Saddle Height Test

morana

I was curious about my optimum saddle height so I decided to use the power tap to see if I could work it out using power. I came to the conclusion that my optimum height in the range tested was 79.5 cms, I covered the most Km's per Kj at this height. My orginal height was 81.5 and I reduced it by 1cm for each test. I used the same gear and cadence in each 5minute test and had the same recovery.......Am I right in my assumptions..........?

OKpro

You are probably correct. Have you ever had a "pro" fit done. If not, I would recommend Wobble Naught bike fitters. They have a online fit calculator that is inexpensive at www.wobblenaught.com. My coach/director is always telling people to lower their saddle. Remember though, if you lower you saddle height, make sure that you move it back as well.

dkrenik

Why move it back? When you do that you're still maintaing the same effective distance. If the isssue is that the rider has too great a distance from the saddle to the pedals, simply lowering it should suffice (if the amount lowered isn't great enough to affect reach and relative position over the bottom bracket). For example, a saddle lowered 5mm in a 74 degree seat tube results in the saddle moving forward only 1.38mm.

Saddle fore/aft position should be used to address issues such as balance and relative position over the bottom bracket (these might be interelated...)

Steve McGregor

I have to agree with the Kreniks on this one. Sorry, Omer.... it seems there is a fad afoot right now to move saddles back wholesale. Granted, it could be argued that this is the more traditional, old school position, so, it's really not a fad. In some cases this might be justified, but without a clear rationale why, it doesn't make sense. In an insidious little twist, I have spoken to several individuals who have been advised based on power data collected on a trainer to move their saddle back. It is nice to see power used as an objective way to help optimize saddle position, but on the trainer we are neglecting the factor of wind resistance. When the saddle is moved back, it *typically* puts the rider in a more upright position and potentially increases drag. A small increase in power production is not worth a similarly small increase in drag because drag increases will overcome the power increases at higher speeds. Of course these are all general statements though. In some cases, a rider may be well served by moving their seat back.

As Krenik pointed out, the wholistic variables of comfort, balance, power production, aerodynamics, and handling all need to be taken into consideration. And of course, improving one, may negatively impact, one, or several, of the others.

Steve

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morana

i didnt bother to move it back I left it in the position that i have used for the last few years. I was just concerned with the height

upstateSC-rider

Did you notice a difference comfort-wise? How did you have it set before, using the straight leg-to-heel method? I know it's not even an inch, just curious.

Lou.

morana

I originally would have used the method you mentioned but cant remember if the shoes were the same model as shoes that I tested in! After that I changed it based purely on feel.

There was a big difference in feel but it wasnt a bad feeling in the lower heights. I also used analyticalcycling.com which requires that you measure your leg. This gave a figure which was slightly lower again. I retested again but started at the lower end and worked up to see if it had an effect but the results were similar. My trainer is a fluid trainer and I think it takes a while for it to stabilise. I will do it again but with longer warmup and change the wattage upwards for the test.

I have lowered my saddle since the experiment

mises

Several issues -

Should be same course and roughly same conditions, temp, wind, time of day (when you normally ride or late afternoon are the highest power generally) etc. Should also sample on consecutive days, use the same warmup procedure, and alter the sequence of testing the heights. You may have just been getting more warmed up as you lowered the saddle.

Should maintain the same cadence at all time through the tests, not just same average. Lower seat will favor higher cadences (and knee damage).

Should also move the seat up and test. Power will very likely increase when saddle is raised and legs near maximum extension. Many tests have given that result.

1cm at a time is way too much change at once if you ride more than a handful of miles a week.

You should also look at HR data to make sure you are not losing massive efficiency to gain a small increase in power. For 5 minutes it won't matter but after 5 hours it definitely will.

Aaberg

I see that it has been a while since threre was any activity on this thread, but I got curious about a one of the points made here.

I thought moving the saddle back would increase the distance to the handlebars so that you have to bend over more in order to reach further... putting you in a less upright position and therefore decrease drag?

Or is this another one of these counter-intuitive things when fitting your bike? (like moving your seat forward actually increases pressure on arms and shoulders, not decreases it as one would intuitively think)