1964 Triumph Tire Fitment Guide

1964 Triumph vehicles use four sizes across three model groups. The Spitfire and Sports Six use either 155R13 radial or 560-13 bias-ply tires on 13-inch wheels. The TR3, TR4 and TR4A use either 165R15 radial or 590-15 bias-ply tires on 15-inch wheels. Rim-width ranges shown on available products run from 3.50 to 4.50 inches for the 13-inch bias-ply size, 4.00 to 5.50 inches for the 13-inch radial size, 4.00 to 4.50 inches for the 590-15 bias-ply size, and 4.50 to 6.00 inches for the 165R15 radial size.

That means year and make alone are not enough for a correct choice on a 1964 Triumph. Start by identifying whether you have a small-chassis 13-inch car such as a Spitfire or Sports Six, or a larger TR-series car that uses a 15-inch wheel. Once the wheel diameter is confirmed, the decision becomes whether you want a bias-ply tire for a more period-style look and feel or a radial for a more contemporary driving character.

On a 1964 Triumph, 560-13 is a numeric bias-ply size. The 5.60 figure is the nominal section width in inches, written without a decimal as 560, and the 13 is the wheel diameter in inches. On 1964 Triumph applications, that size belongs to the Spitfire and Sports Six. Available versions include narrow whitewall and wide whitewall styles, and the products with published fitment details use 13-inch rims in the 3.50-to-4.50-inch range depending on the tire.

Numeric sizing is typical of earlier fitment conventions and is immediately familiar to restorers working toward a mid-1960s presentation. If your car is a Spitfire or Sports Six and you want the traditional stance and response associated with bias-ply construction, 560-13 is the size to examine first. It is still worth checking the actual wheel width on the car before choosing between one product and another, since not every 560-13 covers the exact same rim-width span.

On a 1964 Triumph, 155R13 and 165R15 are metric radial sizes. The first number is the nominal section width in millimeters, the R identifies radial construction, and the last number is the wheel diameter in inches. In this application, 155R13 fits the Spitfire and Sports Six, while 165R15 fits the TR3, TR4 and TR4A. These are classic Euro-style radial sizes and, by convention, are commonly treated as 80-series profiles unless a different aspect ratio is stated.

That naming style helps separate the radial options from the numeric bias-ply sizes used on the same year and make. For Triumph owners, the practical benefit is clarity: once you know whether your car takes a 13-inch or 15-inch wheel, the metric radial code tells you you are looking at the radial branch of the fitment rather than the bias-ply branch. It is a useful distinction when balancing originality, road use, and sidewall appearance.

For a 1964 Triumph Spitfire or Sports Six, the choice between 560-13 and 155R13 is mainly a choice between bias-ply and radial construction on a 13-inch wheel. The 560-13 options come in period-style bias-ply form with whitewall variations, while 155R13 is a radial size offered in blackwall form by Michelin and Dunlop. The radial examples here also carry H speed ratings, which correspond to a 130 mph ceiling.

Owners aiming for a factory-era look or a show-focused presentation often gravitate toward the numeric bias-ply size, while drivers who want a more modern-feeling road tire usually start with the radial. Neither choice should be made on year alone, because both apply only to the smaller Triumph models. Confirm that your car is a Spitfire or Sports Six and that the wheel width falls within the product's approved range before settling on one version.

1964 Triumph tire choices span blackwall, narrow whitewall, and wide whitewall styles, but the range depends on the size. The 155R13 radial choices are blackwall only, while 560-13 bias-ply choices include narrow whitewall and wide whitewall versions. On the 15-inch TR sizes, 165R15 radials are available as blackwall, narrow whitewall, and wide whitewall, and 590-15 bias-ply choices come in blackwall and wide whitewall form.

For many British sports-car restorations, blackwall is the visual baseline buyers expect, especially on sporting Triumphs, but owner preference and event standards can differ. Whitewall choices are available in several of these sizes for drivers who want a different period look or a custom presentation. The best approach is to match the sidewall style to the way your 1964 Triumph will be judged, displayed, or driven rather than treating every available sidewall treatment as equally authentic.

1964 Triumph tire coverage includes Michelin and Dunlop in 155R13, BFGoodrich and Firestone in 560-13, Coker Classic, American Classic, Firestone, and BFGoodrich in 165R15, and BFGoodrich plus Avon in 590-15. That gives owners a mix of European-name and American-name offerings across radial and bias-ply constructions. Brand availability also changes with wheel diameter, so the 13-inch cars and 15-inch TR cars do not draw from the same exact set of options.

Brand choice is best treated as the final step, after the model, wheel diameter, construction type, and sidewall style are sorted out. A Spitfire owner looking at 155R13 will be choosing from a very different group than a TR4 owner shopping 165R15 or 590-15. Once the correct size is established, you can compare sidewall treatment, load marking, rim-width range, and visual character within the brands that apply to that particular Triumph.

Rim-width recommendations vary by size on 1964 Triumph vehicles. The 155R13 radial size covers 4.00 to 5.50 inches, while 560-13 bias-ply products span either 3.50 to 4.00 inches or 4.00 to 4.50 inches depending on the tire. For the TR-series sizes, 165R15 radials fit 4.50 to 6.00 inches, and 590-15 bias-ply products with published fitment details fit 4.00 to 4.50 inches. Those ranges are important because radial and bias-ply options in the same wheel diameter do not always share the same ideal rim width.

That is why wheel measurement matters before choosing a replacement tire for a 1964 Triumph, especially on cars that may have been changed over the decades. A 13-inch wheel does not automatically mean every 13-inch option is equally suitable, and the same is true on the 15-inch TR cars. If your wheel width falls near the edge of a range, it is wise to confirm the exact wheel and tire combination before moving forward.

Tube status on 1964 Triumph tires depends on the product and size. The 155R13 Michelin radial is marked TL, which indicates tubeless construction, while the Dunlop 155R13 example is not marked the same way. The other sizes do not carry a consistent tube marking across every product here, so tube use should be treated as a product-by-product question rather than a single rule for the whole year and make.

The safest approach is to check the sidewall marking on the exact tire you intend to use and then consider the wheel itself. Original sports-car wheels, wire wheels, and older rims may influence whether a tubeless tire can be run as tubeless or whether a tube is still appropriate in practice. If your 1964 Triumph has been restored with non-original wheels, confirm the wheel's condition and design before assuming tube or tubeless service.

Within each 1964 Triumph model group, both tire choices share the same wheel diameter. Spitfire and Sports Six use either 155R13 or 560-13 on 13-inch wheels, and TR3, TR4 and TR4A use either 165R15 or 590-15 on 15-inch wheels. That means the basic diameter match is there within each model family, but wheel width still needs to be checked because the approved rim-width ranges are not identical between the radial and bias-ply choices.

In practical terms, a stock-diameter wheel can often support either construction path for the correct model family, but it should not be treated as automatic interchangeability. Radials often cover wider rim-width spans than the period-style bias-ply equivalents, especially on the 15-inch TR sizes. Measuring the wheel and checking its condition is the step that keeps a seemingly correct size from becoming a poor fit in use.

A 1964 Triumph should be stored away from direct sunlight, electric motors, battery chargers, welders, and other ozone sources that accelerate rubber aging. Keep the car in a dry, stable environment, maintain inflation, and move it periodically so one section of the tire does not carry the load for months at a time. On collector cars, bias-ply tires are generally more prone to temporary flat-spotting during long static storage than radials.

If the car will sit for an extended period, clean the tires, avoid petroleum-based dressings, and consider stands or cradles if storage conditions make long-term loading a concern. That matters on a 1964 Triumph because these are light sports cars that are often driven seasonally rather than weekly. Good storage habits preserve both appearance and drivability, especially when you are trying to protect reproduction sidewalls and period-style construction.

On a 1964 Triumph, tire age usually matters more than mileage because many collector cars accumulate relatively few miles each year. A sensible rule is to begin evaluating tires closely once they are around five to seven years old and to consider replacement as they approach ten years, regardless of tread depth. The DOT date code on the tire is the reference point for age, not the date the car was restored or the date the tire was mounted.

That timeline is especially important on sports cars that may look fine cosmetically while the rubber has hardened with age. Grip, ride quality, and casing integrity can all change long before a low-use 1964 Triumph wears out a tread. If the tires are older, have visible cracking, or have spent years in uncontrolled storage, replacement should move higher on the priority list even if the car is driven only occasionally.

Tires on a 1964 Triumph should be inspected before every drive and given a more careful check before any longer outing. Look for sidewall cracking, cuts, bulges, irregular tread wear, and any sign that the tire is losing pressure between drives. Valve stems also deserve attention, and if your chosen setup uses tubes, the stems and surrounding area should be checked especially carefully because a tube-related issue may show up there first.

That routine is more important on an older British sports car than on a modern daily driver because these cars often spend more time parked than in use. A quick visual check can catch problems that developed quietly in storage, and a pressure check helps protect handling balance on a short-wheelbase roadster. Making inspection a habit is one of the simplest ways to keep a 1964 Triumph enjoyable and predictable on the road.

For a 1964 Triumph Spitfire, bias-ply construction is the starting point most restorers associate with original-era fitment, and 560-13 is the period-style size used on that model family. A 155R13 radial is also available today for the same 13-inch application, but radial construction reflects a later-driving-style choice rather than the baseline tire technology British sports cars of the early 1960s commonly left the factory with. Original-equipment brand details can vary by market and production context, so construction and size usually come first in authenticity discussions.

That makes the restoration question fairly clear for most owners: if your goal is factory-era appearance, start by evaluating the 560-13 bias-ply option and the sidewall style that matches your intended presentation. If the car will be judged, confirm event and marque expectations before deciding on blackwall or whitewall treatment. Triumph clubs and marque specialists remain the best final authority when originality standards become market-specific or trim-specific.

Correct tire fitment absolutely matters when a 1964 Triumph is being judged for authenticity. Size, construction type, and sidewall appearance all affect whether the car looks appropriate for its era and model family. A Spitfire on modern-looking radial fitment or a TR4 on a sidewall treatment that does not suit the presentation can stand out immediately to experienced judges, even if the tire physically fits the wheel and fender opening.

The standard is not always the same from one event to another, which is why owners should separate show goals from general driving goals early in the project. Some displays reward factory-correct restraint, while others are more tolerant of radial substitutions on road-driven cars. If your 1964 Triumph is headed for concours judging, verify the accepted size, construction, and sidewall style with the organizing body or a knowledgeable Triumph club before making a final choice.

For a 1964 Triumph using 590-15, the BFGoodrich and Avon choices differ in sidewall treatment, load marking, and one notable speed-rating detail. BFGoodrich offers blackwall and wide whitewall versions with a published load figure of 1,050 pounds at 32 psi, while the Avon Turbospeed Mk4 appears as a blackwall tire with a published load figure of 1,018 pounds. The Avon example also carries an H speed rating, which corresponds to a 130 mph ceiling.

That comparison matters most to TR3, TR4 and TR4A owners deciding how authentic, how sporting, or how visually restrained they want the finished car to appear. If you want a whitewall in this size, BFGoodrich is the clear path. If you want a blackwall bias-ply with an explicitly stated H speed rating, the Avon version stands apart and may appeal to owners who want a traditional look with that particular sidewall marking.

1964 Triumph tires can be suitable for highway driving when they are the correct size, in sound condition, and used within their construction and speed-rating limits. The 155R13 radial products here carry H ratings with a 130 mph ceiling, and one 590-15 bias-ply option also carries an H rating. Other sizes do not always show the same speed marking, so the exact tire matters. On a mid-1960s Triumph, the car's brakes, suspension, steering, and overall condition are often at least as important as the tire's speed capability at normal highway speeds.

In practice, highway confidence starts with a fresh, properly inflated tire on a wheel that matches the tire's approved dimensions. A radial often gives owners a more familiar modern-road feel, while bias-ply tires ask for more respect for period handling traits. Before sustained highway use, inspect the tires closely and make sure the rest of the car is equally ready for the trip, because tire safety on an older sports car is always part of a larger mechanical picture.

Inflation pressure on a 1964 Triumph should follow the vehicle's factory recommendation for the correct model as the starting point, while also respecting the reproduction tire's own maximum load and pressure marking. The available tires here show published load-and-pressure figures such as 850 pounds at 30 psi for 560-13, 1,050 pounds at 32 psi for 590-15, and roughly 1,168 to 1,170 pounds at 35 to 36 psi for 165R15 radials. Those figures describe the tire's rated capacity point, not automatically the exact operating pressure your specific Triumph should run.

That distinction matters because underinflation, overinflation, and pressure copied from a different size can all change how the car steers and rides. A Spitfire on 560-13 should not be set by a TR4 radial figure, and a 15-inch radial should not be assumed to want the same pressure as a 15-inch bias-ply. Use the owner's manual or marque literature for the vehicle baseline, then confirm that your chosen tire's sidewall rating is being respected.

Before a longer drive in a 1964 Triumph, inspect every tire for cracking, cuts, bulges, punctures, and uneven wear, then verify pressure when the tires are cold. Check valve stems, look at the spare, and make sure the wheel nuts are properly secured. If your setup uses tubes, pay close attention to stems and any sign of slow leakage. Because these are older sports cars, tire inspection should happen alongside checks of brakes, cooling, steering, and fluid levels rather than as a separate task.

Longer drives expose weaknesses that local trips may never reveal, especially on a car that has spent much of its life in seasonal or hobby use. A tire that holds air around town may heat up differently on an extended run, and an aged spare may be useless when you need it most. Giving the full set a careful inspection beforehand is one of the simplest ways to protect both the car and the trip.