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

I got one of these. Never worked properly, especially on the resistence mode, tried various smartphones, it was just a bit shit. Ended up sending it back. Obviously. Felt like wahoo were using their consumers to test the product.

Ah, thanks- that's very interesting. Where did you get yours from?

Wheel based speed is more accurate than GPS on a garmin. That is why when doing aero testing you are always advised to take readings from a wheel based sensor rather than GPS.

Looks rather like my Powertap has now gone wrong- the power figures trend upward, so what you know to be around 200 watts ends up reading 400.

It's an older SLC+ model, with freshly changed batteries in it - does anyone have any troubleshooting advice before I post it to Saris?

Looks rather like my Powertap has now gone wrong- the power figures trend upward, so what you know to be around 200 watts ends up reading 400.

Ooops... Noted.

As a for instance, looking at the data from the ride home (relaxed, wearing normal clothes) my one minute power is 510 watts.

The calibration figure is ~590, which I think's out of the correct range as well?

I'm pretty sure it should take cadence from the P2M. It's a far better value, as it's transmitted as frequently as power. Not just each time the magnet passes the sensor.

That's what I thought. Although I'm not overly bothered about speed accuracy.

Rode without the sensor Sunday and didn't miss it.

Dammit. If you're using trainer Road you don't need a stopwatch. Everything is done for you. Just follow the curve. I love my 'super magneto pro'. The resistance settings are handy. 'Interval' gives a steep curve. So you don't need to change gear so much to follow an intense plan. 'road' is good for recovery spins with my fixed gear attached.

I'd love a kickr. But the fact that I can't attached my fixed would kill it. Low resistance spinning on the fixed is really nice.

I set my FTP using the fixed. Plus I even do the odd sufferfest vid fixed. Means no easy gear for recovery between intervals. Which means epic leg burn. But I used it to prepare for races. Where I'd be forced to follow a groups pace, whether my legs wanted a rest or not. I have a habit of pushing too hard, then resting too easily.

I too think it takes cadence from the p2m but would disagree about it being better. Seems like there's a bigger lag between pushing on and seeing the number climb?

^same with stages. More lag. Magnet sensor seems more accurate.

There is more lag. But the accuracy will ultimately be better.

Yeah, but very frustrating when trying to bash out 15s intervals.

I thought the p2m sent cadence data 20 times a second or something. But that the garmin only displays a average. Is that the lag?

I'm totally guessing here.

There is more lag. But the accuracy will ultimately be better.

The precision will be better perhaps - but not the accuracy:

Yeah I know; I am/was just excited by all the data ;)

That's how I use my PowerTap. I'm in the 'getting fit again' stage and gathering data whilst I do that. I'm a long way off specific training targeting my weaknesses, especially as I have ~15kg to lose. Small increases in the numbers (especially as weight goes down) helps keep me motivated. Most of my data comes from commuting or laps of Richmond Park.

As others have said, don't compare raw Watts, only compare W/kg. The chart in Coggan is good, it's also here: http://cyclingtips.com.au/wp-content/uploads/2009/07/powerprofiling.jpg

I was scraping into mid/high Cat 4 back in 2009 when I was doing lots of Audaxing and I was just starting to make improvements using interval training (5x5 mainly) as I had access to a gym bike at work with consistent power measurement.

I'm waiting to hear back from Paligap as to the costs to replace my torque tube.

Can they stuff G3 workings into an SLC+ hub shell?

Otherwise it's going to be a complete rebuild, and I won't have matching hubs anymore.

This is a bit misleading - it depends what you are training for.

Track, TT or flat circuit racing - watts and aerodynamics are the key factors.

Watts/kg is useful for making a profile but it's a bit like BMI in that it can be a bit misleading. Aside from weight, it also only takes 5s, 1min, 5min and ftp power into account so it's not a totally comprehensive review.

If you're using Ant+ then you're limited to the 1s average (or 3s, or whatever it is)

I need to rethink my power display usage. Need a decent interval screen, with something more frequent than 3s average.

Lap time
Av Lap power
Current power.
Cadence.

Need HR there. Feels like a bridge between 'perceived effort' and 'power output'.

Could dump lap time I guess. It's for hill training. So im finished when I hit the top. Simple.

Q: are there any reasonably priced turbo trainers that do a good job of measuring power? Sub £400 would be ideal. Usable fixed would be dreamy. Everyone I know whose used the Tarcx power products agree's the readouts are nonsense.

I would buy a nice fluid trainer for £200, and a trainer Road subscription. It's calculated power. But it's very good. My FTP is loads less indoors anyway. So using my P2M for power instead of trainer roads own calculated power is a bit meaningless really. I can't really compare the data anyway.

As well as saveing money. You get a simple and solid trainer, with less that can break.

Actually I talked a mate into using trainerroad with sufferfest voids for indoor stuff. He found it loads better to use their power than that of his tacx. So there you are.

miro_o
Q: are there any reasonably priced turbo trainers that do a good job of measuring power? Sub £400 would be ideal. Usable fixed would be dreamy. Everyone I know whose used the Tarcx power products agree's the readouts are nonsense.

No, is the simple answer to that I'm afraid - second hand is the way to go for that money.

Kurt Kinetic trainers have the power pod: http://www.wiggle.co.uk/kurt-kinetic-inride-watt-meter-pod/