Quinn8it

i thought i would post up a review on the Stages Track Power meter, since its a very new product, and while there have been some reviews of the road model, i haven’t seen any for the track version yet.

A little about your reviewer:
I'm a kilo/Sprinter guy- typical big boy weightlifting type. recently my weekly training has been a day on the Ergo, a day at the indoor track (VSC) and a day at the outdoor track (encino), in addition to weights and roller workouts.
I have had a power tap wheel on my road bike for a few years, and did track style training on that bike regularly at one point a couple years back. For the last year i have had a wired SRM power meter on my Ergo- point being that i have 2 reference points to compare the stages data to, but at the end of the day- I live and die by the stopwatch! Any training effort over 250m is self-timed with a stopwatch, and any effort 250m or less is timed by others- that said, i am not that analytical. i don't pour over my data files. I race for times, not watts. So i watch the basics. 5 second power, 10 second power, 30 second and 60 second. i use a Garmin 500 to collect the data- once again- im not overly concerned with the rate at which it reads, i know others are.. I view my files on Strava- also not the most involved training software, but it allows me to see what i want to see. ie: How do today’s efforts compare to my best efforts over the last 6 weeks, and how does the last 6 weeks compare to the entire year. trending up- i hope! My view is, i got pretty fast without much power data, so now that i am adding it in i'm not really changing things much, I can just see more. i find that i use it mostly for tracking progress after workouts and tuning ergo efforts to track efforts- making sure watts and cadences are the same (or higher) for a given time interval, i want my garage training to be as relevant as possible. I do zero on bike pacing with power- my garmin is mounted under my saddle and not visible. I run my efforts how i always have- under 250m are full gas always, and over 250m are paced by time..

The track version of the Stages is only available in Dura Ace. Thats great if you are on DA- i was not. So that was an added expense, but i viewed that as an upgrade, so its not that bad. I bought the DA crank around the same time i ordered the Stages arm. Stages website says “shipping in 4 weeks”. At 4 weeks i called, and was told my crank was built, but waiting on a battery door. i received it at about 51/2 weeks.

The piece itself is beautiful. The crank is barely modified, only a small black piece on the inside of the non-drive side arm. It installs in a minute and that's it- you are in business- power data on the Garmin- everything looks good. (yes, you end up with an arm you are not using)
The Stages has a cadence meter inside- so there is very little to attach to the bike. I added a Bontrager Ant+ Speed sensor, since it was one of the few front wheel and non-cadence sensors available..

one small issue- stages plays down the need to calibrate. I'm not sure if it is less necessary for the road version? the manual says “be sure to calibrate after installation”... so i did and then did a few training days without ever calibrating it again.. my numbers across the board were low compared to my ergo numbers. consistent, but low. I realized that i probably needed to calibrate it more often and started to do that- before every session, and when i change my gear after warm-up, and again when i put my sprint bars back on. I suspect i am now calibrating too often but results have been good.

One interesting feature of the Stages is that it speaks Bluetooth and Ant+ so you can feed rides straight to your iPhone (strava or wahoo) and you can use the Stages App to check for firmware updates and (this is awesome!) calibrate the power meter. I actually got an iPhone after i got the Stages, and it makes calibrating a simple 10 second thing… Calibrating with the Garmin is somewhat clumsy. You have to click through a few screens to get to the calibration and garmin did not always find the Stages right away and had trouble calibrating. Sometimes the Stages would time out before the Garmin had calibrated, requiring you to “wake up” the stages and try again.. now that i have an iPhone- there are zero issues..

As far as operations go- it works like every other power meter I've used. My data from all 3 of my different sources line up very well. no issues as best i can tell. I ended up using the Stages for a solid 5 weeks (that starts after i started calibrating it) on my build up to my last event of the year.

I know that the fact that Stages only collects data from one crank arm was a big point for a lot of people. I've read the arguments and forum post- i had a lot of time to think about it during the 6 weeks it took to arrive. I just don't see any issue from it. I dont see anything weird on the track i don't see anything weird on the rollers.. numbers line up between the SRM and the Stages.. for me its a non-issue.

so like DC Rainmaker says “Would I buy it again?”- well, i did! after about 3 weeks with the track version i decided to switch from the power tap on the road bike to the Stages. This time it only took 3 weeks total for my Sram Rival non-drive crank arm to arrive.. its installed- but im on a 2 week break.. so no rides yet!


I hope this was interesting to some of you- thanks for reading

-Q

carleton

I've been curious about this power meter. Thanks for the review! How much is it?

Quinn8it

oh yeah! Good question!
Dura Ace Track Arm 165mm= $899.99

Sram Rival road arm 165mm=$699.99

carleton

Not bad. Much more affordable than the other options.

Being that SRM uses the Dura Ace BB and the power meter is on the drive side, maybe someone will install this crank arm on the non-drive side and compare the results.

Dalai

Good idea. I ride 170's... Currently even using a Dura ace arm on the left. Thanks.

Quinn8it

DC Rainmaker did a couple thorough reviews where he had as many as 4 power meters running at the same time. (Power tap, quarq, stages, garmin vector)

It seams that none of them line up exactly all the time- at least to the watt, but they are all very close.

One interesting thing is that he picked up variable power readings from different head units reading from the same power meter.. Ie: reading a stages meter with one head unit on the ant+ frequency and one on Bluetooth..

The Stages excels in situations where tempature changes might throw off other meters, although this is likely more of a benefit on the road..

carleton

I contacted DC Rainmaker 2 years ago and had a brief conversation with him about a suggestion he could make to these manufacturers since they listen to him.

The SRM head unit is the only unit on the market that samples from power meters as fast as every 0.5 seconds (every 0.1 second for the Scientific model). Every other head unit samples every 1 second or more. Powertap samples, I think, every 1.25 seconds.

This isn't a big deal for roadies and trackies that do long efforts. But, for track sprinters, sampling at a faster rate gives much more useful data. When analyzing files from short efforts, you get TWICE as much data as the next head unit. Analyzing a 12" trap of a flying 200M with a Garmin would give you 13 (12+1) data points. The same effort using a SRM head unit would yield 25 (24+1) data points. You will be much more likely to catch the true top speed (the most telling metric) that way.

Changing the sampling frequency is a very easy thing for the head unit manufacturers to do. Many already have optional settings to record every 1, 2, or 5 seconds. Why not just add 0.5 to that list?

DC Rainmaker thought it was a good idea and he said that he would mention it. But, I never heard back from him on it even after asking for an update

carleton

I just found out that the newest SRM Powercontrol 7 head unit will record 4 times per second! That's 49 (48+1) samples for a 12" flying 200M.

Quinn,

If you can get an ANT+ SRM head unit, it should mate up just fine and you'll get the faster sampling rate.

https://www.srm.de/products/powercontrol/

But, it costs $950

Impreza_aL

in theory you can put your rival arm on your omniums?

i wanted to give this stages pm a try but i didn't want to switch over to DA. i'm too attached to my campy. since i don't train at the track the motivation to get one is pretty low. i would just like to see what kind of power i put out during a mass start race.

Quinn8it

yes-
the power meter is not limited- its the Garmin..
Stages will be making their sample rate even faster-
https://www.dcrainmaker.com/2013/09/c...streaming.html

the faster sample rate could work for me if i put Stages on my Ergo- where it would be easy to use the iPhone as my head unit..

yes- but it is my understanding that the Q-Factors are different between Rival/Omnium

Quinn8it

I don't disagree with you in theory- and I don't dispute that there may be some benefits.. I guess I just can't really see how the slower sample is such a negative...

I don't really even pay attention to 1-sec data- 5", 30", 60".. That's what matters.. And if I didn't hold a top speed for a second.. Did I ever really get there?

carleton

I agree that average power, cadence, and speed are great metrics. But, especially for sprinting, max values are important, especially for fine-tuning. For example, as you know, the Flying 200M is an event filled with nuances. And the key to doing a PB kilo might be 1 gear inch (up or down).

I really believe that more athletes should analyze the data from warmup efforts to gauge how they are riding that day as well as how temperature and atmospheric conditions are affecting them. Having more data takes the "gut feel" about gear selection and makes it more empirical.

I, for one, look for a certain max cadence when I choose my F200M gear. Depending on what cadences I hit on my race gear during warmup efforts, I'll take that data and adjust the gear for the event. Some days I can get "on top" of a gear, and some days I'm always "behind" it.

All of the above wouldn't matter for most racers. But, this could be a valuable tool for coaches or self-coached athletes.

Imagine if a coach asked all of his/her athletes to use normal Dura-Ace cranks. This isn't a big deal being that now many coaches ask their athletes to have power meters on both their road and track bikes. Running normal DA cranks is MUCH less expensive. Now this coach buys 3 Stages cranks in 165, 167.5 and 170mm plus one good head unit (like the SRM unit mentioned above). This coach could then, on a whim or in scheduled "test days", install the crank arm on the athlete's bike and have data instantly. This could also be used to teach a pursuiter what the prescribed wattage feels like or get baseline splits during pursuit efforts.

I think this would be great for coaches of Juniors or College athletes who simply can't afford full on SRMs (and shouldn't feel the need to).

Maybe a track could buy sets and rent them out. It's much less drama than installing other systems (save maybe Powertap rear wheels).

I know plenty of people who like the idea of power meters, but don't want to dive in and spend $3,000.

carleton

Oh, and there were two questions that one of those world-level coaches would ask me after every timed event (F200M, 500M, or Kilo):

- "What was your max speed?"
- "What was your max cadence?"

Impreza_aL

there are only a few people with a pm at hellyer.

sadly all our notably sprinters have retired... milroy, billington, gio...

we have a lot of mass start racers who can do 11.5-12 flying 200s. which i think is pretty respectable.

Quinn8it

It has been my experience that Max-Watt values often (for me always) come in special situations.. typically slower rolling jumps often in a smaller gear. So i will often hit my max watt for a session in warm-up.... Last Sunday i rode a PR 200m by 1/4 second- did not hit max 1-sec power or even 5" for that matter..

how are you going about analyzing partial second data and what conclusions can you draw and what changes do you make based on that data?

carleton

One question that that coach never asked me: "What was your max wattage?"

In terms of metrics, Speed is king. Cadence is the Prince.

Just like in a car, acceleration is maximum when the engine's RPM (cadence) is in the right range. Same with us.

Rich Voss looked at one F200M files from TTown and deduced that I was jumping too early and coming in too hot in my windup. He suggested that I slow down and do an Earl Henry style F200M. I shaved 0.5" the next time I did a F200M. Basically, the cadence from which I was jumping was too high for me go generate a lot of acceleration (and subsequently speed) into the 200M start line.

Also, as I mentioned before, I can quantify what "on top of the gear" means. For me, it's a max cadence 140-144 RPM. If I roll 130RPM in a bigger gear, I'm sluggish and that usually costs me maybe 2-3 tenths of a second.

brb...work...

carleton

So, pouring over my files during one season, I noticed that my Max Speed as Man1 Team Sprint was HIGHER than my Max Speed in the flying 200M on the same day.

I thought, "Surely that's just a peak. The average over 200M is faster in the flying effort..."

So, I took a 12" section of both efforts. (I use 12" for any Flying 200M wither I do 11.5 or 12.5" to stay consistent). The 12" slice of the Standing 1 Lap effort was faster than the 12" slice of the flying 200M. WUT?

Voss confirmed what I had been experiencing. I was getting "burned up" during my wind ups. I was burning glycogen (turbo juice) during my windup and firing at a diminished rate during the jump for the 200M start line.

Think of the normal f200M windup being like a fighter jet that flies at a high speed then dumps fuel into burners and turns on the after burners. That takes a lot of fuel. My standing start efforts are like a rocket taking off from the ground. I was consistently the same or faster from 0 MPH. The numbers didn't lie.

So, being that I couldn't do a "Standing Flying 200M" in comp, I adjusted. I relaxed during my 2.5 lap windup and never tapped into my glycogen stores...then when the time came, I did what was essentially a low speed Standing Start into my Flying 200M. It worked.

This probably won't work for most people. I think I have a really high percentage of fast twitch muscle fiber and a very low percentage of "fatigue resistant" fibers. I generally suck in any event over 1 minute, group rides, road rides, etc... If I had a better mix of fatigue resistant fibers, then I could do a more conventional windup and probably faster than with this windup.

Quinn8it

good story...

but i don't see how faster than 1sec sample times played into that.. or even power data..

and the thing is- Rich Voss or almost any decent coach could of fixed your wind up and jump just by watching you ride..


I am trying to understand how "sampling at a faster rate" is so important and how one would use that in data analysis?

carleton

You would think. I had many notable coaches watch me ride and offer tips (Steve, Jenny, Jeff Hopkins, etc...) and I never got that advice. It was a huge mystery to me (and them).

Also, some things that show up in files that is hard for a coach to see: Floating on the pedals. This is such a useful technique in the Flying 200M windup and the Kilo. There are times when you press, there are times when you press hard, and there are times when you float. Pressing when you should float wastes energy.

Regarding sampling rates. More data provides higher resolution. Meaning that outliers (unusually high or low values) won't skew things too much (if at all). We all get crazy blips in our readings now and then.

Also, when it comes to data, more is always better. This is why, in that link you sent, that Stages brags that that they can sample 64/second.

In a perfect world, there would be constant readings. Instead of dots in a graph with straight lines connecting (interpolating, guessing), there will be a solid line of data that was witnessed instead of estimated. This estimation is really just taking the average between the two readings and guessing that's what happened between them.

carleton

You would think. I had many coaches/friends watch me ride and offer tips and I never got that advice. It was a huge mystery to me (and them).

Also, some things that show up in files that is hard for a coach to see: Floating on the pedals. This is such a useful technique in the Flying 200M windup and the Kilo. There are times when you press, there are times when you press hard, and there are times when you float. Pressing when you should float wastes energy.

Regarding sampling rates. More data provides higher resolution. Meaning that outliers (unusually high or low values) won't skew things too much (if at all). We all get crazy blips in our readings now and then.

Also, when it comes to data, more is always better. This is why, in that link you sent, that Stages brags that that they can sample 64/second.

In a perfect world, there would be constant readings. Instead of dots in a graph with straight lines connecting (interpolating, guessing), there will be a solid line of data that was witnessed instead of estimated. This estimation is really just taking the average between the two readings and guessing that's what happened between them.

Quinn8it

you are aware that you argument for faster sample times sounds suspiciously like this:


and to be totally clear- im not in disagreement, i am just looking for an explanation of how this data can be utilized

carleton

hahahaha

Then why does SRM do it? Why does the Stages iPhone app do it? Why did DC Rainmaker write this?

Quinn8it

I dont know. I am not trying to be argumentative-

you are an advocate of faster sampling and i am honestly asking you how i could better analyze data if it was collected at a faster rate and what i would then do with that information?

carleton

I started racing using a Powertap head unit (but no powertap hub). So, I had speed, cadence, time data every 1 second or so. Then I switched to SRM and immediately saw the difference in the samples in the file even just comparing speed and cadence data, not power. It was literally double the data.

If some data is good. More data is better.
If some data is good. Less data is worse.

There is a point where a certain amount is enough. But, it is not a 1 per second. It's more like 2 -5 per second. That would be optimal.

carleton

Here is an SRM graph from Brian Peterson during a Team Sprint effort (from Gio's site), measured every 0.5 sec.

https://giovannirey.blogspot.com/2008...ort-stuff.html