1973 Triumph Spitfire Tires

A 1973 Triumph Spitfire uses either a 155R13 radial or a 560-13 bias-ply tire. Both are 13-inch fitments, so the choice is not about changing rim diameter so much as selecting the tire construction and look that best suits the car.

That means the practical next step is checking which wheels are on the car now and deciding whether a radial or bias-ply setup makes more sense for your goals. A Spitfire kept for restoration-minded presentation may point toward 560-13, while a car set up around radial-style driving may lead you toward 155R13.

The 1973 Triumph Spitfire uses a 13-inch rim with both of its primary tire sizes. The radial 155R13 and the bias-ply 560-13 both share that same rim diameter, which simplifies the basic wheel-size question.

Rim diameter is only part of the fitment picture, though, especially on a small sports car. Wheel width should still be checked against the tire being considered, since the radial and bias-ply options do not use the same width ranges. That becomes especially important if the car has replacement steel wheels or aftermarket wheels.

Yes. The 1973 Triumph Spitfire Base uses the same two fitment paths found on this model overall: 155R13 in radial construction and 560-13 in bias-ply construction. Both remain 13-inch tire choices rather than separate wheel-diameter packages.

That shared fitment means the real decision is not identifying a special Base-only size, but choosing the tire type that matches the car's present setup and intended use. Looking at wheel width, tire construction, and the kind of appearance you want will usually settle the question more effectively than sub-model labeling alone.

560-13 is a bias-ply tire size on the 1973 Triumph Spitfire. It uses the older numeric bias-ply sizing format, and the available products in this size are bias-ply tires rather than radials.

That matters because a 560-13 tire brings a different visual character than a radial and may also call for different wheel-width considerations. If the goal is to preserve a traditional presentation, this size makes sense to evaluate first. If the car is being shifted toward radial construction, the equivalent radial sizes should be reviewed carefully before making the change.

Radial equivalents for 560-13 include 155R13 as an 80-series metric radial, P155/75R13 as a P-metric 75-series radial, and P155/70R13 as a P-metric 70-series radial. No bias-look radial equivalent appears for this size here.

Those alternatives give a 1973 Triumph Spitfire owner several ways to move from bias-ply sizing into radial sizing while staying with a 13-inch wheel. A recommended rim-width range of 4-5 inches is associated with the equivalent radial choices, and the final decision should still account for wheel width, vehicle clearance, and the car's current overall setup.

Start by confirming the wheel diameter and width, then compare the radial size being considered against the current 560-13 setup. For this car, 155R13, P155/75R13, and P155/70R13 are the radial equivalents tied to the bias-ply size, and the equivalent rim-width range is 4-5 inches.

A small roadster can be sensitive to tire and wheel changes, so steering clearance, fender clearance, and the condition of suspension and steering components deserve attention before the switch. It also helps to decide whether the car is being kept visually traditional or set up for a more modern radial presentation, since that affects the best path forward.

The main decision is whether the car should use the 155R13 radial size or the 560-13 bias-ply size. Since both are 13-inch fitments, the choice centers on construction, wheel-width compatibility, and whether the car is being set up for a more traditional appearance or a radial-style driving approach.

After that, compare the tire's sidewall treatment, brand, and series against the role the car will play. A restoration-minded Spitfire may call for one direction, while a road-driven car may point toward another. Keeping the actual wheels on the car in mind is important, especially if they are not the same wheels the car originally carried.

The sidewall styles available for the 1973 Triumph Spitfire depend on the tire size and construction chosen. The 155R13 radial options are blackwall tires, while the 560-13 bias-ply options include narrow whitewall and wide whitewall treatments.

That makes sidewall style an appearance decision as much as a fitment decision. A blackwall radial gives the car a cleaner sporting presentation, while the whitewall bias-ply options move it toward a more vintage visual character. The best choice depends on how the car is being restored or displayed, not just on what physically mounts to a 13-inch rim.

The 1973 Triumph Spitfire has tire choices from Michelin and Dunlop in 155R13 radial form, and from BFGoodrich and Firestone in 560-13 bias-ply form. Those brands also separate naturally by tire series and sidewall treatment rather than by size alone.

Brand selection should be considered alongside construction and appearance, since the available products do not all serve the same purpose. Some choices lean toward radial blackwall presentation, while others offer bias-ply whitewall styling. Looking at the complete tire setup rather than choosing on brand name alone usually leads to a more appropriate result for the car.

A period-style 1973 Triumph Spitfire usually starts with deciding whether the car should present as a radial-equipped sports car or as a more traditional bias-ply example. The 560-13 bias-ply size carries the earlier numeric look, while 155R13 keeps the car in a classic small-car radial format.

The best choice depends on the story the finished car is meant to tell. Some restorations benefit from the visual character of a bias-ply tire, while others look right on a blackwall radial. When exact originality matters, it is worth checking marque literature, restoration references, and the car's own history before settling on one construction.

Tire construction changes more than just how the car drives; it also changes how a restored 1973 Triumph Spitfire sits visually. A 560-13 bias-ply brings a more vintage sidewall shape and can be paired with narrow or wide whitewall styling, while 155R13 radial choices here are blackwall tires.

That difference can shift the whole impression of the car, especially on a compact British roadster where the wheel and tire package is always visible. Owners aiming for a traditional display-oriented look may be drawn to the bias-ply path, while those wanting a cleaner sporting presentation may prefer the radial route.

Yes. Modifications can change tire fitment on a 1973 Triumph Spitfire even when the tire size itself looks correct on paper. Aftermarket wheels, altered wheel width, changed offset, lowered suspension, or body and fender changes can all affect how either 155R13 or 560-13 works on the car.

A Spitfire has compact wheel openings, so small setup differences can matter more than they might on a larger car. Any time the car has been modified, it helps to check tire-to-fender clearance, steering clearance at full lock, and the relationship between the chosen tire and the actual wheel dimensions before putting the car into regular road use.

Before driving a 1973 Triumph Spitfire on new tires, inspect the wheels for correct diameter and condition, confirm that lug hardware and mounting surfaces are sound, and verify proper inflation. It is also wise to look over the suspension and steering for looseness, since fresh tires can reveal existing wear quickly.

A short initial drive should include checking for rubbing, steering pull, vibration, and any sign of uneven clearance. After that first outing, recheck air pressure and look for witness marks inside the fenders or on suspension parts. Those simple steps help confirm that the chosen 13-inch tire setup works cleanly on the actual car.

Collector-car tire maintenance starts with regular air-pressure checks and routine visual inspection, even when the 1973 Triumph Spitfire is driven only occasionally. Both 155R13 radials and 560-13 bias-ply tires should be examined for cracking, bulges, cuts, uneven tread wear, and any sign of ongoing air loss.

Storage conditions matter almost as much as mileage on a lightly used sports car. Keeping the Spitfire away from prolonged sunlight, heat, moisture, and ozone sources helps preserve the tires, and periodic movement can reduce the chances of long-term flat spotting. A close inspection before each driving season is a smart habit on a low-use car.