Tag Archives: crank arm

Gear Review: Stages Power Meter

Stages DuraAce 7900 Power Meter

Stages DuraAce 7900 Power Meter

I figured after an entire season of using the Stages Power Meter I was in a good position to be able to fairly assess the product. This is not a highly technical review, but more of a review of my experience with the product and my dealings with the company support. If you are looking for a more in-depth, technical review of the product and comparisons to other products, check out DC Rainmakers’ reviews here and here. I never buy anything without checking DC Rainmakers’ reviews first.

Stages DuraAce 7900 Power Meter

Stages DuraAce 7900 Power Meter

Being a triathlete and a bit of a techno-geek, I was chomping at the bit to get a real power meter. The prices of them definitely had me putting this off for sometime. I also started coaching myself and felt that this was critical to properly assessing and measuring my bike workouts. I thought the money I saved from a coach would help to cover the cost of the power meter. Many units are well over $1000, but the Stages Power Meter came out which was the first real possibility for under $1000.

Cycling, Stages, bike, component, gear, power meter, thing, watts

Stages Power Meter with black electrical tape

I had a little introduction to using real power/watts with my Kinetic inRide unit on my Kinetic Trainer. The only thing is this only works on my trainer, when I am using TrainerRoad. I really wanted to quantify my road rides now that I had a little taste. I eventually added the the Cycleops/Powertap Powercal power/heart rate monitor which calculates your power based on a heart rate algorithm. While this seemed to do a pretty good job assessing an entire ride based on the averages, the instantaneous measure was all over the place. I also had my doubts about its accuracy given that you provided no individual input other than your heart rate. Despite is magically does a fairly decent job for a $100 power meter.

I broke down at the start of the 2014 training season and purchased the Stages Power Meter and replaced my Shimano Dura Ace 7950 left crank arm with the Stages version. It was around ~$900 and change. I probably could have installed this myself, but they recommend using a torque wrench to do it and I have yet to purchase one. Instead I decided to head out to see John at my favorite bike shop, Sleeping Dog Pro Cycles, and have him do it correctly. He indicated that I probably didn’t need to a torque wrench to do it. Ready to roll.

Pros

  • Cost <$1000
  • Accuracy
  • Great support
  • ANT+ & Bluetooth(BTLE)
  • Firmware updates easy
  • Installation(relatively easy)

Cons

  • Portability
  • Single-Leg Measurability
  • Battery cover sealing issues

The unit worked well from the beginning. Since it was Winter when I put it on, I was mostly using it on the trainer in the basement with TrainerRoad. Since I also had the Kinetic inRide going too, I tended to have conflicts with that over Bluetooth. Usually the inRide would prevail, but I was never really sure which meter was being used. I eventually figured out that I could determine which by doing single leg drills with my right leg, since the Stages would not show power when I did that. TrainerRoad has since done a better job of distinguishing the two and have separate lines for both now.
This was more an issue with what hate about Bluetooth(BTLE). You can only pair one specific type of device to a computer/phone at one time. And this is better why? This is why I still prefer ANT+ over BTLE and I think ANT+ will be around for awhile because of this limitation. The nice thing about the Stages Power Meter is that it has both ANT+/BTLE so you are not pigeon-holed into one communication type.

Cycling, Stages, bike, component, gear, power meter, thing, watts

Battery compartment door of Stages Power Meter

The cost of the Stages Power Meter was surely the most appealing factor to me. Although as I write this, several other companies have announced new power meters in this price point just in the last week or so. One is that Garmins’ new Vector system now has a one-pedal option for about $800 with the ability to upgrade to two pedals in the future. The nice thing about that system is that it is easily tranferrable to another bike.
My biggest issue with the Stages device was after I had broken of a couple of the small tabs on the battery compartment door which allow it to lock in place. After I did that I was not able to lock the door in place. I notified Stages and they quickly mailed me out a couple new doors and gaskets. The Stages support is outstanding and they are very responsive to your issues. The new doors still would not close shut, so as a temporary measure I wrapped the unit in black electrical tape.

Cycling, Stages, bike, component, gear, power meter, thing, watts

Backside of Stages Power Meter with black electrical tape

The tape worked fine until I decided to give my bike a good thorough washing. Then it stopped working. Ahh!! Turned out it just shorted the battery and after replacing it with a new CR2032 I was back again. I decided to take a harded look at this situation using a flashlight and a magnifying glass. Turned out one of the tabs that broke off were lodged inside and was keeping the new door tabs from locking. I extracted the broken tab and the doors immediately locked shut. I could have left the electrical tape off at this point, but with my A race at Ironman Lake Placid coming up, I didn’t want to take any chances.
I am glad I did that I took that precautionary measure because we experienced a deluge of rain at IMLP this year. Despite that my Stages Power Meter continued to output my power readings to my Garmin for the entire 112 miles. Some others were not as fortunate. Like my friend Shanna would also has a Stages meter which failed on her during IMLP this year. I think I will keep wrapping it with tape from here on out.

Stages Power Firmware Update on iOS

Stages Power Firmware Update on iOS

Firmware updates for the unit come out very frequently which is nice to know that that are always looking to fine tune the product. The updates are done via your iOS device or smartphone which is convenient. You have to keep the unit triggered so I usually do it will I am riding with my iPhone in the back of my jersey pocket. I have not had any issues doing this.
The unit is very accurate from what I have seen. More importantly it is consistent though. But the numbers I get with my Garmin showing the 3sec avg make sense to me and are not jumping all over the place like the PowerCal did. I am loving training with this tool now. My Garmin 910xt screen now just displays 3s Power, HR, HR zone and Time. I don’t even look at my speed anymore, which doesn’t tell you much anyway unless every possible variable is the same every time. Which it never is. I can also now plan ride workouts based on power zones which has made a huge difference in my riding.

Cycling, Stages, bike, component, gear, power meter, thing, watts

Side view profile of power sensor. Stages Power Meter left crank-arm

The fact that unit only measures one leg could seem like a big one, but I really don’t think it is. Maybe if you are an elite or professional it may be something you need to look at, but for the typical age grouper, we have so many other things to work on this is minor.
All in all I have been very happy with this product. I would recommend it to anyone looking to take their training and races to the next level without breaking the bank. The company is doing well and they firmly stand behind their product. There should be some major advances in power meters coming down the pike so who knows how this may change by tomorrow.

Hope this provided some help and thanks for reading! 🙂