1960 Armstrong-Siddeley Tire Fitment Guide

1960 Armstrong-Siddeley vehicles in this fitment range use two tire sizes: 185R16 and 670-16, and both apply to the Sapphire. Each size mounts on a 16-inch wheel, but they differ in construction. The 185R16 is a radial size with product rim-width ranges that include 4.50 to 6.00 inches and 5.0 to 6.5 inches. The 670-16 is a bias-ply size with a product rim-width range of 4.50 to 5.00 inches where that specification is supplied.

That means the first job is not choosing between different models, but deciding which tire type suits your goals for the car. Owners aiming for a more traditional restoration presentation often start with 670-16, while owners who want a more modern-feeling road tire often begin with 185R16. Before ordering, compare the actual wheel width on your Sapphire against the rim-width range for the specific tire you want to use.

On a 1960 Armstrong-Siddeley, 670-16 is a numeric bias-ply size. The 6.70 refers to the nominal section width, and the 16 refers to the wheel diameter in inches. This format belongs to the bias-ply era, so it describes a tire built with older-style casing construction rather than a radial layout. For the Sapphire, 670-16 is the traditional 16-inch option offered in blackwall form.

That older sizing format matters because it points to both appearance and driving character, not just dimensions. A 670-16 generally suits owners who want the look and feel associated with a period-correct British luxury saloon. It is still important to match the specific tire to the wheel width and to confirm whether the exact product you choose carries any speed marking or load information that affects how you plan to drive the car.

On a 1960 Armstrong-Siddeley, 185R16 is a metric radial size. The 185 indicates a nominal section width of 185 millimeters, the R identifies radial construction, and the 16 is the wheel diameter in inches. In this style of sizing, when no aspect ratio is printed, it is conventionally treated as an 80-series radial. For the Sapphire, 185R16 is the modern-format 16-inch option offered in blackwall form.

That size is useful for owners who want to keep the 16-inch wheel diameter while moving to a later tire construction style. The available products are not all identical, though. Some versions are tube type, and speed ratings vary from S to V depending on the brand. Checking the exact sidewall marking on the tire you choose is the best way to avoid mixing assumptions about tube use or road-speed capability.

For a 1960 Armstrong-Siddeley Sapphire, the main difference between 185R16 and 670-16 is construction rather than wheel diameter, since both fit 16-inch rims. The 670-16 is a bias-ply size and carries the more traditional format and appearance associated with the car's era. The 185R16 is a radial size that keeps the same wheel diameter but moves to a later tire design. That makes the comparison less about basic fitment and more about how you want the car to present and drive.

A show-oriented or authenticity-minded restoration often points owners toward the 670-16. A Sapphire that sees more regular road miles often leads owners toward the 185R16 because radial construction better reflects later driving expectations. Neither choice should be treated as automatic, though. Wheel width, tube requirements, and the speed marking of the exact tire all deserve a final check before you settle on one size.

1960 Armstrong-Siddeley tires are available from Michelin, Avon, Vredestein, and Firestone across the two applicable sizes. The 185R16 radial is available from Michelin, Avon, and Vredestein. The 670-16 bias-ply is available from Firestone and Avon. All of the products in these sizes use blackwall styling, which suits the restrained, formal character expected of a Sapphire from this period.

Brand choice becomes more meaningful once you decide whether you want radial or bias-ply construction. If you are staying with 185R16, you can compare Michelin, Avon, and Vredestein within the same basic size. If you are staying with 670-16, the comparison narrows to Firestone and Avon. From there, details such as speed marking, load figure, and wheel-width compatibility are more useful than brand name alone.

1960 Armstrong-Siddeley tires in both 185R16 and 670-16 are offered in blackwall form. That applies across the radial and bias-ply choices available for the Sapphire. Blackwall styling is consistent with the understated luxury look of many British saloons from this era, especially compared with the more decorative sidewall treatments common in some American applications.

For most Sapphire owners, that keeps the visual decision straightforward and shifts attention to construction and fitment details instead. If your goal is a highly authentic restoration, blackwall appearance is usually the natural direction for a 1960 Armstrong-Siddeley. If your goal is road use, blackwall still works well, but you may find that the bigger practical decision remains whether you want a traditional bias-ply casing or a radial tire with a more modern specification.

Rim-width guidance for 1960 Armstrong-Siddeley tires depends on the size you choose. The 185R16 radial is available with product fitment ranges of 4.50 to 6.00 inches and 5.0 to 6.5 inches, depending on brand. The 670-16 bias-ply is available with a 4.50 to 5.00 inch rim-width range where that dimension is supplied. All of these tires mount on 16-inch wheels, but width compatibility is not identical from one size to the next.

That matters most when a Sapphire still wears its original wheels and you are considering switching constructions. A wheel that works with one 16-inch tire may not be the ideal width for every other 16-inch option. Measuring the actual wheel and matching it to the range for the exact tire you want is the cleanest way to avoid fitment compromises. It also helps preserve proper tire shape and appearance once mounted.

Inner-tube requirements for 1960 Armstrong-Siddeley tires vary by product rather than by wheel diameter alone. In 185R16, the Michelin X Radial is marked TT, which means tube type, while other 185R16 products are not marked the same way. The 670-16 products also do not share one clearly uniform tube marking across the size. Because of that, tube use should be confirmed against the exact tire's sidewall designation and the wheel's construction.

That is especially important on a 1960 British saloon, where original wheel design and restoration history can affect whether a tube is appropriate. If the tire is marked tube type, follow that marking. If the wheel itself has features that call for a tube, that can matter just as much as the tire construction. A restorer or marque specialist can help if the car's wheels have been changed or refinished over the years.

Original 1960 Armstrong-Siddeley Sapphire wheels can generally be considered for both 185R16 and 670-16 because both sizes use a 16-inch rim diameter. That shared diameter is the key point of compatibility at the year-and-model level. The remaining question is wheel width, since the radial and bias-ply options do not share the same width ranges across every product.

A Sapphire owner considering a change from bias-ply to radial should verify the wheel width before assuming the original wheel is suitable for every 185R16 tire. The same caution applies in reverse if a car now wears later radial tires and you want to return to a narrower period-style bias-ply fitment. Diameter match is only the starting point; the exact wheel and exact tire still need to agree.

A 1960 Armstrong-Siddeley should be stored in a cool, dry, dark space away from direct sunlight, electric motors, battery chargers, and other ozone-producing equipment that can age sidewalls prematurely. Keep the tires properly inflated, park on a clean surface, and move the car periodically if it will sit for extended stretches. Bias-ply tires such as 670-16 are more prone to flat-spotting during static storage, while any older-style collector tire can suffer from cosmetic cracking if exposed to heat and ozone for long periods.

If the Sapphire will remain parked for months, many owners either roll it occasionally or support it in a way that reduces continuous load on one contact patch. That helps the car drive more smoothly when it returns to the road. Storage care also protects the look of blackwall tires, which is important on a formal saloon where fresh, clean sidewalls contribute noticeably to the car's overall presentation.

Tires on a 1960 Armstrong-Siddeley are usually evaluated more by age than by mileage. A collector car may cover very few miles while the rubber still hardens, dries, or loses resilience over time. A sensible rule is to begin close inspection around five to seven years of age and to treat around ten years as a point where replacement deserves serious consideration, regardless of remaining tread depth. The DOT date code on the tire is the most reliable age reference.

That age-based approach matters because a lightly used Sapphire can look road-ready while riding on tires that are simply too old to trust on a longer outing. Collector ownership often hides tire aging rather than preventing it. If the car's service history is unclear, checking the date code and giving the tires a careful visual inspection is one of the smartest first steps before planning sustained road use.

Tires on a 1960 Armstrong-Siddeley should be inspected before every drive and again before any longer outing. Look for sidewall cracking, cuts, bulges, embedded debris, uneven wear, and signs that the tire has lost pressure while parked. Because some products in these sizes may involve tube-type use, valve-stem condition also deserves attention, especially on a car that spends long intervals in storage.

A short pre-drive inspection is especially valuable on an older luxury saloon because the car may feel composed even when a tire problem is developing. Catching a crack, soft tire, or aging valve stem in the garage is far easier than dealing with it on the road. If you notice recurring pressure loss, have the tire, tube if fitted, and wheel sealing surfaces checked together rather than treating them as separate issues.

A 1960 Armstrong-Siddeley Sapphire would have been associated primarily with bias-ply tire practice in period, and the 670-16 size reflects that era-appropriate construction and sizing style. The radial 185R16 is also used on the Sapphire today, but it represents a later construction approach rather than the most traditional presentation. No original-equipment brand should be assumed without marque-specific evidence, since factory supply could vary by market and delivery details.

For a restoration that aims to mirror period appearance as closely as possible, 670-16 is the size most owners would examine first. For event-level authenticity, it is worth checking club references, original handbooks, and Armstrong-Siddeley specialist knowledge to confirm whether any market-specific variations applied to your car. That extra step matters more on a niche British marque, where production practices and export differences can be easy to overlook.

Correct tire fitment can matter a great deal when showing a 1960 Armstrong-Siddeley, especially in preservation or concours-oriented settings. Judges and knowledgeable enthusiasts often notice whether the car wears an era-appropriate size, the correct general construction type, and a sidewall style that matches the period character of the car. On a Sapphire, a blackwall presentation aligns well with the car's formal British luxury identity, while a modern radial construction may be seen differently depending on the event's standards.

The practical question is how the car will be judged. Some events reward strict originality, where a numeric bias-ply size may carry more weight. Others are more accepting of radial substitutions if the overall look remains sympathetic to the period. Before finalizing a show car, consult the event rules or marque-club guidance so the tire choice supports the standard you are actually being judged against.

For the 1960 Armstrong-Siddeley in 670-16, Firestone and Avon both offer blackwall bias-ply choices, but they are not identical in specification. The Firestone 670-16 carries a maximum load figure of 1130 pounds at 30 psi and includes a 4.50 to 5.00 inch rim-width range. The Avon Turbospeed uses a 670H16 89H marking and carries an H speed rating, which corresponds to 130 mph, along with a 1,279-pound maximum load figure.

That makes the comparison about more than brand preference alone. One owner may value the Firestone's traditional bias-ply presentation and explicit rim-width guidance, while another may focus on the Avon's speed marking and higher stated load figure. Since both remain period-style bias-ply choices, the deciding factors are usually the exact spec details and how closely the tire aligns with your restoration or touring priorities.

1960 Armstrong-Siddeley tires can be suitable for highway driving when they are the correct size, in sound condition, and used within their speed and load limits. In 185R16, available speed ratings include S at 112 mph and V at 149 mph, depending on brand. In 670-16, one available Avon product carries an H rating at 130 mph, while another product in the size does not use the same speed-letter format. Those figures are well above ordinary highway speeds, but they do not override the condition of the tire or the mechanical limits of the car.

A 1960 Sapphire is still an older luxury saloon with era-specific brakes, suspension, and general road manners, so tire capability is only one part of safe touring. Highway use is most realistic when the tires are fresh, properly inflated, and matched to wheels that suit them. If the car has been sitting, a careful inspection and a conservative first drive are wiser than assuming any reproduction collector tire should immediately be pushed hard.

Inflation pressure for 1960 Armstrong-Siddeley tires should be chosen by size and by the exact tire's published limits rather than copied from another fitment. In 670-16, one Firestone product states 1130 pounds at 30 psi, while one 185R16 Vredestein product states 1,433 pounds at 51 psi. Those figures describe rated load-and-pressure relationships for those specific tires, not a universal running pressure for every Sapphire application.

The best approach is to start with the factory vehicle recommendation from the owner's manual or marque literature, then confirm that it remains appropriate for the exact reproduction or modern tire you are using. Do not transfer a radial's pressure figure to a bias-ply tire, or the reverse, simply because both fit a 16-inch wheel. Construction differences and product design matter enough that pressure should always be size- and tire-specific.

Before taking a 1960 Armstrong-Siddeley on a longer drive, inspect each tire for cracking, cuts, bulges, irregular wear, and proper inflation, then check the valve stems and the spare as carefully as the four road tires. If your chosen tire is tube type, or if your wheel setup uses tubes, pay extra attention to signs of slow leakage and stem condition. A quick look at tread depth alone is not enough on a collector car that may spend long periods parked.

That tire check should be part of a broader inspection of the car's age-sensitive systems, including brakes, cooling, and steering. On a niche British saloon like the Sapphire, long-distance confidence comes from treating the whole car as a touring system rather than assuming the tires can carry the burden alone. If anything about the tires feels questionable, address that first; tire issues are among the easiest problems to catch before the trip begins.