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 Missing power located?

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T O P I C    R E V I E W
sean costin Posted - 01/11/2010 : 20:34:39
I'm still trying to figure out why an upright position can produce more power than recumbent and I have a theory about why this is the case. I think is has something to do with subtle movement that the upright position allows the rider to make with upper body, the hips and mid section. This movement is severely restricted with the fixed seating position characteristic of recumbents.

I'm thinking of designing a dynamic seat that can pivot to take advantage of these muscles.

Anyone have similar thoughts?

Sean

25   L A T E S T    R E P L I E S    (Newest First)
warren Posted - 10/12/2010 : 18:55:28
Here's the Garmin 500 without the heartrate, pedal cadence, and pleather case for $210. Such a deal!
http://probikeoutlet.com/product/garmin-edge-500-68597-1.htm
Larry Lem Posted - 10/12/2010 : 13:22:11
Garmin 500, $350 at Nashbar minus 20% off of a single item = $280 + tax and shipping. Just ordered.

Larry Lem
Larry Lem Posted - 10/07/2010 : 07:45:10
Okay, I'll be buying a Garmin 500 with the cadence sensor and heart rate monitor strap next month.

Sheesh, another heartrate monitor strap...just because of ANT+.
I can see at some race, I'll bring the wrong strap / computer combination.

Larry Lem
sean costin Posted - 10/06/2010 : 18:27:17
I had no idea that you could use a Garmin like this. Unfortunately I placed the order for the Powertap head just hours before for about the same price.

Larry, thank you for considering me one of the silly Americans.

I think Hannon the Cannon has a PowerTap and an SRM. Are you lurking Bill?

Sean
LongJohn Posted - 10/06/2010 : 08:20:01
Larry,

To your first question: No.
I would like to, but I can not even affort a powermeter myself, I have to borrow... (Well, I can affort, but I won't buy because I think they are way too expansive).

On another note; thanks for considering me to the top Europeans.... :-P

I would like to buy the 500, but I do like to mapping option of the 800, 705, 305, etc... But they are more expensive...

You can change what is being displayed which changes the size of the fonts...

See: http://www.cyclingnews.com/reviews/photos/garmin-edge-500-gps-review

The nice thing of the Garmin(s) is that they "talk" ANT+, so they talk to my wireless hrtmonitor and speedo. And will talk with ANY powermeter that has ANT+.

I think I will buy one!

Thomas
Larry Lem Posted - 10/06/2010 : 08:03:45
Has anyone ever run a Powertap hub AND an SRM crank at the same time, been confident in their calibration and determined their drivetrain losses?

From the other thread that I started, 3 of the top Europeans (Thomas, Aure, Gert-Jern) noted that they produce the same power whether on upright or reclined, whereas 3 of the silly Americans (Sean, Randy, Larry) have concluded that we generate less power on recliner bikes. Thomas pointed out that I was measuring at the wheel and maybe my convoluted drivetrain was to blame for the difference.

I was thinking about getting a Garmin 500 over the last 2 weeks, but I hate that the display font size is so small compared to the face of the unit. (I didn't want the map-feature of the other GPS units).

Larry Lem
LongJohn Posted - 10/06/2010 : 07:39:48
Sean,

Opt for a Garmin 500 or 800, they are also ANT+ compliant...

Thomas
sean costin Posted - 10/06/2010 : 04:54:49
Tim,
Larry wasn't being facetious. He was just being a smart ass.

Sean

Power update: I received the powertap wheel, but did not realize that I needed to buy the computer and ancillary parts separately. DOH!

25hz Posted - 10/06/2010 : 04:35:21
Maybe Larry is being facetious (I don't know him, so I don't know), but I have yet to see an instance where Sean bragged about anything. As a multiple world record holder, a little might be warranted, but again, I have never read it or heard it out of Sean. If people ask his "numbers", for anythign, and they are way above other people, that isn't bragging, that's just the numbers. If people have some kind of problem dealing with his numbers, there are two solutions. 1) Don't ask, 2) don't read.

As someone who doesn't have a power meter, I value reading the numbers people produce at certain speeds. If I can fairly closely replicate the bike position, I can indirectly, roughly estimate power numbers for myself, for a given speed.
sean costin Posted - 09/29/2010 : 19:57:27
Larry, I would be factual about wattage without boastfulness. I think people may be surprised at how low my wattage is compared to an upright rider. When I have done those computrainer races I was 50+ watts less on a 15 minute effort. My sprint wattage is probably pretty high. Whatever. You can tell that by the times, so what is the big deal.

This is science man!

Sean

Larry Lem Posted - 09/29/2010 : 07:54:45
Don't be too boastful, either!

Larry Lem
sean costin Posted - 09/29/2010 : 04:59:19
I am hoping to uncover more secrets of the recumbent position very soon. I have a PowerTap wheel on the way that is being built up by Rob English. I promise not to be shy about wattage numbers.

Sean
25hz Posted - 09/29/2010 : 04:20:24
That's why I like one leg drills. If you aren't smooth with the transition, you get some fairly ugly clunking and banging from a choppy stroke. Once switching back to two legs after 3 to 5 sets of one-leggers, two legs feels silky smooth. Then I practice my high speed spinning. Again, if I can get the transition at 160 or 170 rpm, when I slow down to normal cadence around 100 to 110, again, the stroke feels very smooth, very "slow" and very easy to concentrate on.
Gugi100 Posted - 09/28/2010 : 13:43:22
quote:
Originally posted by sean costin

Maintaining a high transitional effort near 4 and 10 o'clock seems to be critical in holding a high cadence at high wattage. That is where it all starts to break down. Exerting effort to lift the leg ( as apposed to letting the pushing leg lift it) is the most difficult aspect physically.

Sean



When cycling fast for lets say an hour the thing I call "timing" becomes at least for me very important. The timing in transition between pushing and pulling. Focusing on this transition can even become addictive. When it goes well it can get you in a "rithmic flow".

Greetings Gert-Jan

25hz Posted - 09/28/2010 : 10:28:51
Funny you should mention the schweeb, because, yes, once I get my piece of property away from urbia, and get my shop and the "compound" set up, my solar panels, windmill, greenhouse and velodrome set up, I drew up plans for my own little schweeb style monorail system BUT, my bikes will actually detach from the system, so you can ride away from them at "landings". Go do your thing, come back, ride up on the landing, pop in 2 pins, and away you go on the monorail, back to the homestead. Chicks will really dig it :)
purplepeopledesign Posted - 09/28/2010 : 04:51:45
quote:
Originally posted by 25hz
I've been busy building thangs :) I've also been riding hard at lunch times as I spend most evenings in my secret lab-or-at-tory. Muwahh hah hah haaaaa . . . :)



Ohhh... so you're the one working on the monorail for the evil villain lair at Google.

:)ensen.

Those who claim to be making history are often the same ones repeating it.

Video of my trike
http://www.youtube.com/watch?v=MdSLRD_2vzc
Photos of my trike
http://www.flickr.com/photos/purplepeople/
25hz Posted - 09/28/2010 : 04:46:32
quote:
Originally posted by sean costin

Jensen,
I think you are right regarding fast and slow twitch. Maintaining a high transitional effort near 4 and 10 o'clock seems to be critical in holding a high cadence at high wattage. That is where it all starts to break down. Exerting effort to lift the leg ( as apposed to letting the pushing leg lift it) is the most difficult aspect physically.

Sean




. . . which is where one of the benefits of short cranks kick in. With short cranks, the knee joint is opened up more, closer to 90º sooner, which makes it easier to apply more power, sooner. With my 130mm cranks, even at 9 o'clock, in the middle of the dead spot, my knee joint is just about at 90º, so, as soon as the pedal rises about the line connecting my hip and the BB axle, I can hit the power. Regardless of crank length, it's hard to apply good pulling/scraping power when the leg is almost straight out near 3 o'clock, but that's not the case when the foot is going through 9 o'clock.

PS - I breifly saw the email message you sent me, Sean, but I haven't read it yet. I've been busy building thangs :) I've also been riding hard at lunch times as I spend most evenings in my secret lab-or-at-tory. Muwahh hah hah haaaaa . . . :)
sean costin Posted - 09/27/2010 : 18:50:54
Jensen,
I think you are right regarding fast and slow twitch. Maintaining a high transitional effort near 4 and 10 o'clock seems to be critical in holding a high cadence at high wattage. That is where it all starts to break down. Exerting effort to lift the leg ( as apposed to letting the pushing leg lift it) is the most difficult aspect physically.

Sean



purplepeopledesign Posted - 09/26/2010 : 14:48:07
quote:
Originally posted by knud
The fast and slow muscle fibres have different tendency to tire: The slow ones get you more power, but tire first (if I get it the right way round), and the fast ones less power, but you can use them longer.


I think it is the other way. Fast twitch muscle fibre is needed for sprint power and slow twitch muscles fibre has better endurance for distance riding.

:)ensen.

Those who claim to be making history are often the same ones repeating it.

Video of my trike
http://www.youtube.com/watch?v=MdSLRD_2vzc
Photos of my trike
http://www.flickr.com/photos/purplepeople/
tim_turner Posted - 09/26/2010 : 14:28:42
I've found I have the max power taking a gear that's giving me 85-88 and elevating it to 92-94.
similarly, if I'm cruising along at 95-98, and I feel like I'm peaked on my ability to put power to the cranks, shifting up a gear and dropping the cadence back down to 88-91 will allow me to push it back up to 92-93 again.

T
knud Posted - 09/25/2010 : 12:21:53
quote:
Originally posted by sean costin
I have been working on improving cadence to average around 90 Rpm on sustained efforts and have discovered greater endurance at higher load. It is a little addicting pushing myself toward higher cadence.



The fast and slow muscle fibres have different tendency to tire: The slow ones get you more power, but tire first (if I get it the right way round), and the fast ones less power, but you can use them longer. So higher cadence means more use of fast muscle fibres and less fatigue.

This gets of course counterbalanced by the fact that your cyclic pedal stroke is not perfectly round, so you will have some losses over one cycle (muscles not hitting the exact moment right when to start and stop excerting power). The higher the cadence the higher the loss. So you might want to train not only higher cadence but also a more precise stroke.

I did train my cadence over a year or so by always cycling one gear too small. This was a mental challenge, to not slip back into the "normal" best gear (this is soooooo automatic after 30 years of cycling), but after that time I could go at a 100 RPM or faster easily. Takes some time, but pays back.

Oh, and shorter cranks for that duration can also help. Going back to longer cranks again is another change, but that is much easier than the switch to higher cadence.

Knud
sean costin Posted - 09/24/2010 : 17:21:54
I've found some missing power in cadence.

On a recumbent it is easy to slip into a lower cadence. If you are 10 rpms less (80 vs 90), you will need to produce about 12% more power per RPM to maintain the same speed.

Very fast riders like Aurélien and Hans Wessels have high cadence and can generate more power through RPM. They are producing similar power numbers on their recumbents as they had on their uprights.

I have been working on improving cadence to average around 90 Rpm on sustained efforts and have discovered greater endurance at higher load. It is a little addicting pushing myself toward higher cadence.

Sean
alevand Posted - 05/07/2010 : 05:21:12
I tried going forward and backward in the seat during each petal stroke, it seemed to help going up a steep hill where I didn't have a low enough gear, slow cadence. Some of the back muscles are involved. I think that side to side swaying seat would not work.

C:
Tony Levand
Hadden Posted - 04/15/2010 : 11:14:04
I think the key thing is to optimise your pedaling style so most of the force is tangential.But to do this you need to be able to measure it then adapt. This probably the one area in cycling where most efficianty can be gained.

Simon sanderson http://www.bhpc.org.uk/simon-sanderson.aspx http://www.youtube.com/my_videos http://www.flickr.com/photos/bhpclub/sets/72157604828238682/
Jeff Wills Posted - 04/14/2010 : 18:19:58
quote:
Originally posted by Kraats


This mechanism in fact gives the standing cyclist the possibility to generate power at bdc by means of tangential forces, which effectively can be used at 90 degrees to generate radial forces at the pedals.

The advantage even is increased because slower contracting muscles at 90 degrees can generate more force.

In this way a standing upright cyclist can effectively use leg power near the bdc.

Unfortunately this trick is not possible for a recumbent.




I don't see why not- on a recumbent, you can drag your foot downward with your leg fully extended and kick it upward with the leg fully contracted. This is where cleated pedal systems really help riders "pedal circles".

__________________
Jeff Wills
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