dnuzzomueller

So during these wonderful winter months in New England here I have found myself with a Kurt Kinetic fluid trainer, and without a power meter. (Curse you limited budget!) Now obviously this is not an "ideal" way to test power but does anyone know if there is some type of software that would allow me to "inject" power data into a GPS file (Or possibly create a secondary file) using the Kurt Kinetic formula?

I am wondering if training peaks would be able to do this?

Creakyknees

If memory serves, they will sell you a speedometer that has their power curve programmed in, so you can track it. Not sure about uploadability.

Martyk22

Trainerroad.com, wonderful!

carleton

1) What problem are you trying to solve here?

2) What did we do before power meters?

Fat Boy

From KK power computer manual:

This power curve is based on the “average” rider on the “outdoor ride” using the following cubic function:
P = (5.244820) * S + (0.01968) * S^3 S = speed in miles per hour, P = power in watts.

Get a Garmin computer to use to data log speed. Do a ride. Download data. Export data into spreadsheet. Use above equation to calculate power. Make pretty graphs.

Or, just look at speed and fudge it while you're riding with a $20 cyclo-computer.

DGozinya

Trainerroad.com. Great stuff!

wanders

Before I got my PM, I printed out the power curve chart from the KK website and used that to go by for X minutes at Y watts.

After I got my PM, I was very disappointed to find how accurate the power curve chart was.

It was dead on.

rbart4506

That's how I did it before the PM...

merlinextraligh

Trainerroad looks pretty cool. I wish they had it for an ipad app.

Creakyknees

SalsaPodio

New version of Golden Cheetah does that for free.

JandersUF

It does. If you can make it work with your computer and components. For some reason, trainerroad works great with my mac, and golden cheetah's real-time features do not.

I am enjoying trainerroad a lot, even though I have a PM. I like using it with Sufferfest videos, as it takes your FTP and gives you power-based intervals to hit instead of 8.25/10. Not a massive thing, but it makes them a bit more fun, and a bit more difficult. It gives you reports of each interval and mini-interval at the end... so you can see if you really outsprinted Boonen at P-R or not.

I also like a lot of their pre-programed intervals/workouts... I have them running on the bottom of the screen while I watch a movie that takes up the top 80%.

Much like the sufferfet videos, trainerroad is just a part-time gig for the two guys making it. I think they charge a low price for a nice product, and if I am going to give anyone money, I like the idea of giving it to these niche home-grown businesses.

chefxian

Race

LeeRoySD

^^this. Loving Trainerroad as well for a lot of reasons.

shovelhd

Have they fixed the Performance Manager so that it shows ATL, CTL and TSB? I went back to 2.1 because I could not get this to work on 3.x. I also have a Garmin ANT+ stick and could not get that to work either.

8ounce

I stumbled on this google doc, and found it really useful with the kk trainer.
https://docs.google.com/spreadsheet/...jcVB3alE#gid=0

wjclint

Saw this thread and thought I would share my thoughts in the hopes that it helps someone, somewhere, sometime, do less research than they would otherwise have to.

Are power curves for trainers accurate? Yes and you can find multiple examples from people who have compared power readings calculated from speed (speed meaning the number times your wheel goes around within a certain amount of time since you aren’t actually moving) on a trainer versus readings from a power meter. In fact a good formula can result in “calculated power” being within a percent or two of “recorded power.” Considering that different power meters can vary by this much, or more, if you already have a trainer you actually already have a power meter – you just need to know the speed to power conversion formula.

Two main factors determine accuracy: 1) the formula you are using; and 2) controlling the variables still present even when using a trainer. The variables are things like clamping pressure, tires, and tire psi. If you keep those variables consistent from ride to ride by always clamping your bike in the trainer the same way every time and keeping your tire pressure consistent, and you use the same formula each time, you have an accurate way to measure your progress even if your formula isn’t technically accurate. If it’s off by 25% for your first ride it will still be off 25% for your 100th ride so you can still measure progress. If you also have an accurate formula you can compare yourself to others if that is important to you.

The formula: You might be able to find the formula for your trainer online. If you can, and use the same formula each time to determine your power, then you can train with power. The published formula for my cheapo mag trainer was pretty far off from what I ended up measuring with a power meter. If you want something more accurate for you, your tires, your setup, etc. then find a power meter to borrow or rent. Do a trainer ride, download your speed and power data into excel, put it in a scatter chart, and have excel calculate the power curve for you under the “trendline” options in excel. Generally you want a third order polynomial, but some trainers, like mag trainers, often have a linear “curve.” You can look at the scatter chart and probably figure out what kind of curve you need and excel can calculate each one for you pretty much instantly.

Once you have your formula you need a way to look at it. Here are some options:

Option 1 – Trainerroad.com: As long as you have an Ant+ speed and cadence sensor and an Ant+ USB stick for your computer you can use this service which provides a lot of great information, in a very usable and stable format. To give you an idea of stability, my wife accidentally unplugged my very old laptop that I was using during a workout. It is so old the battery holds a charge for about 10 seconds. When I restarted the laptop and opened up my workout it was still there recorded as if I had just stopped and saved my workout. They have grown quickly and have a lot of plans for the future to make their service even better including adding things like group rides over the internet. I was looking at Tacx VR trainers and computrainers when trainerroad.com went live and I really lost interest in looking at other options once I started using it. If your trainer isn’t on their list the developers are very responsive and will probably add it for you and if you can borrow a power meter and tell them what trainer you are using they will likely calculate the power curve for you. Plus you get a ton of workouts to do in a way that makes your training progress much more objective and the Sufferfest video integration is very cool. Many of the workouts have on screen tips as you do a workout and there are “plans” available and being developed that pick workouts for you to do on a schedule. In my opinion this is by far the best option out there for indoor training even if you have a power meter and especially if you want to use calculated power from a trainer's power curve.

Option 2 – Paper and Pen: Use your formula and calculate power for speed increments like 5 mph is X power, 10 is Y power, 15 is Z power, etc., write it down and put it on your stem or somewhere else where you can see it. Just look at your speedometer and your chart and you know how much power you are generating (unless you can calculate third order polynomials in your head on the fly in which case just memorize your formula.)

Option 3 – Excel: After the ride download your speed information, assuming you have something that allows you to do that like a Garmin, and calculate the power for each speed recorded. You can then use excel to create charts, calculate intervals, or whatever. Of course that is all after the fact rather than real time and what a pain in the ass.

Option 4 – Golden Cheetah: Golden cheetah has some power curves for a few trainers in the software. If your trainer is on their list, and you can figure out how to get it to work, it will let you display a ton of data on the computer in real time while you train. The downside is you can’t add your own power formula and there are only a few trainers listed. The other big downside is the complexity of the software and the lack of any Ant+ interface that lets you know if you are paired correctly. But it is also extremely customizable and you can create your own workouts to do. You can even use Google streetview to re-ride rides that have GPS data. Then you can do post ride analysis of your data for hours to figure out how to get better (instead of riding more to get better).

Option 5 – Sporttracks: Sporttracks has two plugins you can use. One is TrainerPower where you can have the software, after your ride, calculate the power for the ride. You can use one of very many power curve formulas already in the plugin and can add your own custom formula if you think yours is more accurate. Once you apply the plugin to your ride the software treats the power data exactly the same as if it had been recorded with a power meter and provides a wealth of information for post-ride analysis. There is also now a live recording plugin that works with Ant+ devices including power meters to show your data live as you do the ride. According to the developer of the live recording plugin on the Sporttracks forum a release that allows the plugin to integrate with the TrainerPower plugin is imminent so you can show real time calculated power. If all you want is to see your data on the screen and then use SportTracks to analyze it post-ride then this looks to be a very good low cost option (as soon as the TrainerPower integration is live.)

I hope this helps at least one person figure what options are best for them.

jmX

Software in my sig is what I use when I'm on a bike that doesn't have a power meter. It'll estimate power for a couple different trainers (should be trivial for me to add more some day) and saves out a standard Garmin Fit file with heart rate, cadence, power, etc. Can then use that in WKO, golden cheetah, garmin connect, strava, whatever.

I've not used trainer road, but it looks like its a nice little tool that basically does a simplified version of what I'm doing. Seems odd to pay a monthly fee for some equations though!

motorthings

It would be odd if that's all you got for the monthly fee, but in fact there is much more
- "realtime" feedback of the virtual power numbers, rather than relying on PEL.
- huge list of workouts pre-constructed to meet a wide range of needs
- plans available to let you tailor your workouts towards a specific goal
- tracks the history of all your workouts and results
- full integration with sufferfest videos (a huge plus for me)
- etc etc

jmX, I have watched your project for awhile, and thought it has great potential. I'd love to have the option for a VR type ride onscreen, so hopefully you'll have something ready for public consumption soon so we can enjoy the fruits of your labor as well.

carleton

Golden Cheetah uses real-time recording. I have a few Garmin Edge 500 files from trainer workouts. Is there any way that Golden Cheetah will look at a past trainer file when I rode my Kurt Kinetic Road Pro (one of the trainers that it supports) and estimate my wattage for the ride?

jmX

Trainer road sounds neat, but does it give you a fit file with hr/power (or equivalent) to use in GC/WKO+? I'm not wanting something that re-invents the wheel, and WKO+ or GC pretty much seem to be the standards for post workout analysis. As long as you can get your data out of it, thats great. It's really the whole reason I started my project, as I was too cheap at the time to buy a power meter yet still wanted to do proper training.

Integration with sufferfest videos sounds cool...is that a pre-made workout template that happens to matchup with a sufferfest video, or is it something more involved?

JandersUF

Yes, you can download the .tcx files that trainer road records off of your ANT+ data. So, it makes your computer work as a "little yellow computer" or garmin. You can download from trainer road and export to GC (or strava).

So, the way it works... you tell trainer road your FTP. You start up one of the sufferfest work outs in trainer road. The video plays in nearly-full screen, while the data bar at the bottom tells you how much power to put out, etc. Basically they went in and programmed (for example) the 7.5/10 interval to be 100% FTP, the attacks to be 150%, etc etc. The sufferfest videos aren't universally the same; i mean that 7.5/10 does always mean 100% FTP. The trainer road guys basically made reasonable estimations that mesh with the videos and give IF numbers that are reasonable (say 0.95 for an hour video).

At the end of the video it will also spit out data for every split / attack / interval showing if you hit the suggested numbers.

wjclint

I don't believe Golden Cheetah allows for post processing like that. However, SportTracks and the PowerTrainer plugin will do exactly that which you could then import back into Golden Cheetah.

carleton

Is this something that I can do in Excel?

Basically:
- Export the file to CSV and load into Excel.
- Use the Kurt formula for speed/power when the speed is steady or increasing
- Use Zero if the speed is decreasing


Or should I do some broad averaging (10", 30", 1', complete file?)

rkwaki

What's a power meter?