3 litre tyre choice

[Robert Clifford-Wing]

Being a new member and having recently purchased a 1926 3 litre VdP bodied car, I need to replace five tyres. Do members have any recommendations or preferences for manufacturer or profile?

The vehicle is currently fitted with Firestone 520/21.

Many thanks

[Robert Zannetti]

Rob, welcome to forum. I too have a 3 litre, late 1925 - first registered in 1926. I currently have Dunlops on my car and they are OK. I have looked at a Blockley 5.25 x 21 which is a recent addition to their range and more reasonably priced than the 5.25/6.00 that they also have. It is £149 against £240! There has been some criticism that their tyres can be a little noisy. I have had some problems with wheel wobble and heavy steering. The tyres play a part in both of these problems and I have worked at correcting these whilst retaining the Dunlops. Do you have any problems and are you replacing them just because they are worn out? How are you balancing the wheels? My wheels have the traditional four studs which contain light and heavy washers adjusted to give a spot on static balance. I also balanced my brake drums which were surprisingly out of balance!

[Robert Clifford-Wing]

[Robert Craven]

My 3 Litre has Blockley 525/600 21" and they need replacing. Richards Bros are the nearest supplier to me and I'm waiting for them to open again after Christmas.
I went for the 525/600 in 2012 because the 525x21 looked a bit small and my gearing will be affected if I go down in size to them. Even though I've got 4.5 Litre steering gears I find the steering very heavy when manouevring at low speed and I think that's the effect of the heavy Blockleys, though I've noted other 3 Litres with the 525/600s. Julian Mazjub once suggested to me I needed to increase my tyre pressures but I didn't find it made much difference. Anyway, the tyres are good once I'm on the move.
When I rang Richards Bros in October they told me that though people may be advertising Dunlop 21" they aren't being made at present and I'd be lucky if I actually found any. So there isn't a lot of choice.

[Robert Zannetti]

I believe that heavy steering can be improved by altering the castor angle. There has been a recent blog on forum about this subject. Do you think these problems are only related to owners who are called Robert? North Hants Tyres do Excelsior and Firestone but as the prices are similar to Blockley I would be inclined to go for the Blockleys. I am surprised that the difference in circumference would be enough to have a noticeable effect on gearing between the two 21" Blockleys.

[Robert Craven]

The respective diameters are 810mm and 838mm according to the MWS site (Blockley's site doesn't specify this dimension).
I suppose that's not a lot. 60mph on the larger one would be 58 mph on the smaller one. Less than 100 rpm difference depending on the overall gearing.
But I'd rather not reduce the gearing.
If they're actually in stock (I'm not sure whether they have to be specially ordered by Richards) I'll try eyeing them up when I see them.
According to Longstones, the Firestone and Dunlop are 800mm and 831mm respectively.
I wonder how accurate the dimensions given by these different sites are. After all I assume the Blockley 525/600s are actually some inbetween size and can't somehow be a variable size.

[Robert Clifford-Wing]

So, to be clear, Blockley's and 525/600 X 21" is the favoured tyre @ £240.00 a corner, not the 525 X 21" @ £190.00?

I have the 4.5 litre steering box and have no issues with the steering after the car has started to move.

[Robert Craven]

Ideally I'd like to be able to experiment and I'm wary of giving any positive recommendation.
You might find quite a difference in grip (and therefore low-speed steering) between your old and presumably rather hard 800mm Firestones and new larger grippier 831mm Blockleys.

Paul at Donald Day's once told me they had two 8 litres in their workshop, one with Blockleys and one with other tyres, and the former needed more effort to push around the workshop.

PS, according to Longstones' site the Firestone are 525/21, not 520.

[John Murch]

Rob, I run 525 x 21 Blockley's on my 3ltr. I have a 3.54 axle ratio. I've been very happy with the tyres, there is a little more tyre noise on certain surfaces than with the Dunlops that I used to use. It looks as if I will get over 10000 miles from the current tyres which is better than I got with the Dunlops. I think that they perform better in the wet, and in my opinion look more period.
I had my tyres fitted at Blockley.
John

Eta
I run the tyres at 36psi

[John Murch]

I notice that Vintage Tyre Supplies say that they have the Dunlop 525 x 21 in stock.
Regarding gearing, it depends entirely on your gearbox type and axle ratio if fitting 600 or 525 is a consideration. With the A gearbox and 3.54 ratio i feel that my car is a bit overgeared other than the rare occasions when i hit a motorway. When I first had the car, it had a 3.78 and I do notice that small difference.

[Robert Clifford-Wing]

From an esthetic point of view, do members feel the more bulbous 525/600 is appropriate to the 3 litre or, is that tyre better suited to the large 4.5 litre cars?

[John Murch]

Regarding the esthetics, much will depend on the style of body and wings.
If you have a Le Mans rep style of body with cycle wings, perhaps the larger tyres look more the part. Otherwise I would favour the smaller size as (hopefully) giving lighter steering and looking more like the original fitments.
[img]
This photo is of my car in 1926, the body was subsequently changed, showing the sort of tyres fitted.[/img]

[Paul Spencer]

I have Firestones, but nothing to compare them to as I have always fitted like for like for the 13 years I have had the car. I am perfectly happy with them.

[Robert Clifford-Wing]

[Chris Card]

While changing your tyres, check that the wheel rims are all the same width. I found that I had a mix of rim widths, so had the wheels rebuilt to match the Blockleys that I use on my 4.5L.

Chris

[Robert Clifford-Wing]

Five new Firestone tyres have been fitted with rim guards and tubes. All four wheels took large amounts of weights to balance so, I am optimistic my wheel wobble issues will be solved. Just tracking to check now (3/16" toe in?) and the debit card to console!

[Robert Craven]

I got three new Blockley 525-600 / 21 at Richards Bros today (a very helpful firm who specialise in making wheels, but also sell tyres, though they expect you to bring just the wheels and not the whole car, because they lack space for changing wheels).
We stood the 525 & 525-600 next to each other for comparison and the latter seemed considerably taller and also wider. If I'd been starting from scratch with smaller lower wings and perhaps different gearing from my 3.78 I might have gone for the smaller tyres for their lighter steering (and lighter work in changing wheels), but I decided to stick to what I knew.
It still would be nice to be able to experiment with different sizes and makes.

[Stephen Blakey]

Speaking of tyres...

Longstone's Dougal told me that the EU have banned some of the compounds used to extend the life of rubber and hence modern tyres have a much reduced life expectancy before they perish and decay.

I wonder if anyone has noticed this in practice?

[John Robins]

The Caravan Club recommends changing the tyres on the tin shed at six years regardless of how little the mileage or how good the apparent condition. As far as the tyres on the daily driver are concerned, I seem to ruin more on potholes than I wear out these days.