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Tacx Flux S Smart vs Zwift Hub (classic)

Quick answer

Both the Tacx Flux S Smart and the Zwift Hub (classic) are direct-drive trainers that accept the common road and MTB axles. The Tacx Flux S Smart (1500 W, ±3%, $749) offers Shimano/SRAM HG (HyperGlide), SRAM XD Driver Body, SRAM XDR Driver Body and Campagnolo; the Zwift Hub (classic) (1800 W, ±2.5%, $499) offers Shimano/SRAM HG (HyperGlide). Use the checker below to see which fits your exact bike.

Specs side by side

Tacx Flux S SmartZwift Hub (classic)
Drive typeDirect driveDirect drive
Factory model codeT2900S—
Axle standards130 mm quick-release, 135 mm quick-release, 12 × 142 mm thru-axle and 12 × 148 mm Boost thru-axle130 mm quick-release, 135 mm quick-release, 12 × 142 mm thru-axle and 12 × 148 mm Boost thru-axle
Thru-axle adapterSold separatelyIncluded
Freehub (in box)Shimano/SRAM HG (HyperGlide)Shimano/SRAM HG (HyperGlide)
Freehub optionsShimano/SRAM HG (HyperGlide), SRAM XD Driver Body, SRAM XDR Driver Body and CampagnoloShimano/SRAM HG (HyperGlide)
CassetteSold separatelyPre-installed cassette; speed (8–12) chosen at purchase
Max cassette speed12-speed12-speed
Virtual shiftingNoNo
ProtocolsANT+PLUS, ANT+FEC, BLUETOOTHANT+PLUS, ANT+FEC, BLUETOOTH
Power accuracy±3%±2.5%
Max power1500 W1800 W
Max gradient10%16%
Flywheel6.7 kg4.7 kg
MSRP$749$499
StatusCurrentDiscontinued

Which fits your bike — Tacx Flux S Smart or Zwift Hub (classic)?

29Drops straight in3Fits with parts1Not supported

Frequently asked questions

Both accept the same common road and MTB axles, so the deciding factor is the freehub for your cassette: the Tacx Flux S Smart offers Shimano/SRAM HG (HyperGlide), SRAM XD Driver Body, SRAM XDR Driver Body and Campagnolo, while the Zwift Hub (classic) offers Shimano/SRAM HG (HyperGlide). Run your drivetrain through the checker to see which is a clean drop-in.