gmane.culture.transportation.humanpowered.general

Re: Opinions on Rotor cranks and Q-rings?

Zach Kaplan — 2008-08-28T17:05:59

In 2004 I started using 170 mm Rotor Cranks with 54/42/26 rings on my Bacchetta Aero, replacing 170 mm cranks with 53/39/24 round rings. I noticed right away a smoother pedaling feel and i was able to ride harder before knee pain came on. In actual practice I ended up going the same speed but my knees and legs felt better. I was so impressed that despite the weight and cost, in 2005 I converted my Trice XXL to 165 mm Rotor Cranks with 54/42/26 rings (from 165 mm cranks with 52/42/24 rings) and also added Rotor Cranks to my second Aero. Now I don't own anything with Rotor Cranks because I sold one of the Aeros and the Trice and converted the other Aero to 152 mm cranks with 44/33/23 Q-Rings. The Q-Rings aren't quite as effective at reducing the dead spot at the end of the power stroke as Rotor Cranks but I now prefer Q-Rings because they don't have a weight penalty, allow me to use arms that curve out for better shoe clearance (Rotor has straight right arm and my right foot pronates

Re: rotor cranks

Mark Stonich — 2008-08-26T23:22:31

Abt. 20 years ago my sons were test pilots for the University of Minnesota's human powered hydrofoil project. The the loss of inertia in the dead spot, so common to human powered watercraft, was a major problem. We used BioPace rings, but oriented them to reduce time in the dead zone. They definitely helped, but I think a little more ovalization would have been optimum. We all felt that major and minor axes of 110%:-90% would be a good starting point. But they didn't have the capacity to create such rings. The Durham rings proved too extreme. Unlike a hydrofoil, where every ounce counts, I think a flywheel might be advantageous for a displacement craft. Ideal would be a two rider craft with the cranks 90 degrees out of phase. BTW I was in Sparta WI when the Kevin & Karin Hughes and John Howard records were set. They must have planned for Karin to rest in the evening because Kevin showed up at the Ice HPV races we were holding on an indoor hockey rink . IRRC He had an MTB with long

HPV Event Nov 8 Long Beach Calif

Gaines, William — 2008-08-26T21:45:59

OK folks keep the 8th of November free. That is the date of this year's Halloween Hydrobowl! Same place as before: Long Beach Marine Stadium. Let me know if you want to help. The best help is to let as many as possible know to bring their craft! Does anybody want to organize a ride that weekend? Photos from one past event! http://www.recumbents.com/WISIL/racing2004/longbeach/halloween_hydrobowl .htm Bill Gaines o\_oo+ o-\_oo+ -- This message comes to you via the hpv< at >bikelist.org mailing list, sponsored by http://ihpva.org/ Visit http://bikelist.org/mailman/listinfo/hpv to manage your subscription.

Re: hpv Digest, Vol 49, Issue 15

Patrick Franz — 2008-08-26T20:44:17

The inventor of the otec/sdv drive was at Interbike 3 or 4 years ago. I thought it was a very interesting drive, with the most interesting thing being the ease of creating new pedal paths to test out. There is no reason the guide chainrings have to be the same size, or that there be only two of them, or even that they be round. Might be able to design a nice power path that would fit into a velomobile really well. My only concern about the drive was that the pedals attached to the guide chains via standard sized chain pins. I thought this would be a problem (cyclic bending on such a small pin) but the inventor assured me it was not an issue, that the link arms were designed to keep everything straight. They seem to be getting some systems out there, so I suppose any kinks are getting worked out. It will be interesting to see what they can get that airplane to do. An airplane probably has a similar continuous drag feel like Greg's boat. --Pat Franz TerraCycle, Inc. Recumbent Acc

rotor cranks

Greg Kolodziejzyk — 2008-08-26T14:22:06

Has anyone experimented with elliptical chain rings? I recently got an elliptical chain ring custom made for my human powered boat Critical Power 2 and 24 hour distance record attempt coming up in a couple of weeks on Sept 8th. http://www.adventuresofgreg.com/HPB/2008/08/gps-distance-measuring.html Since there is less momentum on water than rolling on smooth pavement, I found that my legs were being stressed differently during the pedal stroke on the boat than on my M5 lowracer. On the boat there is more resistance all the way around the pedal stroke rather than concentrated at the power positions that I am used to on the road bike and recumbent. The solution was the elliptical chain ring which Matt Cochran at kittadyne http://www.kittadyne.com/ made for me. It concentrates more of the power at the usual power positions. The oval chain ring works very well to better simulate the kind of power distribution that I am trained for by riding the M5. More information about the record attempt and Critical Powe

Re: Opinions on Rotor cranks and Q-rings?

cobaco (aka Bart Cornelis — 2008-08-26T13:01:12

you might want also want to check out the Japanese SDV drive at http://www7a.biglobe.ne.jp/~otec/ they quote a paper and tests run by Japan's AIST (Advanced Industrial Sience and Technology) Institute

Re: Re: Opinions on Rotor cranks and Q-rings?

Mark Stonich — 2008-08-26T03:18:23

Bill, How were the rings oriented? This makes all the difference. Get it wrong and you just make things worse. Mark Stonich; BikeSmith Design & Fabrication 5349 Elliot Ave S. - Minneapolis. MN 55417 Ph. (612) 824-2372 http://bikesmithdesign.com http://mnhpva.org -- This message comes to you via the hpv< at >bikelist.org mailing list, sponsored by http://ihpva.org/ Visit http://bikelist.org/mailman/listinfo/hpv to manage your subscription.

Re: Q rings

Mark Stonich — 2008-08-26T03:49:09

Not unless the ratio between major and minor axes is different. Any time you make two changes at once you don't learn a darn thing from the experiment. My two cents, (and of course I'm biased) is that Rotors help by ensuring that your legs spend less time in the extremely bent position where many people's muscles don't work efficiently. With short cranks you spend zero time with the legs bent that much. Mark Stonich; BikeSmith Design & Fabrication 5349 Elliot Ave S. - Minneapolis. MN 55417 Ph. (612) 824-2372 http://bikesmithdesign.com http://mnhpva.org -- This message comes to you via the hpv< at >bikelist.org mailing list, sponsored by http://ihpva.org/ Visit http://bikelist.org/mailman/listinfo/hpv to manage your subscription.

Re: Opinions on Rotor cranks and Q-rings?

Mark Stonich — 2008-08-26T03:44:02

Neither. On a recumbent, whether BioPace, OvalTech or Q-rings, I want a radial line to the tallest part of the ring to be at 90 degrees to the top run of the chain when the cranks are about 45 degrees before full extension. I believe this is somewhat closer to the BioPace thinking than Rotors for upright bikes. I don't see how they could help as much on an upright as they do on a 'bent. Might help some though. Only one rider in the Tour de France used Q-rings, the winner Sastre. Perhaps the optimum shape for a 'bent would be more oval than for an upright. I now ride both uprights and 'bents. With lumpy rings and 148 to 155m cranks on the 'bents and round with 160-165mm cranks on the uprights, both feel about the same. Darn good. My next experiment will be with 153mm cranks and round vs BioPace on a single speed upright. I'll mount both rings and switch manually 1/2 way through each ride. Don't think I'll prove much in terms of efficiency but I'll find out what I like. Since my go

Re: Re: Opinions on Rotor cranks and Q-rings?

john riley — 2008-08-25T22:51:12

On 25-Aug-08, at 5:12 PM, William Volk wrote: May depend on the era. AFAIK Q rings are oriented differently from the way Biopace used to be oriented. Pre biopace ovals may have been oriented like Q rings, but the ones I remember (Durham?) were pretty extreme. I've never used any of them, but would be willing to try, as long as I was certain that I could figure out the orientation. -- This message comes to you via the hpv< at >bikelist.org mailing list, sponsored by http://ihpva.org/ Visit http://bikelist.org/mailman/listinfo/hpv to manage your subscription.

Re: Opinions on Rotor cranks and Q-rings?

William Volk — 2008-08-25T21:12:09

I hear good things about these but if you tend to spin, maybe not so. I tired ovals a number of years ago, just couldn't adapt to it. It caused knee pain. I think I'm just too adapted to circular rings to change. William Volk -- This message comes to you via the hpv< at >bikelist.org mailing list, sponsored by http://ihpva.org/ Visit http://bikelist.org/mailman/listinfo/hpv to manage your subscription.

Q rings

2008-08-25T20:02:36

I get clear and repeatable improvement in power on my recumbent exercycle when shifting between 50t round, and 50t BioPace rings. When I get up to a heart rate of 140 on the round, I can shift to the Bio and maintain the same speed and rpm at HR 135. Shift back to round and rate goes back up. At this power output, where my legs are just starting to burn, the burn will go away with the bio, and come back with the round. Feels A LOT smoother too. The difference between the major and minor axes is similar between Bios and Qs is similar, so I'd expect similar results. With the added advantage of being able to fine tune the orientation of the Qs. I've sold about a dozen sets of shortened cranks with Q-rings and have had nothing but good feedback about them. All but one have been with the MTB rings 24-34-44 or the new 23-33-44. With short cranks a 44/11 is enough gear for most people. Mark Stonich; BikeSmith Design & Fabrication Correct me if I am wrong Mark. Is it true that the

Re: Opinions on Rotor cranks and Q-rings?

john riley — 2008-08-25T20:05:04

On 25-Aug-08, at 10:55 AM, Mark Stonich wrote: Except the original Biopace idea would have the orientation of the long axis different from the Q ring idea, correct? So you are using Biopace rings like Q rings? -- This message comes to you via the hpv< at >bikelist.org mailing list, sponsored by http://ihpva.org/ Visit http://bikelist.org/mailman/listinfo/hpv to manage your subscription.

Re: Opinions on Rotor cranks and Q-rings?

Mark Stonich — 2008-08-25T14:55:44

We have 8 recumbents, and wouldn't have a round ring on any of them. Your pressure on the pedals varies more on recumbents, with max pressure coming in later in the pedal stroke. This is why when you've been riding recumbents for a while and get on an upright your pedalling feels much smoother. Q rings (or BioPace if you can orient them properly) can put you in your highest effective gear about 45 degrees before full extension so you can make good use of this force, and smooth out your pedalling. I get clear and repeatable improvement in power on my recumbent exercycle when shifting between 50t round, and 50t BioPace rings. When I get up to a heart rate of 140 on the round, I can shift to the Bio and maintain the same speed and rpm at HR 135. Shift back to round and rate goes back up. At this power output, where my legs are just starting to burn, the burn will go away with the bio, and come back with the round. Feels A LOT smoother too. The difference between the major and minor axes i

Opinions on Rotor cranks and Q-rings?

Mike Librik — 2008-08-25T13:04:14

Has anyone out there experimented with these pricey items? I installed a set of Rotor cranks on a fellow's V-Rex some years back, but it didn't work out. One problem may have been that he was simultaneously experimenting with much shorter crank arms, so he didn't have a really direct comparison to what he had before. He did stick with the shorter cranks, but returned the Rotor system to the manufacturer. I've a customer who is considering either Rotor's $800 cranks or their elliptical chainrings. He isn't interested in more speed, but in more efficient power for easier climbing. I've looked into Rotor's Q-rings, but annoyingly it seems they only make these for the larger rings on the crankset, and serious help with climbing would argue for special treatment to the smallest ring. My customer has looked around for opinions online and seen some positive reviews, but one is never sure who to believe and just what the writer's credentials or affiliations are. I figured the HPV list would be a

Re: India's gift to green drive: Bicycle < at > 40kmph

MH — 2008-08-13T11:11:05

I received this from a friend - with diagram. -Mark H. Did you see this? Maybe you can email him. There's a diagram online: Technology Pedal Crank Assembly Technology Description The innovation is a new extendable pedal-crank system that can be mounted on a bicycle, tricycle or other human powered vehicle. Manually driven vehicles move by the torque generated out of the force exerted by the leg of the driver on the pedal. The magnitude of torque is equal to the force multiplied by the perpendicular distance i.e. the length of the crank. Increasing the crank length makes driving difficult. The present innovation is a means to increase the length to about two times the length of an average crank without increasing or altering the radius of the circular path through which the legs of the driver move compared to that of a traditional crank system. The effect

Re: India's gift to green drive: Bicycle < at > 40kmph

LioNiNoiL — 2008-08-13T07:51:41

http://economictimes.indiatimes.com/Indias_gift_to_green_drive_Bicycle__40kmph/articleshow/3319246.cms There is a word for this : "vapourware". Mondal is selling smoke and a dream. Miguel Indurain could sustain 550 watts in a climb (source below) and no crank design is going to allow Joe Six-Pack to surpass Miguel Indurain. http://www.peakscoachinggroup.com/freeinfo/going_uphill_fast.html ++ Cornel Ormsby ++ +Las Vegas, Nevada+ -- This message comes to you via the hpv< at >bikelist.org mailing list, sponsored by http://ihpva.org/ Visit http://bikelist.org/mailman/listinfo/hpv to manage your subscription.

Re: Miles per gallon

JOHN TETZ — 2008-08-13T03:32:50

Brian wrote; http://bicycleuniverse.info/transpo/beef.html Thanks for the information Brian. ] John Tetz -- This message comes to you via the hpv< at >bikelist.org mailing list, sponsored by http://ihpva.org/ Visit http://bikelist.org/mailman/listinfo/hpv to manage your subscription.

Re: Miles per gallon

Nick Hein — 2008-08-13T02:13:13

Paul, It's a factor. Whether you need to eat or not isn't the issue. The issue is that a LOT of petroleum is used to provide feed and water for cattle. A lot of fossil fuels are used to cook food. Nick ----- Original Message ----- From: Paul Bell To: Nick Hein Cc: hpv< at >ihpva.org Sent: Tuesday, August 12, 2008 6:32 PM Subject: Re: [hpv] Miles per gallon On Tue, Aug 12, 2008 at 4:33 PM, Nick Hein verizon.net> wrote: Don't forget to factor in the cost of growing and cooking the fuel for the 2-legged motor. On my best days when I eat all raw fruits and vegetables grown locally I can do even better. I don't think this is really a factor as you need to eat no matter if you drive a car or ride a bike :) You will just be healthier on a bike :) Cheers, Paul Bell -- This message comes to you via the hpv< at >bikelist.org mailing list, sponsored by http://ihpva.org/ Visit http://bikelist.org/mailman/listinfo/hpv to manage your subscription.

RE: Miles per gallon

Greg Nuspel — 2008-08-13T00:12:19

It's all tongue in cheek, but all the numbers were pulled off the web. I should have noted the pages, the copy write police will be hunting me down as I type this. US of imperial gallons? -----Original Message----- From: John Clary [mailto:opusthepoet< at >gmail.com] Sent: Tuesday, August 12, 2008 5:51 PM To: Greg Nuspel Cc: hpv< at >ihpva.org Subject: Re: [hpv] Miles per gallon On Tue, Aug 12, 2008 at 5:01 PM, Greg Nuspel wrote: 12 the I don't know where you got your energy content from, mine lists a gallon of unleaded regular as 33,000 Calories, and oxygenated unleaded regular as 31,800 Calories. It also listed the mileage of a bicycle rider as 900 MPG equivalent for the non-oxygenated unleaded .

Re: Miles per gallon

John Clary — 2008-08-12T23:51:26

I don't know where you got your energy content from, mine lists a gallon of unleaded regular as 33,000 Calories, and oxygenated unleaded regular as 31,800 Calories. It also listed the mileage of a bicycle rider as 900 MPG equivalent for the non-oxygenated unleaded .