Steerer lenght

[baron von greenback]

How do you work out exactly what steerer size you need size of head tube on bike and are all stems and headsets more or less same size especially if you have not got everything ie stem headset cheers

 

[Tootyred]

Are you talking threaded ?

 

[winjohn]

This is a reasonably clear overview.

https://www.parktool.com/en-int/blog/repair-help/fork-steering-column-length-and-sizing