I sense a disturbance in the 3rd Law

[ratz]

thoughts on v2 sram red yaw front mech v v20 shimano ultergra. shift quality is smoother likely due to matched shimano components on v20. v2 fsa chainset. chain rub is non existent on both front mechs. verdict either one bling or smart choice.

It think the Shimano Di2 is going to shift better for the forceable future; it's higher force; and it has auto trim. While harder on the batteries it's going to be more reliable especially shifting under heavy load never had any issues with that. Like the sram, the did will shift better on oval rings if you can move it just a bit rearward with a shim, that will position the derailleur in a stable chain height and keep it out of the way of the variable height of the teeth; doubly useful if using QXL rings.

But the e-tap testing so far has been good, just need to to tune it up; I would rather spend 15 minutes getting it dial in; than 2-3 hours getting the internal shimano battery setup and the wires run. To different challenges really, but even the shimano FD was a tweak fest; and i did ad a sram chain drop guard to our Di2 setups

Would be nice to see sram add some auto trimming via future firmware updates; I think that was arrogant of them to leave off; yaw aint perfect.

The SRAM shifting button combination is amazingly intuitive after about 10 minute on the bike.

 

[jond]

The SRAM shifting button combination is amazingly intuitive after about 10 minute on the bike.

yeah i reckon you are right ratz. i think what ever you are riding at the time is best. so long as you are riding which is the point.

sometimes i think wow this shimano is so butter smooth then later think wow this sram 1:1 is so positive. truth is they are both excellent and rarely do i make the mistake of confusing operation.

one day in two years time i see an etap coming my way.

the latest is usually the greatest

thank God for early adopters who share pragmatically with intelligence.

That would be you ratz.

(the early adopter trusted with brains bit not the our Lord God bit.)

maybe a sainthood from cruzbike if you keep this up.

 

[super slim]

What is the total cost with wiring junctions etc for the Di2, when compared to the SRAM e Tap?

http://rotorbike.com/media/files/2014/11/rotor_2013253026.pdf
Would a 150 mm Rotor 3D+ be a good option?

How far away is the SPD version of the P1, AND can they be used on a 153 mm crank, with Q rings?

 

[ratz]

What is the total cost with wiring junctions etc for the Di2, when compared to the SRAM e Tap?

That's nominal; costs are about equal. The custom internal wiring and drilling I did adds about 30-60 minutes to the build process for me just because don't like those fragile wires on the outside; and there no internal runs in the chain stay so that has to be drilled out. If I did it repeatedly it would probably go faster, but it's still drilling the frame so nerve racking and not something to screw up.

Would a 150 mm Rotor 3D+ be a good option?

Only available in BB30 and BB30 external bearing cups are 2-3mm to big in diameter for the cup clamps so those are a non starter, tried them last spring; it was close but still a failure.

How far away is the SPD version of the P1, AND can they be used on a 153 mm crank, with Q rings?

No clue on SPD, but the P1 samples angle momentum 40 times per rotation so it can do q-rings and short cranks no problems. Same trick that Power2max uses.

 

[super slim]

At this stage to get right and left power output to a Edge 800, I will have to wait for a SPD pedal, or a Powerbeat is shipping to "Down Under", and for 153 mm crank

 

[jond]

I will have to wait for a SPD pedal,

slim my cycling mate louis w. was chasing it up with powertap. they asked him to call them re the mtn bike set up with a big hint. louis is buying a corsa .

i will chat with him soon and get back to you with his findings

 

[super slim]

slim my cycling mate louis w. was chasing it up with powertap. they asked him to call them re the mtn bike set up with a big hint. louis is buying a corsa .

i will chat with him soon and get back to you with his findings

Thanks fellow Aussie!!! even if from NSW!

 

[ratz]

Anyone the goes with P1's, a Garmin GPS, and short cranks will need this tool to correct the crank length setting inside a Garmin
http://fitfilerepairtool.info appears certain model have a "long standing" bug that doesn't make the data field available.

 

[ratz]

*sigh* I forgot to post this much earlier... only 4 hours left.
If you need a bell on your vendetta or silvio; then this really is the one you will be wanting.

https://www.kickstarter.com/project...-doesnt-look-like-a-bike-bell?ref=thanks_link

 

[jond]

Thanks fellow Aussie!!! even if from NSW!

slim spoke to my NSW newie mate louis about p1 power meter. he was told that powertap have no none nil plans to release the pedals in mtb format so no spd option . must be the crash risk too high??? but they appreciated his business.

louis asked why over a week ago but he is yet to receive any answer on that one. louis is a csiro principal and powertap hub user x 2 and will get an answer i would suspect. typical engineer.....ahem. louis want left right power splits. reckons he could make it work from the existing hub with software???

at least he lives in the right state where we press the flush button on the dunny not like south australia ever hopeful and waiting to see what comes out of the pipe at the other end. how on earth do you get coopers pale ale to taste so good..............

 

[super slim]

slim spoke to my NSW newie mate louis about p1 power meter. he was told that powertap have no none nil plans to release the pedals in mtb format so no spd option . must be the crash risk too high??? but they appreciated his business.

louis asked why over a week ago but he is yet to receive any answer on that one. louis is a csiro principal and powertap hub user x 2 and will get an answer i would suspect. typical engineer.....ahem. louis want left right power splits. reckons he could make it work from the existing hub with software???

at least he lives in the right state where we press the flush button on the dunny not like south australia ever hopeful and waiting to see what comes out of the pipe at the other end. how on earth do you get coopers pale ale to taste so good..............

No plans for MTB pedal is that what you meant????
We are a bit slow in Sth Aust, as there is normally not enough water to keep our brains hydrated enough!!!

The shock loads from a big jump, or catching the pedal on a rock could easily destroy the strain gauges OR the circuitry with peak loads!

 

[jond]

We are a bit slow in Sth Aust,

i told you so slim it is all in the water as a social experiment and public health

know a few mtb riders who would gladly take the risk with the pedals especially the cross country hard tail crowd.

 

[super slim]

i told you so slim it is all in the water as a social experiment and public health

know a few mtb riders who would gladly take the risk with the pedals especially the cross country hard tail crowd.

I LIKE the way you deleted most of my text!!! to only contain the important info!

The P1's set up ONLY requiring an Allen key and no external pods to get wiped out on rocks, makes it the best pedal based meter for me.

Do all the power meters sense torque and momentum 40 times per cycle like the P1?

 

[ratz]

Do all the power meters sense torque and momentum 40 times per cycle like the P1?

Nope

Many are one per rotation or twice per rotation you have to check with the vendors. But most of the newer entrants are learning from the past problems and all the attention Froome's data got.

P1, Power2Max confirmed >= 40 times per rotation.

Gotta check with the each vendor for details.

 

[super slim]

I have checked with the DC Rainmaker reports and no comments about the measurements per cycle.

I have also checked the Watteam Powerbeat web site but again no info!
I will Google it!

 

[ratz]

I have checked with the DC Rainmaker reports and no comments about the measurements per cycle.

I have also checked the Watteam Powerbeat web site but again no info!
I will Google it!

From Power2Max
How often we sample: We use a very high sampling rate of 50Hz, i.e. 50 measurements per second. This gives us very precise measurements and allows you to use oval chain rings without problems.

From PowerTap
DO THE P1 PEDALS SUPPORT OVAL/NON-ROUND CHAINRINGS?
Non-round rings are supported perfectly with the P1. We are taking 40 individual angular velocity measurements and subsequently 40 power measurements per pedal stroke. Any acceleration/deceleration within a pedal stroke would be measured. Other systems assume constant angular velocity, which typically reports [higher] power when using non-round rings.

 

[super slim]

From Power2Max
How often we sample: We use a very high sampling rate of 50Hz, i.e. 50 measurements per second. This gives us very precise measurements and allows you to use oval chain rings without problems.

From PowerTap
DO THE P1 PEDALS SUPPORT OVAL/NON-ROUND CHAINRINGS?
Non-round rings are supported perfectly with the P1. We are taking 40 individual angular velocity measurements and subsequently 40 power measurements per pedal stroke. Any acceleration/deceleration within a pedal stroke would be measured. Other systems assume constant angular velocity, which typically reports [higher] power when using non-round rings.

Thanks

 

[LarryOz]

I just called Garmin about their Vector pedal power systems in an effort to find out their sampling rate per revolution.
The customer service guy did not know what the sampling rate is.
They know it is at least once a second - but they can't find out the data.
They said: "We cannot disclose the sampling rate because it is proprietary information" . haha
They will work with elliptical, but there will be fluctuations because of that.

In the end, all I get out of them is that:
Both versions #1 and #2 take multiple samples per rotations.

I submitted a "idea" to them that if they don't publish their sampling rate (or make it high enough to correctly provide accurate power readings for non-round rings) that they will continue to lose customers to PowerTap.
That's it for now - I say if you ride with non-round rings, or plan on it, go with the P1's if you have the choice....

 

[ratz]

I just called Garmin about their Vector pedal power systems in an effort to find out their sampling rate per revolution.
The customer service guy did not know what the sampling rate is.
They know it is at least once a second - but they can't find out the data.
They said: "We cannot disclose the sampling rate because it is proprietary information" . haha
They will work with elliptical, but there will be fluctuations because of that.

In the end, all I get out of them is that:
Both versions #1 and #2 take multiple samples per rotations.

I submitted a "idea" to them that if they don't publish their sampling rate (or make it high enough to correctly provide accurate power readings for non-round rings) that they will continue to lose customers to PowerTap.
That's it for now - I say if you ride with non-round rings, or plan on it, go with the P1's if you have the choice....

Stages will also work but they read 4-5% high but with consistent predictability so you can scale the results; they are event based 1 reading per rotation so angular velocity doesn't really matter. http://support.stagescycling.com/su...wer-meter-with-oval-or-osymetric-chain-rings-

Can I use the Stages Power meter with oval or Osymetric chain rings?
Modified on: Thu, 19 Mar, 2015 at 2:21 PM

Mechanically, the Stages Power meter is 100% compatible for use with Osymetric, Q-Ring, and other non-round chain rings.

Our power measurement through a Stages Power meter is event based, where as an event is one complete pedal revolution. Due to the changes in velocity non-round chain rings produce through the course of an 'event' you will see that your power will be skewed higher than with a round ring, which has a constant velocity throughout each event. Through our own testing, and using a hub-based meter as a control, we conclude that there will be a 4-5% increase on the readings from a Stages Power meter when used with a non-round chain rings. We recommend that our customers take this into account when changing from round to non-round chain rings, as they may need to adjust their functional threshold power accordingly.

 

[ratz]

Many hours later SRAM has me take it to a LBS (where I didn't source it from) and Forces me to run it through their mechanic for verification; then it's off to SRAM for engineer to look at in case they need change the manufacturing process. Then I might see a replacement by May. Should be interesting to see how they handle all of that.

Color me impressed the replacement derailleur is back at the shop; in 3 days. *GASP* they must have airfreighted that explosive battery. Ok so +1 SRAM for quickly getting me back on the project. New Cranks will be ready on Friday, power meters arrive a week from today. Game On; time to get this diary done.