Hi Derek.
You are quite right this has been discussed recently, but as you were
enjoying the delights of St.Moritz and the Stelvio Pass at the time it is
completely understood and forgiven. Many thanks for the excellent pics by
the way. It was good to see you with Peter Healey who is the President of
our Centre here in the New Forest.
It's true that 60 spokes won't fit on drum wheels. They are ok on the back
but the spokes touch the drum on the front. 72 spoke wheels have a slightly
different offset and the spokes clear the drums with no problem. I bought a
set for my Longbridge BN4 project and have checked them for fit.
I agree with you about the 185 tyres. These are a low profile design with
the height of the tyre being approximately 70% of the width. Typically they
should be fitted to a 5.5" rim resulting in a combination that in my opinion
really doesn't suit the 'period' style of the car. Too much rubber.
The more frequent choice for many is for a 165 tyre on the standard 4" rim.
This is equally wrong in my view as the tyre looks small and 'weedy'. I
believe this arises from the design of radial tyres in which all tyres have
a height that is around 90% of the width. So-called low profile tyres have
a height that is less than this 90% standard. As mentioned above the 185/70
being a typical low profile size.
The car was designed for a 5.90"x15" cross-ply tyre and I'm sure the
appearance of the tyre in it's wheelarch was a serious design consideration
when God and Gerry Coker collaborated. I therefore went against the normal
received wisdom in selecting tyres for my project.
Bear with me here while I try and put my logic into text.
Cross-plys have a 100% profile. The height of the sidewall for a 5.90" tyre
is therefore 150mm. Please excuse the metric conversion, it will come clear
in a moment. The unloaded diameter of a 5.90 tyre will therefore be: 15"
(which is 381mm) plus 150mm plus 150mm. A total of 681mm. With me so far? -
Ok. Then I scoured the tyre charts looking for a full height radial with a
diameter close to 681mm. My theory being - if you ignore the flat bit at
the bottom - that the unloaded appearance of a cross-ply will look the same
as a radial of similar diameter.
To cut a long search very short, I found that a Michelin XAS 180HRx15 has a
diameter of 680mm, and a tread pattern that is reasonably classic too.
Bingo! The wheel rim size was then dictated by the tyre width. 72 spoke
15"x5J were selected.
If you are buying in the UK I can recommend Longstone Tyres
(www.longstonetyres.co.uk ). I tried ALL the usual suspects and got the
best deal, best service and best all round support and interest in what I
was doing from these people.
Best regards............AlanB
http://www.nfahc.co.uk
-----Original Message-----
From: djjob@noos.fr
Sent: 31 August 2004 23:22
To: healeys@autox.team.net
Subject: Wire wheels and tyres
I know this has been discussed many times but stick with me.
I need new tyres and Im thinking of moving to 72 spoke painted wires from
48. I have front drums and I understand 60 spokes wont fit on my BN4
I dont want 185 tyres.
What width of 72 spoke wires is the best width for 165 0r 175 tyres.
I will probably get the wheels in England. Any references as to who you
think is best?
regards
Derek
www.healeysix.net
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