1975 Triumph Spitfire Tires

The 1975 Triumph Spitfire uses two primary tire sizes: 155R13 in radial construction and 560-13 in bias-ply construction. Both sizes are associated with the Spitfire and both are built around a 13-inch wheel, so the size decision is tied more to tire type and presentation than to a different rim diameter.

That means the first step is confirming whether the car is set up for a radial-style fitment or a period-style bias-ply tire. Wheel width, the car’s current setup, and the owner’s goals for appearance and road use should all be checked before choosing between the two size formats.

The 1975 Triumph Spitfire uses a 13-inch rim with both of its primary tire sizes, 155R13 and 560-13. Even though the tire constructions differ, the wheel diameter remains the same, which keeps the fitment decision focused on construction type, sidewall style, and wheel-width suitability rather than a change in rim size.

Diameter is only part of the check, though. Actual wheel width still matters, especially when moving between a narrow bias-ply setup and a radial option with its own approved rim-width range. Looking at the wheel itself before selecting tires helps avoid a mismatch between the tire and the car’s current hardware.

Yes. The 1975 Triumph Spitfire Base uses the same two tire-size paths as the overall model coverage: 155R13 in radial form and 560-13 in bias-ply form. There is no separate Base-only tire size that changes the basic fitment picture for this year and model.

That keeps selection relatively simple, because the owner does not need to sort through multiple trim-specific wheel diameters or unrelated sizes. The practical choice is whether the car should wear a radial-format tire or retain the more traditional bias-ply look, then match that decision to the wheel width and intended use.

560-13 is a bias-ply tire size for the 1975 Triumph Spitfire. It uses the older numeric bias-ply sizing system, and the available tires in this size are classic bias-ply products rather than radials. On this Spitfire, 560-13 represents the traditional-looking fitment path on a 13-inch rim.

That matters because bias-ply and radial tires differ in both construction and appearance. Choosing 560-13 usually points toward a more vintage presentation, especially with whitewall options available. Before using that size, it is worth confirming the car’s current wheels and making sure the intended look and driving expectations match a bias-ply setup.

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. Those are the stated radial alternatives tied to the original bias-ply size, and no bias-look radial equivalent is listed for this application.

Each of those options should be treated as an alternative rather than an automatic substitute. A recommended rim-width range of 4 to 5 inches is associated with the equivalent-size comparison, so wheel width, tire dimensions, and clearance around the Spitfire should be checked carefully before making the change.

Start by confirming the wheel diameter and width, then compare the intended radial size against the car’s current setup. For a Spitfire moving away from 560-13 bias-ply tires, the stated radial equivalents are 155R13, P155/75R13, and P155/70R13, with a recommended rim-width range of 4 to 5 inches tied to that comparison.

After that, inspect steering and fender clearance and make sure the car has not been altered with different wheels, suspension changes, or body modifications that affect space around the tire. The decision should also reflect whether the priority is a traditional restoration-style appearance or a radial-format road setup.

The main choice is between the Spitfire’s two primary fitments: 155R13 radial and 560-13 bias-ply. Both use a 13-inch rim, but they differ in construction, sizing format, and visual character. That makes the selection less about finding a hidden third size and more about matching the tire to the car’s current setup and intended use.

A buyer should compare wheel width, construction type, sidewall appearance, and the overall look desired for the car. A blackwall radial can suit a more road-focused setup, while a whitewall bias-ply leans toward a vintage presentation. Product-level details such as rim-width compatibility and load figures also deserve attention.

The available sidewall styles for 1975 Triumph Spitfire tires include blackwall in the 155R13 radial fitment, plus narrow whitewall and wide whitewall in the 560-13 bias-ply fitment. That gives the car two very different visual directions, depending on whether the goal is a cleaner sporting look or a more traditional vintage appearance.

Sidewall style should be chosen after the correct size and construction path are settled. A whitewall treatment can change the whole visual impression of a small sports car, while blackwall radials keep things more understated. It also helps to check photos, period references, and the car’s existing presentation before deciding.

Tires for the 1975 Triumph Spitfire are available from Michelin, Dunlop, BFGoodrich, and Firestone. Michelin and Dunlop cover the 155R13 radial side of the fitment, while BFGoodrich and Firestone appear in the 560-13 bias-ply size. That brand spread gives the buyer a useful mix of radial and traditional bias-ply choices.

Brand should be considered alongside the tire’s construction, series, sidewall style, and wheel-width suitability rather than treated as the only deciding factor. On a Spitfire, the more important question is often whether the car should wear a radial blackwall or a period-style bias-ply tire, then which brand best matches that plan.

For a period-style 1975 Triumph Spitfire, the 560-13 bias-ply size is the more traditional-looking starting point. It uses the vintage numeric bias-ply format and is available in classic bias-ply series from BFGoodrich and Firestone. That combination tends to suit buyers who want the car to present with an older visual character.

The final choice depends on how closely the restoration is being judged and what visual effect is desired. Whitewall width and brand appearance can change the car’s look noticeably, so owners pursuing exact historical accuracy should compare against marque references or restoration documentation rather than relying on size alone.

Tire construction changes more than road feel on a restored 1975 Triumph Spitfire; it also changes the car’s visual language. A 560-13 bias-ply tire delivers a distinctly vintage presentation, especially with narrow whitewall or wide whitewall styling, while a 155R13 radial blackwall gives the Spitfire a cleaner, later-style sporting look.

That difference matters because a small British sports car can look noticeably different depending on sidewall shape and sidewall treatment. Owners building a restoration-oriented car often choose construction with appearance in mind first, then confirm that the wheel width and intended road use still support that direction.

Yes, modifications can affect tire fitment on a 1975 Triumph Spitfire even when the tire size itself is correct. Aftermarket wheels, suspension changes, altered ride height, or bodywork differences can all change how much room is available around a 13-inch tire. That applies whether the car is running 155R13 radials or 560-13 bias-ply tires.

A modified Spitfire should be checked for wheel width, steering clearance, and fender clearance before a new set is chosen. Even small changes on a lightweight sports car can alter how the tire sits in the wheel opening, so current vehicle condition matters more than assuming every example remains stock.

Before driving a 1975 Triumph Spitfire on new tires, inspect the wheels for correct diameter and width, confirm the tires are inflated properly, and look over the suspension and steering for obvious wear that could affect tracking or clearance. A quick visual check around the fenders and inner wheel areas also helps catch rubbing issues early.

The rest of the car deserves attention too, especially on a collector vehicle that may sit for long periods. Lug hardware, brake condition, and signs of air loss should all be checked before a proper road test. Starting with a careful inspection helps the new tires work as intended from the first drive.

Tires on a collector 1975 Triumph Spitfire should be checked regularly for pressure loss, tread wear, cracking, bulges, and cuts, even if the car is driven only occasionally. Low-use sports cars often age their tires through time and storage conditions rather than mileage alone, so condition matters at least as much as remaining tread.

Proper storage helps preserve both radial and bias-ply tires. Keeping the car away from prolonged sunlight, excess heat, moisture, and ozone sources can slow deterioration, and periodic inspections make it easier to catch problems before road use. It also helps to recheck the tires before any longer outing after extended storage.