Tyre Sizes

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twincamman
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Re: Tyre Sizes

Post by twincamman »

Just spotted these at Vintage Tyres, the price looks good as well.
http://www.vintagetyres.com/display.asp ... sf_01=type
MarkyB
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Re: Tyre Sizes

Post by MarkyB »

I'd beware, cheap rarely means good.
http://www.honestjohn.co.uk/forum/post/index.htm?t=1178

All kinds of unlikely places make round black things that fit on your wheels, Japanese bike tyres used to made from some kind of Nylon, very hard wearing but no grip :o

"Once you break something you will see how it was put together"
TvdWerf
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Re: Tyre Sizes

Post by TvdWerf »

My MM from '51 has 5.20*14 tyres, what is the nearest tyre size?
In a table, 3 options are called: 5.20-14 = 165/60-14 or 145/70-14 or 135/80-14 .
what I see looks more like the 135/80 as the 165/60, or am I wrong?
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mike.perry
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Re: Tyre Sizes

Post by mike.perry »

The nearest tyre diameter to 5.20/14 is 155/80/14 which is still slightly smaller diameter. A 175/80/13 tyre on a 5.5 inch rim has the same diameter as 155/80/14.
If you are fitting tubes make sure that there is a rubber band around the inside of the wheel to stop the tube from chafing
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TvdWerf
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Re: Tyre Sizes

Post by TvdWerf »

At the moment, tubeless are still mounted, and only one tyre is leaking a little.
Every 2 months I need to bring him from 0.5 bar to 1.7 bar, but cleaning should be enough I think..
So I prefer to use the tubeless tyres.
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bmcecosse
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Re: Tyre Sizes

Post by bmcecosse »

1.7 Bar is too low ! 1.9 or even perhaps 2.0 if loaded up is more reasonable.
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TvdWerf
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Re: Tyre Sizes

Post by TvdWerf »

He is only parked in my dry and floor heated barn ;)
so when the car is not on the road, 1.7 is no problem.
The tyres are very old, with a lot of cracks, and a high pressure can burst them...
Nobody could tell me how long this car was not on the road, but he is in my barn since 2010.
My Prius has 2.7 bar, for highway use, and I put the pressure on a normal value when they are new :lol:
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bmcecosse
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Re: Tyre Sizes

Post by bmcecosse »

Ahh - well as long as you don't actually drive on them!
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Murray.arnold
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Re: Tyre Sizes

Post by Murray.arnold »

Hi guys. I was driving our own Moggie and the car is wandering. I had a look at the tyres and the side walls are cracking. They are 145 x 80 x 14. I pushed the car and there appears excessive roll on the 80 profile. This obviously translates to the wobbly handeling. Not sure what width my wheels are. I dont see the size writen on them. But whatever they are i plan to lower the profile to max 70 to reduce sidewall roll. I was going for 165s but think i will opt for 155 x 70s. 35 quid a tyre or there about. Plenty options and seeing its a summer car, then summer tyres it will be. I plan to get her on axle stands and let the air out all the tyres to try and preserve the life of them.
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ManyMinors
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Re: Tyre Sizes

Post by ManyMinors »

I don't understand what you mean by "excessive roll on 80 profile tyres"? I have that size on my own Minor (these are the standard size when radial ply tyres are fitted) and have no undue problem with the handling at all despite enthusiastic driving. What pressures are you running? By lowering the profile you will lower the overall gearing which is low enough already on a Minor. If you fit 155 or 165 section tyres, they will be wider and less planted on the fairly narrow wheels. The car is likely to handle less precisely as a result - surely the opposite of what you want?
What make and age are your tyres?
IslipMinor
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Re: Tyre Sizes

Post by IslipMinor »

The original cross ply tyre size of 5.20 x 14 is equivalent to a radial ply size of 145/80R14. The Minor wheel width is only 3", so this is the limiting factor in tyre width that should be fitted, and 145 is generally accepted as the maximum tyre width for a 3" rim. Many fit 155/80R14 and find they work well. 165 or wider need a wider rim, which is what was fitted to the van, so with 'van' wheels 165 width tyres should be fine.

With a 165 width tyre, the profile could be reduced to 70% to correct the rolling radius, and a 165/70R14 is identical in rolling radius to the original cross ply or a 145/80R14 radial ply, but does not work well on a 3" rim, and needs a 4" wide rim to provide the required support.

155/70R14 will probably be OK on the standard 3" rim, but will lack some lateral support, and it is also 2.6% smaller in rolling radius, making the speedo even more optimistic and the engine sound busier than normal!

Other very near equivalents are 165/70R14, 175/65R14, 195/60R14, 185/70R13, 175/60R15 and 205/50R15. These are calculated tyre sizes, and the actual tyre may not be made in all these sizes.
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philthehill
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Re: Tyre Sizes

Post by philthehill »

I take the opposite view - to preserve the tyres I would recommend raising the car on axle stands so that the tyres are not on the floor and producing flats and over inflating the tyres to say 47/50 lb/sq inch and covering them with a dark sheet to block out the UV rays/light. You can get special tyre covers to fit over the tyres so keeping out the UV rays/light.
For example:-
https://www.ebay.co.uk/itm/1-pair-2-x-6 ... SwB-1YwkmB

oliver90owner
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Re: Tyre Sizes

Post by oliver90owner »

Summer car? Garaged throughout the winter? Not much UV around inside a garage unless you don’t live in the UK. We don’t get much of a sun tan in winter, even working outside. Axle stands would be OK with tyres at normal pressure (this is, after all, the designed working pressure). Covering windows and closing doors is likely just as effective

I would roll the car a part turn, now and then, if I were trying to preserve the tyres for umpteen years of use, but tyres should be replaced every few years anyway.

If I was that worried about the tyres, the car would be sheeted to protect the paint, killing the proverbial ‘two birds with one stone’.🙂
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