Spider mounted power meter advice

[carbonazza]

...Has anyone tried the Power2Max power meter?...

The NG, on my road bike for 3 years now.
It is very basic. No app. Nothing fancy, just some arcane operations combining a led signal with putting/removing the charging cable a few sec.

The rubber plug of the charging port is a joke, and I lost it after a few rides.

It is as reliable as the Sigeyi and Quarq on my other bikes. They always work.
But I find the p2max quite ugly, compared to the other two

It failed just once. After a flight, it didn't start at my first ride.
And needed to be recharged, although I did recharge it before the trip.
Other trips later didn't have any problem.

[1Sigma]

P2M is really good. Very stable in my experience.

Don't get Xcadey. They have a disproportionate number of failures for the few PM spiders they manage to sell. Even the batch allocated to Elilee wasn't free from trouble.

Thanks, as always, for the insight, SW.  That is convenient, as it means no waiting

Where are you ordering the ELILEE from?

I am just in communication with them directly.   I am picking up a couple things to see if I want to stock it in the shop

[Nicoloc]

hi guys
I finally received my magene P505 110-3.
I assembled it on my CVR Hardrock cranckset with a set of 52/36 Fonvo Deckas chain ring.
the combo chain ring + powermeter is larger than the original chain ring of the crankset, so i had to adjust the front derailleur top end  screw.
but this led to front derailleur to rub against crank arm

any idea on how to solve that  ?
if i have to change the crank, any suggestion ? what would be the caractéristic to look at ? Q factor ?
thanks for your help
Nicoloc

[St0mpB0x]

So you have gone frome a 50T big ring to a 52T big ring? What do you mean you adjusted the "top end screw"? Did you mean you adjusted the high limit screw?

If so, thats your problem as that doesn't move the derailleur higher, it moves it closer or further away from the frame. It sounds like you need to set up your front derailleur from scratch. I'd reccomend a bike shop because they can be fiddly things and respectfully, it doesn't appear you know what you are doing. Alternatively you could head over to youtube to find a good tutorial.

[1Sigma]

The NG, on my road bike for 3 years now.
It is very basic. No app. Nothing fancy, just some arcane operations combining a led signal with putting/removing the charging cable a few sec.

The rubber plug of the charging port is a joke, and I lost it after a few rides.

It is as reliable as the Sigeyi and Quarq on my other bikes. They always work.
But I find the p2max quite ugly, compared to the other two

It failed just once. After a flight, it didn't start at my first ride.
And needed to be recharged, although I did recharge it before the trip.
Other trips later didn't have any problem.

Seems like the only brand more or less with consist positive reviews is the Sigeyi. 

[carbonazza]

...
but this led to front derailleur to rub against crank arm

any idea on how to solve that  ? ...

I had this issue with a SRAM etap 1st gen.
The position needed to be very precise to fit.
Try to move it up or down, and tweak the alignement.

Can you try with other rings?
Even old ones just to check?
All Magene PM I installed came with their rings.

[TidyDinosaur]

Seems like the only brand more or less with consist positive reviews is the Sigeyi.

Indeed, that is what I also found when searching for a cheap power meter.

cycling100.com has them the cheapest I could find, but the store gets bad reviews, so I did nog order them yet...

[Nicoloc]

looks like i found the guilty componment :  Fonvo ring...
the ring as a design that is not compatible with the Mangene.
I had to grind off some 52 ring rear ribs that were interfeering with the powermeter ring mount (see attachements)
I'll have to check but it lookslike this shaved 2mm and the ring is now spining round.
i'll double check once reassembled on the bike.

[Nicoloc]

Hi all some feedback on the P505 magene powermeter.
Data provided  looks weird to me with lot of variation from one second to another.
i'm comparing the data with my TACX FLux and even if average  power seems to be consistent, the variation in values make no sence.
I contacted Magene support and from their prospective (after sharing some compartive fit file)  , everything is normal...
so my point is that i cant recommend this power meter and as mention in some other post Magene support was useless.
Nicoloc

[TidyDinosaur]

I don't know how powermeters work, but could this not be normal since you only transfer power to the Pedals part of the time? It's not a constant power, but I would expect to see 2 peaks every rotation

[ChrisB]

Hi all some feedback on the P505 magene powermeter.
Data provided  looks weird to me with lot of variation from one second to another.
i'm comparing the data with my TACX FLux and even if average  power seems to be consistent, the variation in values make no sence.
I contacted Magene support and from their prospective (after sharing some compartive fit file)  , everything is normal...
so my point is that i cant recommend this power meter and as mention in some other post Magene support was useless.
Nicoloc

Also using the TACX Flux myself, I would say the flatter data from the indoor trainer has to do with how the system works and some of the software even smoothes the power output (3s average)...
Best would be to compare with another e.g. left arm or pedal power meter as reference. I know this might not be possible if this is your only Powermeter device. Can you share any graphic regarding the power meter output?

A good source for Powermeter information is GPLama on Youtube.
He does testing of power meters on a regular basis, you might find information on how to test and which tools he is using.
Here some example:

BR Chris

[Nicoloc]

hi guys,
for those who wants to compare and see what the P505 data looks like. here are two fit files from the same workout in Zwift (ATTAC).
One from the Magene P505 and the other one from the TACX.

[Boybiskit]

A few months in and the XCadey is proving reliable but power readings didn't seem right based perceived effort with a gym spin bike. So I measured it. Same climb done 3 times back to back. Used elevation, weight and time to calculate estimated power using these formulae:

- Joe Friel / Bible: https://www.trainingbible.com/joesblog/2008/01/climbing-power-formula.html#:~:text=Lim's%20formula%20to%20estimate%20the,for%20rolling%20and%20air%20resistance.
- Broleur: https://www.broleur.com/hill-climb-calculator/

My feelings were right. Xcadey is 12% out. The good news is... it's consistently 11-12% out and I can adjust for it in the app.

Conclusion: 3 months in including wet rides and I'm happy but do your homework to calibrate correctly.

[carbonazza]

...My feelings were right. Xcadey is 12% out...

I would contact Xcadey about it anyway.

[Boybiskit]

Another quick update on this...

1. Xcadey power meter was only 5% out... I forgot I had been fiddling with the settings when I received it assuming it would over read. I messed it up and had forgotten
2. Went for a VERY wet ride last night - puddles up to the BB and axles. Xcadey will working fine this morning.