I have a Quarq Riken AL and decided to throw on a Solid 54T Sram TT Chainring instead of the “regular” 53T a bit ago and the power numbers started reading a bit lower than they should. After a TT on a course I’ve done about 100 times was about 30 watts lower than it should have been for the effort, I decided to test it at 80-90-100-110rpms against my other Riken that was close to the readings with the AL and a 53T chainring. The result was that the higher the RPMs, the bigger the disparity. I’m kind of annoyed since I thought the whole omnical thing was supposed to fix this.
Anyway, my question is whether anyone has had similar issues switching to solid TT chainrings on their quarq. If you did, how did you fix it?
I have two Quarqs (TT and road bike) and swapped in a solid SRAM TT ring to the TT bike about a year ago. I can’t say I’ve really noticed a difference, though I haven’t explicitly measured it by putting a 2nd power meter on the TT bike or anything.
And I think I would have noticed ~30 Watts.
You could try calibrating with Qalvin? (after maybe contacting Quarq for suggestions)
Did you torque all the chainring bolts to the correct number? I had someone just wing mine one time and it through the numbers way off until I readjusted
If that doesn’t fix it, you can do a static torque/slope calibration with a high quality known weight or you can send it back to Quarq with the chainrings on.
I have a Quarq Riken AL and decided to throw on a Solid 54T Sram TT Chainring instead of the “regular” 53T a bit ago and the power numbers started reading a bit lower than they should. After a TT on a course I’ve done about 100 times was about 30 watts lower than it should have been for the effort, I decided to test it at 80-90-100-110rpms against my other Riken that was close to the readings with the AL and a 53T chainring. The result was that the higher the RPMs, the bigger the disparity. I’m kind of annoyed since I thought the whole omnical thing was supposed to fix this.
Anyway, my question is whether anyone has had similar issues switching to solid TT chainrings on their quarq. If you did, how did you fix it?
Every chainring has a different calibration factor. Qalvin has ALL of the SRAM rings preloaded into the software for easy updates. It has some other popular rings in there as well.
Also, 10-12Nm - not 8 - is preferred for steel bolts; and you should be using steel (IMO). 8Nm for aluminum. But I don’t like aluminum chainring bolts.
The calibration factors and chainring variability were for the older now discontinued quarqs.The new versions are advertised with “Omnical” which supposedly eliminated these individual factors and variability. Having said that, nothing beats a weight calibration test, and slope adjustment for ensuring accuracy.