(I hope this isn’t a massive disappointment after my earlier thread, but I was very impressed myself….)

So, what is it?
Basically, CVT (Continually Variable Transmission) for bikes.
It’s something I’ve thought about, knowing how well it works on scooters, but this is the first time I’ve ever seen anything that will fit a bike, although it’s been around a couple of years apparently…..

It’s pretty heavy and bulky as it is, but with a bit of luck they’ll develop it and lighten it up a bit.
So, some pics. That’s my hand you can see there….

The drive side. Takes a standard Shimano-fit sprocket, or a Gates belt drive sprocket apparently…. The small cable housing fits this side

Untitled by PeterPoddy, on Flickr

Non drive side takes a standard 6 bolt disc.

Untitled by PeterPoddy, on Flickr

The twist shifter

Untitled by PeterPoddy, on Flickr

And when you ‘change down’ the little man goes up a hill! 🙂

Untitled by PeterPoddy, on Flickr

Talking to the owner, he thinks it’s aimed more at the commuter market, but he’s fitting it to an MTB and taking it to Wales to give it some stick soon. He says it’s been tested using an electric motor, and towing a bike laden to 200kg, so it should be tough enough.
It cost him around £360, so not expensive IMO.

It fits in a standard MTB frame and dropouts, and the cable housing is very small and neat, and it looks like it fits INSIDE the frame to me, not hanging off the end of the axle.
Apparently is somehow possible to choose a cadence, and have the hub shift automatically to keep that cadence, too. I imagine that’s some sort of electronic control, but I don’t know.

I’ve not picked up a Rohloff wheel to compare, but it is a heavy thing, no doubt about it.

http://www.fallbrooktech.com/nuvinci.asp

Now you’re all going to tell me this has been done on STW 100 times before, no doubt…? 🙂

They weigh a ton, until they can reduce that its got no chance.

CVT, interesting.

I think they’re all mechanical, rather than electronic – they react to torque.

In cars they always ahd a reputation for being fairly inefficient (even by auto gearbox standards) so be interesting to hear how they feel on a bike.

Got a free rent of a bike with one of them in Geneva, worked pretty well, didn’t strike me as anything special atthe time though, was on a utility/shopper sort of bike.

They weigh a ton, until they can reduce that its got no chance.

Don’t care,

They said that about dereileurs initialy.

And I like the shifter!

I was quite impressed myself, as is the owner, and he seems to know more than most about mechanics and bikes, and making components.

It’s pretty heavy and bulky as it is

and inefficient?

How does it work in practice? When you hit a steep hill it immediately changes up (down?) the gears? The shifters are to overide it??

I was stopped on a training ride by a chap riding one of these, it serves a purpose – if you’re not quite fit enough or able enough to ride the distance you wish to on your bike, i.e. a commute, or wish to not use a car or public transport; it could be a very useful tool.

Very heavy, and not exactly cheap at about £1000 for the one the chap who stopped me had.

PS. I did race him on a hill.

Any idea of the gear range?

Of course most users who end up with such a device will probably set it to the top or the bottom or roughly in the middle.

How does it work in practice? When you hit a steep hill it immediately changes up (down?) the gears? The shifters are to overide it??

AFAIK you just use the shifter as normal.

Rickon – are you thinking of a motor? Not sure a different gear shift will make you ride further.

One I used worked like a normal shifter but with seamless change, had a pretty good range too, plenty wide enough for around town anyway

Nah thanks…

I remember reading about these a couple of years ago – don’t they use some kind of fluid/oil that changes viscosity under pressure?

2.8 kg apparently.

Ellsworth are using them in this

Ellsworth have been using them for that cruiser bike for a few years now. Planetary drive or whatever.

I’d love a go on this though I never really notice the gaps in gears so maybe its not for me.