Bicycle transmission...

[Externet]

New design worth sharing for your information...

----> https://www.ceramicspeed.com/en/driven

[Frank]

Cool, but how does it shift?  if the next gear up has one extra point/groove, then the gears are only aligned at one point in the rotation.

 

"In its current form, DrivEn can’t shift between gears, although BikeRadar reports that this could conceivably be managed using a wireless servo to move the rear bearing mechanism fore and aft relative to the cassette." - World’s Most Efficient Bicycle Drivetrain Unveiled at Eurobike | Newfoxy:  http://www.newfoxy.com/2018/07/11/worlds-most-efficient-bicycle-drivetrain-unveiled-at-eurobike/

 

[Frank]

Worlds most efficient bicycle drivetrain?  OK, it's not as practical nor as aerodynamic, but technically...

Penny-farthing - Wikipedia:  https://en.wikipedia.org/wiki/Penny-farthing

 

[John Cuthber]

How (in)efficient is a "traditional" bike chain/ sprocket drive?

[Bender]

23 hours ago, John Cuthber said:

How (in)efficient is a "traditional" bike chain/ sprocket drive?

Between 80-99%, but for a single gear chain or belt drive it's probably close to the 1%.

For recreational or transportation use, it is as pointless as ceramic bearings or a carbon frame, but there are amateurs paying lots of money for those, so why not?

I wonder what happens when some dirt gets on this drive?

[StringJunky]

6 minutes ago, Bender said:

Between 80-99%, but for a single gear chain or belt drive it's probably close to the 1%.

For recreational or transportation use, it is as pointless as ceramic bearings or a carbon frame, but there are amateurs paying lots of money for those, so why not?

I wonder what happens when some dirt gets on this drive?

If you covered up the drivetrain it would keep clean longer.

[Bender]

8 minutes ago, StringJunky said:

If you covered up the drivetrain it would keep clean longer.

I guess so, but the critical part is on the wheel, which you can't efficiently cover (without sealings adding friction).

[StringJunky]

7 minutes ago, Bender said:

I guess so, but the critical part is on the wheel, which you can't efficiently cover (without sealings adding friction).

True.