QuestionThe tire I currently have on my Triumph are 155R13... there's no middle number. The tire store here had a 155/80R13 but that seemed to be somewhat larger tire.
What size fits on the 1977 Triumph? Where can I buy tires?
AnswerOmar,
The original tires on the '77 were either the 155SR13 or a 155/80-13.
The first number in tire size is tread width. The middle number is the ratio of tread width to sidewall height and the final number is rim diameter in inches. The tires without aspect ratio listed are something odd like a 78 aspect ratio.
The 155/80-13 is a bit larger in overall diameter but it's very close. Not enough tread for good cornering but good potential for gas mileage.
Otherwise you can try to find 175/70-13 or 185/60-13. The 185/60-13 may hit the inner fenders, it varies a bit from car to car.
In addition to your local tire stores there are some good online sources such as The TireRack (www.tirerack.com) or Discount Tires Direct (www.tire.com).
In general though, 13" tires are getting harder to find as few new cars still use that small a rim.
Cheers,
Jim
