What trainer profile would YOU use???

What trainer profile would YOU use???

Postby whftherb » Sun May 15, 2011 2:51 pm

Please click here:
http://imageshack.us/photo/my-images/33/ibiketrainersetup001.jpg

And then...

This is my trainer set up. This really old Performance trainer used to be a set of rollers but the front band broke (not replaceable) and rather than spend add'l money, I already had the front stabilizer, so I set it up this way. Not truly a set of rollers, not truly a rear wheel attached trainer (like a Cyclops for example). I do like this however because the trainer has a variable resistance lever (at left) where I can crank down the resistance and really simulate hills. Anyway, aside from that....

I don't have a set of drag coeffients for this thing or a set of parameters for it that helps me get an approximation (and I know this is all about approximating). I'd like to know however, if my iBike is telling the truth about power, or somewhere near as accurate as I can get. The power trainer profile in the iBike iPro II now yields numbers that are way above what I feel/know I can do. The numbers are WAY above.

So, given these factors, what iBike Trainer Power Profile would you use to closer approximate this setup. I'm not enough into the physics of it to even make an educated guess and I'm looking for another brain... Can I borrow yours for a couple of seconds!!!!

Seriously... Any help appreciated.

H
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Re: What trainer profile would YOU use???

Postby racerfern » Sun May 15, 2011 6:15 pm

It should be fairly easy to come up with a profile without any resistance and maybe even with maximum resistance. However, you would also have to come up with profiles at varying levels of resistance and that's the challenge because the resistance setting probably isn't repeatable and has infinite possibilities.
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Re: What trainer profile would YOU use???

Postby whftherb » Mon May 16, 2011 9:10 pm

Well, Fernando - let me ask this.

Of the ones that John and his team provide (and they do a good job of keeping them updated) which of them would you choose for, say, no resistance whatsoever? I really wasn't thinking to have an "infinite" number of profiles; God no!

I have no idea how to "fit" one of the pre-configured trainer profiles to the gear I have. Care to take a guess? How close can we come to something real world?

See, I basically don't know how these things work. What's in that .enc file anyway :-) But, here's a thought (again, I'm not a physicist by any stretch), exactly how would one go about creating (homebrewing) a trainer profile? I wonder if you or someone else knows how it's done?

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Re: What trainer profile would YOU use???

Postby racerfern » Mon May 16, 2011 10:46 pm

I knew I shouldn't have even have offered an opinon!

Click on Edit Trainer Settings, then click on the Rollers tab, finally clicking on the Kreitler tab. Pick the options that are closest to yours. Then click the Coefficients tab just to the right of the Rollers tab. You'll see the results of the options you chose under Kreitler. You could try this with E-Motion also.

That's the easy part. You'll have to send your profile to the iBike and try it against your PE of the activity. If you think you're working harder or less than what the iBike shows then make the adjustment under A or B on the Coefficients tab. This is because the effort is more or less linear. Basically you use C or D to adjust the curve but you shouldn't have a curve.

Assume for a minute that your lever has a marking that you can go exactly to the same spot every time. Now, create a profile for that amount of effort. The problem is you're going to start out with no resistance then crank it up as you warm up. However, you have no way to switch profiles. You would have to stop, upload another profile then start riding again. I don't see another way around that.
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