Road bike vs. recumbent comparison

[Osiris]

What you describe is technique for keeping the boom completely straight. If you want to contribute power, you must swing the boom much harder than simply compensating for pedal feedback (by the way, my calculations above ignore that force... so total upper body power output would be lower).

No, keeping the boom straight is not what I'm talking about, although you understood me correctly in the following sentence:

Point is, to prevent overcorrection you must stop the boom from swinging *too much*.

Exactly. To prevent the boom from swinging too far, you have to equalize the two forces acting on it. If you're pulling the handlebars with more force than your legs can match, then the boom will swing too far and result in a severe front end wobble. Pushing harder on the pedals than your arms can compensate for will have the same effect, as we all noticed when learning to ride a MBB.

Can you easily ride one-handed? Can you ride no-handed at least a bit? Do you feel totally at control at high speed (40+ mph) DHs?

Absolutely. Riding one handed is much easier to do on a Cruzbike than on my other recumbents. I do it all the time. I've gone as fast as 43 mph downhill, but the only instability I experienced was from wind buffeting. I haven't tried riding no handed, but it's probably something I could manage on a perfectly straight road, especially if I wasn't pedaling. Coasting no handed is something I can do on my far less stable M5.

 

[DavidCH]

Let me try this one last time. If you want to avoid weaving all over the road, you will have to pull/push the handlebars in such a way that it doesn't result in an imbalance between the steering force generated by pulling the handlebars to one side and the steering force generated by pushing on the pedals. Your advice to just "swing the boom harder" completely ignores this point. You can't swing the boom harder without also pushing harder against the pedals. If you are already pedaling as hard as you can, swinging the boom harder results in nothing more than a front end weave, just as you described above.

Is there another DavidCH. I looked at the whole 29 pages of this thread and failed to see that message you quoted from me

 

[DavidCH]

Fake quote

There you go

 

[Balor]

Exactly. To prevent the boom from swinging too far, you have to equalize the two forces acting on it. If you're pulling the handlebars with more force than your legs can match, then the boom will swing too far and result in a severe front end wobble. Pushing harder on the pedals than your arms can compensate for will have the same effect, as we all noticed when learning to ride a MBB.

Again, not 'equalise' (otherwise you'll be tracking completely straight), but 'not accelerate too much', because all things that have speed have inertia, hence you must stop bar-pulling and use your leg pressure, trail force and arms in opposite direction to stop your boom (and legs, btw, since they are connected - a totally non-negligible mass) from overswinging - that limits 'useful boom travel' and exerted force. Boom *length* is crucial here because rotational inertia increases linearly with mass but with *square* of radius.
Like I said, I've noticed that 'boom swinging' got much harder after I've switched to shorter (40mm vs 550mm) bars. Wider bars don't only give you more leverage for bar swinging, they allow more control, but certainly less aero.

But once you get really good at taming inertia, you *will* be able to exert more force to the bars. Something around 10 watts at 300 watts is indeed hard to detect reliably even using a power meter (they have error margins that are not much lower than that), but once you get from 'swing' to a 'karate chop' without ending up in a ditch you *will* see a benefit.

Talking of perfusion - your upper body on bent should be much better supplied with blood. Recumbent handcyclists are known for outputting wattages that put a lot of leg-pedalling bentriders to shame.

 

[Osiris]

Is there another DavidCH. I looked at the whole 29 pages of this thread and failed to see that message you quoted from me

No idea how that happened. The quoted portion is clearly Balor's, but somehow you were named as it's author.

 

[Osiris]

Again, not 'equalise' (otherwise you'll be tracking completely straight), but 'not accelerate too much', because all things that have speed have inertia, hence you must stop bar-pulling and use your leg pressure, trail force and arms in opposite direction to stop your boom (and legs, btw, since they are connected - a totally non-negligible mass) from overswinging - that limits 'useful boom travel' and exerted force. Boom *length* is crucial here because rotational inertia increases linearly with mass but with *square* of radius.

We could quibble about terminology, but I think we're talking about the same thing here. My point was that there's a practical limit to how hard you can swing the boom without overpowering the opposite leg, leading to what you refer to as "overswinging".

Talking of perfusion - your upper body on bent should be much better supplied with blood. Recumbent handcyclists are known for outputting wattages that put a lot of leg-pedalling bentriders to shame.

I once turned the pedals as hard as I could using only my arms while the bent was on the trainer. I was curious to know how much power I could generate that way, and was surprised to find that it was as much as 100-110 watts. It occurred to me that if I began to train my arms again, I could probably come close to doubling that output. That's when I began thinking of a recumbent design which combines hand pedals with foot pedals. If such a design could be made stable enough, it should win every sprint, although pedaling with your hands and legs simultaneously would exhaust the rider sooner.

 

[Balor]

I once turned the pedals as hard as I could using only my arms while the bent was on the trainer. I was curious to know how much power I could generate that way, and was surprised to find that it was as much as 100-110 watts. It occurred to me that if I began to train my arms again, I could probably come close to doubling that output. That's when I began thinking of a recumbent design which combines hand pedals with foot pedals. If such a design could be made stable enough, it should win every sprint, although pedaling with your hands and legs simultaneously would exhaust the rider sooner.

There are such designs, and yes they work like that, but they are *usually* not worth the weight and aero penalty for use in long-distance efforts.
MBB design is unique that it allows *some* upper body contribution solely as a side effect of swinging BB arrangement.

 

[Osiris]

There are such designs, and yes they work like that, but they are *usually* not worth the weight and aero penalty for use in long-distance efforts.

Definitely not for long distance, though it might pay off in a sprint. Applying the concept to a velomobile would preserve the advantages but without the aerodynamic penalty.

 

[Balor]

Definitely not for long distance, though it might pay off in a sprint. Applying the concept to a velomobile would preserve the advantages but without the aerodynamic penalty.

Have you heard about hand-powered record at BM this year? Higher than some of the first 'leg-powered' ones, actually!

http://www.ihpva.org/home/

But I cannot say 'without any penalty' though.

This is covered in "great" ideas on recumbents.com:

http://recumbents.com/wisil/misc/great_ideas.htm

Might as well note this section as well, very true unfortunately

http://recumbents.com/wisil/misc/notfaster.htm

 

[ed72]

Have you heard about hand-powered record at BM this year? Higher than some of the first 'leg-powered' ones, actually!

http://www.ihpva.org/home/

But I cannot say 'without any penalty' though.

This is covered in "great" ideas on recumbents.com:

http://recumbents.com/wisil/misc/great_ideas.htm

Might as well note this section as well, very true unfortunately

http://recumbents.com/wisil/misc/notfaster.htm

Hand/Foot Power
You can build a drivetrain that uses both hands and feet to power a bike. More muscles mean faster speeds, right? Some success has been had with non-faired hand/foot powered bikes. They work well for sprinting, but not so well for longer distance races/rides. The issue is that the human legs are more than able to use all of the cardiovascular output that a body can generate. Once you get past the sprint, it’s more efficient to just use the legs. Also in a faired vehicle, hand power is a packaging problem.

(emphasis mine)

If the legs use all of the cardiovascular output, why do cross country skiers and rowers have the highest VO2max outputs?

People assume that because they are panting and sucking wind in Zone 3-5 that the limitation on output is the lung (O2 levels) but the panting is to remove CO2 AND lower blood pH, which would be lower if more muscles would engaged in the same level of power production because more mitochondria is always a good thing whether more muscles are engaged or whether density or size are increased. Metabolism of fat gets you 34 molecules of ATP vs 2 molecules for the inefficient gylcolosis, so, i would think an arm/leg combination would produce more aerobic power than a leg only propulsion. (I am sure it is more complicated as O2 and CO2 compete for Hemoglobin and HCT transport and the ratio of CO2 and O2 during exercise change with training but the key point is once AT is crossed, we are living on borrowed time)

 

[Balor]

If the legs use all of the cardiovascular output, why do cross country skiers and rowers have the highest VO2max outputs?

But do they actually generate more total power? Very hard to measure for skiiers of course, but for rowers numbers I've seen were NOT impressive at all...

 

[ed72]

But do they actually generate more total power? Very hard to measure for skiiers of course, but for rowers numbers I've seen were NOT impressive at all...

Aerobic? Doped? Clean? I think so.

Functional power? Yes. (beyond VT1). Not studies in my backpocket to support, my opinion and of course, this is why I believe 3-5 minute power on a MBB like Cruz should give a power boost on 3-5 minute efforts like climbs. It is not a mechanical phenomenon exclusively, it is a lactate clearance one

 

[Balor]

I think being able to apply 'arm power' when you leg power is 'used up' (as in - hurt too much from long use) is as, or maybe more, significant. I think I should pay much more attention to my upper body, and fiddle with my cockpit some more.

I think of a combination of aero position like one of Larry for downhills and flats AND wider bars that you will use for climbing, something like 46 cm wide road bars sawed off like I did:

https://www.sport-images.ru/media.details.php?mediaID=1284230

I've used 40cm wide ones, I think I need to go wider than that. Sorry to watermarks, I'll need to buy them out

 

[Osiris]

i would think an arm/leg combination would produce more aerobic power than a leg only propulsion.

Olympic kayakers would no doubt agree. Studies have been performed over many decades to create the most efficient paddle stroke, and it's one which combines the power generated by the thighs and upper body muscles. Though this was filmed during a 1000 meter sprint, the technique used for long distance races is essentially the same:

 

[trplay]

Now we move into water sports? Meanwhile another Chop Race opportunity evades the men and women of Cruzbike. Today's Chop was another chance for our "board talk gurus" to lead the much maligned recumbent duo out from the bottom tier but once again, zilch, zero players come forward to lead and inspire. Ah, but it twas a good run today, a very good run.

 

[ed72]

Correct me if I am wrong but Swift requires a high speed internet connection, a decent computer, a smart trainer, an ear bud, a paid subscription, bringing the bike inside and hooking it up.....no thanks, it is sort of like the difference between porn and the real thing.

 

[trplay]

Correct me if I am wrong but Swift requires a high speed internet connection, a decent computer, a smart trainer, an ear bud, a paid subscription, bringing the bike inside and hooking it up.....no thanks, it is sort of like the difference between porn and the real thing.

OK, I'll correct you. No thats incorrect. Requires nothing special in the internet speed. Nothing special in the computer department, you can run it off an ipad for goodness sakes. Although Appel TV ($149) is probably the cheapest with the highest quality resolution available today. No smart trainer ( you do need rollers or standard trainer) if you have a speed sensor which you do (Zwift power calculates the rest). Or you can use your existing power meters, heart rate monitors, cadence gadgets. Which you have. No ear bud necessary. No Paid subscription required. They have a seven day free trial that requires nothing up front requiring cancelation later. No need to bring the bike inside. Take the dumb trainer outside on the porch, oh and bring a fan and a towel. You'll need it. In other words you have everything you need to start rolling right now by using your already paid internet subscription and power meter gadgets. Now that you have the facts what are you waiting for? See you in swifterland!

 

[ccooper]

But do they actually generate more total power? Very hard to measure for skiiers of course, but for rowers numbers I've seen were NOT impressive at all...

I am a rower.
Wattages on an "erg", an indoor trainer, are easy to measure. Here are some examples of wattages that I generate on an erg:

• 1 minute = 475w
• 7 minutes = 340w
• 20 minutes = 260w

I'm not sure what my FTP on a bike is, but it is probably in the range of 260/0.95. Of course, I am not well-trained on the bike.

 

[ed72]

OK, I'll correct you. No thats incorrect. Requires nothing special in the internet speed. Nothing special in the computer department, you can run it off an ipad for goodness sakes. Although Appel TV ($149) is probably the cheapest with the highest quality resolution available today. No smart trainer ( you do need rollers or standard trainer) if you have a speed sensor which you do (Zwift power calculates the rest). Or you can use your existing power meters, heart rate monitors, cadence gadgets. Which you have. No ear bud necessary. No Paid subscription required. They have a seven day free trial that requires nothing up front requiring cancelation later. No need to bring the bike inside. Take the dumb trainer outside on the porch, oh and bring a fan and a towel. You'll need it. In other words you have everything you need to start rolling right now by using your already paid internet subscription and power meter gadgets. Now that you have the facts what are you waiting for? See you in swifterland!

So, I looked into it. You're wrong. And besides if you don't like the discussion here, don't open it.

How many ex-upright riders complain about climbing slower or not making as much power? I figured it out. I also figured out that most bent riders know jack.

Subscription is required, $15 per month.

From what I have read on Paceline, SlowTwitch, and other sites, it doesn't really run on any old computer. You need a graphics card with a minimum of 1 GB on it and the PC should have 8 GB of RAM and the hard drive needs 4 GB free space and a high speed connection. If running on a PC, it has to be 64 bit. Without a SMART trainer, a cadence and speed sensor are needed.

 

[trplay]

So, I looked into it. You're wrong.

Most of the folks using this board have the puter juice (or other) means to run Zwift. Here's whats needed as per straight from the company. Note the number of other items that get the job done. Like I said in my post if you are starting from nothing ATV is the cheapest way to get a high quality set up. Try not to be so cantankerous and hook your stuff up using the free 7 day trial. Had you done so last night you could have climbed the radio tower with Jason and talked zig zag techniques all the way up. I'll try to get you a video of this sometime today.