Seat Pads absorb power??

[ed72]

I use a couple different online applications to monitor my workouts and power levels. I had lost around 20 watts at threshold this Fall and attributed it to laziness although my volume and workouts have been decent. Actually GC had me down 32 watts and XERT had me down 24 watts from peak.

Saturday, I swapped out my Ventist pad for a 1/4 inch yoga mat. My FTP went up 3% on Saturday. It went up another 3-4% on Sunday. I then realized that my power drop in the Fall was about the time I changed seats and also put the Ventist pad on. Probably a coincidence.

Has anyone done tests on various seat pads?

I'll have a chance to do FTP testing in 2-3 weeks (when I should have gained power) and am thinking of putting the Ventist pad back on for my next FTP efforts.

Probably coincidence but wondering if anyone has looked a pads and impact on power to the wheel.

 

[Opik]

My guess is the softness and movement of the seat will impact power. But you need to balance it.

Too soft and too moving to accomodate your movement will make you lose power. To hard and firm then it becomes unbearable.

I think we can get a good example from motorcycle seats. Hard plastic below, then foam, after that leather to cover.

 

[ed72]

I am thinking that a better comparison test would be peak power rather than FTP.

ABBA test.

Run 1: Ventist pad max effort up a steep hill, 5 second max power recorded.
Run 2: Yoga mat max effort up a steep hill, 5 second max power recorded.
Run 3: Yoga mat max effort up a steep hill, 5 second max power recorded.
Run 4: Ventist pad max effort up a steep hill, 5 second max power recorded.

A seat or pad isn't like a steel frame on an upright that would not be expected to absorb power; otherwise, it would heat up. If I remember correctly, someone somewhere conducted comparison tests on a recumbent connected to a trainer comparing the addition of a slab of bacon to the seat vs. normal cushion.

I do not think a valid experiment would be easy to conduct. I also have a hard time accepting the change in seat pad increased my threshold power by 19 watts seemingly overnight and peak power by 26 watts and my 10:03 personal best on a climb down by more than a full minute to 8:55. W' or HIE increased 3.4 kjoules (20%). My training has all been high volume long slow distance with almost zero intervals or hard efforts (old fashioned base period), so, the breakthru in threshold power, peak, and overall anaerobic high intensity energy wasn't expected at all. Power meters can go wrong but hills don't lie.

If I learn something of merit, will post but such a massive increase in power when I changed the pad is probably a just coincidence.

 

[Osiris]

I use a couple different online applications to monitor my workouts and power levels. I had lost around 20 watts at threshold this Fall and attributed it to laziness although my volume and workouts have been decent. Actually GC had me down 32 watts and XERT had me down 24 watts from peak.

Saturday, I swapped out my Ventist pad for a 1/4 inch yoga mat. My FTP went up 3% on Saturday. It went up another 3-4% on Sunday. I then realized that my power drop in the Fall was about the time I changed seats and also put the Ventist pad on. Probably a coincidence.

Has anyone done tests on various seat pads?

No, but when I asked Phil why he put that awful 1/8" yoga mat on the M1, he said it was to minimize power loss. I talked to his trainer about this, and he agreed. It's uncomfortable, but obviously every watt saved in a race matters.

On my other bents (CA2, M5, and V20) equipped with a thick seat pad, you can easily perceive the resulting power loss. Compared to the M1, it's like riding on an air mattress. With each pedal stroke I can feel the seat cover moving around underneath me, causing my torso to slide back and forth. How much energy is being wasted this way I can't say, but it's definitely more noticeable at high outputs (sprints and steep climbs) than when cruising at a steady speed. On hard efforts I try to limit torso movement as much as possible by stiffening my back muscles and pulling hard on the handlebars. At a svelte 166 lbs, there's not much "padding" on my torso these days, but I imagine that for someone with more sub-cutaneous fat, power losses would be correspondingly greater.

 

[ed72]

Who knows. Might be all the long slow distance training with no intervals. My FTP was a rather anemic 228-231 watts all winter. I am at a "respectable" for me 250 watts now...my peak last year was 252 twice. My recent best on an upright was 285 watts with 270-275 being my "normal" peak. Most of this recent gain is probably true increase in my actual power output but some could be the pad because I also saw a drop in peak power of around 25 watts around the time I changed the pad in the Fall but I had also changed to a Thor as well. Since going to the yoga mat, my peak power is "only" up 12 watts but it is up on the two days that I sprinted on my power hill. As I begin to now to do intervals and some threshold work, I hope to see some bigger gains and a chance to test the two pads side by side but the weather is still kind of lousy. It was 38F and 30 mph wind yesterday, so, just motivating to do a ride is all I could muster.

I don't find the yoga mat uncomfortable but I am always in such chronic pain that VO2 max internals don't even get my attention.

 

[Osiris]

Who knows. Might be all the long slow distance training with no intervals. My FTP was a rather anemic 228-231 watts all winter. I am at a "respectable" for me 250 watts now...my peak last year was 252 twice. My recent best on an upright was 285 watts with 270-275 being my "normal" peak. Most of this recent gain is probably true increase in my actual power output but some could be the pad because I also saw a drop in peak power of around 25 watts around the time I changed the pad in the Fall but I had also changed to a Thor as well. Since going to the yoga mat, my peak power is "only" up 12 watts but it is up on the two days that I sprinted on my power hill. As I begin to now to do intervals and some threshold work, I hope to see some bigger gains and a chance to test the two pads side by side but the weather is still kind of lousy. It was 38F and 30 mph wind yesterday, so, just motivating to do a ride is all I could muster.

I don't find the yoga mat uncomfortable but I am always in such chronic pain that VO2 max internals don't even get my attention.

If your head is bobbing up and down even slightly with each pedal stroke, you'll know that's energy being wasted. It doesn't happen at all on my M1, but does on my other bents. Last weekend I joined two TT racers for a training ride, which consisted of 7 minute intervals with 5 minutes of rest in between. I couldn't help but notice how much unwanted upper body movement there was as I was hammering the pedals at the start of each interval. During the five minute rests, there seemed to be no torso movement at all. I've got a Ventisit pad on my Vendetta. The pad itself doesn't flex and compress like the stock foam cover, but it's slippery and causes my torso to slide back and forth during hard efforts. Definitely not ideal for racing, but the stock one is so much worse in every respect. The 1/2" high density foam seat cover that came with my M5 might be the best compromise. It grips my body like fly paper, and it's just thick enough to provide adequate shock absorption over rough pavement. I just wish I could get one that would fit the RailGun seat.

 

[ed72]

If your head is bobbing up and down even slightly with each pedal stroke, you'll know that's energy being wasted. It doesn't happen at all on my M1, but does on my other bents. Last weekend I joined two TT racers for a training ride, which consisted of 7 minute intervals with 5 minutes of rest in between. I couldn't help but notice how much unwanted upper body movement there was as I was hammering the pedals at the start of each interval. During the five minute rests, there seemed to be no torso movement at all. I've got a Ventisit pad on my Vendetta. The pad itself doesn't flex and compress like the stock foam cover, but it's slippery and causes my torso to slide back and forth during hard efforts. Definitely not ideal for racing, but the stock one is so much worse in every respect. The 1/2" high density foam seat cover that came with my M5 might be the best compromise. It grips my body like fly paper, and it's just thick enough to provide adequate shock absorption over rough pavement. I just wish I could get one that would fit the RailGun seat.

I tried to find a camping pad like the M5 pad but no luck. I slide all over the place with the Ventisit pad, too.

I used to live in Europe and/or travel there a lot and loved to watch the TdF prologue TT and others. The smoothness of their power delivery always struck me. Aside from the wiggling of the derriere (something the Polk seat fosters and all the others hinder), they are rock solid. Look at number 11 (Armstrong doper) and 13 (Cancellaro) or 1 (Constador). They don't wrestle the wheels back and forth despite probably putting 500 watts down average (short TT)

 

[billyk]

MBB bikes are fundamentally different than other recumbents in the way the seat back is used. On most recumbents, power is generated like a leg press machine: between the pedal and the seat back. Softness or give will eat power in that situation.

But on a cruzbike, power comes between your hands and your feet like a rowing machine. When I'm accelerating or pushing uphill, my back tends to rise off the seat back. It doesn't matter how soft it is.

 

[ed72]

I dunno about other bent riders but I rarely ever push my back against the seat. The best seat would have the support above the sacrum allowing the hips to float and rotate freely but I have only found one seat that allows this.

There is no possible way for a MMB to have the arms completely counteract the force of the pedal stroke. If that were true, the rider's butt and back would would be suspended in the air. From my experience riding besides a V20, if anything, there is more movement on them and a V20 could potentially benefit more than other bents.

But one good test is worth two opinions. There are already three solid opinions saying the seat pads do impact power to the wheels. I have it directly from another racer that it does absorb power and searched and found a fifth saying the same. No studies. Some claim to have made measurements. I am not sure. Three coincidence? Drop in PP when new pad and seat go on. FTP drops. Change out pad....PP and FTP up. If I was a real racer, I would never share that tidbit. It is worth a test for anyone seeking a few watts.

If the seat pad does absorb power, it is fairly easy to test out. Sharing that here in case anyone is interested in (possibly) free power (well my mat was 25 bucks).

 

[Osiris]

MBB bikes are fundamentally different than other recumbents in the way the seat back is used. On most recumbents, power is generated like a leg press machine: between the pedal and the seat back. Softness or give will eat power in that situation.

But on a cruzbike, power comes between your hands and your feet like a rowing machine. When I'm accelerating or pushing uphill, my back tends to rise off the seat back. It doesn't matter how soft it is.

I think there's a misstatement here. The power to turn the pedals comes from the muscles acting on the hip and knee joints (glutes, quadriceps, iliopsoas, hamstrings, sartorius, and gastrocnemius). The large muscles in the back, if they are active at all, function only as stabilizers to prevent the torso and hips from twisting as each leg extends against resistance.

In the case of a MBB, the arms and torso muscles have to contract in order to counteract the effect of pedal steer, which will to some degree also counteract the tendency of the torso to slide up the seat when pushing hard on the pedals. And this will in some cases result in the lower back rising off the seat slightly. But you could achieve the same effect on RWD recumbents by simply pulling back on the handlebars, which is exactly what many (most?) riders do instinctively when sprinting or climbing steep hills.

 

[Osiris]

But one good test is worth two opinions. There are already three solid opinions saying the seat pads do impact power to the wheels. I have it directly from another racer that it does absorb power and searched and found a fifth saying the same. No studies.

This is just common sense. We know the reason why cycling shoes and bicycle frames are made as stiff as they are. If they weren't, they would deform under load and soak up some of the energy that would otherwise be used to turn the pedals. A squishy seat pad absorbs energy in much the same way as wearing springs on the soles of your shoes would. The only real debate is over how much of a performance impact this has.

Some claim to have made measurements. I am not sure. Three coincidence? Drop in PP when new pad and seat go on. FTP drops. Change out pad....PP and FTP up. If I was a real racer, I would never share that tidbit. It is worth a test for anyone seeking a few watts.

If the seat pad does absorb power, it is fairly easy to test out. Sharing that here in case anyone is interested in (possibly) free power (well my mat was 25 bucks).

As you said previously, it would be really difficult to obtain hard numbers, especially since the difference between a soft and hard seat pad as it relates to efficient power production is going to be most noticeable at max power levels, but may all but disappear at lower outputs. I don't know about you, but I've never been able to exactly match my max power numbers on any bike from one test to the next. Even if I don't change anything about the bike, the maximum power I can generate on any given day will vary, and sometimes the difference is pretty substantial. If I'd swapped seat pads and noticed such a difference, it would be easy to jump to the conclusion that it was the seat pad that accounted for it.

 

[trplay]

You would think riding a smart trainer with and without a cushion would do the trick.

 

[MrSteve]

I think there's a misstatement here. The power to turn the pedals comes from the muscles acting on the hip and knee joints (glutes, quadriceps, iliopsoas, hamstrings, sartorius, and gastrocnemius). The large muscles in the back, if they are active at all, function only as stabilizers to prevent the torso and hips from twisting as each leg extends against resistance.

In the case of a MBB, the arms and torso muscles have to contract in order to counteract the effect of pedal steer, which will to some degree also counteract the tendency of the torso to slide up the seat when pushing hard on the pedals. And this will in some cases result in the lower back rising off the seat slightly. But you could achieve the same effect on RWD recumbents by simply pulling back on the handlebars, which is exactly what many (most?) riders do instinctively when sprinting or climbing steep hills.

"In the case of a MBB, the arms and torso muscles have to contract in order to counteract the effect of pedal steer..."

Not necessarily.
The rider who is under the impression that the only possible way to counter pedal-steer is with the arms is a rider who is ignorant of the performance characteristics of the MBB bicycle.
For example:
If the rider pedals the MBB as if the MBB were an MBB, pedal-steer would naturally be minimal and furthermore, any residual pedal-steer can be eliminated
with a combination of body lean and input from the riders' legs. All with no input from the handlebar.

Also:
The rider's arms do provide extra power when more power is wanted, much like any other sprinter on any other bicycle.
So there.

 

[Osiris]

"In the case of a MBB, the arms and torso muscles have to contract in order to counteract the effect of pedal steer..."

Not necessarily.
The rider who is under the impression that the only possible way to counter pedal-steer is with the arms is a rider who is ignorant of the performance characteristics of the MBB bicycle.
For example:
If the rider pedals the MBB as if the MBB were an MBB, pedal-steer would naturally be minimal and furthermore, any residual pedal-steer can be eliminated
with a combination of body lean and input from the riders' legs. All with no input from the handlebar.

If all you're saying is that it's possible to balance the pushing force produced by one leg with the pulling force produced by the other, that's true. But the muscle groups used in hip/knee extension are several times stronger than the muscles used in hip/knee flexion, so attempting to balance your pedal strokes this way would only be possible at very low power output. The limiting factor would be the amount of power you can generate with the iliopsoas and rectus femoris muscles.

Also:
The rider's arms do provide extra power when more power is wanted, much like any other sprinter on any other bicycle.
So there.

We've been over this before. I'm still waiting for a shred of credible evidence to substantiate that claim.

 

[ed72]

You would think riding a smart trainer with and without a cushion would do the trick.

The without part may or may not work since it imposes a different condition.

IF there is a difference in power, one of my hunches? Sliding or skidding. I notice the Ventitist pad shreds my cycling shorts at the cockus pretty quickly comparatively. Nonetheless, when summer comes.....I will likely have the Ventitest on...

The only way I can conceive of testing would be at either FTP or max peak power using either GoldenCheetah, TP, or XERT. XERT is precise and repeatable in terms of comparing efforts to historical power duration curves or what they call, "Your Signature" ....both PP and FTP are well characterized and easily identifiable using XERT. GC works fine, too, it just does takes half a brain to use.

I found an old thread on a dead forum where some really smart people debated this exact issue and it came down to how to measure. The discussion predated WKO and other modern PD curve algos. So, others have made similar observations. Just no data to back up.

 

[ed72]

If all you're saying is that it's possible to balance the pushing force produced by one leg with the pulling force produced by the other, that's true. But the muscle groups used in hip/knee extension are several times stronger than the muscles used in hip/knee flexion, so attempting to balance your pedal strokes this way would only be possible at very low power output. The limiting factor would be the amount of power you can generate with the iliopsoas and rectus femoris muscles.



We've been over this before. I'm still waiting for a shred of credible evidence to substantiate that claim.

1. You make more power on your V20 than on your M5
2. For my age and racing class, I always had had a good sprint. Jim, Larry, and Jim's son shredded me coming out of every corner on that 104 mile race last summer.

 

[Osiris]

1. You make more power on your V20 than on your M5
2. For my age and racing class, I always had had a good sprint. Jim, Larry, and Jim's son shredded me coming out of every corner on that 104 mile race last summer.

1. I made even more power on my CA2 than I do on the V20. Does that prove that RWD bents are more efficient than MBB bents? Seriously, does it? Or could it be the case that other factors are at work? Like the demonstrable fact that in past comparisons, I generated less power with a more reclined seat, like the M5's Railgun.

And by the way, a few weeks ago I beat an old record of mine on the M5, moving up on the leader board from 9th place to 2nd (this is the one I mentioned on the DF vs recumbent thread). What's significant about that run isn't just that I went faster than ever before, but that my average power output on that segment was the highest I've ever achieved on any recumbent. Previously that honor went to the V20, with a 375W average. But on the M5, I managed to average 395W! What can we conclude from that? Not much, as it turns out. It could mean that I've finally adapted to the M5's more severe geometry. Or it could mean that my energy levels were unusually high that morning. Or that I had just expended less energy during the 15 miles I rode to get to that segment than I usually do. Or it may be due to the fact that I started the run later than usual because I was stuck behind a slow rider. Normally my technique is to increase my speed to 30 mph at the base of the hill and try to lose as little speed as possible on the way to the top. This time I couldn't do that because someone was blocking me. But perhaps the fact that I didn't burn as much energy before crossing the starting line meant that I had more in reserve and lost less speed on the way up as a result. I really don't know. The point is that there are many possible reasons for getting a particular result, and we can't draw any firm conclusions until we've accounted for all the different variables.

2. Comparing different riders on different platforms tells you nothing. You know this. I've seen Jim's power numbers, and if those numbers and mine are anywhere near accurate, I could smoke him in a sprint on any of my RWD bents. All that means is that I'm able to produce more power in a very narrow range than he can. It tells us absolutely nothing about the alleged performance gains of handlebar wagging -- a technique which, for all we know, Jim wasn't even employing when coming out of those turns.

Like I said, not a shred of credible evidence.

 

[ed72]

Well, I think they offered a money back program. That's pretty credible.

The experiment I would run to prove the handle bar waggle advantage.

The efforts would be Vo2 max or approximately 5-6 minutes all out on V20 and also on a RWD bent like the Baccahta.

Measure both the 5 minute power AND oxygen saturation of the VL muscle using using either Moxy or Humon device. I suspect 5-10% more power on the V20 and better O2 level in the legs as the arms take some of the load. There is a reason that cross country skiers have recorded the highest VO2 max figures in history.

Now, the seat pad might be 1-3%....maybe. No idea. Like a dirty vs clean chain. Nothing like lousy tires.

 

[Osiris]

Well, I think they offered a money back program. That's pretty credible.

Money back for what, exactly?

The experiment I would run to prove the handle bar waggle advantage.

The efforts would be Vo2 max or approximately 5-6 minutes all out on V20 and also on a RWD bent like the Baccahta.

Measure both the 5 minute power AND oxygen saturation of the VL muscle using using either Moxy or Humon device. I suspect 5-10% more power on the V20 and better O2 level in the legs as the arms take some of the load. There is a reason that cross country skiers have recorded the highest VO2 max figures in history.

Now, the seat pad might be 1-3%....maybe. No idea. Like a dirty vs clean chain. Nothing like lousy tires.

Too many variables when comparing different bents. If you want to know whether handlebar wagging works as advertised, the way to test that theory is by doing comparisons on the same Cruzbike, noting the difference (if any) with and without handlebar wagging. But as I've said before, any failure to demonstrate the claim would only be met with the objection: "You just weren't doing it right".

 

[ed72]

https://cruzbike.com/pages/fastest-road-bike-guarantee

Not sure the details but it sounds like putting money to back up the claims.

I don't agree on the testing the same cruz waggling vs no waggling because in my mind, some waggling is necessary to prevent tire squirm. Heck, I bet Balor has already done this testing.