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Re: Official power2max support thread [mikar_68] [ In reply to ]
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mikar_68 wrote:
I have to start off by saying that Nicolas at P2M is awesome!!! Their customer service and response time is untouchable.
Thank you Nicolas!!

My question is around power readings compared to my Tacx Fortius trainer. I do not expect the two power readings to be exact, but I did hope it would be closer than 10-20 Watts apart.
My new P2M is reading 10-20w less than my trainer. Is there a calibration I should be aware of?

It is also worth noting that my P2M power was all over the board while my Tacx was reasonably steady.

I calibrated my Tacx before I started and then warmed up. I even stopped a couple time to let my P2M auto-cal.

My cadence is spot on.

Any words of wisdom?


I switched from a powertap to power2max. I found similar results as described above...

I did two tests where I used the powertap and power2max. Overall the power2max was 8 watts less. On a trainer with a Kurt Kinnetic road machine, in a specific gear at a specific cadence... I found my powertap watts to be very steady throughout a ride. With the power2max, I found for the first 20-30 minutes the watts to jump around a little bit after a calibration. When I would notice it to be a little high or low, I would not peddle for 2 seconds and let it recalibrate. It seemed to steady after 20-30 minutes.

Another issue, after a hard interval, I will stand up to stretch my legs, I found this could really screw up the calibration. Especially if this is in the first 20-30 minutes of a ride, I have seen my watts jump 15-20 watts. So anytime I stretch, I sit and calibrate again and be careful to keep my feet still and light.

I have now gotten the hang of calibration, but I'm not thrilled with how it works. I'm finding myself paranoid and thinking about my pauses/rests and if I'm screwing it up.

I have had a couple instances where the power stops for 5-10 seconds also.

Can you give any insight on how it calibrates, what might potential screw it up?
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Re: Official power2max support thread [power2max] [ In reply to ]
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Nicolas, should I plan for any hiccups trying to put these NoQ rotor rings on this P2M classic?

Last edited by: kppolich: Apr 16, 14 21:23
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Re: Official power2max support thread [elag] [ In reply to ]
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this is indeed very worrying; i remember someone askign about this issue - ie standing recovery and Nicolas said it shdnt be a porble - but obviously is

Nicolas any clue; also why does it happen only in first 20-30 mins
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Re: Official power2max support thread [kppolich] [ In reply to ]
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kppolich wrote:
Nicolas, should I plan for any hiccups trying to put these NoQ rotor rings on this P2M classic?

No, you can do that.

I have ride with full aero fibre-lyte charing on Classic power2max / rotor 3d

Se link:

My TT bike
BMC TM01
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Re: Official power2max support thread [elag] [ In reply to ]
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Hi Eric,

thanks for your message.

It's tough for me to diagnose over the distance, but I will try my best:

First about the wattage "dancing around": the power2max measures 50x per second and updates every second. During pedaling power fluctuates very quickly due to the nature of pedaling. Every power meter smoothes data in some way, as completely unsmoothed data would not be readable on the screen - it would fluctuate too quickly. It's possible that the different smoothing of the two power meters make it appear that the wattage are changing relative to each other. For example on my Wahoo Kickr the power displayed changes much more slowly than on the power2max, due to said differences in smoothing. If you look at 10s average that should be less so.

Second about zero offset calibration: every time you stop pedaling (cadence = 0) the unit waits for the torque value to stabilize and sets the zero. It has an algorithm to prevent false zero offsets which is difficult to trick. A very safe way to conduct a zero offset calibration is with the pedals stationary for 5 seconds (to be on the safe side) and the freewheel clicking - which guarantees there is no tension on the chain. If you prefer to do it manually you can get a Garmin to tell you the zero offset it is using by conducting a manual zero. If there is tension on the chain or the pedals are turning it will return an error.

I hope this helps!

Best
Nicolas

---
power2max
http://www.power2max.com/northamerica
official power meter of Movistar Team
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Re: Official power2max support thread [Tillquist] [ In reply to ]
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Hi Tillquist - nope, all good with that combination.

Cheers
Nicolas

---
power2max
http://www.power2max.com/northamerica
official power meter of Movistar Team
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Re: Official power2max support thread [power2max] [ In reply to ]
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Ordering mine right now. Any coupon codes out right now?
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Re: Official power2max support thread [power2max] [ In reply to ]
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power2max wrote:
Hi Eric,


thanks for your message.

It's tough for me to diagnose over the distance, but I will try my best:

First about the wattage "dancing around": the power2max measures 50x per second and updates every second. During pedaling power fluctuates very quickly due to the nature of pedaling. Every power meter smoothes data in some way, as completely unsmoothed data would not be readable on the screen - it would fluctuate too quickly. It's possible that the different smoothing of the two power meters make it appear that the wattage are changing relative to each other. For example on my Wahoo Kickr the power displayed changes much more slowly than on the power2max, due to said differences in smoothing. If you look at 10s average that should be less so. This is not what I meant, I'm sorry If I didn't explain it well. Let me give a more specific example: I will often do multiple intervals indoor on my *trainer*, the goal to hold a specific wattage for every interval. I use a Kurt Kinetic Road machine and have my reading 3s Average. When I used my *powertap*, I would go into the big ring, 3rd gear at a cadence of 94 and be at 165 watts (or within a 1-2 watts). Assuming I stayed at 94 cadence, my power would be 165 watts, all the intervals were consistent.

With the power2max, when I do everything the same above (big ring, 3rd gear at 94 cadecnce) I have found the wattage will stay steady, but it is sometimes higher or lower after a calibration. So for example, after a calibration is will be at 157 steady. Then later after a calibration it could be at 169 steady, 172 etc... it will change after calibration. A couple times I stood up and stretched my calves and then it was 180+ watts. I have found once I hit about 20-30 minutes into the ride it seems to stabilize more.

I will confirm this is not a scientific test, but with my powertap it just seemed to be consistent and make sense, with the power2max the math just doesn't add up for me sometimes.

Second about zero offset calibration: every time you stop pedaling (cadence = 0) the unit waits for the torque value to stabilize and sets the zero. It has an algorithm to prevent false zero offsets which is difficult to trick. A very safe way to conduct a zero offset calibration is with the pedals stationary for 5 seconds (to be on the safe side) and the freewheel clicking - which guarantees there is no tension on the chain. If you prefer to do it manually you can get a Garmin to tell you the zero offset it is using by conducting a manual zero. If there is tension on the chain or the pedals are turning it will return an error. This kinda stinks, because I frequently stand up to stretch my calves. Now I'm always wondering if I screwed up the calibration.

Currently I am indoors on the trainer, the trainer is consistent resistance so I have an idea when it seems off and can recalibrate. Now that the weather is getting nicer I will be outside, no way will I be able to tell if it's off.


My overall feeling is it is accurate for an entire ride, but I have this nagging feeling that I need to keep calibrating so I can offset any screwups.

I hope this helps!

Best
Nicolas

Last edited by: elag: Apr 17, 14 11:13
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Re: Official power2max support thread [cbump] [ In reply to ]
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Well, it's done. Order placed. What's the shipping time been like for you guys?
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Post deleted by rubberbullet [ In reply to ]
Last edited by: rubberbullet: Apr 18, 14 9:44
Re: Official power2max support thread [power2max] [ In reply to ]
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After reading dc rainmaker's review, it appears the p2m self calibrates. However, using the Garmin you can also manually calibrate. Would there ever be a need for the manual calibration or is my thinking correct that a manual calibration would likely be a waste if time for day to day use?
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Re: Official power2max support thread [aries33] [ In reply to ]
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aries33 wrote:
After reading dc rainmaker's review, it appears the p2m self calibrates. However, using the Garmin you can also manually calibrate. Would there ever be a need for the manual calibration or is my thinking correct that a manual calibration would likely be a waste if time for day to day use?

I think manual calibration is probably a waste of time if riding outdoors. If you're going to ride on your trainer indoors it's likely that there will be no coasting. In that case it's probably a good idea to do the manual calibration before the trainer workout begins.

I was at NOLA 70.3 this past Sunday. As I was setting up transition about to head over to the swim start, I attempted a manual calibration of my Type S just out of habit. It wouldn't calibrate - just sat there. Didn't return an error, just wouldn't calibrate. I was a little panicked. I left it and when I got to it in T1, it worked just fine. Worked great for the race.
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Re: Official power2max support thread [power2max] [ In reply to ]
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I'm considering. P2M for my 2012 B16. What would be the cheapest option for me to purchase?

Thanks
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Re: Official power2max support thread [michael_runs] [ In reply to ]
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Hi folks,

sorry for the slow answer, I'm traveling at the moment. Last ones first:
- michaelruns: is it possible that your Type S was in sleep mode because it hadn't been used? Before you do a manual zero turn the cranks, the green LED will flash and the power meter is awake

- aries33: There isn't really need for a manual zero, unless you like to do it. Every time you coast >2 seconds it will auto zero

- rubberbullet: ah that sucks, sorry to hear. I hope you're fine! There is not much that can be done there. I would simply keep using it. If it stops working you can still send it in for crash replacement.

- cbump: from what I can see your unit has shipped, so I expect it to arrive next week.

- elag: standing up to stretch your calves is unproblematic. The only way you have a small chance to upset the auto zero process is if you do a track stand (i.e with tension on the chain) and very constant pressure. Can you please do a specific test for me? Pedal 15s pretty hard (say, twice as hard as in a steady state interval), then coast and do the manual zero several times in a row and record the numbers. Before the first manual zero you will have to wait about 2 seconds, otherwise it will return a calibration error.

A good easter weekend to you all,

Best
Nicolas

---
power2max
http://www.power2max.com/northamerica
official power meter of Movistar Team
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Re: Official power2max support thread [power2max] [ In reply to ]
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Hi Nicolas,

Any idea when 165mm rotor 3D+ will be in stock? I have Raleigh in about a month and hoping to do some riding with it before then. Thanks!
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Re: Official power2max support thread [Teamzero86] [ In reply to ]
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Hi,

we currently have a very limited number in stock.

Best
Nicolas

---
power2max
http://www.power2max.com/northamerica
official power meter of Movistar Team
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Re: Official power2max support thread [power2max] [ In reply to ]
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Hi,

I have had Power2Max since one year and am very pleased with it. After upgrading to a new bike, the power meter was one of few components I brought to the new bike.

One thing I wanted to implement was integrating Osymetric chainrings as well as a DIY Alden carbon cover. Here is my result.

Please note that the battery compartment is left alone. I have added black silicon between the PM, cranks and carbon cover to achieve some pseudo-aerodynamics
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Re: Official power2max support thread [power2max] [ In reply to ]
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power2max wrote:
Hi Tillquist - nope, all good with that combination.

Cheers
Nicolas

Just got a call from my LBS and said the aero NOq rings won't fit on the classic. Nick??
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Re: Official power2max support thread [kppolich] [ In reply to ]
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Hi kppolich,

in 130BCD - no problem.

in 110BCD - aero chain rings need to be modified.

Best
Nicolas

---
power2max
http://www.power2max.com/northamerica
official power meter of Movistar Team
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Re: Official power2max support thread [power2max] [ In reply to ]
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Just wanted to add my experience with the new Type S power2max for S-works cranks. It has been fantastic. Not a single issue at all- no drift in power whatsoever. For the weight weenies it does add 121 grams over the carbon spider (97 over aluminum) but it is definitely a more aero shape. I'll try to post a picture in a few days.

The only issue I have had, that I feel others might want to know is that when running the P2Max on a white BMC TM02 that I had to add 2mm of spacers to the drive side otherwise it rubs under extreme torque. This is probably simply due to the thick white paint, a slight miss on tolerances from BMC, or the bearing got pressed in a bit too much. Haven't had any issues since adding the tiny spacers, but do pay attention if you have a BMC TM01/02.

If you are considering getting one, I highly suggest the new Type S for its more aero shape- just check your frame tolerances on installation and your first ride.
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Re: Official power2max support thread [Nigel] [ In reply to ]
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Hi Nigel,

thanks for the feedback. Is your TM02 a BB30 or PF30 frame? I know that on a PF30 frame the lock ring has a tendency to touch the lock ring, which is due to the short axle on the S-Works cranks - pretty tight construction.

Cheers
Nicolas

---
power2max
http://www.power2max.com/northamerica
official power meter of Movistar Team
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Re: Official power2max support thread [power2max] [ In reply to ]
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Been riding with my Rotor 3D P2M for a little over a month now, very happy with my choice. It has worked flawlessly from the beginning, not a single issue to report. Highly recommended!


_____________________
Don't forget to attack!
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Re: Official power2max support thread [power2max] [ In reply to ]
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Hi Nicolas. I've been riding my new Type S for about two months and it's been great. Great product.

I have a friend who is looking to buy a Power2Max as well. He rides a Ceepo that currently has a GXP bottom bracket with a Quarq he's looking to replace. Which Power2Max will he need? I don't see a GXP option from the filter on the website. He'll be getting the whole package (P2M, cranks, chainrings).
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Re: Official power2max support thread [power2max] [ In reply to ]
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power2max wrote:


- elag: standing up to stretch your calves is unproblematic. The only way you have a small chance to upset the auto zero process is if you do a track stand (i.e with tension on the chain) and very constant pressure. Can you please do a specific test for me? Pedal 15s pretty hard (say, twice as hard as in a steady state interval), then coast and do the manual zero several times in a row and record the numbers. Before the first manual zero you will have to wait about 2 seconds, otherwise it will return a calibration error.


HI, I'm not sure how to do this. I have a garmin 500, when I go to the calibration screen to see the numbers, it always wants to recalibrate. I have a Fenix2, I can try with that next bike ride.

FYI, today was a perfect example of what I'm finding all the time:

On my trainer I did 4x8:00 the goal to be 200 watts for all 4 intervals. i was on my trainer, I was in the exact same gear for every interval. Here is each 8:00 interval:

Avg Watts, Avg Cadence, Avg Speed (remember indoors)
1st: 190 95 17.7
2nd 200 94 17.6 (My cadence and speed are slightly slower, but the power in 10 watts higher??)
3rd 193 96 17.7
4th 203 95 17.6

The cadence and speed make sense to me, they drop and increase at the same time. The watts go up and down randomly. This is what I see all the time, sometimes in big increments, sometimes small. let me know if you want to see the Garmin file.
Last edited by: elag: Apr 24, 14 7:51
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Re: Official power2max support thread [michael_runs] [ In reply to ]
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@michael_runs: The GXP doesn't show up as it's a bottom bracket format that threads into BSA frames or is installed in BB86 frames, like Shimano bottom brackets. Your friend has two options:
1) Remove the GXP bottom bracket and install a Rotor bottom bracket for a Rotor 3D or a FSA bottom bracket for a FSA Gossamer or FSA K-Force Light

2) Get some SRAM S950 or Force22 cranks (we don't have those, I'm afraid) and get a SRAM Type S from us.

Thanks for your recommendation :-).

@elag:
Exactly, when you go to the calibration screen, let the Garmin do the zero offset calibration and note the number. Do it several times in a row and see if that number changes.

I understand your reasoning that speed to power should always be constant on a trainer. The thing is that trainers are uncalibrated resistance units and subject to many influences that can slightly change resistance over the course of the ride and that makes it pretty much impossible to draw conclusions from trainer rides. If you feel uncomfortable we will test your power meter on a calibrated Cyclus2 scientific erg for precision.

Best wishes
Nicolas

---
power2max
http://www.power2max.com/northamerica
official power meter of Movistar Team
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