Sitbone width effect on saddle choice

Performance
22

You may have two issues here.

  1. It sounds like the Power wasn’t great for you even outside, so it may not be surprising that it’s unpleasant inside. A saddle that shape may not be for you, especially in the static position a trainer forces on you.
  2. That static position is going to cause problems for most people. Some sort of movement board (I think Zwift makes one with inflatable supports?) may help somewhat.
23

By the way James from Bikefit James on YT just made a video where he proves that sitbone width doesn’t really matter: https://youtu.be/ljUKzGnfh_Q?t=280

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Just wanted to pop in here to remind members of the EC saddle lending library - a completely user/member-created resource. Announcing the Escape Collective Members' Saddle Lending Library - #9 by caley_fretz

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25

That’s because the listed width of saddles is the outer side width.

The width of the effectively supportive area is much lower, but the distance from there to the outside edge can vary.

26

Those numbers make more sense. I’m a bike fitter, and I almost never have someone outside 105-135mm.

Sit bone width and saddle width are one factor, but not the only one.

I do it this way: people on the wider end of measurements, I get them the widest saddles (168), people in the middle of that range (let’s say around 120mm sit bone width)the first saddles for them to try are 150ish mm saddles, etc.

then the real proof is in the riding: does it support your weight properly and stable (as mentioned, this depends on many other factors besides saddle width and model too).? Does it minimize pressure in unwanted areas?

Does into rub/dig into the inside of your leg?

From that feedback, I might let them try a different model or a different width.

27

Sitbone width should not impact saddle choice. From my own struggles of finding a good saddle the thing that matters the most is the shape of the saddle and how you interface with it. Anecdotal but yesterday I rode a Trek Aeolus saddle in 145mm width, and today I rode an SLR Boost in 130mm. Neither one caused any kind of thigh chaffing that would result in me sitting forward on the saddle nose. However if I ride a Pro Stealth (142mm) or Novus Boost (145mm) all I do is keep sliding forward onto the nose, and needing to nose it down. The later are more flatter profile with less wing taper, whereas the former have more side to side taper and a slight dip in the middle. Another point on shape, the Form Throne is a popular (to areas that carry it) saddle and its smallest size is 150mm. But if you look at the from the side and head on you can see the meat of the width is further back from where you may engage the saddle in a normal riding position.

And this is where I’ll say to take BFJ comments on saddles with a huge grain of salt. Even in the video linked above he makes no mention of saddle profile, but just fixates on width and feet; which to be fair feet are very important to saddle comfort. In a video where he tries out the new Power Saddle he sets it up in a way that would no way be comfortable to anyone. I think Neil does a better job of discussing saddles and how one interfaces with them.

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28

Yep. This. And as you roll forward on the saddle for more aggressive/dynamic positions, you officially roll off the sit bones (the tuberosities), along the same length of bone (the Ischium) to where it’s narrower (the rami). End of TEDtalk.

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