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Here are some messages covering that subject.
There has been a recent thread about tire sizes and their effect on speedometer
error. Rather than re-invent the wheel (pun intended), you might take a look
at the following URL: http://www.tirerack.com/tires/tiretech/size.htm
This is the TireRack's page for calculating tire size. They will give you
the diameter of a given tire. The circumference is equivalent to pi times
the diameter. A rough value for pi is 3.14.
To calculate the effect on speedometer accuracy, merely create a ratio with the
circumference of the new tire size as the numerator (top) and stock tire
circumference as the denominator (bottom). All of this assumes, of course,
that your speedometer/odometer was accurate to begin with. That probably was
never the case but, some 20 to 30 years later, is even less likely today.
If you hunt around on TireRack's website, they give actual diameters for many
of the tires they sell. In theory, one 185/70x15 tire should have the same
diameter as another. Reality is they vary slightly, on the order of 1/10
inch.
Steve; Help me out a little on your request...
Exactly what info do you need concerning speedometer "turns"?
I assume the number of times the speedo cable turns each time the tire
makes one full revolution. Is that right?
As far as factory tire size, as best that I can determine, the 185 r15
is the original size supplied by the factory. However, in recent chat,
you may recall that there was some discussion as to whether this was a "
78 " series aspect ratio tire, or actually closer to a " 75 ". I don't
know.
You also asked for "the speedo error introduced". Sorry, but I don't
understand the question. A little help as to what you need, and I'll
certainly do the best to provide a straight answer.
Keith:
Your calculation of a 2% error in speedometer sounds ok to me. Can you
furnish the following so that I can start compiling the chart:
speedo "turns", factory tire size (forgive my ignorance if its your 185's,
I'm new to E-Types) and what is the speedo error introduced. Some how I
think the answer is 2%, but again my ignorance is showing and I want to get
the table right.
Much thanks for you input, you are the first one to respond.
Steve Patchel
Dave:
Thanks for the point to the Falls Church re. my wheel inquiry. Called
them but they advised they were not equipped to do them. However, they
were very helpful and referred me to a place up on Washington Blvd. in
Eklridge, near BWI. Talked with them and they were extremely helpful.
Even advised me to purchase spokes myself to save their markup on them.
Still got lot's to learn but its fun so far.
Regards,
Mike O'Rourke
General Information:
The "Official" JCNA National Concours D'Elegance Rule Book lists the
following as the correct tire size for E-Types:
Under the old system an "E" aspect ratio tire is a 185, but 205 is correct,
as the industry standards changed in the 70's...only a 205 tire is correct. If you order
tires and ask for an "E" ration, they will try to order 185...that's
wrong, use only a "205")
The "Red line" tires are O.K. for Series II cars. However the "rule"
book notes that 185 x 15 radial s "did not come with a side aspect ratio
molded into the tire. It was however a 75 side aspect ratio tire. The
75 aspect ration is no longer an industry standard. Use either a 70 or 78
aspect ratio. Goodrich and Michelin are sources."
The "book" also notes that "Wall or stripe/color is optional."
On the other hand, if you aren't concerned with being perfectly
"authentic" then try radials on the older models...you will "lower" the
car slightly and as has been noted, get a misread from you speedometer.
But,the car will probably handle much better.
Dan
Mark McChesney
My vote for XKE tires are Goodyear Eagle GT+4 in 195-70 15 size. A good
compromise for "fast street" driving and not so bad on a race track or
slalom course either. Available by mail order for about $80 each...not
bad!
As far as ignition goes I have fitted may car with a Mallory Electronic
distributor (pricey!!) and a MSD 6AL spark box with rev limiter. Car
starts instantly and there is no such thing as "break up" at high rpm.
The setup has proven to be very reliable and trouble free in the three
years it is in. All can be installed with no holes drilled or permanent
alterations to wiring. The MSD box mounts very nicely with an adapter
plate on the bracket adjacent to the washer bottle (Series 1) that is
used on right hand drive cars to mount the booster
Frank Filangeri..........................."Don't always follow the crowd.
I recently got 4 new tires installed on my '67 roadster and when the
mechanic gave me my tires and rims, he also handed me a handfull (and i
mean a healthy handfull) of broken off spokes.
Where can I get new spokes - Where can I get the wheels respoked - How
about a motorcycle shop? If anyone can help out -- THANKS
Chris
Your NOT going back there, right?
If you are just looking for replacement spokes, most of the usual Jag
parts places like XK's unlimited, SICP, Welsh, British Auto, etc carry
them in both regular and stainless steel. Around $2 each I think.
I would also tend to worry about the integrity of the remaining spokes.
Maybe time to start thinking about some new Daytons?
Links to all of the above suppliers are at www.xke-lovers.com.
Cheers.
"A handfull of broken spokes..."
I tell you, that makes me wake up! LLoyds rule of thumb is that if more
than two spokes are loose or missing per wheel, relace it. But first, drive it
slowly into your garage.
The damage done when a wheel gives out is far more expensive than relacing
a wheel. Besides, the wheel will only get worse, wobble more and beat on
your suspension and steering worse and worse, ruin tires and shocks.
Actually, the mechanic should have known better than to put the tires on
those wheels.
Ain't his old dad learned him no couth? (Famous phrase repeated often to
my children as they grew up)
LLoyd - now that will probably be offensive to someone, ehh? -
Jaguar Heaven in Stockton, CA, also specialized in Jags.
Hunt
H u n t D a b n e y & A s s o c i a t e s
There was some discussion several days ago about tires and wheels again,
particullarly replacing spokes. I went to our local Jaguar clubs
all-British car show today and picked up a brochure there from British
Wire Wheel, (800) 732-9866 or (408) 479-4495. They are also on the Parts
and Suppliers page.
They offer everything from just a few spokes to truing and relacing of
your old wheel. They also sell Dunlop and Dayton wire wheels as well as
Avon and other brands of tires.
Just a sample of their services:
E-Type S1 or S2 Dayton wheels with Stainless Steel spokes - 15X5 = $245,
15X6 tubless = $275
Relacing your wheel with new stainless spokes = $140 (Rechroming wheel
and hub extra $215) (Cheaper to buy new Dayton!)
Avon 205/60X15 CR-28 V rated tires = $102 (V rating = up to 150 mph)
Lots of other neat tire stuff, check them out!
Tire and Wheell FAQ's
Here are some messages relating to tires on an E-Type. Hope something here is useful! If you have something to contribute, please send it to e-type@jag-lovers.org.
To: xke-lovers@listserv.azstarnet.com
Subject: Tire Sizing
Reply-To: xke-lovers@listserv.azstarnet.com
From: anderson
To: "'spatchel@radford.com'"
Cc: "'xke-lovers@listserv.azstarnet.com'"
Subject: Tire size / Speedo turns
Date: Mon, 3 Mar 1997 19:24:11 -0600
Keith
Date: Mon, 3 Mar 1997 08:06:00 -0800
To: xke-lovers@listserv.azstarnet.com
From: Steve Patchel
Subject: RE: Speedometer & Tire Size
70 ots
From: wmor@ix.netcom.com
Date: Sun, 02 Feb 1997 15:14:02 -0800
To: xke-lovers@listserv.azstarnet.com
Subject: Re: wheel tuning
67 FHC
Date: Sun, 02 Feb 1997 19:38:11 -0800
From: Dan Watkins
Reply-To: Danjag@mdn.net
To: xke-lovers@listserv.azstarnet.com
Subject: Tires
XKE Series 1 3.8 & 4.2 -- 6.40x15
XKE Series 2 185 x15
XKE Series 3 E70x VR15 (205/70xVR15
74 E-type OTS
From: "Mark McChesney"
Date: Mon, 3 Feb 1997 09:20:21 -0500
In-Reply-To: "David Lowenstein"
"Re: E-Type Tires" (Feb 2, 2:45pm)
Subject: Re: E-Type Tires
Cc: xke-lovers@azstarnet.com
On Feb 2, 2:45pm, David Lowenstein wrote:
Subject: Re: E-Type Tires
> Steve -
> Welcome aboard. I believe there has been at least one and
> perhaps more discussions of tire sizes and types for E-types
> posted on the list, the last one around Jan 1st. You might
> check the digest for some discussions. The quick & dirty
> summary of my recommendation was: If you're going to really
> drive the car, buy performance 205/65 15s and live with the loss
> of less than 0.5" ground clearance and an inaccurate speedo.
> I've got Dunlop D40M2s on mine and
> they're outstanding....Good luck with the new car.
> >
> > What size and style were the original tires? I've heard
> > everything from 185 70 15 to 195 70 15; white wall, red stripe.
> > And having asked what is "original" - then I'd like to know
> > what works best?
Mine has got 225/70-15 Dunlop SP's (very old) on 15x5.5 competition wires (tight fit) and
one day will have 225/50-15 on 15x7 alloy wheels. None of this is even close to
original :-).
'65ots
"The only way to get ride of temptation is to give in to it..." -Oscar Wilde
To: gwcohn@mindspring.com
Subject: Re: Tires & Electronic Ignitions
From: ffilangeri@juno.com (Frank A Filangeri)
Date: Wed, 12 Mar 1997 22:05:17 EST
Hi George,
1962 E OTS Flat Floor..........Nobody goes there anymore.
1966 AH 3000........................It's too crowded." Yogi Berra
Date: Wed, 11 Jun 1997 21:37:58 -0400
From: Chris Veenstra
To: E-TYPE@jag-lovers.org, E-TYPE@jag-lovers.org
Subject: Wire wheels
Date: Wed, 11 Jun 1997 19:36:12 -0700
From: George Cohn
To: Seaborne@coca.net
CC: e-type@jag-lovers.org
Subject: Re: Wire wheels
__________________________
George Cohn
Date: Thu, 12 Jun 97 07:55:56 PDT
From: LLoyd <3030P@vm1.cc.nps.navy.mil>
Subject: Re: Wire wheels
To: Seaborne@coca.net
cc: "E"Lovers"
Date: Thu, 12 Jun 1997 08:51:27 -0700
To: Ulysses Arretteig
From: Hunt Dabney
At 10:04 PM 6/11/97 -0500, Ulysses Arretteig wrote:
>I share your pain. It is best to find a small shop who
>will exchange your tires by hand rather than the
>automated type of bead breaker. With a couple of
>large screwdrivers and a lot of liquid soap you can
>change your own.
>
>Your most ready source of spokes may be your own
>spare tyre. That will buy you a little time while you
>locate spokes (if you don't have any flats).
>
>Years ago (like 20) I lucked into some bent wheels
>and was able to salvage a few spokes which have
>served me well in the ensuing years. Kim Motor Co.
>in Richmond VA breaks up a large number of vehicles
>and may be a source of used wheels. There is a yard
>in Sarasota, FL (if I can find the address I will post it)
>that deals in used Jag parts (lots of sedans, but a good
>source for oil coolers, brake parts and the like).
>Good Luck
>
>Joe
>66FHC
>
Electronic System Development and Design
-----------------------------------------------
fax: (714) 540-8131
Date: Sat, 14 Jun 1997 20:35:13 -0700
From: George Cohn
To: e-type@jag-lovers.org
Subject: Tires and Wheels
_________________________
George Cohn
'70 OTS
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