The original Garmin Tacx Flux was an immediate hit as a direct drive smart trainer that drew from the success and technology of the world class NEO, but even at a great price point, the original FLUX required some upgrades for a greater indoor training market. Enter the FLUX S, which is now compatible with long rear derailleurs, has improved incline simulation to 10%, is consistently accurate to +/- 3%, reads speed / cadence / power and costs less than the original. Garmin Tacx also made some internal changes, some of which were quality control related, as well as physical change to the tension roller, with the goal of improving road feel and addressing issues the original had while the rider was sprinting.

A 14.7 lb flywheel is actually controlled by an electromagnetic system that employs 8 actual magnets, and 8 electromagnets, which creates simulated 55 lb flywheel. Unlike the NEO, the FLUX S is not silent, but the noise levels (without drivetrain) are sub 65 decibels, so the unit is hardly noisy, and the electromagnetic system truly limits vibration. While the NEO has a slight amount of lateral movement built into the leg support system, the FLUX S is intrinsically stiffer. The max power rating is 1500 watts, and communication is fully up to date with: ANT+ FE-C, ANT+ Power, Bluetooth Smart Trainer Control, Bluetooth Smart Power, so you can use essentially any of the 3rd party Apps available today. The 50.3 lb FLUX S uses a fixed base/leg system that takes 3 minutes to bolt on, is very stable and is set-up so a bike with a 700c wheel does not require a front wheel block of any kind.

Garmin Tacx supplies a Shimano/SRAM 11-speed compatible freehub body and a 1.85mm spacer for 9 and 10 speed use. A Campagnolo 11/12 freehub body is sold separately. The FLUX S comes equipped for 130 and 135mm quick release use, and Garmin Tacx sells a Thru-Axle Kit for Direct Drive trainers (T2835) that easily converts the set-up to 12/142 or 12/148mm thru-axle spacing. The footprint is 26.4 x 25.3", so the FLUX S fits on nearly every trainer mat sold. A standard AC power cord is included, and is required for any measurable power output. You could spin freely on it without power, but the resistance is negligible. At $749, this direct drive trainer is more than capable for about 85% of indoor training cyclists and triathletes. As you can access and take advantage of Zwift, TrainerRoad, SufferFest, Rouvy, Kinomap Road Grand Tours and many more training apps, the FLUX S won't leave you wanting. Yes, you can spend $150-$500 more and get increased capability. In which case we recommend you go right to the NEO. No fear there, but your budget has you considering the FLUX S, and for the money it is tough to beat.