if your seat angle is fixed and type of riding you will be doing is also known and a constant, do any other frame geometry parameters (say, bottom bracket height) have any effect on the optimal settings of your q-rings ?
if yes or no, then why ?
then, for the specific case of riding at exactly the position and exactly same cadence and exactly the same workload on a level surface and in one case you are using the small chainring, and in another case you using the big chainring (but a different cog and gearing combination, but same number of gear inches), should the q-rings be set any differently on the big chainring vs. the small chainring ?
folks i have set up with q-rings report huge differences in the effectiveness of q-rings based on the settings of each ring. but yet each setting is only different by the next by only 5 degrees.
i couldn’t figure out why folks are perceiving such big differences, when i thought i set them up the same. i thought the q-ring settings were all based on the seat angle and riding styles.
but it is not.
q-ring settings are highly affected by a few other things never mentioned in the website or literature.
(and this may be of interest to folks that want to go as fast as possible. for just ‘cool looks’ nearly any position will do …)
i have a feeling this is gonna shake out similar to the mysterious " antequil angular pedalling " deal.
or perhaps as a proprietary 300 dollar personal q-ring-specific “fitting” exclusive no sane hobbyist bicycle rider would do without . . . . . . . . . . . . .
i still say they are fun to ride, and look spiffo.
all right, here are 2 pretty big hints. bike is in the same position, the only thing that is changed is the gear selected, the 1st photo is 53 x 11, 2nd photo is 40 x 23.
I’m not sure what you’re getting at. In your first post you reference the same number of gear inches, but you’ve got the two pictures in very different gears. It looks like the max force requirement is slightly further along the pedal stroke for the smaller chainring, are the two rings set at different positions? Is this in reference to the recommendation to have them set at 4 and 3 external/internal respectively?
Greg, I think you’re going to have to phonetically spell this out for us. I just don’t see what you’re getting at. Also, is this only concerning the relationship of the small to large chainring? Or is it a position #1 through #5 issue as well?
the peak load on your legs and the peak chain speed occurs at the same point with both rings in these positions (both rings are set at exactly the same angle in the crankset) because they occur when the biggest ring radius is exactly perpendicular to the chain line. but even without moving the bike or camera, note that the cranks are in* very* different angles in these two photos (the angle relative to the seat tube, or any fixed seat angle), and the difference is near 10 degrees difference (there is only a ~5 deg. difference between each q-ring position).
this is because just changing gears alone moves the chainline much more dramatically than the difference between q-ring settings, and the moving chainline directly controls the angle when your legs will feel the higest loads.
so after you consider your seat tube angle and your riding style, you should consider what chainrings, cogs, and combinations of the two you are most often in, and consider the chainline angle of those combos when you select each q-ring position for the big and small rings.
So you’re saying that a person should gradually move rearward on the saddle as they progress down the cassette? Well then, what we need is an automatic, wireless hydraulic fore/aft seat adjustor, linked to our shifters.
but i am saying that one should consider the chain angles and even the frame geometry when one finally selects the optimal setting.
according to rotor usa, the rider’s fore-aft postioning (i.e., laid back roadie position, or forward tt position) affects the optimal ring position. but they don’t say what the rider’s positon is relative to.
because, for q-rings to work, the rider’s position is *not *relative to the ground, the bike, or the seat angle. it’s relative to the chainline in the gear you are using. and that chainline is highly affected by seemingly random things like the gearing combos, BB height, and even chainstay length.
to prove it, the images above have 2 q-rings set at exactly the same angle on the crankset, but just a gearing change makes a nearly *10 degree *change (this is equivalent to two q-ring settings) on where in the pedal stroke the greatest load occurs.
well, round rings are definitely better in delivering power independently of the positions of the rider and the chainline.
but i think q-rings are possibly better in accommodating the biomechanics of a rider’s legs, but ya gotta consider all the angles of these things in their positioning …
