Lagondaforum

Subject: DB 3 ltr tyres

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By now I have sorted out most little problems within 400 miles of test driving my DB 3 ltr (ignition, carburettors, fuel pipes, fuel filters, spark plug caps, main brake cylinder..). Now I started some test driving on the motorway (here I discovered a blocked fuel filter at the higher througput needed) and that the tyres have suffered from long rest (I should have lifted the car but always thougt it will be finished very soon so why bother..). I think I will buy 2 new front tyres. It has 6.00 x 16H Dunlop now. The best supplier for veteran car tyres in Germany seems oldtimer-reifen.com they have different 6.00 x 16, the only ones that would allow 160+km/h are Dunlop and Avon (both up to 210 km/h). But the Dunlop ones are only rated for max 475 kg load, which would be a bit low for this car. Any inputs on tyre selection for the DB Lagonda, especially the 3 ltr ?

Another point is tyre pressure: the manual specifies 25 lb/sqr in = 1.75 bar for the front and 30 lb/sqr in = 2.1 bar for the rear. I tried higher pressure especially for the front first and than lowered to the specified (hoping that the wobble from the stand still bump would be less) but with fast steering movement left/right the car swings up (feels to soft). What is your experience or recommendation for tyre pressure ?

P.S.
This morning I called oltimer-reifen.de, they recommended to change to 185R16 radials, but I see they have a bit smaller diameter and are a few mm wider which will not look nicer and smaller diameter brings up rpms on the motorway even more plus I do not know if radials turn the steering much harder.

Another recommendation from a friend this morning was Blockley tyres which he is using on his Feltham Aston, but when I look at the profile even the 5 block pattern looks a bit "rough" to me

Suggestions?

Yours,
Peter

Subject: Re: DB 3 ltr tyres

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Hi Peter,
My other "love" is RM series Rileys; I have a 1951 RMB. The standard tyre size for that is also 6.00x16, but many members prefer to fit radials, either 175/16 or 185/16. As you already appreciate, you have to put up with a lower rolling radius, and the tyres might not look quite so "right" on the car. The major benefit is a serious improvement in roadholding & handling...and that with a car that has a fine reputation for those qualities on crossplies. Tyres in these sizes are available nowadays mainly it seems as they are a standard size for taxis, so it might be worth some research to see which have the highest rolling radii. You would need to source inner tubes specifically made for radial tyres, or see if you can get away with a tubeless fitting...the wheels were not made to be airtight, but that doesn't mean they won't be.
Yes steering would be heavier, but it seems they run these at over 30 psi, whereas Riley's recommendation (for crossplies) was 24 psi. There was talk years ago that the higher loadings resulting from the increased grip & different "footprint" would result in increased wear on steering components...but I don't think that has proved true in practice.
Incidentally, you might be amazed at how much rolling radii can differ...I found that, out of the more commonly available tyres for the V12 & LG6, Michelin Conforts have far the highest. Regarding Blockleys; that brand is targeted at pre-war cars, where such tread patterns would look more in keeping.

Laurence

Subject: Re: DB 3 ltr tyres

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Thank you Laurence for your inputs.

I also came across another aspect: width of the tyre. The Dunlop radials which are on the car now come already very close to the anti roll bar when on lock, they have 175 overall width. (may be the anti roll bar is non original?) Michelin 185R16S might be a solution, speed rating is up to 180km/h, load up to 630kg, width is 180mm and diameter is 707mm
http://www.oldtimerreifen24.de/...tml?cHash=f7e3760c56

I have looked at the taxi tyres 175R16 98/96Q | Dunlop | SP Taxi allowed for 160km/h (just a bit low, not that I will drive that fast but for the authorities). Width is 185mm and height 685mm

Peter

Subject: Re: DB 3 ltr tyres

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Hi Peter,

175 sounds a bit narrow for such a large car, but perhaps they cleared the antiroll bar & 185s didn't. The difference must be fairly marginal, you could always space the wheels out slightly. Check more importantly that they don't rub on brake hoses.
"Austone" radial tyres seem quite popular for Rileys, might be worth investigating those. You need to get the diameter as near that of the crossplies as possible to keep the speedo reading accurate...but smaller diameter will give you better acceleration..at the expense of lower maximum speeds of course.

Laurence

Subject: Re: DB 3 ltr tyres

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Laurence,

I could not find Austone in the right dimension (only the Taxi 175R16 which has to low speed limit) I did not check further a direct order in China..

So I ordered now a set of Michelin X-Stop 185R16 (210 EUR each incl VAT plus tubes) and I am curious how handling will be different.

My point on the anti roll bar was wrong, tyres only come that close when the car is lifted

Subject: Re: DB 3 ltr tyres

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Hi Peter,

Be interesting to hear how you find them. My only experience in this direction was changing from 125/12 to 135/12 on my old Fiat 500 (proper air cooled one, not the recent pastiche), & I certainly noticed an improvement on that.

Laurence

Subject: Re: DB 3 ltr tyres

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now the radial ones are fitted, attached images show the former diagonal Dunlop and new radial Michelin. I only did a short test drive, runs very smooth now (because they are new and have no bumps) and steering feels more than exact. The look is ok but the diagonal tyres looked a bit nicer.

Thumbnails of attached images:

Subject: Re: DB 3 ltr tyres

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Hi Peter,

Fortunately tyre treads are less visible on 50s cars than earlier ones. That said, the tread you have there doesn't look "wrong" to me. The Michelin "X" pattern dates back to that era & I think was a similar tread pattern. Accepted not perhaps a factory fitment, but owners could have opted for radials had they wished.

Laurence

Subject: Re: DB 3 ltr tyres

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Now I covered over 1500 miles with the new tires and I am totally satisfied with them. The feeling of steering of the DB3 ltr on major roads with radials is better than any car I ever had: totally precise and direct.

Subject: Re: DB 3 ltr tyres

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Hi Peter,
My Riley has now gone for painting, and as the old tyres have to come off, I've been looking at what tyres are available now.

I've discovered an American tyre firm have recently introduced a 6.00 x 16 radial tyre, yes 6.00 x 16, so it has the appearance and dimensions of a period crossply. It's called Excelsior Stahl, "Stahl" indicating it is a radial; don't confuse it with their standard 6.00 x 16 crossply, which is seriously cheaper but only rated to 93mph. The tread pattern appears to be the same as their higher rated "Comp V" crossply, which I think is a copy of the Englebert racing tyre tread, and it looks pretty good to me. Speed rating is 130mph, so more than adequate for our cars.

They're pretty expensive, only one UK supplier, & their price is £247.50 + VAT (20%). That said, if they last more than twice as long as a good quality crossply, and they should, then they're not bad value. Despite being American, they aren't whitewall, thank goodness.

The only user experience I've been able to discover is from Americans; would have preferred UK/European as road conditions differ, but all seem very positive...only issues seem to be that some feel the sidewall script is too obvious.

Laurence