The turbo trainer

As the resistance of my existing fluid trainer (an Elite Crono Fluid) is dependant purely on speed, I’d need another trainer to base this project on. I briefly considered an eBay cheapie, but thought it was unlikely to be a satisfactory experience, even before getting to any modifications.

So looking for a mid-price trainer with a cable operated resistance lever, I settled on the Tacx Blue Motion 2600. This trainer has the new frame design from the Blue series, but uses the same resistance unit as found in the older Satori model. I managed to pick one of these up for £135 shipped.

For what they’re worth, my initial impressions of the Tacx after a quick spin are;

Good – Smooth. More flywheel weight than the Elite. Stable. Probably a bit less flex in the frame.

Bad – Manually adjusting the roller pressure (I prefer design of the Elite, where rider weight provides the pressure on the roller). More tyre slip (vs the ElastoGel roller on the Elite). Noise, not sure whether it’s actually any louder, but it sounds a bit rattly.

Next up, taking it apart…lever2

There were no obvious screws around the resistance unit, but the lever assembly dismantled relatively easily. After removing the resistance lever, and using a small screwdriver to prise the black cap off, the cable nipple can be pushed out of the slide, and the whole cable pulled free. The original 10 steps of resistance are a factor of the handlebar lever.

Google turned up some useful information and photos for dismantling the resistance unit, but I haven’t needed to do this yet. The pictures linked from the above forum posting show how the sprung loaded magnet slides out from the centre to the edge of the flywheel.

Next step was measuring the travel of the cable and the force required to move it. Full adjustment required 30mm of cable travel, and a peak force (at maximum extension) of about 5KG. Ok, kilograms aren’t a unit of force, but are hopefully more intuitive than Newtons!

Next post will cover thoughts on motor selection, and a first prototype.

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