carleton

Yup.

Lance was known for (or rumored to be known for) targeting 120RPM when he would time trial and climb.

It's different for everyone. Basically, the faster you spin, the less time you have to add torque to each pedal stroke. Your muscles need a certain number of milliseconds to contract and add force. They also like to add force for a certain amount of time before they get exhausted...even between pedal strokes. When a muscle is contracting, it's not relaxed and "refueling".

If the cadence is too low, you are calling on the muscle to contract for longer than optimum. When the cadence is too high, the stroke is over before the muscle can do as much as it could. There is a sweet spot.

Distance runners have a sweet spot as well. Studies have shown that pro distance runners manage to hit the same cadence no matter their gender, height, or stride length. That cadence is around 180 steps per minute.

krispenhartung

In contrast my cadence on time trials is completely variant from road races. In a typical road race my cadence will be on average of 100rpm, then higher on sprints and break-aways. There is a strategic reason for that, which I won't go into here. For time trial efforts, my ideal cadence is between 85 and 90rpm, preferably toward 80rpm. This is because at higher cadences in threshold zone, my heart reaches lactic acid threshold rate before my legs reach power threshold, which is not good because I could be at threshold power but lower end of heart rate VO2max and not be able to sustain a 40K effort. So by backing down my cadence I can maintain higher levels of power/torque with a relatively lower hear rate. It's just how my own physiology works and how it has tested out for me. That may change with track racing, which is starting to condition me to ride with higher cadences. It will be interesting to see how my system adapts.

krispenhartung

DISCLAIMER: I just wanted to add a quick disclaimer to this thread. While it's cool that I was able to modify this Omnium trainer to suit my individual needs, I did validate with Feedback Sports this morning that if you invert one of the progressive roller drums, the unit will not perform to spec and it could potentially damage the internal workings of the drum over time, which would in turn nullify the warranty. So, rider beware. I personally didn't mind spending month on a new sled to perform the modification, but this may not be a viable or prudent thing to do for others. :-)

krispenhartung

FYI, and somewhat interesting, as I did not predict this, and this 4th Omnium test gets me what I was after all along.
I am attaching a new table of results, but now with a 4th Omnium rollers sled configuration. This does not require inverting one of the progressive resistance drums, rather I removed one of the low resistance drums from my Track sled and replaced it with a progressive drum (not inverted). One might have originally thought that a a sled with one progressive resistance drum (not inverted) and one progressive drum (inverted) would produce a similar results (erroneously assuming that an inverted progressive drum behaves like a track drum)....not true. This 4th configuration generates a resistance that is in between the Track sled and the Progressive/Progressive Inverted sled. So there are 4 possible resistance schemes with only 2 types of drums. :-)

carleton

This is so awesome. I'm impressed by how meticulous you are (seriously).

rfreese888

[QUOTE=MarkWW;20085320]I just did a little reading into this, and it sounds like both trainers should be supported. When you switched between your fluid trainer and the feedback, did you change the settings in trainnerroad to use the different power curve? It sounds like virtual power might still be using your fluid trainer power curve.

No I changed the trainer for virtual power in TR software.

krispenhartung

:-) why thank you! I love data. You should see what I do in WKO4. I can't wait to start analyzing my 1k, 2k, 3K, and 4K efforts. I'd do more if I had time. FeedbackSports, on the other hand, is not so thrilled with my experiments on their products. ha ha. I've voided my warranty the sake of data and knowledge, and I ended up with a product that I liked better than what they offered...done deal.

topflightpro

My wife bought me a set of the Feedback track rollers for Christmas. They were backordered though, so I only got them yesterday. I haven't opened or used them yet, but I look forward to using them for warming up during races.

(I was drawn to them because of the size and portability and the fork mount, which means I can easily set them up wherever.)

krispenhartung

I thought I'd do a quick follow up on this post I started. I can officially and candidly say -- having started this thread before training or racing on a track, and now having completed track certification classes at two velodromes, completed a handful of mock upgrade races, upgraded to Cat 4, and raced 3 ominums, placing 3rd and 4th in two of them -- that until I got on the track and raced I didn't know JACK SH*T about choice of trainer or how I would be warming up. :-) Logistics and timing dictated most everything for me in the end. And I'm guessing I'm not alone in this realization, as a roadie going to track.


This is what I ended up with. First, I ditched the Feedback Sports Omnium trainer (which I only use now for road TTs and normal road race warmups). Once I saw nothing but rollers lined up between the infield and apron rails, using the Omnium seemed like a ham sandwich in a synagogue, not to mention looking unnecessarily like a jackass with zero bike handling skills on training wheels. ;-) But practically speaking it was just a pain in the butt to have to take the front wheel on and off of the bike to quickly go from warmup to the rail. Second, I'm using my Kreitler 4.5" rollers now, but only in between races to cool down and warm up...no resistance really necessary (yeah, many of you said this..I didn't get it...DUHHH!!!). Third, my original problem of how to open up my legs on a low resistance trainer, was a no brainer fix...just get on the effing track like the rest of the racers, do some warmup laps, get in a pace line, get a few sprints and pulls in, and blast through Z1-6 to get the vessels opened up, etc. Pretty simple and not rocket science. So that it's, I went from overcomplicating things and trying to customize an Omnium trainer for the perfect resistance, to doing what 99% of the rest of the racers are doing. Loving it, and have 8 more races scheduled between now and August!


K-


p.s. Carleton, thanks for all the great tips, especially the front wheel speed sensor/dual wheel magnet trick.

carleton

Thanks for the update. That's great to hear.

It's very common for creative thinking people to overthink stuff...don't give up on that. You never know. One day you are gonna strike gold. Usually the "gold" to be found is the thing that works for you that's not standard protocol. One thing for me it was also my warmup. I realized that I was doing the wrong kinds of warmups for my body type which led to me "burning matches" during warmup when they didn't count. When I relaxed and did my own thing, I had better race days.

No problem!

rongeorge

Hi Krispenhartung,

I'm inspired by the tests you have done. I pulled up this thread with a Google search. I have the Omnium overdrive unit and fairly curious what my unit is capable of.

I want to try a similar test as yours with the added complexity of 3 different gearing (a low, medium and high gear choice). The test bike will be my road bike. What protocol might you suggest for the test to save time? I'd like to test 4-5 different RPMs in the 3 gears. But did you find that tire pressure was a big factor? I'm mulling a 120psi and a 90psi option to see what is the general trend of the curve.

I'd like to do this for Zwifting so I'd need to find a fairly flat portion of virtual road. Maybe Tempus Fugit in Watopia.

Regards,
Ron

mtndruid

Thanks for all the Omnium info!! I just put a pair of Garmin 3s pedals to measure power on my old Tarmac with the original Sportcrafters Omnium rollers and was disappointed with my power numbers on the Sufferfest app, ie couldnt hit the watts called for on the intervals. I will try to reverse one of the rollers and see if I don't get more normal numbers that I have produced on gym bikes (including the Peleton trainers I can use at some hotels when I travel).