as i’ve got no magnet on anything
.
I’ve got one and was wondering the same thing. It measures cadence by detecting spikes in power on each pedal down stroke. If you go down a hill you can see this by doing a light spin that’s slow enough to not engage the rear hub. You don’t add power to the hub so your cadence will read as zero even though you are spinning because the hub can’t detect any power.
great, thanks!
poorly.
poorly.
Yep - not like it matters a lick however.
I would agree with “poorly”
.
poorly.
Yep - not like it matters a lick however.
It doesn’t matter a lick but if one wants to do “quadrant analysis” (or simply for curiousity’s sake) there are ways to clean up cadence data.
Put the magnet kit on and get accurate cadence and speed.
Put the magnet kit on and get accurate cadence and speed.
You get accurate speed without any other sensor, and accurate cadence really isn’t very important.
I hope speed is accurate… but my LYC still has problems with distance and time.
I hope speed is accurate… but my LYC still has problems with distance and time.
I’ve noticed that my wireless PT can drop a record or two while my old wired PT either recorded accurately or else was clearly off. For example, with my old wired PT there was a consistent little anomaly on a road I used for testing. Finally I noticed that they were in the same location. I went out there and right on the spot where the data got screwy I passed over a utility company access cover. Anyway, with my wireless PT I can occasionally spot “mis-registrations” in the data stream because VE features can be mis-aligned by a couple of meters but if I offset from that point on then all other features line up.
It’s an estimate, but it really doesn’t matter. Long story short, don’t worry about cadence.
I think my issue is something else… and one shared by all ant+ LYC users. On the download, distance and time are high by a 1-1.5%. I have no idea what would cause it, and though Saris claimed they would fix it (a couple years ago), it still isn’t.
A little off-topic, but not completely as it also pertains to the speed measurement on PowerTap wheels. I’ve recently moved my speed sensor from the fork to to behind the BB in a hope to get my bike a (very tiny) bit more aerodynamic. Now I just read Sheldon Brown’s piece on tire roll-out for best accuracy - http://sheldonbrown.com/cyclecomputer-calibration.html#rollout - and he writes:
“Unless you want to count “miles” ridden on a stationary trainer, it is best if you measure the roll-out of the front wheel and mount the computer sensor there. The rear wheel “creeps” along the road surface as you pedal, and can skid during braking, so it gives a less-accurate readout.”
I can imagine this creep, but really, how much do you think we’re really talking about? One of the reasons I have a speed sensor and not using the GPS of my Garmin Edge 500 is to be able to get decently good speed data to be able to ‘Chung’ my TT’s. The speed readings are really less than stellar on my Edge 500 when the sky is obstructed by trees etc.
PS. Since I’m too busy/lazy to report them myselves I have a couple of suggestions for Golden Cheetah that might be useful (so can somebody already registered post these as suggestions to the Golden Cheetah guys - please? :). The first is not adding the elevation gain to the VE in Aerolab when e.g. the VE slope is more than 10% (this value should be adjustable) because this will be when you apply your brakes, at least if you’re doing a flat TT (to be more advanced you could compare the VE slope with the slope recorded by your Garmin and when, say, the difference is more than 4% not add it to the VE profile because it must have been because the brakes have been applied). I have added this functionality in my own spreadsheet and thought it would be a good addition. The other thing is a possibility to export the direction headings in the .csv file along with the other things (speed, distance, times, power, etc.). This way you could better get a shot at superimposing wind speed and direction and take this into account when doing your VE analysis.