RyanArf

I just bought a trainer cuz i crashed and fractured my clavicle. I have a stages power meter on my bike, does any1 no if u can show your speed and distance with it or do you have to buy the Speed/Cadence Sensor. thanks for all the help

DXchulo

Your speed and distance are zero because you aren't moving.

Your power numbers matter more than anything and are way more useful than trying to guess what 20mph on the trainer would translate to out in the real world.

RyanArf

Yes i no im not moving lol but i thought mayb i had to turn it on or somthing but i guess you cant get distance/speed. not that im worried bout my speed but wanted to no how many miles i went. But it doesnt rly matter if i do an hr long workout at x amount of power is all you rly need

dralways

Details on the crash, if you don't mind. Did a part fail or something in the road, etc? Just curious.

Nebby10

Yes, you'll need a speed/cadence sensor since the Stages only does cadence, it's go no way to measure your wheel speed.

Looigi

As already mentioned. It's the level of exertion (power) and duration that matter. Cadence is also useful for training. Distance and speed are zero and irrelevant.

RChung

Cadence usually isn't terribly useful for training but in the odd and specific case of a Stages on a trainer, knowing cadence and wheel speed can be useful since the trainer is what is setting the load.

halfspeed

This is an English speaking forum.

RChung

We no. He brok his clavicle and is typin w one hnd. Mayb u cud improve ur reading comprehension. Or at least ur compassion.

06SpiceRed

Lolz truuu dat

halfspeed

It never occurred to me to modify my comprehensibility when I was typing with one hand during shoulder surgery recovery.

Vicegrip

why is this only for Stages? I use a Kurt fluid and the rpm of the Kurt sets the load as you say. What sets the stages apart from a spider based meter? Nether knows the wheel speed but both measure wattage.

daven

You do need to buy a speed sensor if you want speed/distance info. While I agree with the above posters who state that those measures are irrelevant, it is still mildly interesting to see the 'mileage' covered. But the bottom line is to work at the correct power levels for the correct durations to achieve the workout goal.

If I might suggest an additional tool: TrainerRoad!! I spent most of the winter doing base work and came out weighing less and with a very good fitness base for the build stage. Worth every penny! All you need is a computer, power meter, and a USB/ANT+ adapter.

Vicegrip

With trainer road you can get by without the power meter. You tell TR what trainer you are using and TR calculates the load based on the power/rpm curve of the unit. Not as accurate as a PM but seems to work well enough for many.
The winter before last I used a computer, cadence/ speed sensor, ant dongle and a Kurt fluid trainer with TR to make some measurable gains in the off season. Last winter I used the great outdoors by riding all winter.

Still wonder why the Stages is not able to give the same data as a spider based PM. I can see where a wheel based unit such as a Power tap could read not only power but "distance" as it is not influenced by gearing. anyone know what Rchung was referring to?

MikeyBoyAz

It is not unique to stages. The same will happen with the SRM, Quarq and Rotor Crank Based Power Meters [there are others too]. The only ones which will measure speed are part of the rear wheel or part of the trainer.

RChung

I wasn't saying a speed sensor is useful because of distance, I was saying it's useful because it provides a check on data quality. On a trainer, wheel speed and wheel distance aren't very useful metrics of training. However, speed can help you diagnose problems with your trainer and also with your power measurement.

For example, the trainer sets load by the speed of the roller but for many trainers the load varies with temperature -- even the Kurt Kinetic, though its temperature drift tends to be smaller than many other trainers. In that case, you can often see the relationship between speed and power stabilize as the trainer comes up to temperature equilibrium. That's one way that speed can be useful when using a trainer. But that's about the trainer, not the power meter, so it applies to all power meters.

There's a second way that applies especially to the Stages (and the Ergomo, if anyone still has one of those). All of the Stages and Ergomo users whose data I've seen appear to have different bilateral asymmetry at different combinations of cadence and force. For some it's small, for others it's large, but I've never seen a case where it's constant. If you have a speed sensor on the bike you can do exactly the same comparison as above and look at the relationship between speed and power for different combinations of cadence and force to find out if you're in the group where bilateral asymmetry doesn't change much, or in the group where it does.

rangerdavid

just got my Stages PM this morning and had it installed. Now to pair it up and go for a ride!!!

Vicegrip

Thanks, that is what I figured you were getting to but your earlier post made it sound more sinister than the one leg doubled aspect. What do you see as small and large? I ask as I wonder about the ratio of the variable of right left to the variable to trainer setup and consistency. With regards to the Kurt, and I suspect other tire on a cylinder driving a fluid pump type systems, there are setup issues that vary the power reading and exertion levels. I was able to skew the power readings between the PM and the calculated power that TR made simply in setup of the bike to trainer. Not just numbers, enough for a regular Fred to feel and not only by well out of range poor setup. more or less tire pressure and more or less tire to roller pressure skewed the readings and "feel" As noted the silicone oil in the Kurt has less viscosity to temp shift but there is still a noted decrease in power to RPM when the Kurt heats up. I noted this both with a Stages and a PT wheel used prior to installing the Stages. The numbers given by ether meter were more consistent with each other than the numbers via TR. All the hard to control and account for variables make me wonder that they would overpower any right left numbers. What right / left numbers do you see from the systems that can read both?

I am always interested in how things work and what works well for the job at hand.

RChung

I've only seen a couple of people with Vectors, and one who had Look Power pedals, who sent me files where they paired the files with either a Power Tap or a Quarq. I also have a bunch of files from people who use P2Ms and Rotor and the Quarq Elsa that report a L/R balance, but I don't consider those data to be of the same quality. I've gotten a tiny amount of data from someone running a Pioneer/PowerTap combo but it's too early to say much about that. With all that said, I've seen people whose L/R balance was not far off in the "middle" of the pedal force-pedal speed range but way off at the ends, in both cadence and force. By "way off" I mean something like more than 7 or 8%. "Not far off" means less than 3 or 4%. When I say less than 3% I mean 47/53 or closer.

Bottom line, as I've said, is that if you use the Stages for training your FTP then you're probably going to be okay. That's cuz training FTP is one of the least demanding tasks you can ask of a power meter. If you want to do some of the more arcane things that people do with power meters then you're going to need pretty high data quality and I'm not sure the Stages (or the Ergomo) can deliver that -- but not many people do those things.