Power meter for Vendetta

[LarryOz]

I am currently doing some power meter testing now. I think my Q-rings are making my Garmin power readings low. I keep re-calibrating everything for every ride, and I am seeing up to 20% lower readings. It is really frustrating.
Does anyone else have a KICKR trainer (or other power trainer), Q-rings, and another (on bike) type of power meter they can record simultaneously while riding and recording the stationary one?
(I think Bob does and is working on it). I would be nice to have as many data points as possible to compare and analyse..
Bob has already told me that he would expect the Q-rings in OCP setting #1 to register low, so trying to figure out how much. (could then "adjust" the power reading from Garmin to make sense)
What I haven't done yet is put my "old round rings" back on and do the same. I guess that's on the list too, also with testing the original Q-rings with the new XQL version.
I have also just updated the firmware in both the Garmin Pedals and the KICKR, so eager to see if that helps out a little.
So many toys to test, so little time - still blessed!

 

[LarryOz]

Bob, nice "present" for Mrs. Rats.
I've been watching her workouts and her progression through the winter. Her progress is nothing short of incredible.
That recent set of power intervals - almost hitting 300 watts, and pushing her HR to 175! wow.
All I can say - now that she's going to have a power meter on her bike - is you'd better start looking behind you - yeah and she is definitely going to be wanting a V soon too, and you can't blame her really.

 

[snilard]

I have read that You will get ~4% higher power reading with Q-rings on PM what does not support Q-rings. But it was on DF. I cannot find the article now. But there are some discussion on DC rainmakers review of latest Power2Max.
Are Q-rings on V so huge benefit? A lot of V riders here are using them. Or is it only cool to use Q-rings?

 

[ratz]

I have read that You will get ~4% higher power reading with Q-rings on PM what does not support Q-rings. But it was on DF. I cannot find the article now. But there are some discussion on DC rainmakers review of latest Power2Max.

High or Low depends on where you set your OCP. An OCP of #2, 3, or 4 should read low. #1 or further should read high.

The question comes down to whether the meter is sampling 1 time per revolution. Multiple revolution per minute can be problematic if the meter software algorithm expects round rings to do extrapolation and interpolation. I have read a ton of info from Robert Chung on this topic in the last two months; and spoken directly to Stages support.

On Saturday we are going to put Mrs Ratz's Silvio on the Kickr with the Stages and we'll do some simultaneous testing. She's running OCP4. The only problem with the Kickr is that it has a medium size fly wheel; so we have to test in the 80-300 watt range out side of that "road" inertia versus "trainer" inertia will be off making the comparison invalid. I do have some round rings so if we get completely weird results we can put those on. The one problem with testing on the Silvio is the Suspension fork eating power.

Based on talking to Stages I know they sample 1 time per revolution. I expect her power readings to be 4-5% high on the meter versus what the kickr reports. The Delta doesn't really matter in the end as long as it is consistent. Knowing the offset allows FTP to be calculated on the Trainer and then used for ride planning by just adjust by the 4-5% for the road. They recommend test at 70rpm - 110rpm in ten rpm increments.

Are Q-rings on V so huge benefit? A lot of V riders here are using them. Or is it only cool to use Q-rings?

For a lot of us it smooth out the pedal stroke; We run our "retarded" which gives more more leverage, better acceleration, but less top end speed. Larry on the other hand has his accelerated for more power and less leverage. I tried OCP 1 and -1 and my knees complained to much but boy the power output was fun. 30 minutes of 1 minute 500-600watts intervals. The 2 week healing period convince never todo that again.

 

[LarryOz]

Are Q-rings on V so huge benefit? A lot of V riders here are using them. Or is it only cool to use Q-rings?

I don't know if I'd be willing to spend this kind of money on something just to be cool -I'm too cheap for that!
In my experience the Q-rings really do smooth out the pedal stroke and get the most out of your power stroke. I did not have a power meter to test on when I got them, so do not have any data (that will be forthcoming when I can schedule time for all different chain-rings at my "super-secret-test-facility" !

High or Low depends on where you set your OCP. An OCP of #2, 3, or 4 should read low. #1 or further should read high.

Bob, my preliminary results only using OCP #1 seem to put my power output lower (from my Vector Pedals) than my power read through the KICKR. Are you 100% sure on this?
I still need to test round against Q-rings myself, plus have upgrade firmware in both pedals and KICKR, so much more testing to do. So much testing, so little time.

 

[Rick Youngblood]

Bob, my preliminary results only using OCP #1 seem to put my power output lower (from my Vector Pedals) than my power read through the KICKR. Are you 100% sure on this?
I still need to test round against Q-rings myself, plus have upgrade firmware in both pedals and KICKR, so much more testing to do. So much testing, so little time.

That would be cool to see some data. Round vs. Q-ring - OCP1 vs. OCP3, etc.

 

[Charles.Plager]

For what it's worth, I have no experience with non-round rings. That being said, the physics behind them makes a lot of sense.

There are parts of the stroke where you can push a lot of with your leg. And there are parts of the stroke where you can't. To me, it makes sense if you want to even out your cadence to have a ring bigger where you can push and smaller where you can't.

 

[Rick Youngblood]

There are parts of the stroke where you can push a lot of with your leg. And there are parts of the stroke where you can't. To me, it makes sense if you want to even out your cadence to have a ring bigger where you can push and smaller where you can't.

Yes, this!

Once you get used to q-rings, hop on a bike with round rings. The round rings will then feel very odd and elliptical. You will then notice the dead spot in round rings.

 

[battleaxe0]

Sounds like Q-rings and a power meter will have to be added to the Christmas wishlist

 

[ratz]

Bob, my preliminary results only using OCP #1 seem to put my power output lower (from my Vector Pedals) than my power read through the KICKR. Are you 100% sure on this?

Not quite. What we are expecting is that OCP#1 reads the highest power and OCP#5 reads the lowest at a fixed cadence. Where the comes in relative to a Wheel Sensor or a Power Trainer is the part that we need to test. After dinner tonight I'm going to prep the trainer for Silvio/Vendetta mode and load the V (cold and raining tomorrow) I'll get my 3 hours in tomorrow morning then I'll do some Vendetta testing and follow that up with some Silvio testing and with luck get that all done before tomorrow night.

The plan is to test:

OCP #1, 2,3,4,5 @ 70,80,90,100,110 RPM @ fixed watts via erg mode at 150, 200, and 250 for 30 seconds each
Then a final test of round.

Then repeat on the Silvio.

That's 78 test sets and 40 minutes of data. Figure 5 minutes to change each OCP and about 20 to get to round. That about 90 minutes of work per bike if I don't get distracted so probably about 4 hours of goofing around. I'll probably try and record them as a single data file; with lap markers as "pauses" that should give me two data files one from the garmin and one from the trainer that I can then graph against TIME and overlay should be able to compare; but I need to think about that. I think I should spin down to zero cadence for each RPM level and each WATT level

Did you find out if you can share that wahoo firmware update with me?

 

[LarryOz]

Hey Bob,
Wahoo did not send me a new firmware version, they just said it was available (version 1.1.3.32). I connected my I-pad up to the KICKR and it said there was an update - I OK'd the download and it installed. Had to toggle the Bluetooth on and off on the I-pad, and then cycle the power on the KICKR, then it said it was complete.

I also forwarded you their email telling me about it. No attachments.

Testing:
I have some similar testing in mind for this next week now that I have updated the KICKR, Vector Pedals, and Garmin Head unit.
I have round rings, reg. Q-rings, and XQL Q-rings I want to test. I am only testing on one bike, however I also have a set of 140mm cranks I can compare with against the 150mm, just to make it interesting.

What you have outlined is very comprehensive and pretty much the same path I was starting to going down, so I will duplicate what you are doing so we have the same data points to compare.:
Round rings: @ 70,80,90,100,110 RPM @ fixed watts via erg mode at 150, 200, and 250 for 30 seconds each. = 15 tests
Reg Q-rings: OCP #1, 2,3,4,5 @ 70,80,90,100,110 RPM @ fixed watts via erg mode at 150, 200, and 250 for 30 seconds each = 75 tests
XQL Q-rings: OCP #1, 2,3,4,5 @ 70,80,90,100,110 RPM @ fixed watts via erg mode at 150, 200, and 250 for 30 seconds each = 75 tests
Tests = 165
Repeat with 140mm crank arm (just for fun) = 165 tests
Totals test = 330!
...
I was thinking of writing a TR workout that I could run for each OCP, and give 30 sec segments between changes in RPM. changes in wattage could possibly be back to back since in ERG mode (but might still give 30 secs to adapt to it and make sure cadence is on the money). Would have to really be proactive with the "split" button on the Garmin though to make it match up and easy to compare.
Then of course repeat for each OCP, then repeat for other set of Q-rings, then again for round rings. Lots of work, and even more data.
Lots of ways to skin this cat = lots of ways to mess it up too!

I think I should spin down to zero cadence for each RPM level and each WATT level

I don't know if that is really necessary, if you have a workout automatically adjusting the ERG wattage for you. Just allow time (still maybe 30 secs) for you to adjust to the new wattage and/or cadence so you can be assured of nailing it spot on for the 30 seconds that matter..

Not sure when I will do this, as I still need to put in a hard 4 hours on the track this weekend as my final hard ride before Calvins. (Also intend to collect group of data there too: will 88mm wheels, full discs, reg Q-rings, and XQL Q-rings - but only in the #1OCP position)

 

[ratz]

I was thinking of writing a TR workout that I could run for each OCP, and give 30 sec segments between changes in RPM. changes in wattage could possibly be back to back since in ERG mode (but might still give 30 secs to adapt to it and make sure cadence is on the money).

Hmm that's interesting. I couple probably whip up an Cycleops routing based on FTP. Then for the test; just program the software with a fake FTP of 250. And have hills with Candence prompts; then it's just a matter of putting in hills at 60%, 80% and 100%. Then we could just both ride the same "test" suite. So I build the test. Ride one; change ring, ride one, repeat. I like that.

 

[Lief]

Seriously can't keep up with y'all.
Rick, you said -

Once you get used to q-rings, hop on a bike with round rings. The round rings will then feel very odd and elliptical.

I don't find this to be the case.

The Vendetta (172.5mm crank) has QRings
The Silvio (165mm crank) has Round

If anything - the QRings still have a bump in them now & again.
The round ones never.

Could just be different strokes/folks.
Or could just be that I'm used to it
Or I attribute perceived difference to the different platform.

It's possible that your test will be somewhat skewed in favor of whichever ring you are most comfortable / accustomed to.
Probably do you some good to have an some defined acclimatization period built into the beginning of each test.

(these tests, and the number of factors, sure are time-consuming)

 

[ratz]

Workout's created:

Never used the fixed power ones so made a % one as that I know does ERG like mode.

IRTG - Power Meter Testing - Fixed Power
IRTG - Power Meter Testing - % of FTP Power

 

[Rick Youngblood]

I don't find this to be the case.

The Vendetta (172.5mm crank) has QRings
The Silvio (165mm crank) has Round

If anything - the QRings still have a bump in them now & again.
The round ones never.

Hmmm! For me, once I got acclimated to the Q's, they feel round, and the round feel lumpy. I have about 20,000 miles on Q's and can't stand the lumpyness of round rings.

 

[Lief]

I have about 20,000 miles

That could be a key difference then - I'm only at about 2.5K on Qrings.

 

[Rick Youngblood]

That could be a key difference then - I'm only at about 2.5K on Qrings.

Can you post a picture? Bob and I set ours up independently, but came up with the same setting. I can't find the thread that was started last year that shows Bob's setting.

I would say at 2.5k you should be plenty acclimated.

 

[ratz]

I can't find the thread that was started last year that shows Bob's setting.

http://cruzbike.com/forum/threads/q-ring-upgrade-ahhhhhhhhhhhhh.7784/

 

[Rick Youngblood]

Thanks Bob. Just double checking mine is set up exactly like this. Like the gold ring bolts BTW!

 

[ratz]

Testing completed. I have the raw data now I just need to go analyze it. Files attached; if using them remember to look by "Time" not distance when graphing.