Hello once more Peter,
I’m getting slower as I get older. I need to give myself more time to reflect before opening my mouth.
Looking at the tread pattern of the Blockleys it reminds me of the tread pattern of tyres I once had fitted to a Land Rover I owned a long time ago. The drumming was quite loud both up and down wind but not off-road, unsurprisingly. I’m sure that the Blockleys won’t be as bad, hopefully, not that I’ll be going off-road. What tyres do you have fitted to your SS?
Tim
Hi Tim,
Currently I’m running on Dunlop Gold Seal 5.25 / 5.50 x 18, 6 ply on the front and Excelsior the same size and 6 ply on the rear. I find that both of these tyre types perform very similarly. I have in the past tried the same size 4 ply Dunlops but they deform too easily on corners and squeal and don’t give anything like the nice sharp turn in of the 6 plies.
I think I’m right in saying that the Blockleys are radials and will permit higher cornering forces than the Dunlop cross plies but I find that even with the Dunlops on the limit I tend to break spokes.
The Dunlop tread pattern is this:
The Excelsior is not identical but similar.
Peter
Maybe these would be good: they say, NON-SKID right on the tire…
The nylon is the carcass construction weave not the rubber that hits the road. Having the harder rubber as stipulated means a longer lasting tread. American tyres like BF Goodrich and Firestone have a polyester weave which does not get flats. In fact I left the car in the shed untouched for 5 months with BF Goodrich and no bumping whilst driving was displayed. Have tried quite a few over the years - Firestone are small enough to go into the spare wheel locker but I found didnt seem to last very long especially the driving wheels. Excelsior 525/550 were far too narrow for a 31/2 and screeled easily under turning and braking and displayed serious bumping when only not used for a week. I got rid of them pronto. My favourite so far has been BF Goodrich which last quite well and no flats - problem is they are too big to close the locker cover. My friend stores it deflated and carries a 12v pump.
If anyone locates a 6 ply highway tread polyester 550 or even 600 x 18 tyre I would be very interested to know about it.
I use BF Goodrich on both the 100 and the saloon. and they work well on both.
The 100 has excellent braking in the runoff at the end of the course at Rob Roy and the saloon was often used with 4-5 people on board. if one is looking for silence Bentley advertised as “The Silent Sportscar”
BUt on a mk IV the wind noise will drown out tyre noise , probably even drown out the wireless one put in to hide the noise from the diff which one put some banana peels in to quieten it down.
My father , who worked as Chief Testing Officer for Olympic Tyres said they designed tread pattern so as not to continually repeat the pattern and so get resonance. So while they might look like a repetitive pattern sections were slightly altered to avoid a rhythm…
One of the most important things, to avoid “singing tyres,” is the alteration of the width of the tread blocks, that, AFAIK, all road tyres have.
Hi Tim,
Wheel balancing is essential.
If you haven’t had your brake drums balanced and you are not fitting your new tyres yourself then ask your tyre fitter not to balance them but to give you a few strips of sticky weights so that you can balance them along with the drums. Take a look at the second part of this.
The drums as supplied from the factory are not well balanced and are likely to negate individual wheel balancing.
Peter
I used Ensign tyres from Vintage Tyres on my 1948 DHC:
They are 6 ply rating and use the same moulds as the no longer available Dunlop 5.50x18. I exchanged them for a set of Waymaster tyres which were positively dangerous, sliding when braking or going round corners, wet or dry. VTS were very good, taking the Waymasters back and only charging the extra price of the Ensigns. These have been on for over a year now and I am very pleased with them.
I have an older set of Waymasters on my 1939 saloon which have performed very well, but VTS said that the design and manufacture had changed and virtually admitted that they were not suitable heavy cars like the Mark IV.
Out here tyres are dated and illegal after 10 years.
A rule of thumb, Hard tyres last longer but have less grip in the wet. Soft treads wear quicker but are safer in the wet.
I’ve always gone for the soft and safe combo.
I will not say a word.
I will not say a word.
I will not say a word.
I will not say a word.
The Ensign 6 plies look good - have made contact to find out the tread width, weave material and freight for 4 tyres to Adelaide. I tried 525/550 before and found them far too skinny for a 3 1/2 litre but as has been stated the old Dunlop 550 mould is being used and I may be in luck - just hoping the freight costs dont drown the deal though.As a diversion, I noticed Eds comments about braking. I can fairly easily make the front wheels lock up when the drums are cold but experience severe fade as they heat up. My linings are 35 years old now and although still very thick may be too hard for the best braking. Mine probably still have asbestos. Any thought on making them more efficient.
Regards - Mike
Perhaps I’m rather less demanding but I can’t say I’ve been aware of these problems with the Excelsiors that I have. The tread width is 4.25" which is exactly the same as my Dunlop Gold Seals. I know that the spare wheel compartment in the MkIV is more generous than that in my SS but if I were to opt for a wider tyre I think I would be in real trouble.
As it is, I can only store my spare deflated.
Peter
Hi Peter,
A deflated spare sounds a bit useless. 
But if you carry a 12v compressor ( like most Porsches used to) or a good foot pump maybe it’s ok. With the hand pump I think I would rather skip the pumping and find some other solution. Cheers!
Pekka, You are right that pumping up an 18" tyre is quite an energetic operation but of necessity I have done it in the past (several times before I discovered heavy duty tubes). I do have a little battery operated pump but it is probably slower than the foot pump I normally carry for such emergencies. That said, it is possible to insert the spare into its compartment without it being fully deflated.
Peter.
Or, do what modern cars do, have a smaller size spare that will fit. It’s only needed as a get you home and will be rarely if ever used.
Yes I have a Firestone for a spare - very similar looking tread to the BF Goodrich but an inch or so smaller in diam.
Hi,
Or, although I think some may not like it, just carry one of those foam & compressed air bottles in the trunk. I have one in the original toolkit of the 456 GT. Yes, it’s messy stuff, but if you will replace the failed tube anyways, it will be less messy than with a modern car with tubeless tires. Cheers!
Do they work with Tubes. I carried one for a few years and never had aflat . Which maybe how it works, But some one later told me they only work with tubleless tyres.
Hi Ed,
You may be right, perhaps they do not work on tubes. Or perhaps they might work for the sort of stuff I have experienced (a screw in the tire) but of course not, if a tube has exploded or been torn apart.
But I agree that having one may be a good insurance, We once attended the Goodwood Revival without umbrellas and rain coats, it was a disaster! My friend ended up buying a very nice umbrella from the good ol’ Goodwood shoppe, for £400 GBP!!! :-o 
Had high hopes that the 525/550x18 Ensign tyres would fullfill my search for a 6 ply highway tread that would not display flats from standing. Vintage Tyres replied with the following - "Thank you for your email,
I have included the technical information below for the tyre 525/550-18 Ensigns
the tyre is a 4Ply Nylon construction with a tread width of 100mm.
So! it is a skinny tyre compared to the nearly 5" tread width of the BF Goodrich, only 4 ply construction and fabric is nylon which has a tendency to get flats. My search continues unfortunately. Freight to Australia for the 4 tyres was I thought reasonable.
