Power2Max Power Meters

harringtonp

Hi Guys,

Been doing a lot of reading up on PM's the past few weeks and am close to pulling the trigger on

http://www.power2max.de/europe/en/Produkt/power-meters-en/fsa-gossamer-road/

Was considering

http://www.power2max.de/europe/en/Produkt/power-meters-en/fsa-k-force-light-road/

but the only real difference I can see is 350 Euro for a 200g saving (more actually, with the cheaper one I will just move my existing gossamer rings where as a higher end crank may deserve higher end rings).

Is there anything I am missing ?

With the auto zero feature they say

"Auto Zero: every time you stop pedaling for 3 seconds or more your power2max “rezeros”, making sure you always have precise data. No need to re-zero manually."

Dc Rainmaker says in his review

"First, it supports auto zero. Auto zero means the unit is automatically calibrating itself at specified points in time. In the case of the Power2Max, this is anytime you stop pedaling for two seconds. There is no end-user notification that this has (or hasn’t) occurred however, nor can you turn it off. Functionally, this is no different than pressing the ‘calibrate’ button.

This is unlike most power meters, as the power meter unit doesn’t allow you to turn this on or off. For example, compare below a photo (first) of the PowerTap, and then secondly of the Power2Max configuration screens. Note the lack of Auto Zero option on the second photo (Power2Max)"

Question here is is there any good reason why you might ever want to switch this feature off ?

Anybody here using the more recent power2max (older ones had temperature drift issues) ? How do you find it ?

BTW I was close to pulling the trigger on the new Garmin Vector but a few small things turned me off it.

Paul.

colm_gti

I have a rotor 3d power2max, it looks like a rotor 3d (good) and it measures my power when I pedal (good).

I don't have anything else to compare to, but I does what I want it to do, measure power.

Hmmzis

If you have the FSA Gossamer cranks then you should only need the spider itself. Except if you want to have a spare set of the same cranks.

harringtonp

Thanks Colm,

Am I correct in saying that unlike the FSA versions, you can remove the ROTOR cranks from your version of the PM and you are left the the basic PM, i.e.

http://www.power2max.de/europe/en/Produkt/power-meters-en/power2max-sensor-road/

? So you can put in different cranks down the line if you ever wanted.

harringtonp

Hmmzis wrote: »

If you have the FSA Gossamer cranks then you should only need the spider itself. Except if you want to have a spare set of the same cranks.

I'm pretty sure my Gossamer cranks are fused to the spider but I will double check when I get home

harringtonp

harringtonp wrote: »

I'm pretty sure my Gossamer cranks are fused to the spider but I will double check when I get home

Found a photo, they are, I do plan on using the chainrings in the photo though

colm_gti

harringtonp wrote: »

Thanks Colm,

Am I correct in saying that unlike the FSA versions, you can remove the ROTOR cranks from your version of the PM and you are left the the basic PM, i.e.

http://www.power2max.de/europe/en/Produkt/power-meters-en/power2max-sensor-road/

? So you can put in different cranks down the line if you ever wanted.

Yeah you can remove the spider, but it's specific to rotor 3d cranks, so I can change it between rotor 3d cranks, but not different models.

harringtonp

colm_gti wrote: »

Yeah you can remove the spider, but it's specific to rotor 3d cranks, so I can change it between rotor 3d cranks, but not different models.

OK glad I asked. I had thought that by taking off the 3D cranks you would be left with their basic spider which according to their website lists a few different compatible cranks. Not a big selection but at least an option to go for something really light (e.g. lightning) down the line if you ever wanted:

"If you already have one of the following cranks you only need a power2max power meter and can use your existing crank:

Rotor 3D, 3D Plus, or 3DF
Lightning
BOR RR688
Tune Smart Foot
TA Carmina or Vega

If you currently have another crank you need both the power meter and a crank."

fat bloke

Ah, good to see those crazy power2max Germans are still flummoxing customers and obfuscating what should be simple sales transactions with cash-rich, power-hungry cyclists. :rolleyes:

Leroy42

Just to hijack this thread a bit but was starting to look at power meters myself and just wondering why people are considering this option when Stages is a much cheaper option (yes I know it's not available here yet but will be shortly).

Not trying to say which one is better or not (I don't know) but with Stages being nearly 1/3 cheaper I am just wondering what it is that people are spending the extra money on. Fine if you are a high end racer but for most people surely we don't need the top of the line models.

I do get that stages only measures leg leg and X's 2 for power but there is also some calculation on crank systems to give a figure rather than pure l/r power but surely once it is consistent/reliable and within accepted threshold then it down't really make much difference

this is a genuine question, not trying to troll. I really don't understand and would like to understand it.

Quigs Snr

Stages measures left leg power and bases its calculations on that.... fine if you have exactly even power (I dont... heavily biased towards right leg ) otherwise your absolute power numbers can be out.

Power2max / SRM / Powertap all measure at the drivetrain which in effect is the cumulative power figure of both legs and therefore more accurate for most people.

I had a powertap. My power2max arrives today apparently. Did look at the stages but just not right for me

Redmond101

Note for yourself if getting power2max, they have reduced the price in USA , circa 30% reduction

harringtonp

Redmond101 wrote: »

Note for yourself if getting power2max, they have reduced the price in USA , circa 30% reduction

Was reading about this, power2max say the cost to them is no different than Europe, it is down to less taxes. You could get caught on customs.

harringtonp

Quigs Snr wrote: »

I had a powertap. My power2max arrives today apparently. Did look at the stages but just not right for me

Why did you switch ?

Leroy42

Quigs Snr wrote: »

Stages measures left leg power and bases its calculations on that.... fine if you have exactly even power (I dont... heavily biased towards right leg ) otherwise your absolute power numbers can be out.

But surely power, like HR is really just a number. While of course power can be easily compared against different riders (unlike HR) there are other factors, most notably weight, which must also be taken into account.

On that basis the actual number itself is only useful in terms of it comparison against similar recorded data. So once a power meter is reliable the actual number itself is irrelevant.

Given that the reviews of stages appear (I have no direct knowledge) seem to say that overall the reliability and consistency is sufficient why does it matter than it only measures one leg.

Sky team have showed that the real 'power' to power meters is being able to know at what level you can maintain for certain periods. The actual number on the screen is based on previous gained data.

tunney

Leroy42 wrote: »

But surely power, like HR is really just a number. While of course power can be easily compared against different riders (unlike HR) there are other factors, most notably weight, which must also be taken into account.

On that basis the actual number itself is only useful in terms of it comparison against similar recorded data. So once a power meter is reliable the actual number itself is irrelevant.

Given that the reviews of stages appear (I have no direct knowledge) seem to say that overall the reliability and consistency is sufficient why does it matter than it only measures one leg.

Sky team have showed that the real 'power' to power meters is being able to know at what level you can maintain for certain periods. The actual number on the screen is based on previous gained data.

The reliability? Other than the electronics falling off you mean?
Consistency? Anyone remember ergomo and its consistency? Measuring one leg is a fail.

harringtonp

Leroy42 wrote: »

Just to hijack this thread a bit but was starting to look at power meters myself and just wondering why people are considering this option when Stages is a much cheaper option (yes I know it's not available here yet but will be shortly).

Not trying to say which one is better or not (I don't know) but with Stages being nearly 1/3 cheaper I am just wondering what it is that people are spending the extra money on. Fine if you are a high end racer but for most people surely we don't need the top of the line models.

I do get that stages only measures leg leg and X's 2 for power but there is also some calculation on crank systems to give a figure rather than pure l/r power but surely once it is consistent/reliable and within accepted threshold then it down't really make much difference

this is a genuine question, not trying to troll. I really don't understand and would like to understand it.

Saddleback are the only distributor I'm aware of where you can get a stages PM from Ireland at the moment and they are waiting on them to come in stock. Their cheapest ones (e.g. shimano 105) are 599 stg which at todays rate is 713 euro plus postage. Power2max's entry level is 840 + 18 euro postage (though will cost a bit more if you are not using existing chainrings).

Chips Lovell

1. I can't buy one yet
2. I can only use Shimano or Sram cranks with them
3. They're something of an unknown quantity, whereas I know plenty of happy Power2max users.

harringtonp

fat bloke wrote: »

Ah, good to see those crazy power2max Germans are still flummoxing customers and obfuscating what should be simple sales transactions with cash-rich, power-hungry cyclists. :rolleyes:

Having got a rose bike have to say I've a lot of respect for German engineering and the power2max staff are very studious in answering question after question (presales of course). From what I could see none of the spider based manufacturers options are easy to figure out, particularly if you're looking to move between multiple bikes.

Quigs Snr

harringtonp wrote: »

Why did you switch ?

Leroy42 wrote: »

But surely power, like HR is really just a number. While of course power can be easily compared against different riders (unlike HR) there are other factors, most notably weight, which must also be taken into account.

On that basis the actual number itself is only useful in terms of it comparison against similar recorded data. So once a power meter is reliable the actual number itself is irrelevant.

Given that the reviews of stages appear (I have no direct knowledge) seem to say that overall the reliability and consistency is sufficient why does it matter than it only measures one leg.

Sky team have showed that the real 'power' to power meters is being able to know at what level you can maintain for certain periods. The actual number on the screen is based on previous gained data.

Switching because the Powertap is unreliable garbage. I had no problems with the Powertap Pro+ but "upgrading" to the SL+ was a huge mistake. This model has a whole boatload of reliability issues reported on in the various forums and all of them came true for me after very small mileage (under a light <70kg rider) e.g.... Hub bearings wearing after literally a few hundred km ? Check. Freehub bearings wearing prematurely ? Check. Data dropout issues in wet weather ? Check. Torque tube eventually failing after less than 3000km necessitating a repair almost as expensive as the original purchase ? Check. Getting it repaired and having it fail multiple times thereafter ? No way am I even giving it the opportunity.

Regarding the point that absolute power is irrelevant and that as long as a device like the stages is consistent is it not sufficient for the purposes of training ? Yes, I absolutely agree with that point. However if I can have a more accurate device for the same money (well in my case anyway because I already have a compatible crank) then I'll have that thanks very much !

Leroy42

This is really great, glad I looked into this.

The P2M looks really good and the price is less than I thought. However, I am having a bit of trouble working out what I need.

I currently have Utegra 6700 10 speed compact (50/34) crankset, BSA standard.

From the P2M website I would pick the FSA Gossamer for €840. Can I use my Ultegra Chainrings or do I have to buy them as well? And what about the Bottom bracket? Is that it?

harringtonp

Leroy42 wrote: »

This is really great, glad I looked into this.

The P2M looks really good and the price is less than I thought. However, I am having a bit of trouble working out what I need.

I currently have Utegra 6700 10 speed compact (50/34) crankset, BSA standard.

From the P2M website I would pick the FSA Gossamer for €840. Can I use my Ultegra Chainrings or do I have to buy them as well? And what about the Bottom bracket? Is that it?

I am looking at two bikes and had a long email discussion with them. Figure out your axle width, it is probably 24mm in which case you are looking at one of the PM's (includes Gossamer) with this axle width (all PMs give the width).

Then send them in a photo like

http://www.power2max.de/europe/wp-content/uploads/2013/05/Aussenliegend.jpg

and they will confirm that there are no sizing problems. In an email about why these dimensions were needed they replied

"Yes, both crank arms (left and right with spindle).
Regarding the BB-standard , here are geometric relationships examined in order to prevent collisions and to ensure the mounting. The dipping area of the bracket should not exceed a diameter of 53 mm. Please look at the attachment.
If you're unsure about compatibility, send us a photo in this way. Please take care that the original bottom bracket is installed, the crank set is dismantled. Then we can make a high probability of binding statement to you which option/s of power2max are compatible with your bike frame. Please look at the attachment."

When you order you don't pay straight away. They will send you an email with the delivery week, when payment is expected and bank details.

I'm not sure about the ultegra chainrings, they look different. I have the same setup as yourself (6700 compact) on my main bike but have decided to go with a standard rather than classic PM (on the odd occasion I found myself spinning quite fast in top gear when racing) and will use the Gossamer rings on my TT bike.

jiffybag

harringtonp wrote: »

Saddleback are the only distributor I'm aware of where you can get a stages PM from Ireland at the moment and they are waiting on them to come in stock. Their cheapest ones (e.g. shimano 105) are 599 stg which at todays rate is 713 euro plus postage. Power2max's entry level is 840 + 18 euro postage (though will cost a bit more if you are not using existing chainrings).

Saddleback have appointed a retailer in Northern Ireland for Stages . They have various models already in stock with some customers already using the Stages power meters.

They have been on sale in the US for some time now and seem to be getting plenty of good reviews.

http://www.dcrainmaker.com/2013/01/stages-power-meter-in-depth-review.html

harringtonp

Got the power2max and put it on the bike last night. Noticed that my Edge 705 is not picking up the cadence from it. I know the 705 would probably be used with a specific cadence sensor but in the absence of one I thought it would use the power2max ant+ value.

Anybody know if later garmin devices can read the cadence from it ?

Quigs Snr

harringtonp wrote: »

Got the power2max and put it on the bike last night. Noticed that my Edge 705 is not picking up the cadence from it. I know the 705 would probably be used with a specific cadence sensor but in the absence of one I thought it would use the power2max ant+ value.

Anybody know if later garmin devices can read the cadence from it ?

I rode mine at the weekend with a garmin edge 500, cadence works fine

harringtonp

Thanks, suspect the firmware in the 705 is quite old and wouldn't be surprised if it couldn't display cadence from PM sources. Still I thought stating Ant+ compatibility meant these things should work.

cormpat

For what its worth I have a Garmin Edge 705 paired with a powertap G3 power meter & it displays cadence fine.

Beasty

cormpat wrote: »

For what its worth I have a Garmin Edge 705 paired with a powertap G3 power meter & it displays cadence fine.

Surely your cadence reading is coming from a separate cadence sensor - it certainly can't be coming from the PT hub

cormpat

Beasty wrote: »

Surely your cadence reading is coming from a separate cadence sensor - it certainly can't be coming from the PT hub

I don't have a cadence sensor on the bike I've been using the PT on. Just the 705 & G3. I still get a cadence reading on the Garmin. I presumed the PT was measuring it?

Beasty

cormpat wrote: »

I don't have a cadence sensor on the bike I've been using the PT on. Just the 705 & G3. I still get a cadence reading on the Garmin. I presumed the PT was measuring it?

How can it? - the hub revolves at varying speeds to the cranks (unless it's a fixie)

cormpat

Beasty wrote: »

How can it? - the hub revolves at varying speeds to the cranks (unless it's a fixie)

To be honest, I've no idea & it's not a fixie; Sram Force groupset on the bike.

When I pedal, it displays cadence. How accurate that measure is could be a different story though...