First-time Pt user - Realization stinks

[goodboyr]

http://cycleops.com/p-309-fluid.aspx

Here's the graph on the claimed resistance of the newer unit. This looks to me like a somewhat optimistic view of a fully warmed up unit. Although it appears that 20 mph is about 250 watts, my experience with our our club (powertaps and polar mixture) running the new units is more like 200 - 225 at 20 mph. However, no way its over 300 watts at that speed.

 

[frenchyge]

Agreed. If my older Fluid 2 goes bad, I will get a KK.

That's too bad -- the website says they're built to last.

Funny, a stiffer power curve was the reason I moved from a Cycleops Mag to a KK Road Machine back in '05. I'm surprised that they think a broader range of cyclists would spend $250+ on a trainer to ride indoors all winter.

 

[goodboyr]

That's too bad -- the website says they're built to last.

Funny, a stiffer power curve was the reason I moved from a Cycleops Mag to a KK Road Machine back in '05. I'm surprised that they think a broader range of cyclists would spend $250+ on a trainer to ride indoors all winter.

Well.....my suspicion is that the real reson is to reduce the probability of leakage. The newer units in our group don't get nearly as hot as mine. And I assume the heatup cooldown cycles eventually cause the seals to let go. Makes sense since the lower wattage results in less heat.....problem is they don't get the workout benefit. Basically, they are running at the extreme range of gearing and cadence to get any kind of wattage.

 

[upstateSC-rider]

Well.....my suspicion is that the real reson is to reduce the probability of leakage. The newer units in our group don't get nearly as hot as mine. And I assume the heatup cooldown cycles eventually cause the seals to let go. Makes sense since the lower wattage results in less heat.....problem is they don't get the workout benefit. Basically, they are running at the extreme range of gearing and cadence to get any kind of wattage.

That's a good point, I've heard of Fluid2's leaking before. The one I'm using now is a warranty upgrade, I had an older Fluid2 that lasted a long time but started having a weird vibration. You're right, heat is a killer of seals and I remember my old one getting very hot to the touch. Unlike my current newer one.

 

[frenchyge]

Makes sense since the lower wattage results in less heat.....problem is they don't get the workout benefit. Basically, they are running at the extreme range of gearing and cadence to get any kind of wattage.

Something here is just not adding up. I'd believe that Cycleops changed the design to let the units run cooler (improved the heatsink maybe?), but Rider X is going to be putting the same wattage into the new unit as the old.

The website talks about changing the design (ie, optimal tuning of the power curve ) for a 400w output at 25mph, but the KK machine is only 431w at 25mph. So, I'm not seeing how riders would be spinning out the new Fluid2 and being unable to get their desired wattage (and therefore letting the unit run cooler).

If their trainers come close to the curve that was posted, that really doesn't seem that bad (and puts the OP's FTP closer to 250w at 20mph).

 

[goodboyr]

Something here is just not adding up. I'd believe that Cycleops changed the design to let the units run cooler (improved the heatsink maybe?), but Rider X is going to be putting the same wattage into the new unit as the old.

The website talks about changing the design (ie, optimal tuning of the power curve ) for a 400w output at 25mph, but the KK machine is only 431w at 25mph. So, I'm not seeing how riders would be spinning out the new Fluid2 and being unable to get their desired wattage (and therefore letting the unit run cooler).

If their trainers come close to the curve that was posted, that really doesn't seem that bad (and puts the OP's FTP closer to 250w at 20mph).

Read his post again. His formula tells him he should be around 310 watts. His Powertap tells him 214. He says he might not have totally warmed it up. We know that the Cycleops tend to creep up in resistance when they warmup, so 214 isn't so far off from 250 fully warmed up (+- 10 %). Thats a lot closer than 310. And my older one is at about 305 at 20mph. My friends newer one is at 220 at 20 mph. Its not that they are spinning them out. Its just that the new power curve forces you to run at a higher rear wheel speed for a given output and workout. So since we train relative to our threshold powers, we have to go at a different gear and cadence. The newer ones run at a lower power curve, and they run cooler. I just think that its cause and effect. The wattage in these trainers is disappated as heat. The difference between the old ones and new ones at 20 mph is almost 100 watts. That's a lot of heat input over a workout. I can't believe the newer ones are that much better at rejecting heat and keeping cool. The fan vanes on the flywheel are not that much bigger. In any case, the newer ones are easier. We've traded trainers halfway through a workout and the difference is pretty dramatic.

 

[frenchyge]

In any case, the newer ones are easier. We've traded trainers halfway through a workout and the difference is pretty dramatic.

Not trying to argue, but I'm wondering why you wouldn't just shift up a gear or two and continue riding at the same power you were at before?

That's what's confusing me about your statements about how lower wattages means cooler temps -- why wouldn't the riders just ride the new trainers at the same wattages they were before (albeit at a higher wheel speed and bigger gear)?

 

[swampy1970]

300 watts is a pretty nice number - you should be able to hold ~25mph on a road bike for an hour if you're an averaged sized guy who can ride on the drops.

 

[goodboyr]

Not trying to argue, but I'm wondering why you wouldn't just shift up a gear or two and continue riding at the same power you were at before?

That's what's confusing me about your statements about how lower wattages means cooler temps -- why wouldn't the riders just ride the new trainers at the same wattages they were before (albeit at a higher wheel speed and bigger gear)?

No argument.....I'm enjoying this discussion. Its my fault, I think I havnt been clear. Yes, you are correct. For the person with the easier trainer and the power meter, they just ride at a higher cadence/gear to get to the desired power level. For the person with the kk meter, they get misled into thinking they are at a higher level when they are not, thus the cooler trainer.

The bottom line is that they do tend to top out when we are doing very high wattages. For the regular FTP training, its just a matter of gearing.

 

[frenchyge]

For the person with the kk meter, they get misled into thinking they are at a higher level when they are not, thus the cooler trainer.

Ahhhh.... I think I understand now. If someone's using the KK rear-wheel power computer to show power on a non-KK trainer then I see the problem completely. You'd need to know the new linear and 3rd-power constants for the non-KK trainer in order to have any hope of getting meaningful information from that approach. KK customer service is *awesome*, so maybe an e-mail to them could get the new Fluid2 numbers.

Although, if it was me I'd still ride just as hard as before and say "Wow, now I'm holding 600w thanks to the improved 'road feel' and PowerTuned technology on this new trainer!"

 

[goodboyr]

Ahhhh.... I think I understand now. If someone's using the KK rear-wheel power computer to show power on a non-KK trainer then I see the problem completely. You'd need to know the new linear and 3rd-power constants for the non-KK trainer in order to have any hope of getting meaningful information from that approach. KK customer service is *awesome*, so maybe an e-mail to them could get the new Fluid2 numbers.

Although, if it was me I'd still ride just as hard as before and say "Wow, now I'm holding 600w thanks to the improved 'road feel' and PowerTuned technology on this new trainer!"

Right! And the numbers that KK suggest you put in the KK computer when you're using a Fluid 2 are for the older unit. When you use them on a new Cycleops, they are wrong. I am surprised they don't have the new numbers on the KK site.

 

[far-sided]

This is exactly what I meant. The newer fluid 2's have a different (lower) power curve but the formula from the KK power meter and the formula's quoted in this forum relate to the older model that is similar to the kk trainer. So I hate to say it, but you are probably not a "300 watter". I've got a friend with a power meter who kept sending his fluid 2's back for replacement because they had too low a resistance compared to others in our cycling group with older models. A bunch of us have power meters so it was easy to compare. Eventually he asked the LBS to find out and the answer back from Cycleops was that they had made a change to reduce the resistance supposedly to widen the appeal to a broader range of cyclists.

Looks like you're exactly right. From the Cycleops web-site...

Professional cyclists and renowned scientist Allen Lim worked together to develop a power curve based on a hybrid of road and time trial positions, finding the point at which a speed of 25 mph overlaps with an output of 400 watts.

The numbers I was using had 22mph equal to 401W and 25mph was 571W for the older Fluid2.
Guess it's' time to re-test FTP and just cover up all numbers except for time.

 

[freeagent35]

I use a Computrainer as a point of comparison (PRO Lab model, dyno calibrated). 300 watts at 20 mph sounds kind of high, but then again load can be a real variable. As another point of comparison, I'm 40, 5'8" 175. Resting pulse is about 45. I tend to shoot for 210 average watts over a 1 to 2 hour ride with interval efforts of 400 to 450 sustained (30 seconds to 1 minute), moderate intervals of 350 approx (1 to 2 minutes during climbing sections) and peak sprints of about 600 watts. Average heart rate will run around 160 for such an effort. My upper end is somewhat limited by my gearing (compact 50/12 top end, needed to avoid overgearing on the climbs). I ride at about a CAT 3/4 level.

Clearly the Power Tap is the superior device. I would tend to trust it. It might be interesting to wear a heart rate monitor on both and compare the average pulse rates for the 300 (trainer) vs. 210 (PT) effort. 210 for an hour (average) is harder than it sounds, especially if coasting or drafting is being averaged in.

Happy training.

 

[mikeyp123]

I have the old model Fluid 2 and the KK Road Machine. I found the Fluid 2 to be a total knee killer, too much resitance. Meassured with a PT, the KK at ~20mph gives me about 225 watts. I can't remember what the 20mph was on the Fluid 2, but do remember 17mph was a killer hard workout, probably around 230 watts.

KK gives me more gearing options.. yet not too easy for my wimpy 240 FTP.

 

[goodboyr]

I have the old model Fluid 2 and the KK Road Machine. I found the Fluid 2 to be a total knee killer, too much resitance. Meassured with a PT, the KK at ~20mph gives me about 225 watts. I can't remember what the 20mph was on the Fluid 2, but do remember 17mph was a killer hard workout, probably around 230 watts.

KK gives me more gearing options.. yet not too easy for my wimpy 240 FTP.

I've got the Polar CS600, and here's what I get on the old model Fluid 2. It supports what you said......


mph watts

6 35
10 75
12 100
15 165
17 225
20 320
23 450