Full disclosure: what follows is Seismic‘s own text for the Tekton XT bearings. We’ve just copy and pasted it because… well… there’s a lot of text here. All we’ll add is that, yes, these bearings are bloody good.

The patented self-aligning bearing system behind the Official IGSA Downhill Speed World Record – 80.83 mph by Mischo Erban!

Next-level skate bearing tech – more speed, better handling, longer life!

• Ultra-Precise Alignment
• 50% Stronger XT (Extra-Tough) Steel Casings
• Tighter Assembly Tolerances
• Dust-Resistant Ball Retainers
• Premium Lube

– Superior speed & acceleration
– More consistent wheel contact & grip while cornering
– More predictable slide release & hookup
– Longer wheel & bearing life

PATENTED Spacing System: Built-in half-spacers end in extra-wide contact surfaces (U.S. Pat. #9,126,101) that square up and self-stabilize inside wheels – correcting for flaws in bearing seat levelness, bearing seat spacing, axle diameter, and axle straightness. Combines with Tighter Radial Tolerances (3µ – 5µ) that minimize torsional play inside bearing assemblies. Locks in super-precise alignment, protects against friction and wear – better than any other system. Minimizes noise, too.

XT Construction: More than 50% tougher! Superior steel, thicker outer casings, and advanced heat treatment. Ball raceways hold smooth polish, and bearings stay tight and fast, for far longer! 50%-stiffer casings resist flexing, spin truer / faster, keep seals from popping off on extreme impacts.

7-Ball Assembly: Classic configuration. Best overall durability against frequent high impacts and side loads.

Premium Steel Balls: Superior concentricity, surface smoothness, strength, and durability.

Advanced Dust-Resistant Ball Retainers: Keep bearings cleaner for longer, without the added friction of a second seal. Formed of Dupont® engineering-grade Nylon.

High-End Lubricant: Packed with premium “high-RPM” light grease from Kyodo Japan. Formulated for peak performance under actual skating stresses, not max free-spin time.

Inner Race: Specially contoured under seal to resist contamination. Extends 0.5mm outside to form built-in washer. No bearing spacers, axle washers, or World Record budgets required!

Additional Features: Black outer casings, removable rubber-coated steel seals with printed graphic.

Meets or exceeds all criteria for ABEC-9 rating.

NOTE: The broad Tekton XT flanges may not fit hub-less street wheels with old-style, oversized bearing supports, which sometimes leave the wheel’s central hole smaller than the flange (15mm in diameter). For wheels of this type, use Tekton Classic or Tekton LITE Built-In bearings.