Plissken74 wrote:
I have a Quarq and my wife has P2max [..] 20-25W difference confirmed.Triathlon Forum
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Re: New Power meter(s) depression. [Plissken74]
[ In reply to ]
That's interesting. Have you done a static torque check with the same weights?
Re: New Power meter(s) depression. [RChung]
[ In reply to ]
RChung wrote:
Plissken74 wrote:
I have a Quarq and my wife has P2max [..] 20-25W difference confirmed.
That's interesting. Have you done a static torque check with the same weights?
Never done it. Do you think it would be beneficial also on these 2 models?
Re: New Power meter(s) depression. [Plissken74]
[ In reply to ]
It's possible and, if you already have the weights and a stable base to mount the bikes onto, it can be easier. Maybe both the smart trainer and the Quarq are off, and the P2M is right. Hanging known weights off the pedal will nail that down.
But it's good you did that hill climb.
Once you know that your PMs are right, you can use them for measuring drag.
But it's good you did that hill climb.
Once you know that your PMs are right, you can use them for measuring drag.
Re: New Power meter(s) depression. [RChung]
[ In reply to ]
RChung wrote:
It's possible and, if you already have the weights and a stable base to mount the bikes onto, it can be easier. Maybe both the smart trainer and the Quarq are off, and the P2M is right. Hanging known weights off the pedal will nail that down. But it's good you did that hill climb.
Once you know that your PMs are right, you can use them for measuring drag.
http://www.cyclecoach.com
http://www.aerocoach.com.au
Re: New Power meter(s) depression. [AlexS]
[ In reply to ]
AlexS wrote:
RChung wrote:
Once you know that your PMs are right, you can use them for measuring drag.or keeping an accurate record of one's decline...
Re: New Power meter(s) depression. [AlexS]
[ In reply to ]
AlexS wrote:
or keeping an accurate record of one's decline...Does it need to be an accurate record or can it just be consistent?
Re: New Power meter(s) depression. [jaretj]
[ In reply to ]
jaretj wrote:
AlexS wrote:
or keeping an accurate record of one's decline...
Does it need to be an accurate record or can it just be consistent?
http://www.cyclecoach.com
http://www.aerocoach.com.au
Re: New Power meter(s) depression. [RChung]
[ In reply to ]
RChung wrote:
Tom A. wrote:
Once you have that, measuring average crank rotational velocity is fairly trivial, and those are the 2 inputs to calculate power.Relatively trivial but not entirely. We both know of certain PMs whose cadence measurements can be noisy in certain situations. Sometimes I think manufacturers were too fast in moving away from magnets and reed switches.
it's a shame that taking a simple measurement once a revolution got replaced by something more complex which is then billed as a 'feature' -- yet in the real world provides less accuracy.
so many Quarq users got excited when they were finally free to ditch their (perfectly functional) magnets.
i heard a few stories of people who supposedly destroyed a derailleur when their magnet got sucked onto their chain. in the better part of a decade of riding with power on road bikes, mountain bikes and cross bikes, i've never seen this happen.
Re: New Power meter(s) depression. [tetonrider]
[ In reply to ]
tetonrider wrote:
RChung wrote:
Tom A. wrote:
Once you have that, measuring average crank rotational velocity is fairly trivial, and those are the 2 inputs to calculate power.Relatively trivial but not entirely. We both know of certain PMs whose cadence measurements can be noisy in certain situations. Sometimes I think manufacturers were too fast in moving away from magnets and reed switches.
it's a shame that taking a simple measurement once a revolution got replaced by something more complex which is then billed as a 'feature' -- yet in the real world provides less accuracy.
so many Quarq users got excited when they were finally free to ditch their (perfectly functional) magnets.
i heard a few stories of people who supposedly destroyed a derailleur when their magnet got sucked onto their chain. in the better part of a decade of riding with power on road bikes, mountain bikes and cross bikes, i've never seen this happen.
It happened to someone I was riding with. No damage to the bike however.
I agree though. It's too bad the technological cure for poorly installed magnets was in reality more trade-off than cure
Mark E
Re: New Power meter(s) depression. [mark.ewers]
[ In reply to ]
I've had two magnets dislodge from their holding bracket and get stuck in between two of the rear cogs. No damage as they are small and just made the chain skip a bit in that gear.
The irony is they are the Quarq magnets (while I use SRMs I had some spare Quarq magnets from a time when I used to service faulty Quarqs here in Australia, before the days of SRAM), which while the design of the BB mount magnet bracket is nice and easy to fit, the glue securing the magnet onto the bracket isn't strong enough to survive a knock or being hit by a dropped chain and it could use a better magnet attachment design.
http://www.cyclecoach.com
http://www.aerocoach.com.au
The irony is they are the Quarq magnets (while I use SRMs I had some spare Quarq magnets from a time when I used to service faulty Quarqs here in Australia, before the days of SRAM), which while the design of the BB mount magnet bracket is nice and easy to fit, the glue securing the magnet onto the bracket isn't strong enough to survive a knock or being hit by a dropped chain and it could use a better magnet attachment design.
http://www.cyclecoach.com
http://www.aerocoach.com.au
Re: New Power meter(s) depression. [AlexS]
[ In reply to ]
AlexS wrote:
I've had two magnets dislodge from their holding bracket and get stuck in between two of the rear cogs. No damage as they are small and just made the chain skip a bit in that gear. The irony is they are the Quarq magnets (while I use SRMs I had some spare Quarq magnets from a time when I used to service faulty Quarqs here in Australia, before the days of SRAM), which while the design of the BB mount magnet bracket is nice and easy to fit, the glue securing the magnet onto the bracket isn't strong enough to survive a knock or being hit by a dropped chain and it could use a better magnet attachment design.
Same, I lost three quarq magnets. The first used the provided epoxy putty and BB mount. The second used superglue to adhere the magnet to the bb mount. The third was a pre-adhered bb mount from quarq. Finally I used liberal amount of industrial hot melt to secure a magnet to the bb mount. Worked very well.
Pantelones wrote:
AlexS wrote:
I've had two magnets dislodge from their holding bracket and get stuck in between two of the rear cogs. No damage as they are small and just made the chain skip a bit in that gear. The irony is they are the Quarq magnets (while I use SRMs I had some spare Quarq magnets from a time when I used to service faulty Quarqs here in Australia, before the days of SRAM), which while the design of the BB mount magnet bracket is nice and easy to fit, the glue securing the magnet onto the bracket isn't strong enough to survive a knock or being hit by a dropped chain and it could use a better magnet attachment design.
Same, I lost three quarq magnets. The first used the provided epoxy putty and BB mount. The second used superglue to adhere the magnet to the bb mount. The third was a pre-adhered bb mount from quarq. Finally I used liberal amount of industrial hot melt to secure a magnet to the bb mount. Worked very well.
http://www.cyclecoach.com
http://www.aerocoach.com.au