Kickr Power and Speed

Nov 12, 14 9:48

Post #1 of 66 (7112 views)

My Kickr arrived today, great bit of kit with really solid build quality. I've just got a couple of questions that I'm hoping people with some real life experience with the unit can help with.

I know comparing power meters is a dodgy business but after reading DCRainmakers review it seemed that he found the Kickr to track fairly closely with other units. I'm currently running a Stages and have used a PowerTap in the past. I'm aware that given the different location and method of power measurement the Stages and Kickr are unlikely to provide identical numbers but currently I'm seeing differences between 10 and 20% with the Kickr running high, much different to Rainmakers findings. I'd love to believe the Kickr numbers (and get my pro licence) but sadly I think it's a way out. I've been riding with power for a fair few years and have a good idea of what 300W feels like. Currently getting spin down values of around 850, temperature values seem high compared to environmental temperature. Any folks out there using a Stages with Kickr? Are you seeing them track fairly closely? What sort of spin down values are you getting?

Second question is easier. I know the Kickr is transmitting a speed signal (shown on TR). However, my Garmin is unable to find the speed signal transmitted by the Kickr. Anyone got a Garmin picking of the speed signal from their Kickr?

Many thanks
Jon

Re: Kickr Power and Speed [Jon208] [ In reply to ]

Nov 12, 14 11:30

Post #2 of 66 (7062 views)

I have an SRM so not a stages and the wahoo reads about 20 watts higher always.

Re: Kickr Power and Speed [Jon208] [ In reply to ]

Nov 12, 14 12:31

Post #3 of 66 (7027 views)

Have you tried setting the Garmin to detect a "speed only sensor", I have a gsc-10 (cadence/speed) sensor on the bike that I believe is detected and displayed by TR.

Is it possible in your case that TR is displaying speed based on power + Kickr's known power curve?

My Quarq and my Kickr display values within +/- 2W for what it's worth as well.

Re: Kickr Power and Speed [robin, run] [ In reply to ]

Nov 12, 14 12:49

Post #4 of 66 (7011 views)

I've just spent the evening trawling through the 1393 posts on the DCRainmaker Kickr review and I think I've found the answer to both of these problems:

Plenty of people seem to have a Kickr that reads around 10 - 15% high, from what I could gather they seem to do this repeatably and so many users suggest having and "Indoor FTP" tested off the Kicker which is used for TR etc.

The Kickr transmits speed data as part of a combined power & speed ANT+ stream. At present it doesn't transmit a separate ANT+ speed stream. This means that with my current configuration of having the Stages PM paired with the Garmin I can't get a speed signal from the Kickr on the Garmin. I could pair the Kickr with the Garmin for power but then that'd mess my training data because of the power discrepancy. Think I'll just have to live without Garmin speed data for now and hope Wahoo provide an update that allows an ANT+ speed stream.

Hope that helps others.

Re: Kickr Power and Speed [Jon208] [ In reply to ]

Nov 12, 14 13:39

Post #5 of 66 (6968 views)

It's quite common for people to report higher power readings with a Kickr. I don't have a Stages power meter but do have a Powertap that reports a little low and the Kickr seems to report a little to a lot high. I'm sure the Kickr is reporting high because I don't think that I was holding anywhere close to 300W for a short period the other night since the math doesn't add up based on the RPE and speeds I've logged during any of my outdoor rides. It's annoying but I try not to worry about it too much and instead try to focus on the advantages of having an indoor trainer.

Nanoo Nanoo

Re: Kickr Power and Speed [-W-] [ In reply to ]

Nov 12, 14 15:32

Post #6 of 66 (6919 views)

I have a Power2Max and also have about 20watts higher on the kickr. Did the recommended spin down at the end of a workout in trainer road. Was thinking perhaps of upping the percentage on TR to see if I can get it similar.

Re: Kickr Power and Speed [Jon208] [ In reply to ]

Nov 12, 14 15:42

Post #7 of 66 (6913 views)

I have Kickr as well. Reports about 20 W high relative to Garmin Vector. As mentioned above it does seem repeatable so I work off of different FTP values.

Re: Kickr Power and Speed [Jon208] [ In reply to ]

Nov 12, 14 16:21

Post #8 of 66 (6903 views)

My work around for speed was to get a speed only ant+ sensor and using double sided tape mount the magnet and sensor to the kickr. That way I can have power from my quarq and speed, not that speed is terribly useful indoors but it does help track drivetrain mileage.

Re: Kickr Power and Speed [Jon208] [ In reply to ]

Nov 12, 14 16:52

Post #9 of 66 (6884 views)

My Kickr reads about 13 watts higher than my SRM. I talked to Wahoo support about it and they said that is very common and not bad. Spin down will not fix it. It just is the way it is. I just adjust my ERG workouts +10 watts.

Re: Kickr Power and Speed [Jon208] [ In reply to ]

Nov 12, 14 17:01

Post #10 of 66 (6872 views)

Forgot to mention that my Garmin 910 shows speed from the Kickr. I don't know if you need to setup anything on either or both such as wheel circumference but I did set it up on both.

Nanoo Nanoo

Re: Kickr Power and Speed [Jon208] [ In reply to ]

Nov 12, 14 17:22

Post #11 of 66 (6858 views)

Someone help me out. How is "speed" relevant with an indoor trainer, particularly a power-based indoor trainer?

Amateur recreational hobbyist cyclist
https://www.strava.com/athletes/337152
https://vimeo.com/user11846099

Re: Kickr Power and Speed [refthimos] [ In reply to ]

Nov 12, 14 18:13

Post #12 of 66 (6834 views)

refthimos wrote:

Someone help me out. How is "speed" relevant with an indoor trainer, particularly a power-based indoor trainer?

I'm wondering the same thing and personally think speed is irrelevant with a Kickr. If it's not would someone someone explain why?

Re: Kickr Power and Speed [refthimos] [ In reply to ]

Nov 12, 14 18:28

Post #13 of 66 (6821 views)

Agreed, but if someone is using a multi-player site such as Kinomap, speed could be become more important. I've found the speed on the Kickr (estimated as I'm not using an external sensor) to be very low, but I only stare at the watts and graphs.

Human Person

Re: Kickr Power and Speed [refthimos] [ In reply to ]

Nov 13, 14 6:41

Post #14 of 66 (6709 views)

refthimos wrote:

Someone help me out. How is "speed" relevant with an indoor trainer, particularly a power-based indoor trainer?

Its not but if you are using a powermeter paired with a cycling computer that is configured to stop/start recording based on speed, it is just one less thing to fidget with. Since our bikes already have rear wheel speed sensors, I think attaching a magnet to the trainer one time less cumbersome than having to reconfigure the cycling computer every time you change from trainer to riding on the road.

¯\_(ツ)_/¯

Re: Kickr Power and Speed [Jon208] [ In reply to ]

Nov 13, 14 7:32

Post #15 of 66 (6674 views)

So isn't everyone annoyed with what it look like a pretty big discrepancy in kickr's reported power? I'm actually in the market to get one but reading this and the DCR comments I'm starting to change my mind. In my opinion it's kind of a pain in the ass to have to deal with two sets of power numbers. I've done it when using my road bike with Virtual Power vs my Tri bike with a Power2Max and if you're keeping a training log a la Strava, Training Peaks etc... it totally fucks up your numbers such as total TSS etc... At least if it were consistent from one kickr to another but it seems like everyone is getting a different delta between their PM and kickr so it makes me question Wahoo's quality controls when they can't seem to even calibrate these things correctly.
At this point I'm probably leaning towards getting a Computrainer, at least those things seem to be pretty accurate if you don't mind all the wires and the 1990s technology.

Re: Kickr Power and Speed [sp1ke] [ In reply to ]

Nov 13, 14 7:50

Post #16 of 66 (6656 views)

sp1ke wrote:

So isn't everyone annoyed with what it look like a pretty big discrepancy in kickr's reported power? I'm actually in the market to get one but reading this and the DCR comments I'm starting to change my mind. In my opinion it's kind of a pain in the ass to have to deal with two sets of power numbers. I've done it when using my road bike with Virtual Power vs my Tri bike with a Power2Max and if you're keeping a training log a la Strava, Training Peaks etc... it totally fucks up your numbers such as total TSS etc... At least if it were consistent from one kickr to another but it seems like everyone is getting a different delta between their PM and kickr so it makes me question Wahoo's quality controls when they can't seem to even calibrate these things correctly.
At this point I'm probably leaning towards getting a Computrainer, at least those things seem to be pretty accurate if you don't mind all the wires and the 1990s technology.

Wahoo does sell a calibration kit that hopefully fixes this issue.

Re: Kickr Power and Speed [sp1ke] [ In reply to ]

Nov 13, 14 7:56

Post #17 of 66 (6651 views)

I found the opposite, my Wahoo Kickr reads low which at least makes the workout harder ;) I bought it a week ago.

I think saying it completely f**** up your TSS numbers is an overreaction. Let's say your FTP is 200 and your trainer is off by 10% upwards (220w). Then you do a session with average power of 150w (75TSS I believe), but your Kickr reads 165w (82.5TSS) then your TSS is off by 7. Let's say you do 6hours on the trainer during a week, that's about 42TSS error margin. On a 1000 TSS week, that's a 4% margin of error. The point I'm making is that as TSS error margin is a derivative of FTP/Power error margin, the impact is reduced. If your training plan is so structured that this is a big deal then don't get the Kickr.

If you don't have wheel-based power, take your bike to the shop for a demo. That's the best way to evaluate. I like the open API so you can get a bunch of 3rd party apps to use.

Re: Kickr Power and Speed [sp1ke] [ In reply to ]

Nov 13, 14 8:02

Post #18 of 66 (6643 views)

sp1ke wrote:

So isn't everyone annoyed with what it look like a pretty big discrepancy in kickr's reported power? I'm actually in the market to get one but reading this and the DCR comments I'm starting to change my mind. In my opinion it's kind of a pain in the ass to have to deal with two sets of power numbers. I've done it when using my road bike with Virtual Power vs my Tri bike with a Power2Max and if you're keeping a training log a la Strava, Training Peaks etc... it totally fucks up your numbers such as total TSS etc... At least if it were consistent from one kickr to another but it seems like everyone is getting a different delta between their PM and kickr so it makes me question Wahoo's quality controls when they can't seem to even calibrate these things correctly.
At this point I'm probably leaning towards getting a Computrainer, at least those things seem to be pretty accurate if you don't mind all the wires and the 1990s technology.

I am pretty sure that if you compared powermeters across brands, they wouldn't be that much different than what you're seeing in terms of variance with the Kickr.

Mine seems to be around 10 watts higher than my powertap; I honestly don't know which one is the 'correct' number.

Re: Kickr Power and Speed [lightheir] [ In reply to ]

Nov 13, 14 8:27

Post #19 of 66 (6620 views)

For some reason I got the impression that Wahoo has plans to implement the ability for the Kickr to be paired with an ANT+ powermeter thus allowing the resistance levels to be based on the power meter's output which would eliminate the disparity? Of course Tacx implemented this to some extent with the Bushido T1980 Trainer but the algorithms used to to control resistance in this manner were not very good. If you could not maintain a machine like cadence in an 'Erg' mode workout, the slightest change in cadence (+/- ~3 rpm) yielded huge parabolas in motorbrake resistance and measured wattage (+/- 50-100 watts)

¯\_(ツ)_/¯

Re: Kickr Power and Speed [refthimos] [ In reply to ]

Nov 13, 14 8:32

Post #20 of 66 (6613 views)

refthimos wrote:

Someone help me out. How is "speed" relevant with an indoor trainer, particularly a power-based indoor trainer?

Speed can be translated to 'virtualpower', as per Trainerroad. No, it's not accurate power like a powertap, and no, won't be helpful as a number to use objectively for outdoor training, but extremely valuable to guide indoor workouts and to track progress. If your virtualpower FTP goes up a lot, you're a stronger rider.

Speed on a trainer is one of the most useful numbers when used correctly. Of course, saying "I'm faster than you because I go 25mph on my trainer and you go 22" is fraught with error because of variability between trainers - the comparisons are only valid comparing yourself to your own setup, day after day.

Re: Kickr Power and Speed [sp1ke] [ In reply to ]

Nov 13, 14 8:36

Post #21 of 66 (6610 views)

I'm annoyed by power meter discrepancies and am hopeful that one of the software vendors will finally offer an offset feature. This type of feature could also offer the ability to determine differences between power meters on separate bikes and even graphically show the differences in their power reading curves.

Nanoo Nanoo

Re: Kickr Power and Speed [lightheir] [ In reply to ]

Nov 13, 14 8:55

Post #22 of 66 (6594 views)

lightheir wrote:

refthimos wrote:

Someone help me out. How is "speed" relevant with an indoor trainer, particularly a power-based indoor trainer?

Speed can be translated to 'virtualpower', as per Trainerroad. No, it's not accurate power like a powertap, and no, won't be helpful as a number to use objectively for outdoor training, but extremely valuable to guide indoor workouts and to track progress. If your virtualpower FTP goes up a lot, you're a stronger rider.

Speed on a trainer is one of the most useful numbers when used correctly. Of course, saying "I'm faster than you because I go 25mph on my trainer and you go 22" is fraught with error because of variability between trainers - the comparisons are only valid comparing yourself to your own setup, day after day.

I'm even more confused now. Why would you need speed from a KICKR in order to translate to "virtual power" when the KICKR calculates *actual" power? No I am honestly not trolling, just trying to understand how speed is relevant with a power-based trainer.

Amateur recreational hobbyist cyclist
https://www.strava.com/athletes/337152
https://vimeo.com/user11846099

Re: Kickr Power and Speed [refthimos] [ In reply to ]

Nov 13, 14 8:57

Post #23 of 66 (6591 views)

refthimos wrote:

lightheir wrote:

refthimos wrote:

Someone help me out. How is "speed" relevant with an indoor trainer, particularly a power-based indoor trainer?

Speed can be translated to 'virtualpower', as per Trainerroad. No, it's not accurate power like a powertap, and no, won't be helpful as a number to use objectively for outdoor training, but extremely valuable to guide indoor workouts and to track progress. If your virtualpower FTP goes up a lot, you're a stronger rider.

Speed on a trainer is one of the most useful numbers when used correctly. Of course, saying "I'm faster than you because I go 25mph on my trainer and you go 22" is fraught with error because of variability between trainers - the comparisons are only valid comparing yourself to your own setup, day after day.

I'm even more confused now. Why would you need speed from a KICKR in order to translate to "virtual power" when the KICKR calculates *actual" power? No I am honestly not trolling, just trying to understand how speed is relevant with a power-based trainer.

Sorry, I interpreted your post in the context of a typical fluid trainer, not a Kickr.

For an erg mode trainer like the Kickr, you don't need the speed number, just the power number. So yes, for a Kickr, speed not relevant. For fluid trainers without powermeter, speed is very relevant.

Re: Kickr Power and Speed [lightheir] [ In reply to ]

Nov 13, 14 10:49

Post #24 of 66 (6544 views)

Like someone else mentioned, you might also just want speed / distance to track component wear.

Re: Kickr Power and Speed [Jon208] [ In reply to ]

Nov 13, 14 12:15

Post #25 of 66 (6510 views)

I have a Kickr and a Power2Max on my bike, and my Power2Max has always displayed a higher power number than my Kickr.

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