's Forum Archives - General

Archive Home >> General(1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 )

Rotorsystems. New cranks to eliminate dead spots.(9 posts)

Rotorsystems. New cranks to eliminate dead spots.Sintesi
May 24, 2002 9:17 AM
I don't know if any of you read Procycling but they have a little article about the new Rotorsystems crank. Similar to the Shimano Biopace chainrings, the system is designed to eliminate the dead spot at the bottom of the stroke. It does this by allowing the cranks to move a few degrees off of 180 of each other so you can be already pushing down on your new stroke before the other leg has reached dead bottom (6 o'clock) thereby assisting that leg as it pulls back up.

Here's a link to the Spanish manufacturer's site. Looks interesting if nothing else.
re: Rotorsystems. New cranks to eliminate dead spots.atpjunkie
May 24, 2002 10:16 AM
interesting, but been tried in a couple forms. I'll stick to round rings for now.
These have been ridden to victory at..Sintesi
May 24, 2002 10:29 AM
the tour of majorca (actually KOM), Ruta del Sol, and 4th at the tour of Valencia. Of course this is not proof that these things improve power output by 16% as claimed but at least it is being utilized with success in professional competition.

It's hard to imagine something like this catching on tho.
If these things become popular, does that meanAllisonHayes
May 24, 2002 10:37 AM
we will all become roto-rooters? (Sorry, couldn't help it. I know, stupid joke but I have been having brain cramps all day.)
re: Rotorsystems. New cranks to eliminate dead spots.Vrock
May 24, 2002 3:48 PM
Well, I demoed the system last Weekend and I can assure you that it's not comparable with Biopace rings. IMHO Biopace rings are not that diferent from normal rings.

With the rotor system you feel "A LOT" of acceleracion between the 6 o'clok position and the 12 o'clock position but at the same time, the other crank is spining slowly (It's a weird thing the first time you use it). I don't know if it is is good or bad, and I'm pretty sure that you're not going to be a 16% faster, but it's a truly innovative system. With this system you don't need to focus on a round cadence because it eliminates the dead spot, but on the other hand, it demands stronger cuadriceps. You have push hard on the downstroke and relax in the rest of the cycle.

re: pushing down hard on the downstroke...guido
May 24, 2002 8:20 PM
And we know what hammering did to Jan Ullrich.

Cycling with round chainrings is what spinning is all about. Nobody is going to tell me if you put out 200 watts of effort it will somehow amount to more watts if the dead spot is eliminated. If the deadspot is gone, the legs feel the burn throughout the whole cycle, so you'd slack off a bit, and end up burning the same power. Otherwise, you'd blow up, non? The dead spot gives your legs that fraction of a second to recover.
the idia iscyclopathic
May 25, 2002 6:49 AM
that there's an "optimal" muscle contraction speed. Going much slower at the top or very fast at the bottom is very inefficient and causes losses.

Theoretically absolutely "optimal" system would increase efficiency by 24%. Unfortunately it isn't possible to build one it won't work for all conditions.

So to answer you question the gain comes due to higher efficiency not higher load.
Cool.Sintesi at home
May 25, 2002 3:28 AM
Where did you try it, if you don't mind me asking?
It seems that it would have a clunky feel when your "up" leg (for lack of a better term)went over the top without much resistance and then suddenly engage on the down stroke. But all quads, eh? That doesn't sound too efficient.

The team that was using it in Spain, Relax, said it worked pretty well but getting the legs to adjust to the new style had its consequences in increased muscle soreness that went away over time.
In Madrid...Vrock
May 25, 2002 6:22 AM
I went to Madrid to Watch the first event of the Mountain Bike world cup (I live in Spain) and there was a Rotor Test-zone near the boxxes.
The Relax Fuenlabrada is not the only team using it, There is a Mountain bike team too. Juan Carlos Garro is using it, and he has won a couple of races in the Spanish Cup. Of course I'm not going to say that he won because he is using Rotor but I think that the system is worth to try.