Magene PES P505/P515 Power Meter Crankset - ±1% Accuracy, 625g Lightweight, 330H Battery, 110BCD, ANT+/Bluetooth, IPX7 Waterproof for Cycling

I've been using this close to a year now and it works flawlessly. Installation was easy enough for an amateur home mechanic to do. It is accurate and consistent. Battery lasts a LONG time; I have charged it maybe 2-3 times in the past year and it's never died on me. Fits Shimano 105 chainrings perfectly. I can absolutely recommend this product.

Competitively priced and amazing quality. +1- accuracy. No complaints and seamless fit with Shimano 24mm spindle. Swap and play!

I received it yesterday , i have Scott addict with shimano 105 drivetrain . My bike mechanic installed it for me without any problems , he used the original shimano chainrings . I charged the meter , downloaded the app and requested the code several times without receiving a response . Finally i checked the junk mail folder and found the code. After a few attempts the app found the power meter . I took it on one ride , it updated quite rapidly , I hit 400 watts going up hills but only for a few seconds before i started to slow down . Now i will ride the watts to keep my rides intense . I also have a very accurate estimate of the calories burned . So far I love it . I will be updating . Too bad I can’t figure out how to get a few extra charging cords . I may have to call Magene . Magene responded to my email with a link showing where to buy extra charging cables, I ordered 2 for my piece of mind , it will be shipped from china . I think they should ship the power meter with an extra charging cable . I did my second ride today with the power meter , it functioned flawlessly , it updated quickly , it showed 100-150 watts on level roads , 250-300 watts with the slightest hills . My Cyclemeter app paired easily with the power meter , it shows that battery level is still 100% after 2 rides . The power meter paired easily with my Garmin edge 830 , I created a data screen showing watts and cadence , along with radar and wind data . I hate clutter . So far so good .

The design, construction and performance of this power meter are on par with products 100% or more expensive. We now have to wait and see how it stands to everyday use. If it lasts 3 to 5 years, this is an excellent choice, especially if there is a need for various power meters for different bikes. Assembles with no fuss, connects immediately with your cycle computer. If you have Shimano GRX, you may have to order a 110 bcd for the smaller ring. Usually GRX has a 30 tooth smaller chain ring which is a 96 bcd. The smallest 110 bcd that will fit in the Magene spider is a 34 tooth chain ring.

4mo update. I’ve tested this against my Favero pedals, Kickr and power is dead on with the other power sources, I’ve also had zero issues or drops. This powermeter is amazing, best value out there I switched from a Quarq to this and I’m blown away at how good it is. Power matches my 2 Quarqs perfectly. Zero offset is stable with no drift. The only recommendation I have is to pay close attention to the install instructions, while it looks like a standard shimano crank install there are 3 specific steps for tightening down the crankset that need to be followed closley

Thus far I’ve put on around 600 miles with these cranks and all is going well. As I already had a Shimano bottom bracket and crankset the move to the Magene PES P505 power meter was simple: remove the old Shimano crank, assemble the PES crankset, move over the chainrings (with their Shimano bolts), tighten everything to proper torque specifications, and go! After approximately 100 miles of riding, re-check torque - all good! I used a known-good set of Favero Assioma power meter pedals to compare readings and the Magene unit was within 0.5-1 percent in terms of power readings - so basically a 1:1 equivalent. You will need a flat interface, open-ended external bottom bracket wrench to install the power meter spider on the crankarms - worth buying at the same time as the cranks if one isn’t in the tool kit already. And if you need chainrings the Magene ones are good, tho Shimano 4-bolt 110mm BCD units for recent vintage 105/Ultegra/Dura-Ace work well and probably shift better - you’ll need Shimano’s bolts if not moving them from an existing Shimano crankset. Also: be sure to use blue thread locking compound on the chainring bolts and the power meter spider, and lightly grease the left crankarm to crank axle interface (or use nickel-based anti-seize fluid). The bolt on the left crankarm has blue thread locker pre-applied. And be sure to double-check torque values after around 100 miles of “bed in” as things can loosen with use. Otherwise: it is a solid crankset for a bargain price, easily as good as a SRAM/Quarq unit.

Lasted 8 months. Worked great and then the crank started to wobble. Went to the bike shop multiple times and no matter how much they tried to tighten the crank it kept loosening on every ride until the shifting became impossible. Went online and apparently other people have had this issue. Will contact Magene and see if there is a way to resolve this issue. Will update if I hear back from them.

Let me first admit, mine is not a typical usage of this product. I'm 64 and I put a moderate 15-minute spin on my exercise bike every other day, just to "clear the cobwebs". The bike is a 25-year-old felt-pad-resistance type and I keep it on a covered outdoor patio. The problem I encountered is: It's anybody's guess how much work I'm putting out from one workout to the next. Am I doing better? Am I getting worse? The actual resistance is dependent not only on the tension knob but also the weather conditions, the inherent inaccuracy (backlash) of the tension mechanism itself, whether the felt pads are damp, how far pads have heated up from my peddling so far, etc. I want to do a consistent caloric output (or wattage output) on every workout. So I decided to get this metering crank. The nice thing about this is it doesn't matter if your bike cost $5000 or $5, is stationary or road, this measures output at the crank via an internal strain sensor. My exercise bike had a standard (aka Ashtabula, American) bottom bracket (BB), so before I could install this thing I had to do a two-phase BB conversion. Phase one goes from Ashtabula to Euro (aka BSC, BC, ISO, British) See "Black Ops BB Conversion Kit American to Euro", which is essentially just a pair of internally threaded bushings. Phase two goes from Euro to PF41 (aka BB86, PF24, Shimano 24mm) using the Shimano BB-MT801 kit. Look on YouTube if you need your hand held doing either of these. Since my exercise bike had 1/2 thread pedals, I also had to buy a new set. This crank uses standard 5/8 thread pedals. UPDATE: It seems I sold myself short. After months of using this crank and witnessing my performance actually decline, I was a bit incredulous. So I tried the OneLapFit "zero calibration" function for my crank (which I probably should have done immediately after installing). Now my new normal continuous NP power reports as 170W. Take that you young whipper-snappers. Oh, and I also had to get a 4-arm chain ring with 52 teeth and a 110 BCD. The 52 teeth matches my bike's original chain ring, which lacked the bolt holes. The documentation is really sparse. The assy diagrams are good, but there's no text, just pictures. I suppose they're trying to be universal. What do the LEDs mean during charging? Where do I go and download the app? No mention. I'm not a bike mechanic and have never worked on bikes, but the hardware installation went smoothly. Just be aware that most of the parts are dedicated right or left and have right or left hand threads. Don't go forcing anything. Watching the YouTube vids before you assemble is a must. Also, unless you're an enthusiast, you probably won't know this: In order to get a summary of your workout, like I do, you will need a bike computer. Not wanting to do a week of research on what was the best computer to get, I just went with the Magene C406 --which ended up working fine. See my separate product review of that. So now I can report that I can do 170W average power output for 15 minutes and moderate effort, with a 42 cadence, and pretty good left/right balance. That's nothing to be proud of, but probably OK for age 64.