationship occurs. The epicyclical movement of the two circles
either

loosen or tighten the wheel, depending on which direction it is
turning.


I did not invent this. The book Lotus Engineering book devotes a
couple of

pages to the topic. Chapman supposedly illustrated the epicyclic
movement

to his engineers with a jar cap (representing the K0) inside a
masking tape

roll (representing the tapered Elan wheel center). Try it.

I also read somewhere (I recall in Motorsport) that actually it is
braking,

not accelerating, that loosens the KO.

Now, the question is - does a wheel spacer between the KO and the
wheel

center act like gear and reverse the movement?

Presumably, if the wheel surface is flat as well as the spacer
surface that

bears upon it, as on the Spyder wheels that Bob described, there is
no

epicyclic movement and all is safe. But if the spacer-wheel
interface is

tapered or allows an intervening epicyclical relationship to occur,
do we

upset the main epicyclical relationship?

I hope this is very clear to you. To be honest, it isn't to me,
and I

haven't had much success with the cap-and tape-roll experiment
either.


This is what happens with a very focused, highly specialized
interest - one

has all this trivia of interest to no one else. That is why the
Elan List

is so busy.

Regards,

Andres
45/8439
jivers
Second Gear
Second Gear
 
Posts: 76
Joined: 21 Sep 2003

PostPost by: gobw2 » Fri Jun 28, 2002 3:22 am

Uh oh if I figured all this out right, then we got our knock-off's on
backwards. Guess that is why the wheels fall off . %-) ? George
On Thu, 27 Jun 2002 11:12:32 +0800 "Andres B. Sta. Maria"
<***@***.***> writes:
Hello, Jeff,

Sorry, my note to you was half in jest. But partly serious ...

As you know, the Rudge-Whitworth knock-off (I think the British say
"knock-on"?) system, found on MGs, Triumphs, Jaguars, etc., tighten
in the
opposite way from the Lotus system. For instance, on an MG, the LH
side
tightens CW.

The Lotus system is the reverse, with the LH side tightening CCW
(left side
with left-hand thread - more logical and easier to remember).

The difference is based on the fact that in the R-W system, the KO
bears
against a taper formed on the outer rim of the wheel center. On the
Lotus,
the KO is bears against a taper on the inside of the wheel center.
On a
slightly loose KO, the two circles (the wheel center and the KO) are
not
concentric and touch at only one point, and accordingly an
epicyclical
relationship occurs. The epicyclical movement of the two circles
either
loosen or tighten the wheel, depending on which direction it is
turning.

I did not invent this. The book Lotus Engineering book devotes a
couple of
pages to the topic. Chapman supposedly illustrated the epicyclic
movement
to his engineers with a jar cap (representing the K0) inside a
masking tape
roll (representing the tapered Elan wheel center). Try it.

I also read somewhere (I recall in Motorsport) that actually it is
braking,
not accelerating, that loosens the KO.

Now, the question is - does a wheel spacer between the KO and the
wheel
center act like gear and reverse the movement?

Presumably, if the wheel surface is flat as well as the spacer
surface that
bears upon it, as on the Spyder wheels that Bob described, there is
no
epicyclic movement and all is safe. But if the spacer-wheel
interface is
tapered or allows an intervening epicyclical relationship to occur,
do we
upset the main epicyclical relationship?

I hope this is very clear to you. To be honest, it isn't to me, and
I
haven't had much success with the cap-and tape-roll experiment
either.

This is what happens with a very focused, highly specialized
interest - one
has all this trivia of interest to no one else. That is why the
Elan List
is so busy.

Regards,

Andres
45/8439
gobw2
Fourth Gear
Fourth Gear
 
Posts: 968
Joined: 25 Sep 2003

PostPost by: rdssdi » Fri Jun 28, 2002 4:19 am

The spacers supplied by Spyder Engineering with the KO alloy wheels fit into
a shallow "recess" in the wheel.

The recess is flat as is the "wheel side" of the spacer. The "knock off" side
is tapered to accept the taper of the spinner.

Bob
1969 Elan +2
rdssdi
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1421
Joined: 30 Sep 2003

PostPost by: "elj221c" » Fri Jun 28, 2002 8:47 am

This one seems set to run and run!

It is interesting for me as when I finaly get my S2 back on the road,
I will be in the market for new wheels, as my JAP alloys are rather
old, and at least one suplier has refused to fit new tyres because of
their age and construction. The Pearce wheels I believe are sand
cast, and have quite a thick hub section, and do not use a spacer of
any kind. The standard chrome spinner (as opposed to a JAP alloy one)
bears directly on a substantial taper machined in the wheel.

In the case of the Minilites, am I right in assuming that a spacer is
needed only because the hub section of the wheel is their standard
thickness, regardless of whether the wheel is bolt-on or knock-on? Is
the spacer then on the ouside of the wheel with the taper for the
spinner? That sounds like the description given for the Spyder wheel.
Is the Spyder wheel actually produced by Minilite?

Maybe I will go for the Matty suplied 26R replicas in 5 pin form.
Does anybody have any experience of them?

Roy
'65 S2
"elj221c"
 

PostPost by: elancoupe » Fri Jun 28, 2002 11:13 am

----- Original Message -----
From: elj221c
Is the Spyder wheel actually produced by Minilite?

Maybe I will go for the Matty suplied 26R replicas in 5 pin form.
Does anybody have any experience of them?







I have 5 pin 26R replicas as produced by UK Racing Castings, 5 inches wide. Nice quality, other than the pin holes not being drilled deep enough. This wanted to push out the pins, so I deepened the holes.
Offset is slightly more to the outside, if you don't have flares (I don't), you will need to use slightly narrower tires. In the case of a street car, skinny tires can be slidable fun!
To complete the package,I added 26R spinners from TTR, threaded for standard hubs.

MIke B
Mike
elancoupe
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Location: Spam-on-Rye

PostPost by: "peteandjanet" » Fri Jun 28, 2002 1:31 pm

-----Original Message-----
From: elj221c [mailto:***@***.***
Sent: 28 June 2002 09:47
To: ***@***.***
Subject: [LotusElan.net] Re: KO spacers


This one seems set to run and run!


In the case of the Minilites, am I right in assuming that a spacer is
needed only because the hub section of the wheel is their standard

thickness, regardless of whether the wheel is bolt-on or knock-on? Is
the spacer then on the ouside of the wheel with the taper for the
spinner? That sounds like the description given for the Spyder wheel.
Is the Spyder wheel actually produced by Minilite? No.

There is no spacer with the Minilites! The wheels are machined for each
particular application, the insert is on the "outside" of the wheel and is
there to provide a hard surface for the spinner to lock against.


Cheers,

Pete
"peteandjanet"
 

PostPost by: DAVE » Fri Jun 28, 2002 1:52 pm

Roy and all,
FYI I have a brand new [still in the boxes] set of Panasports for sale.
Substanially built up at hub.
"We don't need no stinking rings."
;-]

At 08:47 AM 6/28/2002 -0000, you wrote:
Maybe I will go for the Matty suplied 26R replicas in 5 pin form.
Does anybody have any experience of them?
Roy
'65 S2
DAVE
 

PostPost by: ardee_selby » Fri Jun 28, 2002 2:50 pm

--- In [email protected], DAVE <[email protected]> wrote:
...I have a new set of Panasports ... Substanially built up at hub.

"We don't need no stinking rings." ;-]

What's shown here then?
<http://groups.yahoo.com/group/lotuselan/files/Panasport.jpg>
ardee_selby
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2255
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PostPost by: "Robert D. LaMoreaux » Fri Jun 28, 2002 7:37 pm

My new Panasports have a hard steel ring pressed into the wheels. It
appears to be stainless and it is in there quite tight. This was one reason
I bought panasports instead of superlights. I didn't trust having the ring
separate and thus able to turn.

Rob LaMoreaux
Ann Arbor, MI 48108-1273
Home: 734-971-5583
Work: 734-822-9696
Fax: 734-973-1103
Home email: ***@***.***
Work email: ***@***.***
Too many Hobbies.... Too Little Time
1969 Lotus Elan....It's not a restoration, it's a never-ending adventure.
"Robert D. LaMoreaux
 

PostPost by: rdssdi » Fri Jun 28, 2002 7:45 pm

I believe the Spyder wheel is made by Twin Pines or Two pines in The UK.

Bob
1969 Elan +2
rdssdi
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Posts: 1421
Joined: 30 Sep 2003

PostPost by: "peteandjanet" » Fri Jun 28, 2002 8:21 pm

Looks like a ring-piece to me %>

-----Original Message-----
From: ardee_selby [mailto:***@***.***
Sent: 28 June 2002 15:51
To: ***@***.***
Subject: [LotusElan.net] Re: KO spacers


--- In [email protected], DAVE <[email protected]> wrote:
...I have a new set of Panasports ... Substanially built up at hub.

"We don't need no stinking rings." ;-]

What's shown here then?
<http://groups.yahoo.com/group/lotuselan/files/Panasport.jpg>










"peteandjanet"
 

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