1976 Triumph Tire Fitment Guide

1976 Triumph vehicles use five sizes across three models. The Spitfire uses 155R13 and 560-13 on 13-inch rims, the TR6 uses 185R15 on 15-inch rims, and the TR7 uses either 185/70R13 or 185R13 on 13-inch rims. Rim-width guidance also varies by size where it is established: 155R13 fits 4.00- to 5.50-inch rims, 560-13 fits 3.50- to 4.50-inch rims depending on product, 185R15 fits roughly 4.5- to 6.5-inch rims, and 185/70R13 fits roughly 4.5- to 6.5-inch rims.

The practical takeaway is that 1976 Triumph fitment starts with the exact model, not just the year and make. A TR6 owner should not assume compatibility with Spitfire or TR7 sizes, and a TR7 owner still needs to determine which of its two 13-inch radial sizes is correct for the car's wheels and intended look. Once the model is confirmed, compare the actual wheel diameter and width before selecting a tire.

On a 1976 Triumph, 560-13 is a numeric bias-ply tire size. The 5.60 figure refers to the nominal section width, while 13 is the wheel diameter in inches. On the Spitfire, this size appears in bias-ply construction and is offered with narrow whitewall and wide whitewall sidewall treatments, with load ratings reaching 850 pounds at 30 psi.

That matters because 560-13 reads very differently from a modern metric tire code. It is the kind of size a restoration-minded Spitfire owner will recognize as an older-format fitment, and it carries a distinctly period presentation compared with the radial 155R13 alternative. Before choosing it, verify that the wheel width falls within the tire's approved range for the exact product you want to run.

On 1976 Triumph tires, sizes such as 155R13, 185R15, and 185R13 are Euro-metric radial formats. The first number is the nominal section width in millimeters, the R denotes radial construction, and the final number is the wheel diameter in inches. Because no aspect ratio is written into those sizes, they are conventionally treated as full-profile 80-series metric radials rather than lower-profile tires like a 185/70R13.

That distinction helps separate a fuller-profile radial from a shorter sidewall option. On a 1976 Triumph, 155R13 belongs to the Spitfire, 185R15 belongs to the TR6, and 185R13 belongs to the TR7, so the code is doing two jobs at once: identifying the construction and signaling which wheel diameter the tire fits. Matching that final diameter to the actual wheel is the first checkpoint before anything else.

For a 1976 Triumph Spitfire, the decision between 155R13 and 560-13 is largely a choice between radial and bias-ply construction. The 155R13 is a full-profile metric radial offered in blackwall form, while the 560-13 is a numeric bias-ply available with narrow whitewall or wide whitewall styling. Both fit 13-inch wheels, but they do not serve the same owner priorities.

A Spitfire aimed at period appearance, show presentation, or an older-style driving feel will usually point toward the 560-13. A Spitfire driven more regularly on modern roads will often point toward the 155R13 because it keeps the same wheel diameter while moving to radial construction. The smart way to choose is to decide first whether the car's mission is restoration authenticity or regular use, then verify wheel width against the specific tire.

1976 Triumph tires are available in several sidewall styles depending on size. The Spitfire's 155R13 comes in blackwall, while its 560-13 bias-ply options include narrow whitewall and wide whitewall versions. The TR6's 185R15 appears in redline, narrow whitewall, and blackwall form, and the TR7's 185/70R13 appears in redline, wide whitewall, and blackwall form; 185R13 is available as a blackwall.

Sidewall style is often the visual cue that ties the tire to the era and personality of the car. A blackwall generally suits a cleaner sports-car look, while whitewall or redline styling can push the appearance toward a more distinctive period presentation. Because 1976 Triumph spans three very different sports-car personalities, it is worth deciding whether your goal is understated road use, period flair, or a specific restoration look before narrowing to a product.

Michelin, Dunlop, BFGoodrich, Firestone, Avon, and Coker Classic all make tires for 1976 Triumph applications represented here. Michelin and Dunlop cover the Spitfire's 155R13, BFGoodrich and Firestone cover the Spitfire's 560-13, Coker Classic and Michelin cover the TR6's 185R15, BFGoodrich, Avon, and Dunlop cover the TR7's 185/70R13, and Michelin covers the TR7's 185R13.

Brand choice lets you refine the tire beyond simple size. Some offerings lean toward a classic sidewall presentation, some toward traditional European radial character, and some toward a stronger restoration look through redlines or whitewalls. Once the correct size is established for your 1976 Triumph model, compare the available brands by sidewall style, speed rating, and approved rim-width range rather than assuming every tire in the same nominal size serves the same purpose.

Rim-width requirements for 1976 Triumph tires depend on the size and sometimes on the product within that size. The 155R13 fits 4.00- to 5.50-inch rims, 560-13 fits either 3.50- to 4.00-inch or 4.00- to 4.50-inch rims depending on brand, 185R15 fits from about 4.5 to 6.5 inches, and 185/70R13 fits from about 4.5 to 6.5 inches. A rim-width figure is not established here for the available 185R13 product.

That range matters because a tire can share the right wheel diameter but still be wrong for the wheel's width. This is especially important on a 1976 Triumph that may have replacement wheels or long-ago changes from stock. Measure the wheel, compare it to the exact tire's approved range, and avoid assuming that every tire with the same diameter code will mount correctly on the same rim.

Inner-tube requirements on 1976 Triumph tires depend on the exact size and product. The 185R15 Michelin products and the 185R13 Michelin product carry TL markings for tubeless use, while 155R13 varies by product because one version carries a TL marking and another does not. The 560-13 bias-ply options and 185/70R13 radial options do not all carry a consistent tube designation here, so the exact sidewall marking on the tire should guide the final setup.

Wheel condition and wheel design still matter even when the tire itself is marked tubeless. On an older Triumph, especially one with original or restored wheels, it is wise to confirm whether the wheel is suitable for tubeless service and whether the valve-stem and bead-seat condition are up to the job. When there is any doubt, match the tire's sidewall marking to the wheel's condition rather than making a broad assumption from the size alone.

Original 1976 Triumph wheels cannot be treated as universal across the full make, because the sizes span both 13-inch and 15-inch rim diameters. A Spitfire or TR7 using 13-inch tires is in a different wheel-diameter category from a TR6 using 185R15. Even within the 13-inch group, wheel width still needs to match the tire's approved range.

The safest approach is to think model first, then wheel diameter, then wheel width. A Spitfire owner comparing 155R13 and 560-13 can stay within the same 13-inch diameter but still needs to verify that the wheel width suits the specific radial or bias-ply product. A TR7 owner comparing 185R13 and 185/70R13 also stays within 13 inches, but the exact profile and rim-width compatibility should still be confirmed before mounting.

A 1976 Triumph should be stored in a cool, dry space away from direct sunlight, electric motors, battery chargers, and other ozone sources that age rubber. Keep the tires properly inflated, roll the car periodically if possible, and avoid leaving it parked for long stretches on damp concrete. The Spitfire's bias-ply 560-13 option is especially prone to flat-spotting during static storage, while any older-style collector tire can suffer from sidewall cracking if the environment is harsh.

Storage habits have a real effect on how a collector tire looks and drives later. If the car will sit for months at a time, tire cradles or properly placed stands can reduce stress, but they should be used carefully and with the suspension's needs in mind. A quick monthly check of pressure and visible sidewall condition can preserve both appearance and road manners far better than letting the car sit untouched through an entire season.

Tires on a 1976 Triumph should be judged more by age and condition than by mileage, because many collector cars see limited annual use. A good rule is to begin evaluating them closely at around five to seven years of age and to treat about ten years as a point where replacement deserves serious consideration regardless of remaining tread. The DOT date code on the tire sidewall is the clearest reference for age.

That timeline matters because a lightly driven Triumph can still wear out its tires chemically before it wears them out mechanically. Sidewall cracking, hardening rubber, vibration, and a decline in wet-road behavior can appear even on a tire that looks acceptable at a glance. For a seasonal sports car, the better habit is to track age in your maintenance records and inspect the tires with time in mind, not just tread depth.

Tires on a 1976 Triumph should be inspected before every drive, and again before any longer outing or highway trip. Look for cracking, cuts, bulges, uneven wear, and any sign that the tire has lost pressure since the last use. If your car runs a tire that may use a tube or has a separate tube-type setup, the valve stem and pressure retention deserve extra attention as part of that check.

Frequent inspection matters because an older sports car may sit for weeks, then go straight onto winding roads or highway speeds. Catching a slow leak, a damaged sidewall, or an aging valve stem in the garage is far easier than dealing with it on the shoulder. It also helps you notice alignment or suspension issues early, since uneven wear on a light British car often shows up in the tires before anything else feels obviously wrong.

A 1976 Triumph Spitfire would have been a radial-era sports car, but buyers and restorers still encounter both radial and bias-ply presentations when recreating period appearance. The two sizes associated with the model here are 155R13 in radial form and 560-13 in bias-ply form, both on 13-inch wheels. No single original-equipment brand should be assumed from that alone, and market-specific details can vary.

For restoration work, the important first step is deciding what kind of originality you are chasing. A factory-style road car, a period-flavored show presentation, and a driver built around present-day road manners can point in slightly different directions even when the wheel diameter stays the same. If the car will be judged, confirm the accepted size, construction, and sidewall style with a Triumph marque club or event rulebook before committing.

Correct tire fitment absolutely matters when showing a 1976 Triumph, especially in classes that emphasize originality. Judges and knowledgeable enthusiasts often notice whether the size matches the model, whether the construction looks era-appropriate, and whether the sidewall style suits the car's period presentation. A TR6 on the wrong wheel diameter or a Spitfire wearing a style that clashes with its restoration theme can stand out quickly.

That does not mean every show car must wear the same type of tire, but it does mean the choice should be intentional. A radial can be entirely appropriate on one 1976 Triumph build, while a bias-ply or a more period-styled sidewall may be the stronger fit on another. If your goal is points judging rather than casual display, verify event-specific standards with Triumph clubs and restoration references before finalizing the tire choice.

For a 1976 Triumph TR6 in 185R15, Michelin XVS and Coker Classic Radial differ in sidewall presentation, speed rating options, and some fitment details. Coker Classic appears here as a redline with a load rating of 1,355 pounds at 35 psi and a 5.00- to 6.50-inch rim-width range. Michelin XVS appears in blackwall and narrow whitewall forms, with H-rated versions to 130 mph and a V-rated version to 149 mph, and its approved rim widths run from about 4.5 to 6.5 inches depending on version.

The practical choice comes down to what visual and driving character you want from the TR6. A redline gives the car a distinctly different period impression than a blackwall or narrow whitewall, while the Michelin line also introduces a higher-speed V-rated option for owners who want that specification. Once the style is settled, compare the exact wheel width on your TR6 so the tire's approved mounting range lines up correctly.

1976 Triumph tires can be suitable for highway driving when the correct size is mounted properly, the tires are in sound condition, and the speed rating matches realistic use. The radial offerings here include H-rated products to 130 mph and V-rated products to 149 mph in certain sizes, including 185R15 and 185/70R13 applications. Those ratings are comfortably above normal U.S. highway speeds, although the car's age, suspension condition, brakes, and alignment often matter more in real use than the tire's theoretical maximum.

The bigger issue with a vintage Triumph is not usually whether the tire can handle highway speed in isolation, but whether the entire car is ready for sustained road use. Check for age cracking, proper inflation, stable steering, and even wear before heading out. A sound radial setup will generally be the more natural choice for regular highway miles, while any bias-ply-equipped car deserves extra attention to condition and handling expectations.

Inflation pressure on 1976 Triumph tires should follow the vehicle manufacturer's recommendation for the car and the tire maker's guidance for the exact product. Some tires here include load-and-pressure references, such as 560-13 at 850 pounds at 30 psi, 185R15 at 1,355 pounds at 35 psi in one application, and 185/70R13 at 1,135 pounds at 35 psi in one application. Those figures are tire ratings, not a universal instruction to run every 1976 Triumph at the same pressure.

That distinction is important because pressure tuning on a light sports car affects ride, wear, and steering feel quickly. Use the owner's manual or marque guidance as the baseline for front and rear pressures, then confirm that your chosen reproduction tire's maximum-rated pressure is not being confused with the recommended running pressure. Never transfer a pressure figure from a TR6 tire to a Spitfire or TR7 simply because the numbers appear nearby.

Before taking a 1976 Triumph on a longer drive, inspect all four tires and the spare for cracks, cuts, punctures, bulges, uneven wear, and correct cold inflation pressure. Make sure the valve stems are sound, and pay special attention to any setup that may involve tubes or older wheel hardware. A longer trip is also the right time to confirm that the tires are seated properly, the lug hardware is secure, and the tread is free of age-related separation concerns.

Tires are only one part of the checklist on a vintage Triumph, but they are the easiest place to catch trouble early. Pair the tire inspection with a look at wheel bearings, brakes, coolant, belts, and basic fluid levels so the car is ready as a whole. If the tires have been sitting for an extended period, a short local test drive before the main trip can reveal vibration, pull, or pressure-loss issues while help is still close at hand.