This is IDENTICAL to the UltraFIT mini - bike, found elsewhere on Amazon -
Ultrafit Mini BikeOn one I received today, the tension device does not work, and NEVER WILL without modification. Due to POOR design, assembly or QC procedures the threaded bush is incorrectly attached to the brake arm assembly (viewed through the meter orifice).
The tensioner goes through the outer case and into the 'brake' tension arm. The idea being as you increase (+) tension the brake arm moves forward onto a friction material belt on the main flywheel, causing the pedalling to be harder, and (-) reverses the procedure. Simple but effective?
Well it would be except for the fact that the 'threaded bush' has been made a 'push fit into the 'brake arm', so, instead of moving the arm forward, the bush simply pushes out of it's hole.
This can all be viewed happening quite easily.
Remove the meter, just as if you were replacing the battery, and 'hang over the side out of the way'
Tilt the machine backward so that you can see the tension screw thread and 'brake' arm, (a torch is handy here).
Turn the tension knob fully clockwise, and watch the black bush that the tension screw goes through.
You will see it 'pushing out' of the grey painted 'brake arm. Screw counter clockwise and the bush is 'pulled' back into position.
I have emailed the German supplier with the above information and returned the product to Amazon for refund.
It's a shame really because the rest of the build seems quite sturdy and the little computer works fine. OK the supplied computer battery was flat, but it is only a single AAA.
I would buy another AND give it at least 4 STARS!, if Amazon or the supplier could guarantee that the problem has been addressed, but it 'looks' Chinese in origin and though a simple spot weld would fix the issue, even if that happened, there are probably at least another five container loads of dodgy ones in the pipeline.
Ce la Vie!