Kurt Kinetic Rock & Roll Road turbo trainer

There's a turbo trainer for every pocket and every style of rider out there. If you've got deep pockets and some money to throw at an indoor trainer and you're more of a quality or experience than quantity of stats kind of a person then you could do a lot worse than American outfit Kurt Kinetic's top end unit the Rock & Roll. There's no bells and whistles but the ride experience is right up there among the best, and if you're planning some long sessions it's certainly built to last. The ability to move the bike around adds an extra dimension to the training, too.

Your first workout will be getting the thing in the house and up together. All turbos are not made the same: at 19kg the Kurt is a true behemoth and at 121cm wide has a footprint twice the size of a normal triangular-framed unit, so if it's replacing an old machine in a confined space you do need to check it'll fit. Putting the steel frame together is easy, as is attaching the resistance unit. The QR clamp is wide enough to take a standard Shimano unit although you may want to swap for an old one to avoid scratches.

The most obvious difference with the Rock 'n' Roll, other than its size, is the elastomer sandwich that allows the bike to move from side to side when you're training. The instructions show you the process of tightening the bolts to the correct load although by following them to the letter I ended up with a rear wheel touching the carpet; luckily i noticed before I wore a big hole in it. The position of the bike, and the amount of movement, can be adjusted by tightening or loosening the bolts.

There's a big difference in the resistance unit too, though that's not so obvious. Kurt make great play of the fact that other fluid filled turbos are prone to failure at the point where the shaft enters the fluid bath. They're mostly well sealed, of course, but it's a weak point and Kurt claim their punishing in-house tests with their cadence robot, Crank Armstrong, can break a competitor's resistance unit within hours. Theirs, on the other hand, has logged over 40,000 miles without a problem. So, what's the secret? Well, the Kurt resistance unit is in two parts – a flywheel and a fluid chamber – that are magnetically coupled, so the fluid section is independent of the flywheel. The magnets are strong enough to cope with more torque than even the robot can supply, so you won't uncouple them on the sprints, and there are no seals to wear and fail. It's a simple and very elegant solution.

The Rock 'n' Roll uses a silicone fluid that keeps the same viscosity regardless of temperature, not that that's a problem as the cooling fins do a good job of keeping the Kurt fairly cool; it's warm after an hour but not hot. The designers spent a long time working on the power curve of the trainer and called upon the help of bike analytics über-brain Tom Compton of www.analyticcycling.com to come up with a curve that simulated an 'average' rider. Kurt's website is full of equations and fairly intense tables that show you what power is being generated at what speed, and you can get computers that work with the trainer to calculate your power output while giving you a host of other functions to use both on and off the turbo. There's a wired unit with all the usual computer functions (including cadence) and a wireless one that adds an HRM and an altimeter, so if you're after numbers you can have them as an optional extra. They'll stay on the bike though: neither computer can download the training info to your PC.

I'm happy with this up to a point but by adjusting the contact force and tyre pressure on my bike I was able to repeatably influence the roll down time from 20mph by over a second: clearly the speed of the roller isn't the only factor affecting resistance in this system. This didn't surprise me, and it rather makes a nonsense of Kurt quoting power down to the thousandth of a watt for a certain speed. I've taken their chart and rounded the numbers up or down to the nearest 5, and this makes it a whole lot easier to read without really affecting the accuracy: it's not like you can pedal at exactly 20mph for any length of time. I'd have to say the the numbers they do quote look to be pretty believable: while I can fairly comfortably manage a 2x20' session at 20mph (260W) it's a real struggle at 21mph (290W): about what I'd expect given my current level of fitness. The resistance is repeatable too, giving you a basis for RAMP tests and other nightmarish fitness markers through the season. The turbo comes bundled with a 'Threshold Test and Suffer Fest' DVD that you can use for this though I found it a bit, well, American.

The Rock 'n' Roll is very quiet in use, and the ride feel from the 6lb flywheel is really excellent. The power curve flattens out to very low resistance at low speeds and ramps up very quickly over 20mph, so it's great for interval training as well as being buttery smooth for long steady sessions. Climbing isn't so good as the resistance isn't high enough at low cadence – even in a big gear – to get you working really hard. The side to side movement is disconcerting at first before you realise it's actually very natural: when you're tired at the end of a session you start flinging the bike about like you would on the road. It works best with the turntable riser that Kurt supply as an optional extra, as this allows the front wheel to move and increases the feeling of freedom. Because the bike is suspended on elastomers it's much more comfortable than a rigid framed turbo too. I felt much less saddle sore after an hour on the Kurt than I normally do.

Verdict

Overall the build quality and ride feel of the Kurt are what mark it out. If you're sure this is the trainer for you you're unlikely to need to ever buy a second one, especially since there's an unconditional lifetime warranty. It doesn't do anything massively clever but if you're committed to doing the hours and you're not after a more interactive experience from one of the VR trainers then it's certainly one for the shopping list. Solid, repeatable training is the key to winter fitness and the Kurt offers that in abundance.