Mainstream Freehub Brands Used On Bikes
A cassette system is nestled right between the freehub and the chain running across. So, your freehub and cassette both have to be compatible with each other for the rear wheel to rotate smoothly. Although Shimano originally invented the freehub tool, companies like Sram and Campagnolo developed their specimens later. Currently, Shimano and SRAM are two major brands that dominate the market. The spline setup and ratcheting mechanism, therefore, depends on brands. You cannot fit SRAM freehubs in Shimano cassettes and vice versa. Let’s discuss the compatibility issue in detail.
Shimano Freehub & Cassette Compatibility
Shimano is known for its HG or Hyperglide freehubs. It’s the most common freehub design introduced by the brand in the 80s. Although the 9 splines freehub is quite popular now, the Shimano HG-Style had 13 splines on it back then. The Shimano Hyperglide series offers the proper alignment to the cassette so the gear can shift properly.
HG "8-10" Speed Mountain Freehub - Shimano Hyperglide 8-10 Speed Mountain Freehub is compatible with the 8/9/11 speed mountain cassette. Shimano's instruction for the 10-speed cassette makes the space narrower than in the previous versions, and a 1mm spacer becomes mandatory to fit the cogset. Finally, the 11-speed road cassette came in, which is not compatible with this version of the freehub.
Shimano HG 10 Speed ONLY Freehub - Shimano HG 10-Speed-Only Freehub is exclusively for the 10-speed version where other non-10-speed cassettes don’t fit. Splines are taller in this freehub, which is why this version is for 10-speed Shimano cassettes only.
Shimano HG 11/12 Speed Road Freehub - Another standard Shimano Freehub is HG 11/12 speed road freehub, which is compatible with most Shimano cassettes. It is exclusively for the 11 and 12-speed cassettes, but if you have an 8/9/11-speed mountain cassette, they would fit on this kind of freehub with a 1.85mm spacer. For a 10-speed cassette, an additional 1mm spacer is needed along with the 1.85mm spacer.
Shimano Micro Spline (MS) 11/12 Speed - As the name suggests, this freehub has 23 micro splines, way more than the usual HG series freehubs. Where the regular HG freehubs have 13 splines, this Micro Spline freehub has double that, 23 small splines. A narrow freehub means you can only install a small sprocket, even smaller than 11 teeth. Shimano made this revision to accommodate 12-speed MTB cassettes, so it’s another exclusive version to install on 12-speed cassettes.
Shimano Hyperglide+ 12 Speed Road - Recently, Shimano has introduced another updated version of the 12-Speed Road variation that may look similar to the Micro Splines freehub. This version of freehub is strictly for the 12-speed road cassettes only. No spacer is needed to install the cogset, which is incompatible with the 11-speed one. Shimano is claimed to use the Hyperglide+ technology in this freehub, previously used in off-road bikes. This freehub specimen is designed for Dura-Ace (R9200) and Ultegra (R8100) cassettes.
SRAM Freehub & Cassette Compatibility
Another market leader in this category is undoubtedly SRAM. It also has HG-style cassettes. You can segregate most SRAM freehubs into two categories: XD and XD-R series. Let’s talk about them in detail.
SRAM XD 11 & 12 Speed - SRAM XD freehub is designed to work on 11 and 12-speed cassettes. The SRAM XD freehub is entirely different from what you see in the Shimano HG series and has a unique design. The splines you can find in SRAM XD freehub are not like traditional Shimano freehubs. The SRAM XD freehub is lighter than Shimano Hyperglide series freehubs, and SRAM has made it more durable than others. This XD driver is also designed to fit small sprockets of 10 teeth.
XD-R 11 & 12 Speed - Although the SRAM XD series was initially designed for MTB cassettes, the XDR freehub is primarily used for 11 and 12-speed road bikes. It can also accommodate an XD MTB cassette if you install a 1.85mm spacer.
Campagnolo Freehub & Cassette Compatibility
Campagnolo makes it to the list as well. Campagnolo is known for manufacturing high-end bicycle components and related accessories. The brand also makes freehub exclusively for Campagnolo cassettes only.
Campy 9 & 10 & 11 & 12 Speed - Campy 9/10/11/12 speed freehub is only for 9/10/11/12 speed Ultra-Drive cassettes. You cannot fit other speed options on this freehub. You don’t need an additional spacer to fit the speeds above Campagnolo cassettes.
N3W 13 Speed - Campagnolo’s N3W freehub was initially designed for the new Campagnolo Ekar gravel groupsets. The distribution of splines is similar to what you see in Campy, but it is 4.4mm shorter. It can accommodate 12 or 12 speeds and is perfectly backward-compatible.
How do you determine the speed of the cassette?
The best way to identify your speed is to count the gears on your rear wheel. Your gear can have so many teeth on the sprocket; counting them allows you to determine the aspect of the cassette you’re currently using. Having multiple gears only proves that you don’t have a single-speed bike; instead, your bike is multi-speed. Usually, road bikes possess smaller sprockets with 11, 12, or 13 teeth than MTB bikes, so when you shift your gear, the jumps between two gears will be smaller. This also means your bike can accelerate more efficiently with small sprockets. On the flip side, big sprockets with more teeth and big jumps between gears make your life easier while climbing hills.
There are several cases when freehubs can be used with cassettes they weren't designed for. A spacer comes in handy in such cases to install the cassette. Your freehub may be compatible with multiple-speed cassettes with or without spacers. Another thing to keep in mind is the derailleur. Whatever you install in your bike, your derailleur must also be compatible with smooth gear shifting, cranking uphill, or elevating the overall riding experience.