Quarq & Temperature Compensation

Rich Stanbaugh

I'm looking at upgrading my bike - and will be required to upgrade power meter with the new setup. I've been reading a lot of reviews, talking to friends, etc. and am stuck on one point:

Brand vs Functionality

I do not want to tie my power meter to my wheels, so was looking at the Quarq Elsa. I was very surprised to learn that there is no automatic temperature compensation in the Quark. I've only done two IM, but both of them had pretty significant temperature swings on the road (IMLT 2013 & IMLC 2014).

DC Rainmaker's evaluation showed very significant temperature drift with the Quarq. This lead me to read accounts from IMLT where people were getting nefarious data from their power meters.

Question is: Trusted Brand with known issues vs. newer products/modern functionality?

Thoughts?

GMAN 19030

That's why you would perform an auto-calibration on the fly (back pedaling 5x). This will rezero and the new offset will account for the temperature change.

morpheus

this ^^

and, even DC said that the newer models are much better than the older Cinco's.

My Cinco was drifting pretty bad and they gave me a Riken as a warranty replacement. I chose it cuz I'm not in a place to breakdown L vs R power.

jsumara

We know that Power = Torque x RPM. So power is a calculated value and not measured directly.

The PM uses strain gauges to determine torque and the frequency from the strain gauges and in a no-load situation (zero torque) is what we calibrate.

So, we set (establish) the no-load frequency at the beginning of every ride - "calibrate" – and this produces the “zero offset” number you sometimes see on your Garmin. And as Bob said, we should "re-calibrate" during rides as well  because the strain gauges are sensitive enough to be affected by changes in ambient temperature.

By the way, I have a Quarq Riken. It was sent to me *free* by Quarq when my old S976 failed. My experience with Quarq is very positive. 

MattAaronson

I do a backpedal every hour to make sure the calibration stays good. In a race I do it more often...every 3x 5 miles I take a 30 sec break to recalibrate, so about 3x during the course of a half-iron bike. I actually look forward to that break, and I isolate it from my stats by keeping it recorded as it's own "lap".

Rich Stanbaugh

I ended up going with the Type S Power2Max... let's see how that works out!

cldavis

Jim - I saw that you use a Quarq Riken, which is what I have and I have been very happy with it.  However, I changed the battery last night and now my power numbers are crazy low in the 20's and 30's.  I auto calibrated according to the manual but still no change.  Do you have any thoughts or suggestions.  Thanks! 

jsumara

Christina - I've changed the battery once on my Quarq Riken and had no issue. However, just last week I was seeing extremely low Power Numbers but it wasn't the Quarq, it was my Garmin. I reset the Garmin be disabling (then re-enabling) the Ant+ Power. If that doesn't work, I suggest you contact Quarq. They were very responsive with me and will offer suggestions to get this corrected.