Ducati Sporting Club UK > General > Idle Chat > Reverse Rotating Brake Disc Rotor - GEEK TIME !

[Iconic944ss]

As also spotted in MCN...

Interesting website:

http://www.reverserotatingrotors.com/index.html

Frank

[chicken]

that looks fablus. Given my lack of upper-body strength, I'm going to buy two!.

[Scotty Monster]

sounds like bollx is you ask me

[chicken]

I'm no expert and I fully expect Shazaam to pop up and work this out but doesn't it depend upon the relative weight of the wheel (and tyre) moving forward compared to the two discs that are moving backwards (adjusting for the larger diameter).

There might be some power loss as the friction from the gears will be higher than from bearings in a standard wheel but that would be an acceleration issue not a steering one.

Not that long ago powered flight was thought to be impossible.

[skidlids]

Does it effect the unsprung mass of the bike, ie does it make the front wheel heavier and therefore have an adverse effect on the suspension.
Do I have to read 10 pages in to find this information or is it not mentioned

[Jools]

With the discs turning faster than the wheel they MAY just cancel out the gyroscopic effect of the wheel and make the steering constant effort (although I'm not sure that I'd want lightweight super sensitive steering when I turned in to a very fast sweeper - I think that the weighting of the steering helps here).

But they've got to add to the unsprung weight of the wheel and largely negate any perceived advantage of steering effort by making the wheel less able to track over the road and harder for the suspension to control.

So on balance, I think I would prefer to stick with lighter wheels to ease steering and reduce unsprung weight.

To be honest, I think these will go down with hub centre steering as a good idea in theory but too complex in practice.

Mind you, hub centred steering AND reverse discs now there's a thought

[Scotty Monster]

reet im no matematition or owt like that but how the hell does one spinny thing cancel another out. you still have the same amount of rotating mass and hence surly the same gyroscopic forces ?

[Iconic944ss]

Erm...lol...dunno

I feel a 'Homer' moment coming on right now - however, here is some nice reading from my choice website at present: Wikipedia

http://en.wikipedia.org/wiki/Gyroscopic

(check out the link on 'Countersteer' as well.

F

[Jools]

So, in a nutshell the mass and rotation speed of the wheel will generate torque that acts perpendicular to the axle, which is why the bars get harder to turn because there is more torque the faster the wheel turns.

By spinning the discs in the opposite direction it will also result in torque - but acting in the opposite direction to that generated by the wheel, so it will cancel out the torque that's acting on the axle. The discs are lighter than the wheel, so they won't generate as much torgue for a given rotational speed, but if you spin the discs faster than the wheel you can counteract almost all the torque that the wheel generates.

The faster the wheel goes, the faster the discs turn to oppose the torque on the steering generated by the wheel, so in theory, the bike's steering should be equally weighted at 10 mph and at 100 mph or even faster. You probably wouldn't want to cancel out all the torque otherwise the steering would feel weightless and give no feedback.

That's as I understand it. I still think that the idea is too complex and too much of a compromise because it will also make the wheel heavier and more difficult for the suspension to control

[Scotty Monster]

blinded by science