Marmon 78 Series Tires

The Marmon 78 Series uses two listed tire sizes across 1928 and 1929: 29X5.50 and 550-19. The 550-19 size fits a 19-inch rim, with available products built for rim widths from 2.50 to 3.00 inches. The 29X5.50 size is an antique diameter-by-section format used in the same years, but that code does not itself state the wheel diameter.

That means a 1928 or 1929 Marmon 78 Series owner needs to identify the wheel and tire arrangement actually on the car before choosing a replacement. Start by reading the sidewall of the existing tire if present, then measure or confirm the wheel diameter directly. On a car that has been restored or reconfigured over time, the year by itself should not be treated as the final answer.

On a Marmon 78 Series, 29X5.50 is an antique diameter-by-section size. The first number, 29, refers to the tire’s overall outside diameter in inches, not the wheel diameter. The second number, 5.50, is the nominal section width, which is why this format can be confusing to buyers used to later numeric or modern radial sizing systems.

A Marmon 78 Series owner should read 29X5.50 as a period-correct early size expression rather than a direct wheel-size label. The practical next step is to verify the wheel itself and compare that setup with the rest of the car’s restoration. That is especially important on late-1920s cars, where later wheel and tire combinations may have been fitted during earlier ownership.

A 1928 Marmon 78 Series has two tire sizes listed because more than one fitment arrangement appears for that same model year: 29X5.50 and 550-19. Those are not simply two spellings of the same size. They represent different sizing conventions, and one of them, 550-19, specifically identifies a 19-inch rim while 29X5.50 does not.

The right way to sort that out is to identify the specific wheel and tire setup on your own Marmon 78 Series instead of relying on the year alone. Check the wheel diameter, compare the existing tire markings if they are still readable, and review restoration paperwork or period references tied to the car. That approach will narrow the choice much more accurately than model year alone.

The Marmon 78 Series uses at least one confirmed 19-inch rim fitment, tied to the 550-19 tire size. The antique-format 29X5.50 size does not include the wheel diameter in the size code, so its rim diameter cannot be read directly from that marking. On this Marmon 78 Series listing, the critical distinction is that not every size code tells you the wheel size in the same way.

A Marmon 78 Series owner should treat wheel diameter as a measurement to verify on the car, not an assumption. If the car is wearing 550-19, you can match to a 19-inch wheel and the listed rim-width range. If the car is marked 29X5.50 or carries older replacement tires, confirm the wheel before proceeding so the tire and rim relationship stays true to the actual setup.

A 1929 Marmon 78 Series can use either 29X5.50 or 550-19, so the correct size is confirmed by the wheel and existing fitment rather than by year alone. The most direct clues are the size molded into the old tire, the measured wheel diameter, and any restoration records that stayed with the car. The 550-19 option is specifically for a 19-inch rim.

For a practical check, inspect all four wheels to make sure the car has a matched set and has not been assembled from mixed components over time. Then compare sidewall markings and wheel dimensions against the listed sizes. If the car is a restoration project, period photos, marque literature, and a Marmon specialist can help confirm which arrangement best matches the car’s current configuration.

Marmon 78 Series tires in the listed 550-19 size are available in both blackwall and wide whitewall form. Both available products are BFGoodrich bias-ply tires from the Silvertown Classic Bias Ply line. That gives buyers a choice between a more understated black sidewall appearance and a more formal whitewall presentation on the same basic size.

The right sidewall style depends on how the Marmon 78 Series is being restored and presented. A blackwall look is often favored for a simpler, more restrained appearance, while a wide whitewall creates a more dressy period presence. Match the sidewall to the overall restoration theme and the trim level of the car rather than choosing on appearance alone.

The listed Marmon 78 Series products are from BFGoodrich. Both currently listed 550-19 offerings come from the BFGoodrich Silvertown Classic Bias Ply series, with one blackwall version and one 3.25-inch whitewall version. That means the available brand selection on this model page is concentrated rather than spread across multiple manufacturers.

For a Marmon 78 Series owner, that makes the selection process more about choosing the correct size and sidewall presentation than comparing many competing brand options. Once the wheel diameter and size format are verified, the remaining decision is usually whether the car calls for a blackwall or a wider whitewall appearance. That is often guided by restoration style and event use.

A Marmon 78 Series should be stored in a cool, dry, dark space with the tires kept away from direct sunlight, ozone sources, and prolonged contact with damp concrete. Bias-ply collector tires benefit from stable temperature and from keeping the car clean and unloaded as evenly as possible. If the car will sit for an extended period, maintaining proper inflation is important to reduce flat spotting and casing stress.

In practical terms, move the Marmon 78 Series occasionally if it is stored on its tires, or use methods that reduce concentrated load on one spot for many months at a time. Check inflation before and after long storage, and inspect sidewalls for cracking or deformation before returning the car to use. Thoughtful storage habits usually matter more on collector tires than annual mileage does.

Tires on a Marmon 78 Series should be inspected before each drive and more thoroughly at regular intervals even if the car sees very little mileage. A late-1920s luxury car places real weight on its tires, and bias-ply construction deserves close attention to sidewall condition, tread separation signs, bead area condition, and valve stem health. Collector cars often age their tires through time and environment rather than through wear alone.

A practical routine is to give the Marmon 78 Series a walk-around before every outing, then perform a fuller inspection several times a year while the car is on stands or with the wheels turned for access. Look for cracks, bulges, uneven wear, and any changes in how the car sits. If anything seems unusual, have the tires and wheels evaluated before adding more road miles.

Marmon 78 Series tires should be replaced when age, cracking, hardening, deformation, or structural concerns appear, even if the tread still looks usable. Collector tires often age out before they wear out, especially on cars that spend long periods in storage. Tread depth alone is not a reliable measure of serviceability on a low-mileage pre-war automobile.

For a Marmon 78 Series, replacement decisions should be made with the tire’s age, condition, and intended use in mind, not just appearance from a few feet away. Any tire showing visible sidewall deterioration or changes in shape should come out of service. If an older period tire is still on the car, a specialist inspection is the right step before any continued road use.

The Marmon 78 Series is associated here with two period-style size expressions for 1928 and 1929: 29X5.50 and 550-19. That tells you the car sits in a transitional late-1920s tire era where more than one fitment convention can appear. The available modern replacement products listed on this page are BFGoodrich Silvertown Classic Bias Ply tires in 550-19, but that should not be treated as a blanket statement for every individual car.

A careful restoration of a Marmon 78 Series should tie the tire choice to the actual wheel equipment, restoration history, and period references for the specific automobile. Original photos, factory literature, and Marmon marque resources are the best way to confirm how a particular car was equipped. That is especially useful when the same model year appears with more than one listed size.

Correct tire fitment can absolutely affect both the presentation and judging of a Marmon 78 Series. Size, overall stance, sidewall treatment, and period-appropriate construction all contribute to whether the car looks mechanically and historically coherent. On a recognized luxury marque from the late 1920s, judges and informed buyers often notice tire details quickly because they strongly influence the car’s proportions.

For a Marmon 78 Series owner, that means the tire decision should support the level of restoration being pursued. A touring driver may prioritize a sound, usable period-style bias-ply fitment, while a show car may need closer attention to sidewall style and exact visual character. Marque clubs and event judging standards are the right references when authenticity is a central goal.

Marmon 78 Series tires in the listed 550-19 size are available in blackwall and wide whitewall styles. Either can suit a late-1920s luxury car depending on the presentation being recreated, because sidewall treatment was part of the period visual language and varied with owner taste and vehicle character. The key point is to choose a sidewall style that looks consistent with the car’s trim, finish, and intended restoration standard.

A Marmon 78 Series restored for formal show presentation may favor the visual impact of a wide whitewall, while a more restrained or road-oriented restoration may look more natural on blackwalls. Review period images of similarly equipped Marmons and compare them with your car’s body and trim. Consistency across all five tires, including the spare if fitted, also matters to the finished result.

A properly selected, properly mounted collector tire can be suitable for public-road use on a Marmon 78 Series when the rest of the car is in sound mechanical condition. These listed 550-19 products are bias-ply tires, which suit the character of a late-1920s automobile but still require expectations appropriate to period construction and chassis design. Safe use depends on the condition of the entire vehicle, not the tire alone.

Before regular road driving, a Marmon 78 Series should have its wheels, brakes, steering, suspension, and alignment reviewed along with the tires and tubes. The car should then be driven within the limits of its age, tire type, and braking capability. Smooth inputs, moderate speeds, and short familiar routes are the right starting point after fitting new tires or returning the car to service.

Before driving a Marmon 78 Series, check tire inflation, visible sidewall condition, tread condition, valve stems, wheel security, and any signs that the car has been sitting unevenly. On a pre-war car with bias-ply tires, you also want to confirm that the car tracks straight at low speed and that there are no obvious steering or brake issues. A brief visual inspection catches many problems before they become dangerous.

In practice, make the check part of every outing with the Marmon 78 Series rather than a seasonal task. Look for new cracks, bulges, or an unusual lean at one corner, and listen for any wheel or tire-related vibration once underway. If the car has been stored for an extended period, a more thorough inspection is wise before moving beyond a very short test drive.

A Marmon 78 Series should be driven at moderate, conservative speeds when using period-style bias-ply tires, even when those tires are newly manufactured replacements. The appropriate pace is set by the whole vehicle’s age, suspension design, braking ability, and steering feel rather than by modern traffic expectations. A late-1920s luxury car was not engineered around modern radial behavior or modern stopping distances.

For real-world use, bring a Marmon 78 Series up to speed gradually and keep it in the range where the car feels settled, responsive, and easy to stop. Avoid sustained high-speed running, abrupt lane changes, and rough pavement where possible. The safest approach is to drive the car in a way that respects both the tire construction and the capabilities of the chassis beneath it.