pcarrasco

a) 55? approx, compared to Biopace (15? compared with Osymetrics and XIX century oval chainrings) b) What means 9.999?... If we were talking about simply 9.9 vs 10, the oval would be so reduced that in fact the chainring is round. What Faniefiets says is correct, but depends so much on the timing for "switching gears". With the Q-Rings we are varying gear twice every cycle, but only choosing the best timing for "switching gears" (using the OCP - regulation ) we can improve performance. In fact a non-proper OCP makes you to go not so good, and an intended wrong regulation makes you to pedal horrible. Then I suppose the conclusion for those of you scientists, is that you pedal horrible (with the oval improperly oriented) only due to the negative placebo effect.

No extra effort??... It will be huge effort to convince you to let them a try. I tried to compare these two bikes: a single speed and a multi-sprocket. Please could you tell us why you can deliver more power with the second one while the physics remain impassible?... I try this because it is the same concept for the Q-Rings but of course affecting less.

Johan: Please stick to the lab. Racing data cannot improve on a controlled environment. For oval chainrings, lab is not good enough, due to the different inertias involved. I suppose the extraordinarily positive results of that test has much to do with this.

Something more efficient need less input for the same output. Now please, forget Physics for a little bit. Because it is not how much glycogen you consume for the same sprint, it is if you win or not the sprint. This is efficiency for the sprinter. Then, which is the input for this sprinter... answer: all he can put in the bike for that agony minute is Ok. This is the efficiency we are looking for... mainly.

Johan, Marianne won CX Worlds 06 on Q-Rings and started the season for road in a new Team (DSB) who obligated her to mount round rings. After several tests and races she made the team reconsider this point and converted the whole Team in a Q equiped Team. After winning the road world championship in Salzburg, you don't know how expensive was for her Team and herself the option to refuse Shimano sponsoring (for 2007) due to the zero possibility for using Q's (if she has Shimano material). Then SRAM tried to make a contract in the same way, and failed, so decided to allow the whole Team using Q-Rings. Little by little, Sram allowed the same for their other teams except the ProTour Saunier Duval...

Q-Ring make the INSTANTANEOUS speed to vary approx ?5% at each revolution when the cadence is the same. Depending on the setting you choose, make you to pedal at faster or slower (cadence) than normal (or simply the same). I am collecting from the racers experience that climbing they don't feel the same necessity to reduce cadence as for round chainrings. As well they report that pedaling standing up when climbing is much easier, which makes sense because the way to pedal standing is not so continuous as seated (it is more like pistons).

Using different gears you can adapt your effort to the power conditions, and it is exactly the same with Rotor and Q-Rings: for each revolution we adapt the instantaneous gear closer to your optimum for each pedal location. And this instantaneous optimum gear is not only a statics result, which obviously shows that we can apply more torque at 90? (from Upper Dead Spot) than at 0? (just the UDS); we consider as well all the inertias involved when pedaling (total cyclist+machine inertia and the reciprocating legs inertias), and for that reason we suggest to have the maximum gear around 108? (this is #3 setting).

The rear derailleur should be moving forward and backwards twice per revolution. You can calculate considering the aditional chain (to 40 cm) needed to raise its end about 1 cm. This is (40^2 + 1^2)^.5 (Pitagoras)=40.012498...less than 1 mm Finally this is less than the real movements due to the terrain and also to the variations of the cyclist pedaling speed. So there is not any additional wear reported. pcarrasco2007-08-02 11:26:05