Thread: Sizing of Wheels/Tyres

Originally Posted by Land-lord

What does 7.50 x 16 mean?

What size in mm should the rims be to suit this size tyre?

7.50 x 16 is a tyre with a circular cross section of the bit that holds the air, with a nominal diameter of 7.5 inches or 190.5mm and a bead diameter of 16 inches or 406.4mm.

The wheels for these will be 16" or 406.4mm diameter on the bead seat and around 5.5" or 140mm between the bead shoulders. If they are standard Landrover wheels they should be stamped with the part number, the width and diameter in inches and the offset in mm.

John

Rims are still measured in inches. The world is going metric but rims are still in inches. Forget about converting your measurments from imparial to metric - too much of a headache and will get you no-where.

When looking for tyres the sizes will be given in either US, metric or imperial system, with the rim diameter in inches.

For example:
imperial
7.50 x 16 - section width of 7.50 inches for a 16 inch rim
7.50R16 denotes the same tyre but of radial construction

metric
235/85R16 - section width of 235mm, hight of tyre section (aka profile) 85% of width, radial construction on a 16 inch rim

US
31x10.5/15 - tyre diameter (height of fitted tyre) 31 inch, section width 10.5 inch on a 15 inch rim

Standard Landy LWB or SWB rims are 16 inch diameter. Your best bet for tyre size is 7.50R16. Good height, quite narrow, popular size (in some cases such as Steeltreks the ONLY size). Look for LT (Light Truck) marking - stronger than 'car' tyres.
If you want something a little wider without going overboard you can go for 235/85R16 - same rolling diameter as 7.50s but wider (about 9 inches). Have these on the old Turtle and they performed very well...

Personally I wouldn't choose SWB rims. They are quite narrow with very little offset keeping the tyre inside the body. LWB rims give yo more tyre size options, are a little wider with better offset, effectively pushing the tyre outwards giving just a little bit more stability. I cannot comment of the strength of either rim. SWB LR rims are 5" wide LWB 5.5".

Tyre pattern / brand - totally up to you and your wallet. Read all the other discussions regarding tyre choice...

My rim dia is 17.7" across.

Is this OK to fit the 7.50 x 16" tyres?

Originally Posted by Land-lord

My rim dia is 17.7" across.

Is this OK to fit the 7.50 x 16" tyres?

The measurement you should be making is across the shoulder that the tyre bead sits on. The overall diameter including the side flanges can vary with the maker of the wheel. For example, I have just checked some wheels here, and the Landrover wheels I have handy vary from 17.7 to 17.6, but the Lada wheels are only 17.5" although they are all suitable for 7.50x16 tyres. So I would say you wheels are in fact 16", and probably suitable for 7.50x16 tyres. If they are original Landrover wheels they should have the size stamped on them, although I think some early wheels only had the part number.

John

They used to fit Michelins as standard equipoment on Defenders in the same size 7.50 x 16.....Michelin XPC......a brilliant on-road tyre that is surprisingly good off road for its rather "undramatic" appearance.....and theyre reinforced. Not cheap, but they last for a VERY long mileage.......

......I agree with a previous comment that the Olympics are diabollically dangerous on wet roads - as just about ALL Olympics were.....and the very hard compound doesn't wear all that well.......bits break off in rough rocky going.

......for what it's worth, I've got Goodyear AT on my S2a and they are quite OK on and off road.

Originally Posted by JDNSW

The measurement you should be making is across the shoulder that the tyre bead sits on. The overall diameter including the side flanges can vary with the maker of the wheel. For example, I have just checked some wheels here, and the Landrover wheels I have handy vary from 17.7 to 17.6, but the Lada wheels are only 17.5" although they are all suitable for 7.50x16 tyres. So I would say you wheels are in fact 16", and probably suitable for 7.50x16 tyres. If they are original Landrover wheels they should have the size stamped on them, although I think some early wheels only had the part number.

John

THanks JDNSW..

AS per your quote above - how did you arrive @ 16" when the tape measure says 17.7" rim dia?