Received a new saddle today, to replace a defective Brooks, which is notorious for its short rails.

To my considerable surprise the new saddle (which is probably positioned further back) appears to have a significant impact of my power. I would usually measure 125W on average (according to a Stages PM). Today it increased by a full third to 169W (??!!). Might be psychological (new saddle, hey! let's pedal!), or physiological (better position over the spindles).

It should be obvious already -- I am not a racer, not even an roadie. This is a touring bike, and I wear sandals over platform pedals.

If someone has an explanation, please share. I'd read somewhere that fore-aft positioning had an impact on power, but I was assuming negligible unless your were in the business of racing.

It's typical to need a seatpost with about 20-25mm setback with Brooks saddles.
What seatpost do you have?
What is the new saddle?

Seatpost - Thomson Elite
Saddle - Selle Anatomica X1

(yes, the Brooks was a bit too much forward, but I didn't mind. No issue wrt leg/knee pain. So, yes, I assume that the new saddle is more aft. I could understand that this type of adjustment will impact power, but I was surprised by the apparent difference.)

To my considerable surprise the new saddle (which is probably positioned further back) appears to have a significant impact of my power.




compare apples with apples ... try it in the exact same posititon as your previous saddle... olr try your old saddle in the new position?

You miss the point.

Why can't we make cider with oranges, would be closer to what I was saying.

I was going to scoff at this, but I ride Selle Anatomica on one bike. So yeah, i'll bite = the right saddle can make you faster, but now I can add more Powerful, too. Way to go quads, good cooperation with the sitbones!

i'm so confused a touring bike with platforms and a power meter?

I am waiting for an SQlab 610 that should arrive shortly. Very curious about this. The SA is designed with a cutout that is often thought to be mostly about relieving pressure under the perineum. Interestingly, SA's site states that the cutout allows both sides of the saddle to move independently. Which is an important design consideration that has led SQlab to come up with their active design (7% left to right rocking motion). Whereas the design appears to be mostly motivated by comfort considerations, it could also improve power.

OTOH, if saddle design had such an impact on pedaling, that would have been heavily advertised. So it is either a fluke, or a sign that proper fit has a considerable impact on performance.

Will update in a month or so.

1. I prefer to ride with Teva sandals. I've installed Shimano Saint pedals and couldn't be happier.

2. I (sometimes) am quite methodical. I routinely run with an HRM. For bicycles, power meters provide another interesting layer of information. I wouldn't have invested tons of money on this, but was lucky to find a used Stages XT unit at a very very good price. My objective, other than curiosity, was to track average power over a season, and over the years. Another useful use is to be able to get a better idea of the maximum gradient that I can negotiate.

since you are using HR, how did the HR's compare? have you determined your FTP or LTHR? Those would answer the questions you are having about your saddle making a difference

Unfortunately no. I rarely ride with an HRM. But :

1. I will be starting tomorrow, HRM and ride recording (which won't really help since the Flyer is gone)
2. I didn't feel more exhausted than usual. Yet the difference in measured Watts is quite important.

One possibility would be that (a) the problem with my Flyer was due to an asymmetric leather cover, which could have led to measurable differences in left-right power. Unfortunately, (b) Stages is a NDS crank that assumes symmetric outputs. I things go according to plan, I'll compare an SQlab, a Selle Anatomica and a Brooks replacement (B17 or Flyer), on zero and 25mm setback seatposts (Thomson Elite and Suntour SP12). I am also planning a meeting with a professional bike fitters to get to the bottom of this. Will update in any case.

Sorry, i missed the flat pedals and sandals. My unscientific guess is that in no way are you measuring Power Output, unless you define that as Stomping Harder on the downstroke, regardless of the saddle. Impossible, IMHO, to spin powerful circles at any reasonably high RPM in sandals and flat pedals.

Sorta like when data indicates that wider/larger tires roll with less resistance. Some silly people fail to get that the data meant 25/28/maybe 30mm tires can possibly be a faster race tire than a 23mm and erroneously extrapolated that 35/38/42/50mm tires were faster than racing 25mms, because 'fatter is faster'.

Two data points do not prove a theory that is inherently flawed, or mis-instrumented.
Stated generically, i have heard it best put as = Don't believe everything you think. I would add, 'even when it makes sense to you'.

Glad you didn't spend much for your power output sensor.
edit: Not questioning or criticizing your preference for Tevas & flat pedals. Sounds like it suits. Enjoy.

You're absolutely right. Nobody does it with road shoes and clips either, and yet the power meters still work. Howd dey do dat?

Yes yes, absolutely.

I have no theory at this point, only an unexpected observation. I posted here precisely to learn about the impact of saddle fitting on power measurements.

Since it'll take more than a month for me to get a replacement for the Brooks, I won't be in a position to reach anything remotely conclusive. We'll eventually see.

(just wanted to add that power meters report the pressure that is exerted on the drivetrain, irrespective of riding technique. The questions of how effective a rider's body is capable of generating X watts of pressure over some period of time, or how effectively power translates into speed are indeed important, but way beyond the scope of my observation)

Looking at it from another angle, we can make the usual conversion, saying that 1 Kcal ~ 1 Kj. Calculating, it comes out that to increase power by 44 watts, you'd burn an extra 158 Kcal/hr. Now that's a heckuva lot. It's a 35% increase in power and burn. For sure you'd notice that. It's not magic. You can't get power out of the air. You produce it through various chemical reactions in your body. So I'd say it's all mental, which doesn't mean it's not happening. You're more comfortable, your muscular demands are more balanced, you feel better, you ride harder, you breathe faster, your HR goes up. So in that way, maybe the new position did produce more power. We're all looking for the secret sauce.

Were you going faster than you normally manage to go?

Not from where I sit.


Above my pay grade to know why, but we don't. Maybe because Apples are cheaper, and maybe because the Citric Acid in Oranges inhibits fermentation, but the thing is, there is no such thing as Orange Cider.




But that does not invalidate what he said, which is, near as I can tell, that you haven't accounted for enough variables to begin formulating hypotheses. Can we agree that Time Trial and Pursuit racers focus more on power than a Commuter or Tourist? Track and Time Trial bikes have 75* seat tube angles to get the rider forward. Time Trialists turn seat posts around to get the saddle a ridiculous amount forward. Time Trialists pedal at the forward tip of the saddle to get further forward. The longer rails of the Selle allowed the o.p. to get his saddle further...yah... <shrug> Brooks saddles aren't known to be the narrowest saddle a guy could throw a leg over. It might be (since we are speculating) that the longer, narrower Selle allows for a less hampered knee action.

Maybe a bit, but not likely as much as measured power. Looking at a bike calculator a 30% increase in power should translate into a 20%+ speed increase. Very doubtful.

It looks more like a measurement issue. Stages power meters use a single sensor on the NDS crank to estimate total power. It is possible that saddles may impact the left-right relative power. (In particular since my previous saddle was asymmetrical).

So sitting further back would reduce power, which is the opposite of what happens in my case.

(From what I understand, TTs ride in a more forward position largely because their torso is closer to the horizontal.)

(And yes, citrus' acidity is the answer )

So, what is an asymmetrical saddle?

My previous (defective?) saddle had the leather cover riveted out of axis. It exerted more pressure on the right side of my groin, my right sitbone was a bit lower than the left, etc. I kept riding it for a couple of years expecting the leather to eventually conform to my anatomy, but it didn't happen. My understanding being that once the saddle took its initial broken-in shape, it would not self correct over time.

At some point this summer, while touring, I got fed up wiggling to relieve my butt. I've tensioned the saddle, set it level (Brooks are often tilted upwards, more so in my case to relieve pressure) hoping to "reset" it. Three days later I was in pain (inflamed soft tissues). Contacted the dealer while the saddle was still under warranty, and tried to learn about alternatives (Brooks dominates touring such that I'd never bother to look elsewhere). Ordered two saddles and am now in the early phase of trying them out.

It's quite normal to take a pry bar to the Brooks saddle rails while mounted on the seatpost and 'tweak' them. I'd say 50% of the saddles needs some tuning this way.

Interesting. Never heard about that. Millions of threads about Proofide and several referring to odd saddle shape but without suggestion on how to fix it.

I personally wouldn't have any idea about how prying the rails might have improved the fit. If you can explain in writing, please do!

(In my case, one wing was at least 1/4” lower than the other, the nose was slightly twisted and the cylindric part (1/3rd from the tip) was convex on of side, and concave on the other)

this. and you were compensating for an ill-fitting saddle.