Best tyre sizes

[redhouse53]

Looking at replaceing my ageing tyres for more modern ones, currently fitted with 155/13’s but need to know tge best sidewall profile, or any recommendations for makes etc,

Thanks

[Steve AKA vitessesteve]

This has been covered before for example see: http://www.clubtriumph.org/cgi-bin/forum10/Blah.pl?m-1345131836/

You might also find http://www.mintylamb.co.uk/?page=tyre.htm useful.

[redhouse53]

Cheers, so 155/70/13 would suit, the car is a gt6 on standard 4 1/2” steel rims

[1300_wales]

I have 175/70/13 on my spit but that is on 6 inch rims, I would have thought you would be better with 155/80/13.

As for good tyres I am using yokohama blu earth at the moment and they are better than the falkens that I had.

Try this site for good prices: http://www.blackcircles.com/ its powered by tesco and you can earn clubcard points too.


Thanks,
Mike.

[rotoflex]

Cliftyhanger said that he is running 175/70 tires on 4.5J wheels for autocross.

The numbers are worried to death here:
http://club.triumph.org.uk/cgi-bin/forum10/Blah.pl?m-1333535260/s-all/

I ran the pre-metric 165 SR 13 size forever on my 4.5J wheels.

Some things to bear in mind are:
1.  The aspect ratio on the old sizes where it's not specified is /82 for all of the widths
2.  In metric sizes (the ones with a / ) with specified aspect ratios, the sidewall height will change in relation to the width, so the appearance of the car will differ as well with a shorter sidewall (more space between tire & wheel well).
You'll have to do math with the metric sizes to see what the sidewall height will be.
3.  It's been mentioned that in our cars, part of the suspension action for keeping the wheels flat on the ground when in action was expected to be in sidewall flex, so shorter sidewalls change things.

Some observations:
1.  The 155/80 13 tires later spec'd by Triumph when metric sizes came out had shorter sidewalls than the original spec 155 13 tires.  More space is visible between the tire and body, but there's less sidewall flex.
2.  165/80 tires are the closest but slightly shorter in sidewall height to the 165 13 tires I ran without difficulty, but a little taller than the original 155 13 tire spec.
3.  175/70 13 tires are shorter than the original spec of 155 13.
4   175/80 13 tires would have a sidewall height of 140 mm, probably too tall to go in the wheel wells without fouling.
5.  Lower sidewall heights won't leave as much air between the tire & body if you've lowered the car from original height.