New Saris H4 smart trainer ups accuracy at lower price

Saris says its new direct drive trainer can handle up to 2,300 watts

Saris direct drive smart trainer side view.

Saris has released the H4, a new direct drive smart trainer offering several upgrades over the Saris H3, while retaining the same 20lb fly-wheel, low-noise claims and a similar appearance.


Saris says its new trainer is more accurate than the H3, has a higher maximum power of 2,300 watts and can handle simulated inclines of 25 per cent.

Compatibility is updated to accommodate 12-speed drivetrains.

Saris says the new trainer continues its “legacy of exceptional quality and durability” with a made-in-America aluminium housing.

The H4 retails for $999.99. Saris says it will keep the H3 in its line-up for a lower price of $799.

Saris H4 changes

The H4 has yellow detailing, whereas the H3 was just black.

Two main changes from the H3 are the H4’s increased accuracy and higher maximum wattage.

The H4 has a claimed accuracy of +/-1 per cent, whereas the accuracy of the H3 was said to be +/-2 per cent.

The maximum power the H4 can handle is 2,300 watts, up from the H3’s 2,000 watts, and the brand says this will enable riders to use the trainer for “high-octane sprints”.

Saris has increased the gradient simulation on its new trainer by 5 per cent, with the H4 able to simulate ramps of up to 25 per cent.

The brand says the direct drive trainer has “improved cadence”, but BikeRadar is yet to see any details on how it has changed from the H3.


Cog size can be limited if you’re running a derailleur with a long cage.

The Saris H4 is compatible with a range of bikes.

It can be used with thru-axle rear hubs of 142mm and 148mm, as well as quick-release rear hubs of 130mm and 135mm.

The H4 can fit 8-speed to 12-speed Shimano and SRAM cassettes, accommodating older drivetrains and the latest 12-speed cassettes.

Saris says the maximum-size cog that can fit on the H4 is 36-teeth.

If you are running a Shimano SLX, XT or XTR rear derailleur, the maximum cog size is 32-teeth, due to the long derailleur cage, which could hit the leg of the trainer.

You can purchase XD/XDR freehubs for the H4 separately. Saris says it’s not compatible with HyperGlide cassettes.

The H4 connects via ANT+ and Bluetooth to many of the best indoor cycling apps, including Zwift.

How does the Saris H4 compare to the competition?

The H4 has wide feet.

The H3 was competitive with many of the best smart trainers, while coming in at a comparatively low price.

The updates Saris has made to the H4 mirror what other brands have done in the years since the H3’s release, indicating the brand may retain its competitive place in the smart-trainer market.

The increased accuracy is the same refinement we saw with the Wahoo Kickr V5 and the maximum gradient sees the H4 remain competitive with other smart trainers, such as the Elite Justo.


The  H4 doesn’t have all the features of its competitors. For instance, it lacks the multi-channel Bluetooth and compatibility of riser systems found on Wahoo and Elite trainers. However, some may be happy to forfeit such features for the monetary saving.