Power Meters / Powermeters (SRM, Powertap, Quarq, Ergomo, Vector, Stages, power2max, P2M, 4iii, InPower, Cinch)

"Xpedo Thrust" = ex-paedo thrust = what were they thinking?

Maybe they aren't as filthy minded as you?

Anyway, pics released over on you know where.

Potentially they will be pretty good - the way they've built the force sensors into the pedal means that you won't need to faff about with getting the perfect torque when you install them, which is a bit annoying with the Vectors. I built a set of force pedals for our lab using the same principle, keeping all the strain gauges at the pedal body rather than the axle, so as long as they've managed to minimise drift and have the gauges in the right orientation they should be okay.

Xav

Don't you have to accurately measure the angle of the pedal relative to the crank in order to translate pedal force into crankshaft torque? In that case, you need a shaft encoder on the pedal spindle, and your output torque accuracy will be wholly dependent on the accuracy with which you manage to measure the nominal 'zero angle' position after installing the spindle into the crank.

Maybe they aren't as filthy minded as you?
Anyway, pics released over on you know where.

Or maybe they don't have an entire generation of television 'stars' going to jail. Either way, calling something Thrust is the same thing as calling it Mega Flange or Pump Harder Plus.

Don't you have to accurately measure the angle of the pedal relative to the crank in order to translate pedal force into crankshaft torque? In that case, you need a shaft encoder on the pedal spindle, and your output torque accuracy will be wholly dependent on the accuracy with which you manage to measure the nominal 'zero angle' position after installing the spindle into the crank.

Yes, I would expect an accelerometer in conjunction with something on the pedal shaft, we'll just have to see what the initial calibration step is. It could be something as simple as leaving your shoe clipped in and then rotating the crank backwards to find the point of highest torque (90deg), or installing just one pedal first or something. The other option is to have a specific orientation for the pedal axle like the Look pedals.

Xav

If you put an optical shaft encoder on the axle, the calibration step is to put the pedal plate at a specific angle to the crank and press the button that tells the computer 'this is zero'. Since you can put the encoding marks on the spindle and the receiver in the pedal body, there's no need for any moving electrical contacts, and no need for the spindle to have a particular orientation, so you could implement it in a way that's cheap, sealed from the elements and fairly idiot-proof.

Unfortunately, the product already looks like a joke, since it looks as though it only measures force on the pedal platform, not fore/aft force on the cleat too. If they're only measuring one component of the pedal force, I don't hold out much hope that they will care much about which direction that force is acting relative to the radius, so any "Power" metering will be based on a massive fudge-factor to guess how pedal platform pressure translates to crankshaft torque.

Who has been getting the Brim Bothers email updates about their pedals?

Me

What is the general opinion on them?

There is a pre-production review on DC Rainmakers site- but they were a long way off ready.

Concerns then were overly high readings, an odd spike, and a trivial software issue if I recall correctly.

So- hard to tell. They are interesting.

Its a seriously interesting option. I have 4 bikes that I use the same shoes for.

I probably dont need Power for the cargo bike. But it would be interesting for longer rides (over 10km With both kids on the back is a long ride). Last time I tackled a big hill I was seeing double at the top.

The fatbike is meant to be for endurance rides in the Winter snow. Although I'd only really care about amassing TSS for those. So the PowerCal would be fine.

Both the fixed gear, and the SS 29er get serious training use. I'd love to have half decent realtime Power data for them.

The Power2Max is everything I hoped it would be. As in it just works, without any technical input from me.

Had a little issue apon installation. Had everything fitted. Yet I couldnt get anything to pair with it. Solved this by realising the spare battery they kindly included was 'the' battery. Instructions, aint nobody got time for them.

Instructions are there to read only if something goes wrong.

Like maps.

Never read maps. NEVER.

Disappointing 20minute test today. Now slightly deflated.

Tweak the offset until you are happy

People (Steve Irwin) have done 18s off 278 watts, use it as an excuse to buy more aero stuff.

People (Steve Irwin) have done 18s off 278 watts, use it as an excuse to buy more aero stuff.

Lol. I like that. Rather than buying new kit to reward myself for improvements maybe I should buy new kit to commiserate myself when I seem to be going backwards :-). New bars (the same as yours) arrived this morning, I'll be mocking up my position on the TT bike over the next few days and then sending it to the LBS to fit all the important bits.

He is one of the most aero people EVER. EVER.

And that was a float day and some. But he's fast.

As mentioned above I did both a 5minute and 20minute test yesterday so that my coach could estimate my FTP and set my power zones for training. However, my average power during the 20minute test was considerably lower (c. 20W lower) than my previous 20minute peak power achieved during a much longer training ride.

Which number would you use to estimate your FTP etc? I think my coach wants to use the numbers from the actual test, but this seems odd when I clearly can put out better numbers (and have done several times). My 20minute power from the test was even 10W lower than my 60minute peak power from a week or so ago.

Its nice to use the test. As its under repeatable conditions. So you can follow progress.

But it sounds like a bum test.

Personally I'd use the training ride figure for Power zones. Then note the test result for comparison With future tests.

Surely Your Coach knows best though?

Probably, but always good to get a scone opinion from teh internetz.

Don't compare indoor trainer watts and 'real' riding watts. Riding conditions, temp, motivation and muscle recruitment all different.

I'm happy if I can do 90% of my best outdoor numbers on a turbo.