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Prototype - Evolving Daily

FSA Afterburner Stem Stem

Stem: Bar clamp 31.8 mm; Length 100 mm. 2 verified variants.

What the checker says2will not fit

Run variant by variant through the mountain bike builder’s own engine. Every sentence below is the checker’s, unedited. Nothing here says this part fits your bike; it says what it does and does not fit among the parts we hold.

Checked against 5922 verified mountain bike parts in this catalog. 5799 produced no finding of any kind. Each variant produces 2 distinct errors and 0 distinct warnings.

Will not fit

  • Will not fiterror · HandlebarBar/stem clamp mismatch: Handlebar is 35mm but Stem is 31.8mm - a bigger bar cannot fit a smaller stem clamp. On 122 of the 270 verified handlebars in this catalog. Applies to all 2 variants.
  • Will not fiterror · HandlebarBar/stem clamp mismatch: a 25.4mm bar does not clamp in a 31.8mm stem - the clamp diameters differ. A shim or adapter may make other sizes or standards work, but that is a modification, not a fit. On 1 of the 270 verified handlebars in this catalog. Applies to all 2 variants.
The checker compares the dimensions listed in what we check, and what we don’t. “No conflicts found” means no conflict among those dimensions — not a guarantee that a build works. Errors mean it won’t fit; warnings mean it works but check; infos are notes.

$78.00 to $92.00 MSRP·128 to 144 g

What the maker states

Clamp
Bar clamp 31.8 mm
Length
100 mm

2 verified variants

VariantPrice (MSRP)WeightSourceLast checkedBuild
Afterburner Stem$78.00144 gmaker’s page2026-09-08Build with this
Afterburner Stem (-12deg)$92.00128 gmaker’s page2026-09-08Build with this
Source

Source: each variant links the maker’s own page in the table above. Last checked 2026-09-08.

Checked against

The checker ran this model against every verified part below that it has a slot for, the same way it checks a build in the builder. What follows is the verdict it actually produced for that specific pairing — not a recommendation, and not a guarantee any of these parts fits your own bike.

6 of 1776 counterparts with a page of their own that the checker actually probed this model against, in alphabetical order by brand and model — never by price, popularity or the verdict itself.

Where this sits

FSA Afterburner Stem is the first model on that list.Next: FSA Comet StemAll FSA stemsOpen a variant in the builder to see the ones that apply to your own parts