Oval Chainrings (Q / Rotorings)

[louiso]

Had a chat to some guys in Natal who are using the rotorings on their bikes. According to them an excellent investment as it reduce the deadspot and is really effective on climbs. Must say it looks

terrible.

Any hubbers with some advice or experience with these chainrings.

[Mudsimus]

I know Ivanb is the man to speak to. I'm also look for some info. You dont perhaps have the internet addres for the chainrings?

[Windbreaker]

I've also got a question that MDK555 or one of the other tandem fundi's can answer (not you Big H - you just think you know all the answers ).

 

Why aren't the two cranks on a tandem offset by a few degrees - similar to the angle created by the q rings? That would eliminate the dead spot. Or not?

[Mudsimus]

I also gave that one some thought. I think it will make standing very hard...and it will mean that there will be a point that one rider will do most of the work.

[louiso]

The only websites I could find:

http://www.pureendurance.net/rotor_q_rings

 

http://www.rotorcranksusa.com/i1-q-rings.shtml

 

Trust this could assist you.

[jog5000]

Arent they the same as Shimano Biopace? I thought it was proven that they werent that good.

[Cashandra]

I've got myself a set, and they are awesome, they give me more power on my downstroke, used them for the SA TT and walked away with gold, definitely got my vote of confidence, you have 5 settings on them and can change them depending on the route ( hilly or flat) Put on the new TT version yesterday which is a 54 blade, feels and looks awsome ( solid black blade ) you can contact Ivan ( importer of the Q ring) 073 3735999 and web is www.rotorbike.com  ENJOY.

[BikeMax]

 

I've also got a question that MDK555 or one of the other tandem fundi's can answer (not you Big H - you just think you know all the answers ).

 

Why aren't the two cranks on a tandem offset by a few degrees - similar to the angle created by the q rings? That would eliminate the dead spot. Or not?

 

Quite a few racing tandems do just that - questionable whether it makes any difference.

 

Going faster on a bike is not about pedalling technique - it is about better w/kg.

 

Faster riders do not eliminate the "dead spot" they push down harder.

 

[mdk555]

I've also got a question that MDK555 or one of the other tandem fundi's can answer (not you Big H - you just think you know all the answers ).

 

Why aren't the two cranks on a tandem offset by a few degrees - similar to the angle created by the q rings? That would eliminate the dead spot. Or not?

Yep is does help eliminate the deadspot.  In the USA offsetting the cranks by up 5 teeth is very popular and the general feeling is that it does help especially on the climbs however when it comes to racing (and trust me they are big into racing tandems with up to 50 tandems competing on tight 1 - 3 km circuits) not only are the cranks in sync, but they are shortened by up to 5 cm.  I have seen pics of tandems going thru corners that wil scare the living daylight out of all of us and there can be no room for error.

 

Me versus offsetting cranks versus oval rings -  no thanks as it looks very uncool and rather perfect the full circle (push, scape, pull)

[Bike Tech]

http://www.noncircularchainring.be

 

In case you want to learn more about non circular chainrings, please read above mentioned scientific study. I am looking forward to receive your comments.

 

 

Bike Tech2007-08-19 07:19:22

[BikeMax]

 

http://www.noncircularchainring.be

 

In case you want to learn more about non circular chainrings' date=' please read above mentioned scientific study. I am looking forward to receive your comments.

 

 

[/quote']

 

 

How do you deal with the fact that the limit to cycling performance is cardiovascular, and therefore it is not possible to increase the amount of work done by changing the phase of the pedals (unless you prove that circualr rings see a significant loss of energy in the pedal stroke - which you have not shown)

 

[Barend de Arend]

 

I've also got a question that MDK555 or one of the other tandem fundi's can answer (not you Big H - you just think you know all the answers ).

 

Why aren't the two cranks on a tandem offset by a few degrees - similar to the angle created by the q rings? That would eliminate the dead spot. Or not?

 

Quite a few racing tandems do just that - questionable whether it makes any difference.

 

Going faster on a bike is not about pedalling technique - it is about better w/kg.

 

Faster riders do not eliminate the "dead spot" they push down harder.

 

Depending on the angle, that'll be exactly what happens.  You can't push harder with Q-Ring because its the same legs.

 

However, you can spend more time pushing, and less time moving your legs forwards or backwards.  If the gear is harder up/down and easier forward/backwards you will definitely spend a higher percentage of your cycling time in the power part of the circle.

 

So the net effect is: a higher percentage in the "good" part of your stroke, and a lower percentage in the "bad" stroke.

 

[amdretard]

Here we go again ! *sits and gets the popcorn ready

[Barend de Arend]

 

Here we go again ! *sits and gets the popcorn ready

 

Salt, butter, sugar or plain.

 

[amdretard]

Last time i had salt and it got a bit much ! i think caramel this time []

[dylankeyter]

haha, wow the other one was over 40 posts wasnt it?!