First-time Pt user - Realization stinks

RChung

[Rubbing hands in glee]Mu-aaaaah-haaa-haaaa-haaaa [/rubbing hands in glee].

goodboyr

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.

Steve_B

Time to sell it and get a KK.

Alex Simmons

Yep.

That's the trouble with inference

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goodboyr

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

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

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

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

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

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

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

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

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.