ilovecycling

I did a few short sprints in my apartment's parking lot to test it out. It was dark so I couldn't play with it for very long. The numbers seem strange to me, but then again I have no idea how this thing is supposed to work. I need to educate myself on training with power so I can actually take advantage of this thing. I will be racing next season so the sooner I can learn the better.

Also, what is your preferred method of displaying power on your Garmin 500/705/800? Do you have a page dedicated to just power info, or do you combine power with another performance stat like cadence, elevation, etc?

https://connect.garmin.com/activity/115144717

Hapsmo911

Try asking here https://www.bikeforums.net/showthread...-comments-here!

ilovecycling

Thanks for the link. I tried reading all the posts in there and followed some other links as well. I'm very confused. It seems like I have a lot to learn.

For those of you that have Quarq PMs, what do I need to know as far as maintenance and calibration? I read earlier today in a review article that there is some sort of iPhone app I can buy that will allow me to calibrate the unit for different riding circumstances or if I were to change the chain rings to 52/36, for example. Is this true? Is there a way to zero the unit occasionally to ensure I'm getting accurate power readings?

caloso

When I remember, I try to calibrate it before a ride. Menu > Bike Settings > Ant + Powermeter > Calibrate.

Also, I have one page set up as my interval power page: 3 fields: 3s power, lap power, lap time.

ilovecycling

Ahh, so it's calibrated through the Edge 500. I didn't think about that. What exactly is it calibrating though? It's not like it can change the numbers the power meter is giving it. Does the power meter even need to be in range when you calibrate it?

caloso

To tell you the truth, I don't know how it does it.

scirocco

It's a bit of a misnomer - it's just setting the zero point.

ilovecycling

How does it not know that no input is the zero point? I don't get it. Do I have to back pedal or do anything for the computer to know the Quarq is in range and working for it to zero properly?

caloso

Yes, you hit the calibrate button while the cranks are motionless and at 9 and 3. You can also zero it on the fly by backpedaling.

scirocco

It is relying on you to provide the correct input at the time that you hit "Calibrate" (i.e. zero force = zero power). It doesn't know what "no input" is for sure - that is what you are telling it when you zero it. You could deliberately screw up the zero setting by providing force on the pedals when you hit Calibrate - and then it would read wrong until the next time you set the zero again.

gerundium

EDIT: stupid technical explanation.

strain gauges are used in Power meters, they need to be zeroed to function properly. they usually work by converting their mechanical deformation into an electrical current which can be measured more easily but you need to know what the values of the current are at 0 power generated to be able to make the calculations from the current measurements you are doing and the strain that the gauge is truly under.

that's also why you have to have cranks setup in fixed positions (9 and 3), the cranks themselves cause a torque on the bottom bracket axle already and you don't want that torque to be taken into account for your power measurement.

aham23

step back, take a deep breath, and do some reading. otherwise the world of power will overwhelm you and this fancy new toy of yours will be listed on eBay in 3 months.

the Quarq comes ready to go out of the box from the factory. as stated above you simple need to zero it out before every ride. it should return a number in the -500 to +500 range. you zero it out on the road as well by spinning the pedals backwards 4 or 5 times. all of this is explained in the very short user manual that came with the unit.

next, get Golden Cheetah or Training Peaks for uploading your data so you can fully utlize it. later.

Inertianinja

For Garmin Display - on the 705, i have it set to "Average Power 3s" just because the numbers jump around so much when it's continuous readings.

As far as calibration:
- There is the quick version - the type you do with the Garmin - which involves simply hitting the calibrate button on the garmin. in that instance, just look at aham23's post. if you get a large number (e.g. 5 digits), contact Quarq's support.
- there is also a calibration that is done by hanging a known weight from one pedal, but you don't need to deal with that.
- also as aham23 said, when you go out for a ride, backpedal like six revolutions and it'll "zero" the readings. you'll see the reading on the garmin go to " ______" for a second.

For using it as a beginner:
I'm just a little bit ahead of you - i've had it for a few months. For the beginning i think its best use is physical education. Try these:
- note your power readings as you ride and see what different power levels "feel" like
- note what kind of power it takes to get up a hill at a certain speed
- how much power you save by getting aero at a constant speed
- how long you can hold X watts...or whether you can control your legs to keep in a certain watt range in the first place
- what it feels like to keep a relatively constant power output for a certain amount of time.

For example, i'll do some workouts where i'll be like "i'm going to do 250W constant for as long as i can." It'll improve your pedaling, pacing, sense of effort, etc. Then upload rides to the Garmin Connect (or whatever you use) and note your power, heart rate, cadence, etc and how they relate to each other. It's fun to geek out on the data. From there you can start doing real testing...for that there's plenty on the internet & that book "training and racing with a power meter."

LowCel 

Why does everyone suggest zeroing at 3 and 9? When I called Quarq they recommend drive side crank arm at 6:00. Is there something I should know?

crazyarm07

This was my understanding also (and how I've always done it). The way it was explained to me is that the drive side crank needs to be at 6:00 so its weight doesn't place torque on the chainrings, which allows for a truer zero, if that makes sense.

brian416

That's what you do for an SRM, maybe they have the two confused?

aham23

the little quick reference guide that comes with the Quarq does state the "6" position should be used with zeroing. later.

Forza

I zero mine w/the driveside @ 6:00...If you are riding through significant temperature changes, you should zero on the fly (by back pedaling). I backpedal every so often as a general practice.

To the OP, I suggest picking up the book Training and Racing with a Power Meter. It's a little wordy, etc...but, worth it. I started reading it prior to purchasing my Quarq, and was using Training Peaks (HR based), so I wasn't learning too much at once and becoming overwhelmed.

Forza

I should add for the Garmin (I use a 500)..this is my setup.

Page 1: Power/Speed/Power Zone/Cadence/HR Zone/HR
Page 2: Power Specifics/%FTP/Max Watt/Avg Watts/Speed. When Garmin does their update this fall, I'll use IF and NP on this page
Page 3: Elapsed Time/Time/Calories/Temperature/Elevation/Avg Speed/Distance

merlinextraligh

I just zero my by backpedaling. Rarely do I do the calibrate thing through the Garmin, and have never truley calibrated it with a known weight.

It seems to give consistent results, which is all I need.

petalpower

I'm going to try your interval power page. Thanks.

caloso

Got the idea from our exiled friend umd. Instantaneous power is too variable. Personally, I think a 6s avg. would be about perfect but the 500 only gives you a 3s or 30s option. 3 seconds is a good compromise. For the duration of the interval I try to make the 3s and lap average match my target power.