Setup for TruTrainer rollers?

[jim_s]

Does anyone have a reliable set of trainer coefficients for for TruTrainer rollers?

[jim_s]

I found a posting here (http://www.serotta.com/forum/archive/in ... 23118.html) where the poster claims to have speed vs hp vs watts readings for the TruTrainer - no idea how he arrived at those, nor what his weight, tire pressure, power meter calibration state, aura color, etc are, but if one takes those numbers on blind faith, and solves for 4 equations in 4 unknowns (based on the iBike trainer coefficients form), you arrive at:

A = 0.3
B = 7.938333333
C = 0.054
D = 0.002216667

the results of which match precisely with the watts numbers claimed by the above poster. (as they should - the question still remains as to the veracity of that posted data...)

Anyway, this might be a decent starting point. The TruTrainer belongs to a friend of mine and we were playing around on it today w/ the iBike - I'll try to get back on it in the next few days and see how the reported numbers (using these values above) feel compared to road efforts and trainer efforts that I'm pretty intimately familiar with.

Down side of all this now, is that I think I'm kinda hooked on rollers. (though I was just about effectively spun-out on the TruTrainer - its smooth, but its got some big-ole drums on it. Think I need some smaller drums - its kinda off-topic but if anyone has any roller advice for a roller-noob, I'd be open to hearing it - I'm thinking Kreitler 3.0 or even 2.5 if I happen to find a compelling deal on a set of moderately-used 2.5's. Similarly, if anyone is looking to rid themselves of a set of Kreitlers for a reasonable price, let me know.)

[R Mc]

You's done found your roller snob right here.

I have an ancient set of American classics (6 1.25" drums: 2 for the front wheel, 4 for the rear), which provide such ridiculous levels of resistance that they make me ride outside in all but the worst conditions. Over the years, though, I've learned that they are bearable and almost even fun with super-high psi . . .

My advice: get the 2.5 inch Kreitlers--once you get used to rollers with resistance, trainers are awful. (And you can do all the cool-kid workouts [one-legged pedalling, etc.] on the rollers that you can on a trainer, + you're developing good bike handling, and your brain is getting something ride-related to do.

And you don't have to change out skewers . . .

[rhino]

Don't worry, there's more than a few roller snobs out here - on tubulars too! That said, is it worth getting the "trainer lock" to use on rollers? I'm just looking at putting this system together and still need to understand what's involved. Anyone know the steps to get this rolling

Thanks,
Skot

[jim_s]

Skot - I'm no expert at this, but I used the trainer featre on my Blackburn (stationary) trainer for a few months and was very satisfied with that. I've just recently purchased rollers and am having more of a challenge getting the power numbers dialed in for that (stationary trainer power curves seem to be very widely-available, while roller power curves seem much harder to come by, and only Kreitler and E-Motion roller settings seem to be directly available in the iBike software.) Despite the challenges of getting a solid power curve figured out for my rollers (CycleOps/SportCrafters), I have already found significant value in using the iBike on the rollers. Even if the numbers aren't correct from an absolute perspective (ie, they may read 270w for 20MP, but it feels more like 220-230w), they're consistent and repeatable, which from a training perspective is really what matters to me (ie, if I train at what it says is 270 today, I can trust that I'll be able to train at that same level tomorrow, even if it really is 220-230w in the end).

So, long story short, I personally think the trainer feature is worth the $40 for my purposes, and the rollers are a whole lot more enjoyable to ride than the trainer!