Minoura RDA ‘Rim Trainer’
Contact: Zyro 01423 325325
Steel A frame trainer using rim driven magnetic resistance controlled through remote handlebar lever.
Test logbook: One hour varying intensity ride in the workshop.
We’re as sorry as you are to be testing turbo trainers just as spring starts to get underway. But seeing as we’re not allowed out to play on our trails, getting the stationary miles in at home may be the only way to offset utter despondency and feeble fitness when we’re allowed back out. So dig out your old mountain biking videos and get home training.Minoura RDA ‘Rim Trainer’
The traditional problem with home or “turbo” trainers is their need for a slick rear tyre to run on the smooth resistance roller. This means changing tyres every time you want to workout on your mountain bike, but not with this cunning device
As the name suggests the Rim trainer uses two sprung rollers that run on the rim wall rather than the tyre, meaning you can leave your knobs on. A belt drive from the left hand roller links to the adjustable magnetic resistance unit and its small balancing flywheel. This magnetic unit uses a standard shift cable to connect to a remote handlebar mounted control lever, so the workload can be changed while you’re riding.
The RDA uses a big rectangular and tube section A frame that can be folded for storage (though the resistance unit still sticks out) with fat soft rubber feet to keep noise and vibration to a minimum if you’re using it on a non-solid floor. The rear axle is held firmly in two cups which are wound in and out with chunky plastic handles to get the wheel centralised. Different sized wheels are accomodated by unbolting the roller units and sliding them up either side of the frame and there’s enough adjustment for 700c through to 26″ wheels.Riding the rim
Although you can leave your knobbliest tyres on, the first thing to point out is that they need to be fairly clean. If they’re covered with mud, as you accelerate, traces of your last ride will separate from the tyre and splatter round the room at high velocity. The other caveat is that the rollers won’t have enough purchase on disc rims that don’t have a sidewall. To stop the rollers from skipping, sliding and growling you’ll also need to clean any mud or brake block residue off the rims as well.
Even with them cleaned it takes a few minutes for the rollers to warm up enough to stop them skidding under sudden acceleration, but at least this means you can’t go flat out until you’ve warmed up properly.
Once you’re rolling, the use of standard mountain bike gears and the ‘remote control’ covers a full range of exertion levels. The ‘hard’ setting (of 7 possible options) is enough to destroy your legs in seconds, and the frame is stable enough to handle out of the saddle moments. The only flaw is that the action can be slightly choppy if you’re a pedal stamper, so learn to smooth your stroke – it’s better ‘real bike’ technique anyway. At the other end of the scale, the easy setting lets you spin through smoothly to recover, however busted your legs.
Thanks to the magnetic resistance and rim action noise is low, running from steady hum to low whistle at full tilt, but we’d still recommend using it on a tiled or concrete floor to minimise vibration disturbance of the neighbours.
Verdict: A great option for those who want convenient indoor mountain bike training. Simple and straightforward to set up, with a useful handlebar mounted control and quiet enough to keep the neighbours calm. Slight slippage problems mean it’s not for the most musclebound sprinters, and it won’t run on disc rims, but it’s a tough, stable trainer that’ll serve you through several winters or outbreaks of trail closing diseases. Remember to get the big lumps of mud off the tyres before you use it though.