Wheel Thread Mounts: 6x70mm vs 3x50mm

What the bolt pattern numbers mean

A bolt pattern on a racing wheel rim is written as two numbers: the bolt count and the bolt circle diameter. In 6x70mm, six bolts sit evenly spaced on a circle 70 millimeters across. In 3x50mm, three bolts sit on a circle 50 millimeters across. The wheel base carries the threaded holes; the rim carries the matching holes or studs.

The first number is always the bolt count, and the second is the diameter of the circle the bolts sit on. The notation is compact, so a listing can state the whole mounting requirement in one line. The same notation appears on many product pages and manuals.

The pattern is a compatibility statement, not a quality rating. A base built for one pattern will not accept a rim made for the other without an adapter, and adapters are not a standard part of every product line.

When a rim listing states a pattern, it tells you which bases the rim is designed to fit. When a listing does not state one, the maker's compatibility list is the place to check.

The notation is common in mechanical mounts across sim racing hardware. Understanding it lets you compare two rims from different sellers by reading the stated numbers rather than relying on a listing photo.

Why wheel bases use different bolt patterns

There is no industry-wide standard for rim mounting. Each maker designs the mounting face around its own wheel base, quick release, and rim line. That is why a rim from one maker usually does not bolt to a base from another maker without extra parts.

The bolt pattern is one part of the mounting system. The base may also have a center shaft, an alignment pin, or electrical contacts for the buttons on the rim. The pattern alone does not tell you whether the rim's electronics will work with the base.

Makers such as Logitech G, Thrustmaster, and Fanatec publish their own product lines and mounting details on their official pages. If you are comparing direct drive bases, the direct drive racing wheels guide compares them on stated details.

A 6x70mm pattern and a 3x50mm pattern are not interchangeable. The numbers are specific to each maker's design. A buyer who sees both on two listings is looking at two different mounting systems.

Bolt pattern versus quick release

A bolt pattern is the fixed way a rim attaches with screws. A quick release is a separate mechanism that lets you swap rims without tools. Some bases use a quick release on top of the bolt pattern, some use the bolt pattern alone.

Fanatec's site describes a quick release that lets you switch wheels in seconds. Logitech G's catalog lists quick release as a product feature. When a base has a quick release, the bolt pattern still matters because the adapter itself bolts to the rim. For the difference, see quick release system on wheels.

If you plan to swap rims often, a quick release is the part to look at. If you plan to mount one rim and leave it, the bolt pattern is the only detail you need to confirm.

How to read a rim listing for the mounting pattern

Rim listings often state the pattern in the title or bullet list. Words like 6x70mm or 3x50mm are the pattern written directly. When the listing names a quick release instead, the pattern is usually on the maker's product page for that rim.

A missing pattern is not a mistake. Many listings name the compatible bases instead of the pattern, because the buyer's question is whether the rim fits the base, not what the bolt circle is.

Thrustmaster's site, for example, sells wheel add-ons as separate products and lists the platforms they support. The mounting detail for a specific base lives in the product page of that base. If a wheel listing does not state the pattern, the maker's page for the base does.

What to check before buying a separate rim

Before you buy a rim alone, confirm three things on the maker's page: the bolt pattern or quick release type, the electrical connector for the buttons if the rim has them, and the stated compatibility list for your base model.

The site's guides compare complete wheels on stated details, not individual rims. Rim compatibility is a maker-specific question, and the maker's manual and support pages are the source for the pattern. The best racing wheel guide is a useful starting point for a complete wheel purchase.

For a first wheel, the simpler path is a complete bundle. The racing wheel and pedals guide compares bundles that state their platform and drive type. The mounting pattern only matters when you later add a rim.

Complete wheels versus separate rims

A complete wheel comes with a rim, a base, and usually pedals in one box. The mounting question does not arise because the maker pairs the parts. This is the most direct route for a first purchase, and the site's guides, such as the racing wheel for PC guide, compare these bundles on stated details.

A separate rim is a later purchase, made to fit a base you already own. The bolt pattern is the first compatibility check. The rest of the check list covers the electrical connector, the button layout, and the maker's compatibility list.

What the site can and cannot tell you

The site reads stated details from listings and maker pages. It does not publish a list of which bolt pattern fits which base, because that data is not stated in the source pages.

For a mounting pattern question, the maker's compatibility list is the only reliable answer. If a listing does not state the pattern, the seller or the maker can confirm it.

What to pick for your situation

Questions

What does 6x70mm mean on a rim listing?

Six bolt holes evenly spaced on a circle 70 millimeters across. The rim mounts to a wheel base with matching threaded holes.

Can a 6x70mm rim fit a base made for 3x50mm?

Not without an adapter. The two patterns describe different bolt circles, and a rim made for one will not line up with the holes on the other. Check the maker's compatibility list for your base model before ordering a separate rim.

Is the bolt pattern the same as a quick release?

No. The bolt pattern is the screw mounting face; a quick release is a separate mechanism for swapping rims without tools. See the quick release guide for the difference.

Where do I find the bolt pattern for my wheel base?

In the maker's manual or product page for the base. The maker's support pages and compatibility list are the source for the mounting pattern. Wheel bases from Logitech G, Thrustmaster, and Fanatec each publish their own mounting details on their official pages.

Why do some rim listings not state a pattern?

The listing may name the compatible bases instead of the bolt circle. When neither is stated, ask the seller or the maker to confirm the pattern.

Does the site compare rims by bolt pattern?

No. The guides compare complete wheels on stated details. Rim mounting compatibility is a maker-specific question that the maker's compatibility list answers.