I could not find this on Google but I have a cyclops wind trainer. Noisy but works fine and I finally put my computer on back wheel. I road 22.5 miles in an hour and generally on the 53-16 gear with some shifts to add resistance. I average 86-92 cadence. Any way to get a wattage approximate for this level. I consider myself a strong cyclist for 53 and hate the trainer but it does get you a workout. Hope to be back running when hamstring gets better.

From: Power Curves | PowerCurve Sensor

That's suprisingly low compared to a fluid trainer.



53x11 at 90rpm on the Wind trainer is only 300 watts, which is going to limit any work over threshold for a lot of people.

It would likely be ok for 2x20's for most people, but shorter intervals (30 seconds to 5 minutes) you'd spin out if the curve is accurate.

That looks surprisingly high, to go 20 mph you need 250w?

The Kurt Kinetci numbers, IIRC are based on a 1% grade.

In fact, Kreuzotter an online power calculator, gives you 248 watts at 20mph, for their default rider, in the drops, and on a 1% grade.
Exactly how it correlates to the road depends on how aero you are, and how much you weigh.

For me personally, it a bit harder on the trainer to maintain 20mph, than on a flat road.

In the end all that matters about speed on a trainer is the extent to which you can use it to extrapolate an approximation of power.

I haven't ridden it since last winter, but I recall 24mph ~= 300W as measured by my Powertap. I'd been led to believe that with the right tension on the tire the published curve and my measured watts would match.

Well I found the cycleops site and they claim a wind trainer at 30 mph is 600 watts. Interesting in I never think of watts as a ride it is all about time and distance. This morning for couple of short burst I was able to get up to 31-32 miles per hour. I felt like I was working much harder than going over the road and trying to hit 30 mph. Also for whatever reason I think the trainer may actually be good for real training. I noticed this last weekend I had much better stroke and power riding outside and the week before I had done some 1 hour days on the trainer. On the road I can coast a bit an let up but put me on a trainer and I have to spin the cranks to get it to work.

FWIW, these numbers are a little lower but in the ballpark with my observations in the real world with my powermeter. In fact, I usually use 21 mph (no wind, flat road) as a rough equivalent for 250w when I am on my FG without a PM. But then as you say, a lot has to do with how aero you are, and I have a fair amount of bar drop and I try to focus on a flat back during these intervals.

The problem with trying to apply this to a trainer is that we have no idea how much resistance the trainer is giving. How hard is the the roller cranked down? I can set mine up so the at the roller barely touches the tire and then spin a 53x12 at 120rpm but is that 400w? Is it 150w? Who knows?

Your Powertap knows.

Yes, my pm says 19 on the kk is 220 watts, and 22 is 300 watts. Pretty close to the published curve.

the chart reads 400w at 25 mph.

Exactly. I have a powermeter but the OP does not. If he did, he wouldn't be asking about a way to approximate it.

But he doesn't need to approximate it, as that has already been done for him, as shown in post #2 .

I guess I missed the point you were getting at.

The table is only an approximation. Depending on how tight the roller is to the tire it can differ.

Of course it's only an approximation, but it's not going to vary by 250w, right? The bulk of resistance comes from the fan (or other resistance unit), not the tire on the drum. If tire/drum pressure is too light, the tire slips; too tight and it takes some energy to deform the tire against the roller, but again, seems small. I'll go downstairs and try it, because I never have and I'm curious.

Okay, so I did get in a few revolutions with different tire-to-drum pressures, and I gotta say it was more noticeable than I expected!

The trainer is downstairs near where my wife was watching TV, so I had to abandon the experiment on my Cyclops Fluid 2 quickly and without getting anything more than an impression, so I'll just leave it there for now, and try to get a better sense tomorrow.

The add-on to the Kurt trainers that provides wattage (inRide?) has a spindown calibration process for getting accurate wattage -- or I assume wattage that is consistent with their published table. I bought my KK before the inRide was available, so I confirmed/adjusted the power curve for mine by being very consistent on tire air pressure, and consistently cranking the roller down the same number of turns (exactly 2.5 turns from the tire just beginning to brush the roller), and then measuring the required speeds for the wattages I was interested in.

My measured wattages didn't match the Kurt curve, though it wasn't far off (and for me ultimately doesn't matter, since I end up doing a time crunched'ish approach of all-out/tempo/cool down and don't worry too much about the exact watts). If I do an FTP test on the trainer, I swap a Powertap wheel onto the bike I ride on the trainer.

Before TrainerRoad became popular, the only trainer I found that had published power curves was the Kurt's, and that was the reason I bought one. The OP asked about what wattage correlated to his effort, and from the charts, it looks to be a huge difference in effort for the same speed of one brand/type of trainer to the next (though the Cyclops chart didn't come from the mfg). The difference shouldn't be surprising, and just reinforces that speed (and resulting distance) are meaningless on a trainer, at least until you can get the power curve chart, and even then you may need to be suspect of it.

I guess it all gets back to the debate over whether the numbers need to more exact or more consistent, and that in the end, watts are watts, no getting around that.

That's why I like that my Nashbar trainer has no pressure setting. Bike and rider weight determine the pressure. You can't make a mistake.

Based on the curve posted above, and the online reviews, I question where they're getting that 600 watts.

According to at least one review, you can spin the thing out at 45mph CycleOps Wind Trainer - Trainers | Competitive Cyclist

The KK fluid trainer also claims 600 watts at 30mph. And I can guarantee you, no one short of Marcel Kittel can spin that out at 45mph.

Now I know why you're a weight weeny.