Cycling UK Forum

In this this video (Italian, you need to enable english subtitles), a recumbent bicycle is in use, modified to be encapsulated in an aerodynamic shell and to exceed 100km/h

From what I understand from watching the video, the derailleur is Arduino-based, with (likely) servo-motors that move the entire sprocket set.

Does anyone has any detailed documentation about this special derailleur?

it isn't an entirely new idea; long ago, there was an english derailleur which maintained a near-perfect chainline by shifting the sprockets from side to side.

Nice! I got two of the words in the title - extreme recumbent... and they're not kidding!

Brucey wrote: ↑3 Jun 2024, 2:21pm it isn't an entirely new idea; long ago, there was an english derailleur which maintained a near-perfect chainline by shifting the sprockets from side to side.

Trivelox, it was called; with a jockey wheel chain tensioner.
Hollow axle and SA style toggle chain to move the sprockets. I’ve only seen them on tandems

Was it unlucky? Or did it have any defect?

And don't forget the Elswick Hopper Vampire Convincable, which moved the chain wheel side to side.
Those silly French derailleurs sap the power of English men with their crooked chain line.
So keep your chain straight.
https://bikeville.net/wp-content/upload ... e9-189.jpg

Googling, found a few lines about the Trivelox, here and here ... It was a 3speed made in 1936.

Extreme recumbent indeed. They say that in the highest gear, it moves 25 meters with a pedal stroke.
Mamma mia!

It's an italian university team based in Turin, more info here https://www.policumbent.it/it/contacts/

531colin wrote: ↑3 Jun 2024, 3:26pm

Brucey wrote: ↑3 Jun 2024, 2:21pm it isn't an entirely new idea; long ago, there was an english derailleur which maintained a near-perfect chainline by shifting the sprockets from side to side.

Trivelox, it was called; with a jockey wheel chain tensioner.
Hollow axle and SA style toggle chain to move the sprockets. I’ve only seen them on tandems

I have a PRACTICAL MECHANICS magazine from July 1952 that features an article detailing how to convert a Tri-Velox three speed gear to a four speed.

LUXUARY !

The big S has patented an enclosed gearbox using 2 cassettes which can be moved along shafts to give a range of gears. Coming in the future.
https://www.emtbforums.com/threads/shim ... -mtb.8679/

Brucey wrote: ↑3 Jun 2024, 2:21pm it isn't an entirely new idea; long ago, there was an english derailleur which maintained a near-perfect chainline by shifting the sprockets from side to side.

Trivelox. I had a 3 speed 1939 tandem so fitted. The block moved, chain line constant. Improvements in chain technology during WW2 were such that when company restarted post-45 it used a moving chain line!
I recall it as a tricky thing to restore!