Crank based, single or dual sided vs hub power

[V18]

*flies away... Not too far. To watch from a telephone cable to voyeur safely*

[Capricorn]

New one at tapei cycle show based on tyre pressure oscillations. 5% variance. Don't shoot the messenger. www.aroflybike.com

i thought that was pretty darn out of the box as they come! For the price and if that accuracy correlates well, they would have a big winner. Road only i'd imagine

[s14phoenix]

It just also seems that there are problems with all the power meters.

 

If they are not unreliable, or heavy, or lack software support etc etc.

 

Think I may just not bother with any of them. seems there is flaws all over the place.

 

Not too bee funny but even DC Rainmakers reviews are confusing - he seems to like all of them and none are bad except the one side only meters.

 

So which dual sided power meters are good and accurate and last long and have good software and are not hub based as that I have eliminated now along with one sided power meters like Stages single and 4iiii single and has anyone used their doubles?

[Capricorn]

It just also seems that there are problems with all the power meters.

 

If they are not unreliable, or heavy, or lack software support etc etc.

 

Think I may just not bother with any of them. seems there is flaws all over the place.

 

Not too bee funny but even DC Rainmakers reviews are confusing - he seems to like all of them and none are bad except the one side only meters.

 

So which dual sided power meters are good and accurate and last long and have good software and are not hub based as that I have eliminated now along with one sided power meters like Stages single and 4iiii single and has anyone used their doubles?

crank spider: SRAM Quarq Dzero, Power2max NG, 

pedals:  garmin vector, SRM Look ekxact, powertap P2

 

Personally, I was eyeballing Dzero. Aceptable accuracy (< 1.5%), ANT+ and BLE compatible, and because a crank is something I personally don't see myself changing any time soon, much less ever (outside of crashes that is).

If cost was irrelevant I'd go with SRM (<1% accuracy).

[DieselnDust]

It just also seems that there are problems with all the power meters.

 

If they are not unreliable, or heavy, or lack software support etc etc.

 

Think I may just not bother with any of them. seems there is flaws all over the place.

 

Not too bee funny but even DC Rainmakers reviews are confusing - he seems to like all of them and none are bad except the one side only meters.

 

So which dual sided power meters are good and accurate and last long and have good software and are not hub based as that I have eliminated now along with one sided power meters like Stages single and 4iiii single and has anyone used their doubles?

 

 

Not sure what the problems with the estblished brands are but I find single sided to work just fine. It depends on what you want to measure. If you want as much data as possible like L/R balance and torque effect then dual sided, hub or crank is pretty much what you need.

If you simply want to train in zones, track your normalised power and follow a structured plan then one sided is pretty much all you need

[DieselnDust]

crank spider: SRAM Quarq Dzero, Power2max NG, 

pedals:  garmin vector, SRM Look ekxact, powertap P2

 

Personally, I was eyeballing Dzero. Aceptable accuracy (< 1.5%), ANT+ and BLE compatible, and because a crank is something I personally don't see myself changing any time soon, much less ever (outside of crashes that is).

If cost was irrelevant I'd go with SRM (<1% accuracy).

 

 

SRM/LOOK Exact has many problems

Garmin Vector still gets mixed reviews

 

Units that have established reliability are SRM cranks, Pioneer, Stages L and L/R, 4iiii, Power2Max, Team Zwatt (including Rotor 2inPower, Race Face and Easton)

 

 

For MTB we're pretty much limited to Power tap G3 MTB rear hub, Stages L (Cannondale, Shimano and SRAM), 4iiii Precision (alloy cranks only), Power2max, SRM SRAM and Quarq.

 

all work, jut depends on what you want from it

[mecheng89]

It just also seems that there are problems with all the power meters.

 

If they are not unreliable, or heavy, or lack software support etc etc.

 

Think I may just not bother with any of them. seems there is flaws all over the place.

 

Not to be funny but even DC Rainmakers reviews are confusing - he seems to like all of them and none are bad except the one side only meters.

 

So which dual sided power meters are good and accurate and last long and have good software and are not hub based as that I have eliminated now along with one sided power meters like Stages single and 4iiii single and has anyone used their doubles?

I wouldn't call them problems. Many engineers with much bigger brains than us sit behind these projects. PMs have come such a long way. No one has spoken about Powertap P1 pedals.. I like how they look, just a pity they're too pricey. Swopping pedals are the ultimate solution between training and racing bikes. If you want to buy, buy something that has local support. BicyclePower are a fab bunch of guys *I'm not being paid to say this*. 

 

From what I gather, he is neither an engineer nor a consumer journalist or a former professional sports person. So his actual knowledge of the equipment is limited to what he sees, feels and experiences on the road/indoor/in the pool etc. 

 

Although his reviews are generally quite thorough superficially, they are his reviews and personal opinions. His website is always my first stop when it comes to looking something up at a first glance, but speaking to other users (of the equipment you're interested in) is way more useful than one (!) oke's opinion.

[mecheng89]

Huh?

Can you explain what you are thinking here please

Power (in watts or Joules per second) equals torque (in Newton meters) multiplied by the angular velocity of your pedal stroke (in radians/second). 

 

Think of your favourite hill. If you can keep 200W up there at a cadence of 90rpm (or 9.42rad/s), you require a torque of 21.22 Newton meters (Nm). BUT if you HALVE that cadence, you require double the torque for the same amount of power (200W). People who like to crush the crank have a higher torque capability, which favours a low-cadence ascent. 

That's why some do TORQUE intervals. When you build up the torque your muscles are able to produce for the same cadence, your POWER goes up, and it becomes less likely you'll g et dropped. 

[s14phoenix]

Power (in watts or Joules per second) equals torque (in Newton meters) multiplied by the angular velocity of your pedal stroke (in radians/second). 

 

Think of your favourite hill. If you can keep 200W up there at a cadence of 90rpm (or 9.42rad/s), you require a torque of 21.22 Newton meters (Nm). BUT if you HALVE that cadence, you require double the torque for the same amount of power (200W). People who like to crush the crank have a higher torque capability, which favours a low-cadence ascent. 

That's why some do TORQUE intervals. When you build up the torque your muscles are able to produce for the same cadence, your POWER goes up, and it becomes less likely you'll g et dropped. 

 

It is this very reason I cannot understand why some of crank based power meters show lower power at the higher cadence with same wheel speed and resistance. the calculations are either to blame or the amount of error factor at higher cadence seems much higher so the power figure drops.

 

I am very interested in the Garmin pedals purely due to the amount of data that comes with them. Seems reviews are all over the place but mostly good as of recent. I have kept the 4iiii single sided crank arm as it seems most constant and I can just adjust to the values it gives me and guage effort accordingly - for the most part it was a free power meter in terms of weight as it the cadence magnet almost weighed the same and the cost was super low due to a CTCT special price. When I can fund a set of Vector3s I will do so. The fact that the 4iiii outputs cadence also is great feature which I did not even think about at the time either.

[DieselnDust]

Power (in watts or Joules per second) equals torque (in Newton meters) multiplied by the angular velocity of your pedal stroke (in radians/second). 

 

Think of your favourite hill. If you can keep 200W up there at a cadence of 90rpm (or 9.42rad/s), you require a torque of 21.22 Newton meters (Nm). BUT if you HALVE that cadence, you require double the torque for the same amount of power (200W). People who like to crush the crank have a higher torque capability, which favours a low-cadence ascent. 

That's why some do TORQUE intervals. When you build up the torque your muscles are able to produce for the same cadence, your POWER goes up, and it becomes less likely you'll g et dropped. 

 

 

ah I see where John was going with it. thanks

[RobbieRetief]

Hi Guys,

 

Just a little bit of advice... there's a great crank-based power meter brand out there done by Bicycle Power Trading. This crank based system is called Power2Max and I've found it to be ever reliable and good quality, at a good price ! Have a look at www.bicyclepower.co.za

[mecheng89]

It is this very reason I cannot understand why some of crank based power meters show lower power at the higher cadence with same wheel speed and resistance. the calculations are either to blame or the amount of error factor at higher cadence seems much higher so the power figure drops.

 

I am very interested in the Garmin pedals purely due to the amount of data that comes with them. Seems reviews are all over the place but mostly good as of recent. I have kept the 4iiii single sided crank arm as it seems most constant and I can just adjust to the values it gives me and guage effort accordingly - for the most part it was a free power meter in terms of weight as it the cadence magnet almost weighed the same and the cost was super low due to a CTCT special price. When I can fund a set of Vector3s I will do so. The fact that the 4iiii outputs cadence also is great feature which I did not even think about at the time either.

Correct me if I'm wrong, but that's the single sided model. So you're stuck with the same information your 4iiii gives you. You'd want the V3 (not the S) to give you the power balance etc? https://buy.garmin.com/en-ZA/ZA/p/606555

 

All PMs give you a cadence data field (even the Powerhub somehow, I'm still trying to figure that out). Your wheel speed plays no role in your power calculation, your linear speed does (which your GPS can pick up, or your wheel speed sensor). 

[riteshm]

Hi,

 

I would steer very clear from Garmin Vector 3 pedals. I am on my second set (after more than a year of using them). Garmin resolved the battery door issues however the power data is erratic, with normalised power varying by more than 20%, for similar heart rate and routes, hence cant be used effectively for proper training.  I have to continuously perform zero off sets in early morning rides, to obtain reliable data.

 

My suggestion is to stick with crankbased powermeters. The Quarq Dzero is very good value for money although it does not have the data analytics of Rotor.

[Jehosefat]

I have heard rumours that Garmin are going to be announcing/releasing the Vector 4 pedals later this year so if you're not in a rush maybe you can get a good deal on the 3s once those come out.

 

Personally I have a Stages Dual sided and it's great. It usually gives the same normalised power as my Hammer to within a few Watts. Also as it turns out, my left leg is a fair amount stronger than my right so if I just had the single sided option it would overestimate my power by around 4-5%.

[DieselnDust]

If the V4 is coming out then what would be the point of buying flawed V3's??

 

There are plenty of reliable PMs out there that don't provide drama i.e. they just work.

 

Quarq

Power2Max

Stages

4iiii

Powertap

 

 

The more challenging to obtain like Pioneer, SRM, ZWATT Team, are also good.

 

Lifes too short to mess around with unreliable equipment.

 

 

I have heard rumours that Garmin are going to be announcing/releasing the Vector 4 pedals later this year so if you're not in a rush maybe you can get a good deal on the 3s once those come out.

 

Personally I have a Stages Dual sided and it's great. It usually gives the same normalised power as my Hammer to within a few Watts. Also as it turns out, my left leg is a fair amount stronger than my right so if I just had the single sided option it would overestimate my power by around 4-5%.

 

 

Not sure how you work that out but you'd be in the minority of users in having such a large discrepancy in L/R balance. Most people fall within the accuracy of the PM. 

I've got a P2M and a Stages and the numbers they generate correlate very well.

[riteshm]

I have heard rumours that Garmin are going to be announcing/releasing the Vector 4 pedals later this year so if you're not in a rush maybe you can get a good deal on the 3s once those come out.

 

Personally I have a Stages Dual sided and it's great. It usually gives the same normalised power as my Hammer to within a few Watts. Also as it turns out, my left leg is a fair amount stronger than my right so if I just had the single sided option it would overestimate my power by around 4-5%.

Usually indoors, the powermeters generally track well against the indoor trainer. (I tested the Vector 3 against the Kickr 3 at three power ranges) The real challenge is outdoors, where the conditions vary. I had a Stages Gen2; they were solid and reliable however you can't use on a bike with a bottom bracket brake, hence the move to the Garmin V3.