Interesting and odd

[Ouiji Veck]

I don't know what to think.

Is it worth the unsprung weight, assuming it works at all.?

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

[Guest ratchethack]

Hmmmmmmmm......Irascible Curmudgeon here. Interesting, yes. But it looks like another worthless gimmick to me - at least from a Road Geez perspective.

 

Consider:

 

As you mentioned, Weej, it not only adds unsprung weight, which would seem to offset much of the benefit of reducing precession and gyro effect.

 

Like so many other gimmicks, any benefits at all would seem to be realized only at triple legal speeds...

 

You'd think the factory engineers who design racing chassis and suspensions would've been using it long ago if it had real value on the track...

 

I. C. signing off...

[Greg Field]

I think he's onto something here.

 

Mny of the last really high-performance prop planes had counter-rotating props for this very same reason.

 

It was most definitely worth the weight and complexity.

 

This is the first truly original idea in bike design I've seen in many years. I wish him luck!

[Ouiji Veck]

I really love "out of the box" thinking..( Burt Rutan is my hero)

but this looks a little convuluted...un like perimiter rotors which just

looks right.

Yea Greg...counter rotating props on boats and planes works real

good. Like I said I love that kind of thinking.

While working on a friends RC hellicopter I came up with the

ingenious idea of vectoring the exhaust of a Huey and get rid of the

tail rotor..all by myself. Of course my bright idea was 15 yrs. late

for the NOTAR. Oh well...back to the drawing board.

 

I've also spent my lifes savings on "great ideas" twice now.

Ideas are easy. Bringing something to market is another story.

1% inspriration 99% persperation 500% money.

[dlaing]

I think it is great idea!

Increased rotor speed for better braking!

Less front wheel gyro force will help at the "legal" speeds we ride.

This idea will have to be proven on the race track.

Already Yamaha is dominating GP with reverse rotating engine(Rossi on the bike does not hurt)

Reverse rotating front rotors is an even better idea because it more directly effects your steering and is not dependent on engine RPM.

Although I suppose there are some downsides like more expensive, increased sprung weight and increased drag.

I would be happy just going to lighter wheels.

[Paul Minnaert]

it's interesting, I can tell that having a lighter front wheel, made my bike steer much more easy at speed.

[helicopterjim R.I.P.]

It isn't new. Keith Harte ran something similar back in the early 80's on his racing Pantah's. Paul McMillan said it really changed the way the bike leaned into corners, the braking was more sensitive and stronger and it also seemed to have a bit of anti-dive effect . Unfortunately it was protested so they had to stop using it.

[dlaing]

Unfortunately it was protested so they had to stop using it.

85482[/snapback]

Good Grief!

Is there any racing class that is unlimited other than mandating no more than two wheels and a twisty race track?

[rocker59]

The concept has been around for decades.

 

HD/Aermachhi used a similar system on racers in the 1970s.

 

There is one on display at Barber's Museum in Birmingham, Alabama...

 

Its on a front wheel stand. Spin the front wheel and watch the brakes go backwards. Fun, fun!

 

Great idea, but too heavy and complex to be workable on race bikes. That is why its been 25-years since anyone has used the system.

 

I would bet that Performance Machine, or some other HD farkle producer, will be putting them on choppers before they see any use on sportsbikes or racebikes.

 

Some spinners and counter-rotating brake rotors would contrast nicely on the next OCC 'theme bike'...

 

<_>

[Steve G.]

Wouldn't the heat build up of the rotor going literally twice as fast as normal [because it's going backwards] cause issues with fluid temperature, ie, fade?

Ciao, Steve G.

[helicopterjim R.I.P.]

Wouldn't the heat build up of the rotor going literally twice as fast as normal [because it's going backwards] cause issues with fluid temperature, ie, fade?

                                                                        Ciao, Steve G.

85516[/snapback]

 

Not that I remember on the race bikes. They were very favoured by the 2 riders who used them but only in sprint races as I recall.

[helicopterjim R.I.P.]

Hmmmmmmmm......Irascible Curmudgeon here.  Interesting, yes.  But it looks like another worthless gimmick to me - at least from a Road Geez perspective. 

 

Consider: 

 

As you mentioned, Weej, it not only adds unsprung weight, which would seem to offset much of the benefit of reducing precession and gyro effect.

 

Like so many other gimmicks, any benefits at all would seem to be realized only at triple legal speeds...    

 

You'd think the factory engineers who design racing chassis and suspensions would've been using it long ago if it had real value on the track...

 

I. C. signing off...

85448[/snapback]

 

You are probably very right from a typical street riders perspective and from a racers perspective it would be on lots of bikes if it made a difference (although Paul mcMillan thought it did) but there are a lot of riders who only consider glitz, bling and 'I'm more technical than you' so there just may be a market for it!!

[dlaing]

Wouldn't the heat build up of the rotor going literally twice as fast as normal [because it's going backwards] cause issues with fluid temperature, ie, fade?

                                                                        Ciao, Steve G.

85516[/snapback]

Potentially yes, but you could and probably should use a more massive or better ventilated rotor. Because it would be decreasing not increasing steering resistance, it would not be a big problem to go with 5mm thick Brembos

....but unsprung wait is another issue.

Compare it to rim mounted brakes

where brake leverage is similary increased, as is cooling area, but it is all at the expense of increased steering resistance.

[Guest ratchethack]

Wouldn't the heat build up of the rotor going literally twice as fast as normal [because it's going backwards] cause issues with fluid temperature, ie, fade?

                                                                        Ciao, Steve G.

Weej was right about how interesting this is. It got me thinking, too.

 

I haven't seen detailed drawings - they seem to be suspiciously absent at the Web site, despite a colorful 3D "cutaway" rendering that omits the simple, but critical working parts.

 

But if you look at the "background" shot on many of the pages at the site (presumably this has something to do with it ), you see 4 planetary gears radially arranged and meshed inside a large internally-toothed gear. The planetary gears would presumably all mesh with a single central gear driving the rotors. This would be the working principle. I can visualize this, and it would certainly work logically.

 

With this design, my understanding of mechanics and physics tells me that the rotors spin at the same speed as normal rotors, but in the opposite direction. Now relative to the velocity of the wheel, their speed is double - but speed relative to the wheel is irrelevant. It's only the speed relative to the fork and chassis that counts here, and this is the same as stock.

 

In any case, by the First Law of Thermodynamics, and discounting frictional losses of all those gear teeth and their bearings, the temperature of the rotors, pads, and calipers will be neither more nor less than directly proportional to the amount of work they're actually doing in slowing the bike, regardless of the speed of the rotors - and this would be true whether they rotate at the same speed or any ratio thereof. In other words, the amount of heat generated is directly proportional to the stopping force ONLY, regardless of angular velocity. So regardless of speed of the rotors, I would not expect any problem with heat over that of stock brakes.

 

Capiche?

 

Now why you'd need 4 planetary gears instead of 2 - that's just plain beyond me, since any more than 2 (to balance the hub) would seem superflous.

 

In any case, it's a considerable pile of hardened steel parts - gears and bearings - added to the hub. For our purposes, if you thought the unsprung boat-anchor bevel drive of the V11 created a handling problem at the rear - how about adding another unsprung boat-anchor at the front???

[Guest Nogbad]

It's bollocks.