Automatic transmission

liviu_serbu

Hi, I have this proposal for debate:
https://www.linkedin.com/pulse/bicycle-transmission-continuously-self-adjusting-gear-liviu?utm_source=share&utm_medium=member_android&utm_campaign=share_via

gethinceri

Not a new idea, but maybe your engineering is unique. The problems you experience which you believe need to be solved are very minor indeed.
It’s been done before, it isn’t widely done now. There’s a lesson in that.

First.Aspect

It is fairly well known set of benefits. There's even a video of a Williams F1 car equipped with one online, which despite the extra weight, would certainly have been faster. Hence it was preemptively banned by the FIA.

For competitive cycling I think the added weight and transmission losses would render the idea pointless. And, if it wasn't pointless, it would be banned by the UCI.

CVT does have a place in leisure cycling, probably for ebikes, but even there it's struggled for market share.

For example, ever hear of Nuvici hubs? https://calfeedesign.com/store/NuVinci-CVT-Hub-p430673625

Which is my point - they've existed for 15 years at least.

DeVlaeminck

Can someone delete this thread in case the bike industry get ideas and within 5 years it'll be hard to buy a bike without it.

trevor.hall12

I remember seeing a shimano steps ebike doing auto shifts depending on the torque on the pedals .

pblakeney

I predicted auto shifting on electronic group sets years ago.
The user sets predefined cadence shifts.

First.Aspect

The article is talking about some form of CVT, not a bike equivalent of an automatic car.

pblakeney

First.Aspect said:

The article is talking about some form of CVT, not a bike equivalent of an automatic car.

True, but CVT has been dismissed for the reasons given above.
End of discussion?

First.Aspect

pblakeney said:

First.Aspect said:

The article is talking about some form of CVT, not a bike equivalent of an automatic car.

True, but CVT has been dismissed for the reasons given above.
End of discussion?

Actually, in some contexts, city bikes etc. it could be really good. Essentially an alternative to a Rolhoff for example. The idea of a constant cadence and automation is borne of a misconception about what a cyclist needs, in my view, but that's not the only reason a CVT drivetrain would be useful.

My understanding of the Nuvici system is that it is really inefficient, and relies on friction between two tangential surfaces, which tend to slip. Were someone to come up with a halfway decent alternative for a bicycle, I could see it selling.

pblakeney

Fair enough but my proposal should be easy enough to implement given the hardware is already there. Software is all that is needed.
The proposed system has merits for low maintenance and probably cost. Good for commuters.

First.Aspect

pblakeney said:

Fair enough but my proposal should be easy enough to implement given the hardware is already there. Software is all that is needed.
The proposed system has merits for low maintenance and probably cost. Good for commuters.

I don't see how automating a conventional drive train reduces costs or maintenance in the slightest.

kingstongraham

Shimano already have some automatic shifting available on e-bikes based on cadence and speed.

kingstongraham

I quite like the idea of the OP if it can work and has the maintenance advantages of a single speed. I guess the front chainring would be a different size to give a different "standard power" for a given cadence?

MidlandsGrimpeur2

What is the Alfine di2 internal hub and how does it differ from what the op is suggesting?

gethinceri

MidlandsGrimpeur2 said:

What is the Alfine di2 internal hub and how does it differ from what the op is suggesting?

The Alfine Di2 hub exists.

pblakeney

First.Aspect said:

pblakeney said:

Fair enough but my proposal should be easy enough to implement given the hardware is already there. Software is all that is needed.
The proposed system has merits for low maintenance and probably cost. Good for commuters.

I don't see how automating a conventional drive train reduces costs or maintenance in the slightest.

I meant the OP's proposed system for commuters.

pblakeney

kingstongraham said:

Shimano already have some automatic shifting available on e-bikes based on cadence and speed.

I knew it would come eventually. Seemed an obvious progression.

First.Aspect

gethinceri said:

MidlandsGrimpeur2 said:

What is the Alfine di2 internal hub and how does it differ from what the op is suggesting?

The Alfine Di2 hub exists.

The OP is suggesting CVT (we think). Look it up.

The inference is that the OP is getting a patent application on file before disclosing. This may or may not involve still needing to invent it.

gethinceri

I know. I have.
My inference, from these words....
"so I can provide my collaboration if it proves to be useful, or any other party for this matter, willing to patent it and put it in production."... is that he has idea'd it and wants others to do the rest.

First.Aspect

gethinceri said:

I know. I have.
My inference, from these words....
"so I can provide my collaboration if it proves to be useful, or any other party for this matter, willing to patent it and put it in production."... is that he has idea'd it and wants others to do the rest.

Hard to say, but I suspect he has an early stage idea and no funding. If so, he's doing better than a lot of private inventors by not already disclosing it.

Either way, it's going nowhere unless he can fund it. And no one is going to fund anything unless they know what it is.

It is a common enough catch 22.

focuszing723

https://www.youtube.com/watch?v=5NyTHrEsAyY
Anybody remember CeramicSpeed chainless?

First.Aspect

Remarkable solution looking for a problem.