The Triumph 2000 / 2500 / 2·5 Register Forum

Whats the recommended size to fit? Currently has 165 R13 82P on steels, I don't think these are right?
What should they be and any recommendations for type and where to get a cheap set of 4 just to get it on the road.

Hello Simon,

I think the originals were 175/80 x 13 but probably a difficult size to get today. I use 185/70 x 13 on my car, shouldn't be too difficult to find at a reasonable price?

Alec

There is a guy near Bradford, W.Yorks, who I am led to believe has a reasonable stock of new 175 x 13 tyres at about £20 each I think. He was at the National on the Saturday, and had one of said tyres with him, although I personally didn't look at it closely. Must be worth a look at that price if you're anywhere near Bradford. I think his name is Peter Mann, I think he's a Register member, but I don't have any contact details, but I'm sure someone on here will know.

The original radial fitment was 175 R 13's as Alec says, which in modern sizes is 175/80 13 (the 80 profile is the standard profile). I would try to obtain the correct size for your steel wheels, although they are difficult to source now, but fitting different sizes in both width and profile may cause your speedo to be out, and IMHO not look right. A standard car on the incorrect tyre sizes to me looks totally wrong.
There is a way of calculating the rolling circumference of alternative sizes of tyre so that the speedo reads correctly, and the diameter looks as near as possible to the original 175 13 size, and I'm sure someone on here will know the figures!

http://www.brspecialtuning.co.uk/Tyre%2 ... ulator.htm
185/70/14 or 195/60/15 have a virtually identical rolling circumference to 175R13 but obviously you would need different wheel rims.

I was going to suggest that you go to 14" rims which would give you a greater range of tyres.
If you don't like S mags most rear wheel drive Japo's will fit.
Tony.

The original size was 175/13 but that would have been with 82% profile rather than the now normal 80% profile. Not a lot of difference really.

Calculating tyre diameter is easy if you want to do it by hand rather than use the internet.

The diameter is 13" + the bit of the tyre at the top and the bit at the bottom. Ignoring the flattening, these are the same.

The bit at the top (and bottom) is the width (175) times the profile (80%) IN mm! I.E. 140mm.

Convert to inches by dividing by 25.4 = 5.5". So the total diameter is 13 + 5.5 + 5.5 = 24"

If you put different tyres on you can recalculate the diameter for them and compare that with the 24" above. The ratio of the new diameter and the 24" will be how far out the speedo will be!

There are other things you can do to correct that such as speedo types and gearbox speedo drive gears, but that's too involved for a simple post on here!

Cheers,
Mike.

There are some new Maxxis 175 R 13 tyres listed on Fleabay currently by Vintage tyres - £48 each including delivery...........

Thanks all, I went for the uniroyal ones from the place Clifford posted, as CW said they were good, oh and they were cheap!

http://www.tyreleader.co.uk/car-tyres/u ... 86t-349353