Kurt Kinetic Rock and Roll 2 trainer + inRide kit

I tested the original incarnation of the Rock and Roll trainer back in 2010 and I was impressed back then. The latest version, which allows you to use Kinetic's new inRide power measurement system (available separately, but we've tested them together) makes it even better. There are some questions about the value – specifically, the value of the inRide add-on – but none about the performance of the turbo, which is as good as it gets.

Kurt have a guaranteed leak-free resistance unit, which they use on all their trainers. It's completely sealed, and only connected to the flywheel and roller via a magnetic coupling. That coupling is so strong there's no danger of detaching it with a sprint effort, and the fact that the unit has no moving seals means there's very little that can go wrong. It gets an unconditional lifetime warranty to back it up.

The other standout feature of the Rock and Roll is that the whole of the trainer assembly is isolated from the base by a rubber bumper, which allows the bike to move about when you're climbing all over it on a hard effort. The trainer's wide footprint and 19kg all-in weight mean it stays put even when you're wobbling about on top. You can adjust the amount of wobble by tensioning up the bolts holding the top section to the bottom.

The idea is that the feel of riding is more natural, and also that riding the trainer engages your core muscles and helps to build strength there, as well as in your legs. A stable core means better power transfer to the pedals, too. Kurt have revised the base of the Rock and Roll so that it's not quite as wide as it was. Even so, it's still a good deal wider than a standard trainer, so if you're short on space it's probably not for you.

Different trainers are good at different things. What the Rock and Roll excelled at last time around was the riding feel. It really is about as good as they come. The sealed resistance unit is quiet, the large 6lb flywheel gives a smooth feel at the pedals and the suspended top section means the bike moves with you. It's really, really good. It works best with the riser that Kurt also sell, which allows the front wheel to pivot.

Kurt have done a lot of work on the power curve of the resistance unit so that it's easy to spin at low speeds and ramps up quite aggressively as you get faster, so there's plenty of resistance on hand without the need for adjustments.

All in all, the performance is similar to last time, which isn't a surprise as the trainer itself hasn't been radically updated. What has changed, however, is the ability to hook is up to an iPhone or iPad using the Kinetic inRide system, available separately for £175.

Kurt have always been happy that their resistance unit is built to sufficiently tight tolerances that you can extrapolate a meaningful power measurement from it; in the previous incarnation they supplied it with a wattage chart that was accurate to thousandths of a watt for a given speed. As I said in the earlier review, that's clearly nonsense: the trainer isn't the only source of resistance in the system and adjusting the tyre contact can significantly affect the drag. The inRide system takes all that into account though.

The package consists of a tiny magnet – which goes into the roller – and two bluetooth sensors, made by Wahoo Fitness. You get a heart rate monitor strap, and a sensor to stick on the back of the Rock and Roll to pick up the cadence of the roller. They both pair with Kinetic's new inRide app, which will work on both iPhone and iPad (there's no Android version). The cadence information is translated into both speed, and power, by the algorithms in the app.

Importantly, the app also factors in the quality of the tyre contact. For each workout you do (or series of workouts, if you're keen) there's a ten-minute warm-up followed by a roll-down test. You build up the speed to exactly 33.8km/h (a nice round figure) and then it tells you to stop pedalling. from the roll-down information gathered from that, the app adjusts the power algorithm for a given speed.

And does it work? Yes, it seems to. The Kurt gave me realistic and repeatable numbers when I was using it, and the inRide app is a pretty decent effort given it's a first go.

You can set up your own workouts to attempt. Currently I'm on a training plan that mostly involves riding intervals, so I set a few up to try. It's a bit of a laborious process getting all the information in there. You have to create each interval segment separately, and you enter the time, start power and finish power on a series of scrolling wheels. All power settings are expressed as a percentage of your Functional Threshold Power (FTP) so you'll need to know that, or at least be able to guess it. There's a preset workout in the app that'll give you a number.

The main thing you want power measurements to be is repeatable. If you can generate more power than before, or the same power for a given heart rate, then that looks a lot like progress. The baseline assumption though is that the figures are comparable. Given my experience of the Kinetic, I'd say that they are. Whether that 300W is actually 300W, or 280W or 320W, is less relevant; the process of doing a roll-down test before each session has delivered very consistent numbers for me. 300W on the trainer feels the same, and does the same things to me in terms of tiredness and heart rate, in a repeatable way.

The app allows you to define a series of data screens, with a frankly dizzying array of figures and metrics to put in the nine available slots. I won't list them here as there are too many, but it covers all the various ways you could describe speed, heart rate, power, time and intervals. You'll certainly be able to find the ones you want. You can leave slots empty if you want less data. You can set up heart rate and power zones for zonal training.

Once you've finished your session you can set it to automatically upload to Strava or TrainingPeaks, to keep track of your progress. I've been uploading to Strava, and the data the inRide app spits out is impressive. There's a few odd spikes in the speed graph (which seem to happen at consistent intervals), but other than that the data is excellent. The grab above is of a 8 x 3-minute interval session with a rising effort warm-up. Depending what training package you like to use, you can analyse your rides with whatever tools are at your disposal. I primarily like to just keep a record of what I've done.

The inRide kit, and app, bring a new dimension to the Rock and Roll. Where before it was a brilliant tool for the kind of person who likes to dedicate a winter to indoor riding and isn't too bothered about the numbers, inRide makes it a fully featured power trainer with simple sharing to your training tool. It's a really compelling package if you're not after video training or hill simulation.

It's not cheap though. £175 for the inRide kit seems a bit over the odds. Okay they've had to develop the app but the basis of that app – the power algorithm – already existed when the first Rock 'n' Roll came out. And the two Bluetooth sensors have a combined value of about £70. Given that, it's difficult to justify the full retail price, even though it does an excellent job. I've far fewer qualms about forking out £400+ for the trainer itself: it's an excellent unit that's built to last, with about the best ride feel you can get.

Verdict

As good a ride feel as any indoor trainer, and now with the option to measure power via your iPad or iPhone