Skateboard Wheel Durometer Comparator

Last updated 2026-08-23

Skateboard wheel hardness is printed as a "durometer" number — 78A, 99A, 84B — but the A and B in those numbers are not decoration. They're two different gauges, and a number from one doesn't mean what the same number means on the other. Bones Wheels' own site explains why it uses both, and states its brands' own current per-line numbers in plain text. We fetched that directly, plus two more brands' own current product listings, and built the converter none of the existing guides do.

84 is not softer than 92 — depending on the letter Bones' own page states the Shore A gauge "does not compute accurately" above roughly 95A, which is why its hardest wheels are measured on the B scale instead — a scale that, per the same page, "reads 20 points lower" than A would for the identical physical hardness. Converted onto a common A-scale basis, an 84B wheel sits around 104A: harder than every A-scale number in the table below, even though "84" looks like the smallest number on the page. Enter what's printed on your wheel to see where it actually lands.

Named brands' own current numbers, one common scale

Every row below is a real product line, converted to the A-scale basis, from a brand's own current page. None of these are B-scale products we could confirm by direct fetch this session — see the note above the input for why, and for why the input still accepts a B-scale value anyway.

Brand	Line	Durometer (A-scale)	Source
Ricta	Clouds	78A	Ricta Wheels' own wheels page
OJ	Mini Super Juice / Super Juice	78A	OJ Wheels' own site
Ricta	Clouds	86A	Ricta Wheels' own wheels page
OJ	Keyframe 2	87A	OJ Wheels' own site
Ricta	Clouds	92A	Ricta Wheels' own wheels page
Bones	X-Formula (XF)	95A	Bones Wheels' own formulas page
Bones	X-Formula (XF)	97A	Bones Wheels' own formulas page
Bones	X-Formula (XF)	99A	Bones Wheels' own formulas page
Bones	Street Tech Formula (STF)	99A	Bones Wheels' own formulas page
OJ	Full Combo	99A	OJ Wheels' own site
OJ	Chubbies (Double Duros, tread)	99A	OJ Wheels' own site
Bones	Street Tech Formula (STF)	103A	Bones Wheels' own formulas page

What this does not do

It does not claim any brand's A-scale number is inaccurate. Bones' own page makes that specific claim about the A scale generally above ~95A — Bones' own STF line (99A, 103A) is printed in A above that point regardless, which this page states as a fact from Bones' own two pages, not as an accusation.
It has no B-scale row in the product table, because no brand's own product page confirmed one to this fetcher this session (see the header comment). Typing a B-scale value still works — the conversion is Bones' own stated 20-point relationship, applied to what you enter, not to an unconfirmed product number.
It does not cover Spitfire, whose own domain returned HTTP 403 on every page tried this session — named here, not compared.
It converts a printed number, not a lab measurement. A specific wheel's actual hardness can vary from its printed durometer by manufacturing tolerance; this page compares what brands print, the same way the rest of this claim compares labels.

Runs entirely in your browser. Nothing you type is sent anywhere. The cut-resistant glove rating comparator converts between two other non-interchangeable scales for the same physical property; the resistance band color comparator found the same "same label, different real value" shape in a completely different market.