Power meter suggestions for T47bb bike

[samky]

As title states, looking for input on power meters and long term user experience for a two brands.
I originally didn't want anything too crazy (<$300) as this will be my first power meter apart from using a wahoo kickr during winter/spring. So I've been looking at a few china options but have also considered mid tier options as well.

Magene P505 - $233 shipped is my #1 choice, but the bike frame i've ordered (elves falath evo+) has a t47 bb and magene states the p505 is not compatible with t47, however thru searches on here and various forums ive seen some have been able to install the p505 on t47 bb. I believe the evo+ will have an internal 85.5mm from what I can figure. If anyone has has success/experience installing one on a t47bb let me know!

Xcadey left side power meter - $190 shipped- https://www.aliexpress.us/item/2251832812903949.html
Looks like it would be a good fit, no worries about compatibility with the Shimano 105 2x12 i ordered. However I can't find much long term user reviews on this. My main worry here is waterproofing and failure after long term exposure to elements. I've read some comments in discussions from 2+ years ago on various yt videos, forums etc stating that once exposed to rain they fail but I cant tell if these are the old version or current version offered on aliex.

Other options: Favero mx-1 PM medals (I prefer spd mtb shoes for road biking) on a black friday sale (if there is one) - price would probably be around 350-400 on sale as far as I can tell from previous BF sales. This would be a buy once cry once option.

I know there are a few other brands of left side PM such as 4iiii, stage (out of business so no support), wondering if I'm missing any good quality options for a budget PM. Or if there are any new PM coming from these brands that would potentially make older models decline in price next spring, as I dont necessarily NEED a PM right this instant. All insight welcome, Thanks!

[CountUgolino]

This is probably not going to be a popular opinion on this forum, but I would buy a used Quarq.  I have had two Chinese power meters, one stopped reading cadence (no power without cadence) and the other broke during a rainy 600k.  The Magene seems to have good reviews and seems like an overall solid product, but I have 3 Quarqs, and I purchased each one used for less than the price of a new Magene.  Between my Quarqs, I have over 20,000 miles and have had zero issues.  2 of them are currently on T47x85.5 bikes-- no issues there either.

[Sakizashi]

Right now, i would probably get a rotor in power as their axle-based PM crank is currently 267USD for black friday: https://rotorbike.com/rotor-inpower-dm-road-gloss.html

[samky]

This is probably not going to be a popular opinion on this forum, but I would buy a used Quarq.  I have had two Chinese power meters, one stopped reading cadence (no power without cadence) and the other broke during a rainy 600k.  The Magene seems to have good reviews and seems like an overall solid product, but I have 3 Quarqs, and I purchased each one used for less than the price of a new Magene.  Between my Quarqs, I have over 20,000 miles and have had zero issues.  2 of them are currently on T47x85.5 bikes-- no issues there either.

Yeah getting something non chinese QC'd and supported for electronics is probably the most reliable long term, but the price and huge user base of the magene is super attractive for a first time power meter user.

@Sakizashi thats a killer deal! thanks for sharing. Although maybe you can help me with this... I'm mechanically inclined but when it comes to bikes I've been having to do a ton of research regarding what fits what, what components can work together etc, as there seems to be a vast difference of standards between brands lol.
So correct me if Im wrong.
I have a shimano 105 r7100 52/36 crankset being shipped to my house currently that I got from aliex for $120. (which is why I was looking at left sided shimano crank arms originally) To use the rotor brand, Id need to get a 30mm t47 bb for my frame instead of the t47 24mm that I currently had ordered with it? + a different spider to support the shimano gears I already have? Or just go full rotor gears as well? The only reason I was wanting to keep shimano gears was simply because I ordered an 8100 series cassette/chain for hyperglide+ ability (not sure if its worth the extra or not but figured I'd try it) and wasn't sure If a different crankset would affect that, but as far as I can tell HG+ is only at the rear.

[Sakizashi]

Yeah getting something non chinese QC'd and supported for electronics is probably the most reliable long term, but the price and huge user base of the magene is super attractive for a first time power meter user.

@Sakizashi thats a killer deal! thanks for sharing. Although maybe you can help me with this... I'm mechanically inclined but when it comes to bikes I've been having to do a ton of research regarding what fits what, what components can work together etc, as there seems to be a vast difference of standards between brands lol.
So correct me if Im wrong.
I have a shimano 105 r7100 52/36 crankset being shipped to my house currently that I got from aliex for $120. (which is why I was looking at left sided shimano crank arms originally) To use the rotor brand, Id need to get a 30mm t47 bb for my frame instead of the t47 24mm that I currently had ordered with it? + a different spider to support the shimano gears I already have? Or just go full rotor gears as well? The only reason I was wanting to keep shimano gears was simply because I ordered an 8100 series cassette/chain for hyperglide+ ability (not sure if its worth the extra or not but figured I'd try it) and wasn't sure If a different crankset would affect that, but as far as I can tell HG+ is only at the rear.

I would confirm this with Rotor, but I believe you would need a 30mm T47 BB, and Rotor chainrings. The chain and cassette you ordered will work fine. I would also get a spacer kit with 0.5 and 1mm spacers.

[samky]

I would confirm this with Rotor, but I believe you would need a 30mm T47 BB, and Rotor chainrings. The chain and cassette you ordered will work fine. I would also get a spacer kit with 0.5 and 1mm spacers.

Yeah seems you're correct. As far as I can tell, the only way is to use rotor chainrings, unless I found an adapter for rotor crank to shimano gears, would be $400 shipped for the crank+gearset. Guess that would leave me the option to return or resell the 105 crankset, but at the same time i've been reading that rotor shifting isnt nearly as good as shimano, not that I shift up front that often anyway so it probably doesnt matter that much.
Also I really cant find all that much information on the inpower performance.

At that price point probably just best to wait and see if I can pick up a set of favero pedals during a black friday sale

[Serge_K]

Purely anecdotal, but I'm still rocking my Garmin vector 2 single sided after yeaaaaars of use. Road platform obviously.
Are you sure you will continue to use MTB pedals for road? I guess if you use carbon soles it matters less, but the road platform is wider and feels nicer.
I really like pedal based power meters. You can travel with one pedal, have different bikes, if you want to upgrade bikes, you're not leaving money on the table. Your power readings are always consistent because you use the same device.
I suspect that crank based power meter hype is in part due to groupset manufacturers wanting to charge top dollar for their stuff, and saying "loooook, it's got a power meter, so ofc it costs 5k".

[BikerJens]

I can’t give a long term review of the Magene P505, but there have been absolute Zero errors or concerns after around 4000 km on mine. And I’m not made of sugar and lives in Denmark, so I will guess atleast 1000 of those are in wet conditions.

Also, they are expanding quite a lot in the market. So I picked it up at a “local” dealership. So I have easy warranty etc. close by.

Regarding the MTB pedals.. I had those in the begining too. They came with my first bike. The difference it made when I changed to SPD - both comfortable and power wise. Wauw.

[carbonazza]

This is probably not going to be a popular opinion on this forum, but I would buy a used Quarq

As a counterpoint, my first road Quarq suddenly started gifting me about 500W average power on my rides... unfortunately, just two months after the two-year warranty expired.

SRAM support was very kind and offered me a replacement. I only had to pay for the GPX to DUB conversion (my choice).
Meanwhile, both my XCADEY on the MTB and the Quarq on my gravel bike have been running strong for years, despite frequent mud plastering.

The takeaway: all devices are probably reliable, but bad luck can strike sometimes. A confirmed reliable user support is key.

[Da11as]

First of all, for the training purpose I highly recommend NOT to jump between readings from your trainer and PM. Better stick to the same device i.e. use PM on your trainer as the power source.
Secondly, don't be a cheapskate on PM, if you want something good yet affordable, check P2Max NGEco. This is one of the best and most reliable PM on the market.
I suggest you to go NGEco+Rotor 24mm crankset. In such way you will get highly adjustable reliable modular system with good axle that will fit almost any BB standard. I got 2 PM from P2Max: one with Sram 3 bolt interface and another with Rotor interface. You can then transfer PM between bikes if you decide to jump on another frame.
I was stupid enough to sell the Rotor PM with one of my bikes and regret it a lot, as I can't fit 30mm axle in BB86 shells without compromising on the bearings.

Right now, i would probably get a rotor in power as their axle-based PM crank is currently 267USD for black friday: https://rotorbike.com/rotor-inpower-dm-road-gloss.html

Rotor one's are pretty inconsistent with their readings, they're never made any good PM. Better to go with Quarq then.

[00Garza]

Right now, i would probably get a rotor in power as their axle-based PM crank is currently 267USD for black friday: https://rotorbike.com/rotor-inpower-dm-road-gloss.html

That's probably the lowest price on a big name pm. I wonder if the Wheeltop acquisition has anything to do with this. Or maybe just the growing presence of chinese pm's bringing prices down.   

[patliean1]

All my road bikes run Quarq power meters. Mostly spider-based, but I do have a set of PowerTap P2 pedals when PowerTap was acquired by SRAM. Ultra reliable and accurate for past 4 years. And battery life is like 6 months.

The only exceptions are I have a Magene PES base on my latest Tavelo Arow. Also reliable. And a 4iiii left-side power meter on my gravel bike. Reliable/accurate too if you have a good pedal stroke.

During the pandemic you could find Quarq/SRAM spider power meters for $300, and SRAM Force D1 groupsets for $800. What a time to be alive.

Unless you're really into training metrics, most people would be totally fine with a single-sided PM if your chainstays clear it. Thankfully T47 opens the door more so than BB86.

[jonathanf2]

How about the Magene P505 power meter spider and your choice of crankset and chainrings? That's what I did. I don't think you'd be limited to BB type either.

https://www.aliexpress.us/item/2255801082615667.html?

[Lotnik]

If you already have Shimano 105 crank on order check out offer of the Inpeak.

https://inpeak.pl/en/shop/powercrank-e-power-meter-single-custom/

For 229 euros they will install you left side powermeter on your crank arm.

[tgarne]

Rotor one's are pretty inconsistent with their readings, they're never made any good PM. Better to go with Quarq then.

yeah. Going Rotor is always a good confidence boost. They are notoriously known for high power readings