Road bike vs. recumbent comparison

[Balor]

you can to a certain point until eventual you put enough power out that it starts shifting you around in the seat which is sapping your efficiency. I did a lot of this exact thing when zwifting with my broken wrist because I rode around most the time never holding the bars at all.

My point exactly. An other way to prevent this 'shifting around' is to switch to 'scraping pedalling' technique (described in Railgun FAQ) and working one leg against the other as well. This way you either get some help from gravity again, or isolate forces in your pelvis or both.
Neither of this techniques (so is bar-pulling) is 'free' in terms of oxygen consumption I presume, though - gravity-assisted 'push-push' style (at fairaly low cadence) IS pinnacle of efficiency according to all information I have (like Ed, I'm an ultra guy (not nearly the same caliber though), so I'm very concerned about efficiency).

 

[Balor]

well i'm sitting here on my trainer trying to change my wattage without changing cadence and not having any luck. Any tips from you guys?

Change your gearing?
Or change your pedalling style (more 'scraping', rounder stroke).

 

[Balor]

Good luck with your quandary. Come Zwift with me if you ever get the time.

By the way, I'm quite willing . What's your Strava and Zwift profiles? I've shared my I think...

 

[trplay]

when you are going to do an event go on the cruzbike discord channel and announce it. That will open the can of worms.

 

[RojoRacing]

My point exactly. An other way to prevent this 'shifting around' is to switch to 'scraping pedalling' technique (described in Railgun FAQ) and working one leg against the other as well. This way you either get some help from gravity again, or isolate forces in your pelvis or both.
Neither of this techniques (so is bar-pulling) is 'free' in terms of oxygen consumption I presume, though - gravity-assisted 'push-push' style (at fairaly low cadence) IS pinnacle of efficiency according to all information I have (like Ed, I'm an ultra guy (not nearly the same caliber though), so I'm very concerned about efficiency).

No such thing as an action requiring no energy that's a fact. Scraping can help but you can't pull as hard or for as long as you can push because the muscle groups aren't equal. You should never be just pulling the bars or just pushing the bars because that would require you to weight one side twice as much as the other to counteract the pedal steering torque. So if you push the right bar with one unit of power you'll need to push the left bar with 2 units of power requiring 3 units of power. If you pull on the right bar with one unit of power then all you need is one unit of power pushing on the left bar to remain centered so a total of two units of power.

By gravity assisted push push style are you referring to DF bikes? If so then yeah having 150-200lbs of weight balast to push against in a vertical plane vs a 20 deg horizontal plane can have its benefits.

 

[Osiris]

well i'm sitting here on my trainer trying to change my wattage without changing cadence and not having any luck. Any tips from you guys?

Shift gears.

 

[Osiris]

No such thing as an action requiring no energy that's a fact. Scraping can help but you can't pull as hard or for as long as you can push because the muscle groups aren't equal.

I think Kent Polk would agree with this; he doesn't recommend the "scraping" technique when performing a sprint. In my case, I start "scraping" the pedals only when my quads are exhausted. In several of my early tests, I deliberately pedaled while focusing on my quads until they were so fatigued that it became a real struggle just to maintain their current power output. Then I switched to the scraping method and watched in amazement as my power readings increased by 20-30 watts. I managed to hold it here for about half a mile until it felt as if my hamstrings were fried. I thought this was a fluke and repeated the experiment many times, but I got the same result in each case. "Switching" muscle groups in this manner really works, the only hard part is not losing focus so that you'll resume pedaling with your quads without realizing it. In subsequent weeks, I used this technique to smash my records in all the Strava segments of a mile or longer where my quads would normally burn out before reaching the end. In one case I went from 12th place to 1st, in another I went from 6th place to 2nd. These were uphill segments which I tend to perform poorly on, and had pretty much written off as segments I'd never make the top 10 in.

 

[Osiris]

I took the V20 out for my usual 30 mile spin this morning and performed another test using the handlebar waggling technique. Timing the pedal movements to coincide with handlebars wagging was nearly flawless this time, but just as before, there was no noticeable change in power output. I've come to the conclusion that this method of evaluating the merits of handlebar wagging is pretty useless. The problem is that when applying anything less than max power, it's impossible to see how much, if any, additional power is being generated with the upper body. I then decided on a new testing methodology on the final uphill segment, which involves picking a specific power output and seeing how long I can maintain it. I've run this segment hundreds of times over the years, and I know almost to the yard how long I can hold 300 watts. The trouble was that after performing the previous power test and a couple of subsequent sprints, I was too exhausted to do the experiment properly. What I was hoping to see was that I could maintain 300 watts for a greater distance than before by wagging the handlebars, but it was not to be. Instead of making it to my usual signpost before dipping below 300 watts, I tired out long before I got there. Fortunately I've got the next two days to repeat the experiment, and I'm confident that this type of testing procedure will answer the question one way or the other.

 

[trplay]

I'm confident that this type of testing procedure will answer the question one way or the other.

Years of this discussion and that is all it takes to resolve the issue. Now thats funny. Just make sure you are pull -pushing and not push-pulling (feet and hands going same way as opposed to towards each other). There is a difference and in the beginning most people gravitate towards the wrong method .

 

[Osiris]

Years of this discussion and that is all it takes to resolve the issue. Now thats funny.

Not to worry. I'm sure Balor and I will be able to find a way to continue the debate for another couple of years. I can already foresee a couple of objections...

Just make sure you are pull -pushing and not push-pulling (feet and hands going same way as opposed to towards each other). There is a difference and in the beginning most people gravitate towards the wrong method .

If you're used to riding a Cruzbike normally, it only takes a few tries to get the handlebar wagging technique right; after that it feels as natural as walking. If you perform the technique backward as you describe above, it feels as if your cranks have turned to rubber.

 

[trplay]

Well once you settle this mystery take a break and come join the Cruzbike Zwift group for a race or two.

 

[Balor]

I can already foresee a couple of objections...

Nope, that's pretty much what I meant myself

If you perform the technique backward as you describe above, it feels as if your cranks have turned to rubber.

And well, shouldn't it be a kind of 'proof by negation'?

 

[Osiris]

I was going to take the V20 out again today, at the last minute I changed my mind and decided to take the DF instead. There are several Strava segments on my favorite 30 mile loop that I use to gauge my level of fitness. These are mostly uphill segments, so I can ride them hard without hitting dangerously high speeds. Today I maxed out on one of them with an average of 420 watts and an average speed of 21 mph. This is probably the most power I've ever been able to sustain on that hill, yet my average speed was nowhere near what I've been able to reach on any of my recumbents. Just to show how ridiculously inefficient a DF is, compare today's result to yesterday's on the very same segment while riding the V20: average watts = 309 and average speed = 23 mph. So despite putting out 111 watts more on the DF, my average speed was still 2 mph slower. My personal record, good enough for 9th place, was set back in May of 2017 on my M5 CHR. That time, an average power output of 314 watts was all it took to maintain an average speed of 26.5 mph. When you compare these numbers, it's clear that recumbents totally outclass diamond frames in terms of efficiency.

Comparing cadence is revealing because it helps to answer an obvious question: why am I able to generate so much more power on a DF than I can on any of my recumbents? Compare the average cadence listed by bike/recumbent on the same segment:

M5 CHR = 83 rpm
V20 = 79 rpm
Specialized Venge = 115 rpm

The cadence in each case was chosen simply by what felt most comfortable at the time, but spinning faster by 32-36 rpm on the DF gave me a considerable power boost. To get an idea of how much cadence affects power production, I looked up my KOM on another segment where I deliberately pedaled at the highest cadence I could sustain on a recumbent, which in that case turned out to be 101 rpm. That run resulted in an average power output of 491 watts for 1:02 minutes. Not all of that can be attributed to higher cadence alone, but certainly a good portion of it can.

I don't know why my legs feel so sluggish on a recumbent after thousands of miles, but if I could increase my cadence to match what I'm capable of on a DF, it may erase much of the power difference that I'm currently seeing.

 

[RojoRacing]

I was going to take the V20 out again today, at the last minute I changed my mind and decided to take the DF instead. There are several Strava segments on my favorite 30 mile loop that I use to gauge my level of fitness. These are mostly uphill segments, so I can ride them hard without hitting dangerously high speeds. Today I maxed out on one of them with an average of 420 watts and an average speed of 21 mph. This is probably the most power I've ever been able to sustain on that hill, yet my average speed was nowhere near what I've been able to reach on any of my recumbents. Just to show how ridiculously inefficient a DF is, compare today's result to yesterday's on the very same segment while riding the V20: average watts = 309 and average speed = 23 mph. So despite putting out 111 watts more on the DF, my average speed was still 2 mph slower. My personal record, good enough for 9th place, was set back in May of 2017 on my M5 CHR. That time, an average power output of 314 watts was all it took to maintain an average speed of 26.5 mph. When you compare these numbers, it's clear that recumbents totally outclass diamond frames in terms of efficiency.

Comparing cadence is revealing because it helps to answer an obvious question: why am I able to generate so much more power on a DF than I can on any of my recumbents? Compare the average cadence listed by bike/recumbent on the same segment:

M5 CHR = 83 rpm
V20 = 79 rpm
Specialized Venge = 115 rpm

The cadence in each case was chosen simply by what felt most comfortable at the time, but spinning faster by 32-36 rpm on the DF gave me a considerable power boost. To get an idea of how much cadence affects power production, I looked up my KOM on another segment where I deliberately pedaled at the highest cadence I could sustain on a recumbent, which in that case turned out to be 101 rpm. That run resulted in an average power output of 491 watts for 1:02 minutes. Not all of that can be attributed to higher cadence alone, but certainly a good portion of it can.

I don't know why my legs feel so sluggish on a recumbent after thousands of miles, but if I could increase my cadence to match what I'm capable of on a DF, it may erase much of the power difference that I'm currently seeing.

assuming you're running a somewhat normal length crank on the bents I don't see much of a problem with their cadence, my natural cadence is 80 avg overall and 90 avg when at threshold or above. On the other hand you DF cadence seems quite high to be sustainable for anything but a long sprint. Looking at it from another angle your effort wasn't sustainable being it was only a 1 min effort so it's easy to toss out smoothness and control from the equation in lieu of pure focus on power. This can be easily done on the DF bikes because they are naturally stable so shortcuts on stability are acceptable but on the bents where control is almost always required for stability you can't just go for pure power with no control. I'm not saying it can't be done on a bent because I do it just fine, I'm just suggesting you're just not as comfortable on the bents and your high power technique requires more practice.

 

[Osiris]

assuming you're running a somewhat normal length crank on the bents I don't see much of a problem with their cadence, my natural cadence is 80 avg overall and 90 avg when at threshold or above. On the other hand you DF cadence seems quite high to be sustainable for anything but a long sprint.

Sprints are the only thing I enjoy doing. My genetics favor short bursts of power, so I always excelled in sports like weight lifting, wrestling, and sprinting, but I was terrible at anything requiring endurance. Typically my solo rides could be characterized as a number of sprints with long recovery periods in between.

Looking at it from another angle your effort wasn't sustainable being it was only a 1 min effort so it's easy to toss out smoothness and control from the equation in lieu of pure focus on power. This can be easily done on the DF bikes because they are naturally stable so shortcuts on stability are acceptable but on the bents where control is almost always required for stability you can't just go for pure power with no control. I'm not saying it can't be done on a bent because I do it just fine, I'm just suggesting you're just not as comfortable on the bents and your high power technique requires more practice.

I'm not sure what you mean by 'control' in this context. I can go as hard as my legs will push while keeping the bent traveling in a straight line and without rocking from side to side. Even when locked in place on a trainer where stability is not a factor, I just can't turn the pedals nearly as fast on a bent as I can on a DF. I have no idea why that is, but judging by the responses I've gotten, this seems to be a common complaint among bent riders.

 

[paco1961]

Sprints are the only thing I enjoy doing. My genetics favor short bursts of power, so I always excelled in sports like weight lifting, wrestling, and sprinting, but I was terrible at anything requiring endurance. Typically my solo rides could be characterized as a number of sprints with long recovery periods in between.



I'm not sure what you mean by 'control' in this context. I can go as hard as my legs will push while keeping the bent traveling in a straight line and without rocking from side to side. Even when locked in place on a trainer where stability is not a factor, I just can't turn the pedals nearly as fast on a bent as I can on a DF. I have no idea why that is, but judging by the responses I've gotten, this seems to be a common complaint among bent riders.

I think at high rpm this has to be a function of having to use the rectus femoris muscle bundle to thrust the knees up in what has to be considered a fairly un-natural motion compared to the more familiar DF motion we’re all used to from walking and running our whole lives. Basically there’s a whole lot more knee and thigh lift on a bent that was to put a hurtin on the high speed spin

 

[RojoRacing]

Sprints are the only thing I enjoy doing. My genetics favor short bursts of power, so I always excelled in sports like weight lifting, wrestling, and sprinting, but I was terrible at anything requiring endurance. Typically my solo rides could be characterized as a number of sprints with long recovery periods in between.



I'm not sure what you mean by 'control' in this context. I can go as hard as my legs will push while keeping the bent traveling in a straight line and without rocking from side to side. Even when locked in place on a trainer where stability is not a factor, I just can't turn the pedals nearly as fast on a bent as I can on a DF. I have no idea why that is, but judging by the responses I've gotten, this seems to be a common complaint among bent riders.

I just assume the common complains from the bent riders as a whole are a bit off simply because they are an odd bunch of people to want to ride bents in the first place. By control I mean you give a certain % of muscle motor control to keeping your bike steady(not necessarily in a strait line), the remaining % goes to powering the bike. As you increase the effort the power you put through the bike causes slight imbalances so you are forced to add a little more feedback to keep it stable, in theory the % ratio should remain constant, this isn't an exact science just a loose explanation. When the effort get far enough beyond your physical limit you start trying pull power from places you normally wouldn't and this causes further imbalances and chances are by this point you're already slacking off on keeping the bike stable. This is why in races you see some riders get totally out of control during the sprint finishes. Now with all the said a DF bike naturally wants to go strait on it's own but a bent is the opposite and wants to turn and keep on turning hard once you get it started. This means on a bent you are more required to keep control or quickly end up on your butt. Now you already said you have no trouble controlling the bike at speed but there are lots of things that can effect the balance between your power and control like your subconscious survival instinct, from and fit on the bike and so on.

Go out and spin your bents at 120 rpms in a slightly easier gear so you can hold it for several mins. If you say you can't then at least try and in the moment dissect why it is you're holding back. I'm betting 10 to 1 it's because you don't feel in control at that rpm on the bent but until you have a cause of why, you'll never figure out how.

Also flip the question on it's head and ask why you need 115 rpms on the DF to make 400 watts? Unless it's a moderate DH those no reason to "have" to spin that fast because we have plenty of gears on our bikes. Why can't you make 400 watts at 90 rpm on your DF bike?

 

[DavidCH]

at 120 rpms in a slightly easier gear so you can hold it for several mins

You mean going up slight hill right? If I did 120 rpm for that long I would have to be changing gear and at the end of 3 minutes probably doing 60kph with a heart rate of 180... ok next time I'm out I will try it. But it's very flat where I live. I can't believe the acceleration of the vendetta. Its like the tesla's of cars

 

[Osiris]

I just assume the common complains from the bent riders as a whole are a bit off simply because they are an odd bunch of people to want to ride bents in the first place.

I think this is just another example of the all too human propensity to assign much greater weight to your own experience than to what others are telling you about their experience.

By control I mean you give a certain % of muscle motor control to keeping your bike steady(not necessarily in a strait line), the remaining % goes to powering the bike. As you increase the effort the power you put through the bike causes slight imbalances so you are forced to add a little more feedback to keep it stable, in theory the % ratio should remain constant, this isn't an exact science just a loose explanation. When the effort get far enough beyond your physical limit you start trying pull power from places you normally wouldn't and this causes further imbalances and chances are by this point you're already slacking off on keeping the bike stable. This is why in races you see some riders get totally out of control during the sprint finishes. Now with all the said a DF bike naturally wants to go strait on it's own but a bent is the opposite and wants to turn and keep on turning hard once you get it started. This means on a bent you are more required to keep control or quickly end up on your butt. Now you already said you have no trouble controlling the bike at speed but there are lots of things that can effect the balance between your power and control like your subconscious survival instinct, from and fit on the bike and so on.

I can only repeat what I said before, which is that I have never experienced a problem controlling any of my bents in sprints, and that my inability to spin the pedals as fast as I can on a DF is clearly evident even on a trainer, where control is simply not a factor. There is something different about the kinesthetics of pedaling a bent that is different for DF's, but I don't know what.

Go out and spin your bents at 120 rpms in a slightly easier gear so you can hold it for several mins. If you say you can't then at least try and in the moment dissect why it is you're holding back. I'm betting 10 to 1 it's because you don't feel in control at that rpm on the bent but until you have a cause of why, you'll never figure out how.

The fastest I've been able to turn the pedals on any of my bents is around 125 rpm (on a trainer), and I was only able to maintain that pace for about 20 seconds before fatigue set in. By contrast, a couple of weeks ago while riding my DF I hit 167 rpm in a short sprint. The difference couldn't be more apparent.

Also flip the question on it's head and ask why you need 115 rpms on the DF to make 400 watts? Unless it's a moderate DH those no reason to "have" to spin that fast because we have plenty of gears on our bikes. Why can't you make 400 watts at 90 rpm on your DF bike?

Making 400 watts at 90 rpm is pretty easy. The reason I spin so much higher is simply because pedaling at a high cadence allows me to keep the power on longer before my muscles tire out. It's no different than performing a squat at the gym, where I could either do one repetition with 500 lbs, or 10 repetitions with 450 lbs. In the latter case, I'll have lifted 9X as much weight before tiring out.

 

[jond]

I wish you guys would reach a conclusion to this argument so I can determine if I should get a Vendetta or not. 20 pages and no firm conclusion. I am so confused.

Don’t be confused. It’s usually necessary to involve your upper body to ride a vendetta mbb though some skilled pilots can indeed ride no hands.

So you either believe that upper body involvement contributes to forward momentum or it does not.

Might I suggest the yes camp are all but one. ( ambiguity intended to not offend) I’m nice like that.

If you believe it does not then you may as well ride a fixed boom machine and not waste energy pulling pushing your bars around a pivot point.

Of course upper body involvement does help propel the bike forward and is fundamental to the platform.

What else is my upper body doing if not........... spin drying the dirty washing. Please.

How much..... as much as 30% extra. For me no way. I’m built like a cyclist.

But it’s real and works. Especially at lower effort and cadence.

It’s a skill.

At the pointy end the addition is not so noticeable as you’re maxed out anyhow and you’re required to involve your upper body.

Thing is it would be possible to engineer out your legs and ride arms only to prove that upper body input moves the mbb platform forward.

Next.