POWER

[Mr Haematocrit]

Where did you order a Stages in the UK?

Available in UK now but still not working with any carbon crank
http://www.bikeradar.com/road/news/article/stages-cycling-power-meters-come-to-the-uk-38203/

 

[Sittingduck]

Ok

DC Rainmaker summarises the main differences between the hubs here. He's got a few other articles on Power Taps so have a browse. I don't think you can get the SL anymore, the Pro is the entry level, and G3 is the more performance focused unit.

One of the neat things about the G3 is the ability to change the battery yourself, the Pro I believe has to be sent to Paligap.

Ok cheers, I will read through the Rainmaker stuff and ponder my options.

 

[amaferanga]

One of the neat things about the G3 is the ability to change the battery yourself, the Pro I believe has to be sent to Paligap.

That doesn't sound right. Every other PowerTap hub has batteries that can be replaced without sending the hub off to Paligap.

 

[VamP]

That doesn't sound right. Every other PowerTap hub has batteries that can be replaced without sending the hub off to Paligap.

You're right. The removable electronics pod that G3 has enables antenna or battery connection repairs, but even the previous PTs had a user serviceable battery. I hadn't realised that.

 

[Mr Haematocrit]

According to Garmin the max width of the crank at the pedal interface is 15mm. Guess the S-Works is too fat, then, and the the transmitter pod won't connect properly with the gubbins inside the spindle

This is exactly the case the plug in the transmitter pod does not connect properly. The spindle in the sworks cranks seem to be a little recessed which prevents the plug from creating a good connection, its out by nano meters at most.

You can see the plugs on the pods in this image

 

[VamP]

It really annoys me the way you have work your way through the sub-menus on the 500 to get to the zeroing field. Wish there was a shortcut! Or a dedicated button!

Hahah!

Latest firmware update (3.30) for the 500 includes a functionality, whereby each time it's turned on and detects a PM it asks whether you want to calibrate. Two button presses in place of 10. What am I going to do with all that saved time?

 

[Rob3rt]

They should add a data field that acts as a zero button and also displays the current calibration figure, so you can either tap the number to update it, or when you freewheel (Powertap/P2M) or pedal backwards (Quarq) the number updates. I zero mine at least 3 times per ride.

 

[VamP]

Why 3 times?

 

[Rob3rt]

Once at the start, then again around 20 minutes in, or before the real training efforts start, in order to eliminate any drift during warm-up, taking bike from inside to outside or as the room warms up etc and then once again at the end to check for consistency of data.

 

[Howard]

I thought power meters had temperature compensation built in? Or do you have an old P2M?

I zero my SRM once, in the house, before I go out.

 

[Rob3rt]

I have a Quarq.

Most power meters will experience drift throughout a ride.

It is good practice to zero at the end as well, how else will you know if something has gone awry and all the data is compromised.

 

[VamP]

I typically zero once. very occasionally twice, and never see any drift.

How much drift are you seeing Rob?

 

[Rob3rt]

I typically zero once. very occasionally twice, and never see any drift.

How much drift are you seeing Rob?

Not a lot but for the sake of the best data possible, it is worth doing and you are immediately aware if something has gone wrong.

BTW Powertap's zero whenever you freewheel.

 

[Howard]

I like the idea of zeroing at the end of the ride, to make sure nothing wacky happened in the middle - but if it did that should be obvious from the power file.

If my SRM started drifting I'd pack it off back to Deutschland.

 

[Rob3rt]

I like the idea of zeroing at the end of the ride, to make sure nothing wacky happened in the middle - but if it did that should be obvious from the power file.

If my SRM started drifting I'd pack it off back to Deutschland.

Not always, for example, at the start of the year, I had some issues with my Quarq, it worked perfectly on the turbo and for gentle road rides, then in a TT all of a sudden I was averaging 380W (apparently), the power file alone didn't show anything odd since the problem occured at the moment I pulled away from the standing start and applied a huge (relative) torque on the cranks. Turned out that when I pulled away, that huge torque caused the offset to shift by large amounts, you simply couldn't detect this without noting the offsets before and after a race.

In the end I remedied the problem by taking the chainrings off, cleaning all the interfaces and putting it back together and torquing it all back up, been perfect since.