How cheap ?! (Any fixes)

Why bother? Any enthusiasm for using the device will wane 1000 times quicker than the life expectancy of the equipment.

Are we talking about a Dyson, or Apple?

Ain't that the truth.

I think any cycle simulator that uses a simple friction device and without any sort or flywheel is going to be horrid to use. Unless one has a compelling reason to *only* exercise ones legs whilst seated in a chair I can't see any reason to use a device like this.

Tim

SWMBO has MS can can't walk.

Rather than a ball bearing I would be looking for an insert which spreads the load and which would be less likely to score or wear the main shaft. Simplest might just be a little brass plug, or perhaps replace the whole screw adjuster with brass studding. Alternative materials, phosphor bronze or a fabric reinforced thermoplastic like Tufnol. "Ordinary" plastics are likely to have a low friction coefficient and may well melt if you are working them hard.

I can't help thinking you might need to tighten it every 30 seconds if it was providing a reasonable amount of resistance. A better design would have a coil spring between the screw and the rubbing pad to compensate for wear (rather like brushes in an electric motor).

Can she sit on a saddle or do other weight-bearing exercise (supported/steadied with her arms if necessary)?

Tim

Semi circular plate between screw and axle? With a thick piece of PVC sheet in between?

I looked for similar devices on Google image, and they're ALL like that. Which makes me think that the screw does not press directly on the shaft, but on an intermediate friction device. If the screw impinged directly on the shaft, the full range of resistance would be contained within a few degrees of rotation of the knob.

Or attach to a generator to charge up your power tool batteries.

Brian

Yes I know. I'd probably use something more if all my excersions were actually charging batteries, for example rather than just heating up a break pad or in this case screw. Brian

Yes well, no comment on that. To be fair to Dysan, I've never had any problems with their gear, and many friends have found them very nice if something does go wrong. Also Apple do have a free helpline for blind people using their products and a dedicated team of customer service trained people at their shops. However service is very hard to justify when it impacts price and many people seem happy to have el cheapo stuff if it works just about well enough for what they want. Brian

I have to say that this was my thought too, but the OP said he had seen the bits pre-assembly. I agree that a much better design would be to have the screw pressing on a stiff spring which pushes something like clutch or brake pad material.

Have the screw press e.g. a roller skate wheel against the axle hard enough to deform it. There's still not going to be much resistance, but AIUI this sort of device is more about helping mobility and circulation than it is about building strength/fitness.

Totally possible, but requiring the space and funds for a "proper" exercise bike. Nothing insurmountable, but even SWMBO would be the first to admit that over the years she's said she would find loads of things useful which are now gathering dust in the garage ....

The only path to the axle is the threaded guide.

Maybe a plug of high-temperature melting point plastic between axle and screw ? Although we'd probably be setting the smoke alarm off :)

I can't speak for all, but this one is definitely metal-on-metal. And yes, the "adjustment" is pretty much "on" (briefly) or off.

This is an endemic problem these days. Yes, the thing was cheap - but then it doesn't really do the job (see also cloths that last a few months, shoes that last less than a year, paintbrushes etc).

It wouldn't matter so much if there was a way to pay "a bit extra" for longevity or suitability. But those days are long gone.

Oh agreed. SWMBO actually has quite good strength from years of "paddling" the wheelchair, rather than using the arms. The current ambition is to keep the ligaments stretched, so that a step or two is possible if needed.

If you can take two steps (i.e. on a staircase) then all of a sudden 80%+ of the world becomes accessible to someone in a wheelchair.

Maybe there's enough clearance inside to mount a bicycle brake pad on the end of the adjustment screw, such that the pad presses against the axle.

And after the bollocking I got for buying the OH a torch last Christmas (not a romantic present apparently) I now know what NOT to buy her this Christmas:-)