JetBlack S1 Sport Trainer + Lite App

JetBlack's S1 Sport sits at the bottom of a range that goes all the way up to excellent units like the WhisperDrive – the quietest Mat has ever used. This isn't excellent, though; it's pretty average overall, and probably the noisiest trainer I've used. So JetBlack has both ends of the noise spectrum covered.

The S1 is simple and basic. It has a preset resistance unit attached to a sturdy alloy frame. And it really is sturdy; that's the best thing about it. It grips your bike firmly and can deal with a bit of sprinting out of the saddle without fear of it tipping over or letting go. The two legs fold into the U-shaped main frame and that makes it a pretty portable package if you want to sling it in the car and use it at a race to warm up, for example.

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Actually, that's the best-case scenario for the S1. The resistance unit is pretty average, with a rather choppy response to power; there's no big flywheel to keep things turning. So it's okay for steady state warm-ups and the odd sprint, but it's not really that versatile or a particularly nice trainer to use.

The main issue, though, is noise. The Brand X TT-01 I recently tested was pretty shouty but this takes things to a new level. It's more or less unusable in the house if there's anyone else around, unless you're blessed with a cellar or really thick doors. So for a winter of indoor use, it's not that practical.

JetBlack offers a free app to use with the turbo. It has some interesting stuff in it, including a fair few set workouts. It's a bit patchy, though: connecting any ANT+ sensor on Android caused it to crash so I ended up using a Bluetooth speed and cadence sensor with the iPad instead. That worked better. I told it what turbo I had, but there's nothing (that I can see) to stop you trying out the app with any old trainer and a Bluetooth sensor, if you're curious.

If you're worried that might affect the app's ability to give you a power reading then don't be, because the power numbers it spits out are pretty fanciful, at least for the S1.

Here's a five-minute session I did, measuring the power on the bike via a set of Garmin pedals and also recording the power in the app from whatever algorithm JetBlack uses. As you can see, at the start the app was reading way under true power, not much more than half. Except when I sprinted, at which point the app spike is bigger than the pedals'.

I tried slacking off the roller until the power readings were more or less comparable at 150W, but that was no use. On the rising effort at the end, the power from the app climbs much more quickly than the true power. And also, the roller contact was so light that I had to spin up to about 80kph to get to 300W of effort.

The app is probably much more accurate on the more expensive trainers, especially units like the WhisperDrive where the roller/tyre variable is removed. But it's not so much use when paired with this trainer, although you can still use it with a heart rate strap to do zone-based training and exercises like that.

> Check out our guide to the best indoor trainers here

Overall the S1 Sport is okay, but hard to recommend. It's well built but really noisy and the resistance unit doesn't give a great feel. The Brand-X TT01 I mentioned above is nominally £99.99 but since it's a Chain Reaction own brand and is being knocked out for £70 I think it's safe to say that's the true RRP.

If I wanted a cheap trainer to try indoor exercises or to sling in the car to warm up at races, I'd go with that over this. It has adjustable resistance, it's not as noisy and you get a riser thrown in. If you want a good indoor experience then you really need to be spending north of £100 on a trainer a couple of rungs up the ladder.

Verdict

Okay for race warm-ups but very noisy, and the bundled app is a bit patchy, especially with power