How To Buy Mountain Bike Headset

When buying a mountain bike headset, it is important to consider the type of bike you have and your riding style. The most common types of headsets are threadless, integrated, and semi-integrated. Threadless headsets are the most common type and they are also the easiest to install.

Integrated headsets attach directly to the frame of your bike. They can be difficult to install but offer a more stable connection between your handlebars and fork. Semi-integrated headsets have bearings that attach to the frame but use an external bearing cup for installation. This is a good option for riders who want their handlebars to be able to rotate easily or who want their headset protected from dirt or water.

How do I know what headset to get for my bike?

The identifier starts by describing the headset type with a two letter code – ‘EC’ stands for external cup; ‘ZS’ for zero-stack/ internal headset; and ‘IS’ for integrated headset. The number following the headset type denotes the head tube bore diameter (or bearing/cup outer diameter).^[1]

How do I know what headset bearings I need?

If you have the stock or original headset bearings, you can measure the outside diameter of those bearings to be sure. You’ll likely find numbers like: 41mm, 41.8mm (we round up and label this 42mm), 47mm, and 52mm.^[2]

How do I know if a fork will fit my bike?

Take your existing front wheel out and measure the current axle diameter to work out further narrow down what fork your bike can accommodate.^[3]

How do you measure MTB head tube?

We measure the ‘effective’ top tube, which is from the top of head tube centre to the seatpost centre, measured horizontally. This is more informative than the actual distance along the top tube. Either way, though, top tube measurements are pretty unreliable for bike fitting because seat angles vary from bike to bike.^[4]

Do I need headset spacers?

Put simply, headset spacers enable you to easily adjust the height of your handlebars, which is an essential element of bike fit for BMX, MTB and road riders. In the particular case of the latter (road cycling), the correct bar height is key for comfort and performance.^[5]

Should you grease headset bearings?

The headset bearings are one of the most common points to grease and it is advisable that in addition to greasing the bearings, you also grease the fork crown and in the frame where they sit, as well as the rest of the steering parts, but you must be careful not to grease the steerer tube at the point the stem is …^[6]

How are threaded headset sizes measured?

Measure the inside and outside diameter of the fork at the top where the stem goes in – if the outer dimension is 25.0 mm and the internal dimension is 22.0 mm the headset you require is French. If it is 25.4 mm on the outside and 22.2 mm on the inside then it is ISO/JIS.^[7]

Can you fit a tapered fork to a straight steerer?

If you happen to have a straight steerer fork, there are simple adapters that will allow them to fit a 1.5 Tapered frame, and you can fit a 1.5 Tapered fork into a 1.5 straight head tube frame, but you cannot put a 1.5 tapered fork into a 1 1/8” straight steerer frame.^[8]

Are all threaded headsets the same size?

Threaded headset sizes are designated by the outer diameter of the steering column. This can seem confusing, because the head cups do not measure the named standard. The threaded standards are 1 inch, 1-1/8 inch, and 1-1/4 inch headsets. The various standards are generally not interchangeable.^[9]

Do all forks need a crown race?

The crown race is the only thing that separates the headtube and fork. Without it, the headtube (of the frame) and fork will sit flush against each other. With no gap between the two surfaces, they will grind against each other, causing damage to both the forks and headtube.^[10]

Can you put a tapered fork on a non tapered frame?

In most cases, yes.^[11]

Can I change my bike headset?

Remove the headset spacers and withdraw the fork. The fork may need a tap on the end of the steerer with a rubber mallet to get it moving. Step 4: If you don’t have a headset cup remover, then it’s bodge time! Since you’re replacing the headset, it’s probably already knackered, so it doesn’t matter if you damage it.^[12]