Hi!
I'm looking to put together a bike for my daughter and have some basic pieces to work with, eg: frame, front fork etc.
I need a new quill stem and from what I see in some diagrams and read on some sites, the measurement is confusing me…
I've gotten the impression that a quill stem is measured by the outside diameter of the fork tube. For some stems I've been looking at they explicitly say: "Fits a fork with an upper outside diameter of 25.4mm". First of all this doesn't make sense to me, why not measure it by the inner diameter since that's what it needs to fit into…
And secondly I only seem to find lots of options for 22.2mm and 25.4mm. The outer measurement of the tube on my fork is 28.6, but the inner is 25.4.
When I check my other bikes they all have stems of 25.4mm (stem outer diameter) which is what would also fit in the new fork.
Have I got it all wrong? Should a quill stem marketed as 25.4 fit into my fork?
Example:
Details say (in Swedish):
"Passar i en framgaffel som är 25,4 mm bred."
Translated:
"Fits into a front fork that is 25,4 mm wide."
Thankful for any help!
by albertbertilsson
2 Comments
I don’t know about the stem from your post, because the wording is a bit weird. I’d say it should fit into your fork, but can you ask the shop for clarification?
They come in two sizes because threaded forks come in two sizes (1″ & 1 1/8 ). The 1 1/8″ takes 25.4 stems (and coincidentally the 1″ fork’s outer diameter is also 25.4mm, but that one takes 22.2 stems)
I think the Ø25,4mm actually refers to the diameter of the Handlebar clamp
Ø25,4 is the common diameter for handlebars on Tourer/citybikes etc.
The quill stem with the wedge fits INTO any standard Tourer/citybike fork.
The Ø22,2 type is for BMX handlebars
But it has the same diameter quill stem INTO the fork.
Racing road bikes use Ø31,8/Ø35 handlebars
And their stem (ahead bar) clamps ONTO the fork tube and don’t sit inside like on citybikes.