Power2Max Open Source Spider

A new P2M spider?
Seems to use an interesting design where the spider is “universal”, with a separate mounting plate that allows for connection to various types of direct mount cranks. Could see it working with rotor/easton/sram etc mounting standards, while allowing one to keep the same chainrings.

Probably not huge mass appeal, but would be useful for me when using shimano 2x chainrings on bikes where I have rotor and sram cranks. Also for MTB where i’d be able to use the same spider on my sram 3-bolt and eewings cranks (need to flip the orientation of the spider in order to clear the battery hump.

Cool to have more options.


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Interesting idea. P2M’s pricing hasn’t really followed the rest of the market and I’m confused how they are hanging in there with Sigeyi, Magene, Xcadey, and even Quarq (depending on the sale or unit) undercutting them. Their original sales pitch was basically ‘cheaper than Quarq.’ I’ve still got two Type-S units in service and they work great.

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How do the Sigeyi, Magene, and Xcadey compare on features and reliability?

P2M over Quarq is likely a hard sell right now for anybody on SRAM - the Force/Red PM (spider-only) is $480 (USD) vs $490+ for P2M NGEco (which locks out some features via firmware IIRC).

I’ve heard good things about Sigeyi, but never actually seen one in the real world. Those other two brands are new to me.

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Sure, if you’re thinking NG only. Reality is although advertised at 2% accuracy, NGeco both accuracy and feature-wise, good enough for 99.9% of riders. It’s also much closer to 1% in accuracy in real life in my experience (Personally tested with multiple units against assioma)

So at $540 I’d say it’s banger of a deal for what it offers.

Sure, I’m leaving Chinese products out of conversation only because they make a lot of other groups of cycling products irrelevant as well, not just power meters. e.g. find me a western wheelset around $1000 that is deep aero profile and weigh around 1350 grams.

You may be missing the point. Chinese wheelsets have had a significant influence on the pricing of western wheelsets. The point of my comment was to say ‘how is this company not impacted by that yet with X competition there?’ Responding in a way that ignores that doesn’t seem very useful to me. E.g. ‘it is a good deal if you ignore half the market.’ In the full situation it does not appear to be a good deal at all: per AlistairSH the NGECO has pay for play features and doesn’t compare to the base Quarq spiders that are at MSRP $10 less, and generally are to be found for around $380 when on sale.

This looks like a strong play for them to reduce SKU count internally. If you’ve only got to make a single road, gravel, and MTB model, their stocking costs go way down while their responsiveness to the market goes up. The machining on that spider interface looks problematic.
On high volume units, their prices are pretty competitive. Quarq is at $483 street, P2M is $490. The yet-to-proven brands are still $375-400. P2M has the most fitments, so thats how they get their customers anyway. They crank based PMs aren’t really competing with each other, they’re competing with pedals. I mean if you’ve got a shimano crank, you’re going to get crankarm or pedal PM in most cases.

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I’m only suggesting compare apple to apples. sigeyi etc were mentioned above. That’s not apples to apples.

I love quarq and used many iterations of it. However I find p2max to be WAY more flexible with so many crank options (especially this new modular model) that not only does it not make it a better option than quarq at only 10 dollars more, but a better option, period.

Your choices can differ and you may prefer quarq ofcourse. But as far as spider based pm’s go, and after owning an embarrassing number of pm’s I find p2max geco, without the pay2play bells and whistles to be equal or better than most. if you’re on a sram ecosystem, absolutely, get a quarq.

Yeah that may be the differentiator that keeps them in the market for now. Sigeyi does have a lot of spiders though and could match P2M’s amount in the future. P2M Isn’t SRM or something, as I said earlier they positioned themselves originally as a lower cost option on the market and that has completely flipped with Quarq’s pricing being below theirs.

Your choices can differ and you may prefer quarq ofcourse

This conversation isn’t about personal preferences but the market mix. Like I said, I own two P2m spiders and a few Quarqs as well.

I’m only suggesting compare apple to apples. sigeyi etc were mentioned above. That’s not apples to apples.

The Sigey meter’s specs exceed the NGECO and compare more closely to the NG. It’s a completely fair comparison:

Dual-leg power measurement, accurate to +/- 1.0%, 300 hours of battery life, rechargeable battery, very lightweight, left/right power balance, ANT+ and Bluetooth compatibility, auto-zero (automatic calibration).

Where as the NGECO has no rechargeable battery, 2% accuracy, no l/r balance. NG SRAM: $940. Sigeyi SRAM: $380.

What is problematic in your opinion about the spider interface?

It has a tapered interface to the PM, no bolts. It needs to interface multiple crankarm types on the backside of that. in other words, it needs pinch that same universal spider to multiple thicknesses of cranks. That cloverleaf interface also has to be to a tight tolerance all around the finger for size and taper and relative to the other fingers on both sides…and not wear a lot. I could be very wrong as I don’t see all the angles here.

to paraphrase Dave Rome (when he was speaking about the armchair engineers saying that sram transmission was terribly designed)…

it’s almost as if XYZ company has engineers who think about this sort of stuff…


I’m not saying it doesn’t work, I’m just saying it looks difficult. Now I don’t see a pic of the unmounted spider or have any detail from the engineers, but if it was as easy as putting an cheap insert into a universal spider, they would have just done that years ago.

Also, Dave Rome bulls****s as much as anyone else. For example, he’ll go on and on and on about a hex key. While the nicer bits do have some nice qualities (hardness for sure), you’re still playing the field on the bolt side. How many exact bolt heads are out there? Making an internal bolt head interface isn’t as exacting as making the tool and who knows where there bolts come from. Fancy hex keys aren’t all that and the smaller ones are more likely to break on you because they are hardened. Don’t get me started on torque wrenches…

In any case, this is the internet and I’m going to speculate all I want.


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This isn’t a charitable characterization. Those brands offer something the Chinese brands don’t (better support, newer technologies, higher end composites, etc). I’m pretty clearly asking what Power2Max offers in the same light, and you’re dismissing the question based on a generalization “we can just keep making threads to no end” … okay then. You can try to enforce arbitrary rules on a conversation but they aren’t really relevant.

Clearly we are coming from completely different perspectives

Yeah you keep trying to make this about personal preferences and it doesn’t need to be at all. There is no need whatsoever for you to suggest my arguments represent my personal preferences in a meter.

but you can’t tell me a Quarq is good value vs P2M Geco no matter what the paper says. In every day use, you will miss absolutely NOTHING for your training with a Geco

If you don’t think specs matter I’m confused why you chose to get into a conversation about specs. You could make the same statement about basically ever meter on the market.

Moderator note: Flags have been made and will be reviewed by TR reps.

Please return to the topic at hand or I will pause/lock the thread which I don’t want to do.

There are just a few rules.

1. Be excellent to each other

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