Offset Bike Crank Eliminates Power Vacuum

submitted by dponce80 65 days ago (via http://www.ohgizmo.com/2006/04...)

What the hell does that mean? If you give two hoots about biking, you should check this out. It's a special system that ensures the two pedals are never 180 degrees to each other, eliminating that "dead spot" at the top of every stroke. Move over Lance Armstrong!

89 comments blog this email thiscategory: technology

89 Comments

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by Dash-2 on 4/02/06

+ 1 digg

Goodbye kidneys...

I must have this!
[reply]
by dizdaz89 on 4/02/06

+ 14 diggs

Direct link for anyone who cares, http://www.rotorbike.com/eng/home.htm
[reply]
by streetlightpoet on 4/02/06

+ 2 diggs

cool idea, but my guess is that it will go the same way as biopace chainwheels.
[reply]
1. by steveoa3d on 4/03/06
  
  + 2 diggs
  
  I totally forgot about BioPace Chainwheels. I HATED those things ! Same idea as it made it easier to pedal at the top of the crank rotation...
  
  I think this is a solution to a problem that doesn't exist, the dead spot is there but if the ride has a decent RPM they overcome that problem. Spin to win after all...
2. by FishyJoe on 4/03/06
  
  + 1 digg
  
  Bio-pace worked the opposite, it made the dead spot harder. Similar in principle to the cranks, elliptical chainrings have been showing up on a number of pro bikes. The most notable being Bobby Julich.
3. by dingledoink on 4/03/06
  
  + 1 digg
  
  Agreed....... it's too non-traditional to be accepted by the masses.
  
  http://www.sheldonbrown.com/biopace.html
4. by jonom on 4/03/06
  
  + 1 digg
  
  I miss biopace - I loved those things! Once you got used to how they worked they were brilliant, hill climbing was much easier.
5. by ironbear on 4/03/06
  
  + 2 diggs
  
  Biopace is a simpler implementation, and it really works well for some kinds of riding. On a mountain bike in actual mountains, for instance.
by schlagzeuger on 4/02/06

+ 8 diggs

cool - and it costs less than $1000. what a bargain
[reply]
1. by klaymen on 4/03/06
  
  + 2 diggs
  
  wait, was that supposed to be sarcasm?
2. by seanmc303 on 4/03/06
  
  + 5 diggs
  
  I hear you, schlagzeuger. In this modern world where you can by a low end computer for a couple hundred (a significant amount of technology), you can also buy something like this. A piece of metal. Hmmmmm.... Let me think about this. Microprocessor around $100. Slightly twisted piece of Metal $693 or $963. I love biking, but I have never understood why something like this cost more than my first car. Bike "technology" has got to be the slowest progressing form of technology and also the most expensive to own for what you get.
3. by TheBeaver on 4/03/06
  
  + 0 diggs
  
  Never underestimate the spending potential of a man with a hobby.
4. by toad3k on 4/03/06
  
  + 5 diggs
  
  I once spent $150 on a yoyo. It was a really good yoyo though.
by wabbiteh on 4/02/06

+ 13 diggs

For those who have no idea what this does...:
http://www.rotorbike.com/eng/simulador_RS4_RD2_53.htm
animated gif, yay!
[reply]
1. by steveoa3d on 4/03/06
  
  + 8 diggs
  
  It looks like it adds weight to the place that you don't want weight, your spinning parts ! Every ounce of weight on something that spins is equal to 8 ounces of dead weight.
  
  The rule in bike building is the spinning things get lightened up first, thats why titanium spindles and so on are so popular, then if you have money left you lighten that other parts.
  
  This system might be fine for the casual rider with a 50 pound bike that spins a low RPM's, but a racer wouldn't be interested.
2. by UprightJoe on 4/03/06
  
  + 7 diggs
  
  I was trying to look at what it weighed to compare it to other high-end cranks but I don't understand the unit of measure they list on the page. They list the lightest one as weighing 1.230 grs. What's grs? It's obviously not grams - that would be too light.
  
  It could be 1230 grams - in which case it would be about double the weight of a comparably priced fixed crank. Definitely costly in terms of weight but if it makes up for it in power output, it could still be worth it.
3. by atbnet on 4/03/06
  
  + 3 diggs
  
  It is 1230 grams Some countries, mostly European switch the decimal and comma.
4. by jguerry on 4/03/06
  
  + 2 diggs
  
  why would they do that? (switch the decimal and comma)
  
  so 100,000,000.000 is really 100.000.000,000 ?
  
  weird.
5. by 3lite on 4/04/06
  
  + 1 digg
  
  actually, we europeans don't switch the decimal and comma. you do.
  get my point? who's weird now?
  cheerz
by beelz on 4/02/06

+ 2 diggs

smart. simple.
[reply]
1. by Pentarix on 4/03/06
  
  - 3 diggs
  
  freaking sweet, great find!
2. by Adam_A-F on 4/03/06
  
  + 6 diggs
  
  Smart. But not simple. What could be simpler than a regular crank?
by liquidjill on 4/02/06

+ 2 diggs

Dugg. This is innovative and something that I personally am interested in. Now.. to come up with the cash....
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by diggadeep on 4/03/06

[below viewing threshold, show comment hide comment] - 8 diggs

is it not possible to just modify an existing design by slamming the bike with a hammer?

[reply]
1. by mbreitem on 4/03/06
  
  + 7 diggs
  
  No, because if you do that, when the foot that's up finally comes down, the other foot will be behind the top of the stroke, and not ahead. It doesn't work with a fixed arrangement. This system makes it so that the top foot is always a little bit ahead of the top of the stroke, giving you an edge, especially in tough climbs.
2. by arnar on 4/03/06
  
  + 6 diggs
  
  Just to be an arse: "the two pedals are never 180 degrees" - can't be true, unless the intermediate value theorem [1] is wrong. :o)
  
  http://en.wikipedia.org/wiki/Intermediate_Value_Theorem
  
  Still, dugg for being clever.
3. by jguerry on 4/03/06
  
  + 0 diggs
  
  haha, only under the influence of high temperatures.
by breakneckridge on 4/03/06

+ 3 diggs

There is no reason for the price to be so high. The price will definitely come down significantly sooner rather than later. But I digg it.
[reply]
by jav1231 on 4/03/06

+ 4 diggs

There have been several attempts at similar devices. Last year at the TdF I think a couple of riders rode eliptical large rings to give an advantage. I think there's another crankset that has a sort of flop-effect where the cranks work independtly, a little more pronounced than this one. Everyone seems to fall back to the good-ole fixed crank, though.
[reply]
by genma on 4/03/06

[below viewing threshold, show comment hide comment] - 11 diggs

I refuse to believe this is a new idea, or one that has slipped past the Lance Armstrong training team. how did this get so many diggs.
[reply]
1. by dgen_x on 4/03/06
  
  + 4 diggs
  
  it's not a new idea...and has been posted several times...
  
  and will probably be posted again in the next month or so...
  
  I hate it when new blogs pick up old news...
  "New model for 2005
  Steel splined spindle
  Integrated bottom bracket
  Chainrings: 39/53"
  
  Wow...new model for 2005! Amazing!
2. by CingleMolt on 4/03/06
  
  + 5 diggs
  
  Once again.. someone underestimates the power of the dupe. If I haven't read it, it's news to me!
3. by tehJR on 4/03/06
  
  + 4 diggs
  
  Another Digg feature I'm looking forward too:
  
  The ability for users to filter out stories similar to those that they have dugg in the past. Maybe it would get rid of some of the complaining.
  
  And once users can customize their main page to only the categories they want to see, people shouldn't have any reason to post USELESS comments. Somehow I think they will continue. Some people need to feel angry/upset/peeved about everything.
by benzzene on 4/03/06

+ 10 diggs

Just to be pedantic: The statement "the two pedals are never 180 degrees to each other" isn't true. They are, just not when the pedals are at the top and bottom. Nifty idea though.
[reply]
1. by marnaq on 4/03/06
  
  + 5 diggs
  
  Correct. This is all about eliminating the deadly 6 o' clock position.
by fly1m1 on 4/03/06

[below viewing threshold, show comment hide comment] - 11 diggs

This is crap! At some point in the circle, your feet will still be straight up and down, but the crank will be slightly off axis. The net result will be exactly no different. The truth is it makes the circle your feet go in a shorter distance around, making you use more power to go the same speed. Basic geometry people. Now on the the next rip-off.
[reply]
1. by rossburnett on 4/03/06
  
  + 4 diggs
  
  And yet, it seems to work for some folks: http://www.rotorcranksusa.com/reviews.htm
  
  But what do they know - much better to just theorize.
2. by digital56k on 4/03/06
  
  + 7 diggs
  
  "The truth is it makes the circle your feet go in a shorter distance around, making you use more power to go the same speed. Basic geometry people. Now on the the next rip-off."
  
  How does it make "the circle your feet go in a shorter distance around"? Is there some magical new facet of physics involved here? The radius is the same, all that is happening is that the pedal has a different angular rate at different parts of the circle, but the average rate is the same.
  
  If you disagree, maybe you can explain in "basic geometry" how the distance around a circle with a fixed radius gets shorter?
by IHaveIssues on 4/03/06

+ 3 diggs

From TFA:
"No more jamming your knees, injuries to tendons due to that dead spot, and better maintenance of traction as wheels do not slow down and do not have that unnatural jumpiness."

As a roadie I have never experienced any of this, but then again I enjoy "ankling".

[reply]
1. by recursive on 4/03/06
  
  + 2 diggs
  
  Sheldon on ankling:
  http://www.sheldonbrown.com/gloss_a.html
2. by jonom on 4/03/06
  
  + 1 digg
  
  Hey I do that sometimes - didn't realise there was a name for it!
by retral on 4/03/06

+ 0 diggs

Hrmm... I'd have to try it first, and for a mininum of 700 dollars there, you could probably get one custom milled out of titanium e.e (joking, but it is pretty pricey) It is, however, hard to believe (like someone said above) that this is a new idea.. there's gotta be some sort of catch.
[reply]
by jinexile on 4/03/06

+ 2 diggs

God I hate vague headlines like these, I can't see the description from the live bookmark until I click on it, I was wondering what bicycle cranks had to do with household cleaning appliances.
[reply]
by motbob on 4/03/06

+ 1 digg

YES!!! I have been waiting for this my ENTIRE LIFE!!!! This was my top three wish list before today:

1. World Peace
2. An invention that eliminates the dead spot on bicycle pedals
3. Less filling

Thank you for making my dream a reality!
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by MicroBerto on 4/03/06

- 1 digg

Awesome, but will it be uncomfortable and weird, like learning to pedal again?
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by r4wbon3 on 4/03/06

- 1 digg

Great.. Now I can make one leg bigger than the other !!
[reply]
1. by artanis on 4/03/06
  
  + 1 digg
  
  You think they're selling a slightly offset fixed rotor for $700? Watch and see how it works:
  
  http://www.rotorbike.com/eng/simulador_RS4_RD2_53.htm
by rrrobothouse on 4/03/06

+ 3 diggs

Lance Armstrong would just take it and use it against you anyway.
[reply]
1. by intangible on 4/03/06
  
  + 1 digg
  
  What do you mean, like he would hit you with it?
by Morky on 4/03/06

+ 5 diggs

There is never a dead spot if you are using pedal clips and are cranking correctly.
[reply]
by jacks0n on 4/03/06

+ 0 diggs

"As a roadie I have never experienced any of this, but then again I enjoy "ankling"."
True.. Neither have I. I'll only believe it when it's supported by some trials.
The thing is, the dead spot is TDC (top dead centre), or BDC (bottom dead centre). With this new crank, you still experience this, your feet/legs still go through the same cycle, just at different intervals. This thing won't do anything. Will performance be enhanced? Probally. But because of the placebo affect, not science. Give it a year or so and we'll know it's a waste of money.
[reply]
by Nelson69 on 4/03/06

+ 4 diggs

I think I'll be sticking with my carbon campy cranks...
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by Dangerman on 4/03/06

+ 14 diggs

If you are using clipless pedals and are spinning properly there is absolutely no need for a contraption like this. When the pedals are perp to the ground the pedals should be in a motion that is moving forward and backward laterally as your calves are pushing forward and pulling back.
Jamming your leg down on the pedal is the best way to suffer cartilaginous injuries as well as suffer constant IT band pain.
The idea is that the pedals are turning the crank, not that you are mashing them down. An experienced cyclist that has any idea of technique will not need a kludge like this.
Use a reputable bike shop that can put you on a bike that fits and ask for some technique advice, you 'll be amazed what you can learn.
[reply]
1. by panicofficer on 4/03/06
  
  + 4 diggs
  
  Finally, someone with some sense. I totally agree. This device looks like a way for someone to cash in on an issue that really is not a problem if you're using the proper technique. No digg.
2. by netgeek on 4/03/06
  
  + 4 diggs
  
  Bingo!. Just another crutch for people who don't have proper spin technique.
  
  Coach Troy would not approve!!.. ;)
3. by brhad56 on 4/03/06
  
  + 0 diggs
  
  There is a dead spot regardless of clips or clipless.
4. by Dangerman on 4/03/06
  
  + 2 diggs
  
  @brhad56
  Uhh, no there isn't. When you are attached to the pedals and properly spinning them the bottom quarter and the top quarter of the cycle are powered by a lateral motion that increases to 100% as the stroke approaches 90 degrees. You are effectively pushing forward and back with your cleats at this point. When I teach spinning, I encourage riders to think of the motion as being akin to treading water.
  You are not only mashing the pedals or pulling up with the cleats, you should be TURNING the cranks. It is very much like when you turn a crank handle with your hands, your hand never reaches a dead spot because the spindle is attached to a rotating barrel that is constantly turning in your hand, this is the exact same thing that is occurring when you turn the crack while clipped in. It is less pronounced when using toe clips, unless you are using bat shoes that allow you to pull backward.
  Try riding a fixed gear and tell me there is a dead spot.
5. by Chrispikula on 4/03/06
  
  + 3 diggs
  
  There is no dead spot 'cause proper technique says you always push tangently to the circle. Bad techniques is called push-push for a reason.
by kilofox on 4/03/06

+ 4 diggs

I agree with all the smooth leggers.... not needed if you have a good spin. Don't have one? Get a fixed gear... you will have no choice but to spin.

Additionally you have a ton of fun if someone wants to ride your fixed gear and tell them its a single speed instead.
[reply]
1. by Dangerman on 4/03/06
  
  + 1 digg
  
  Props to the fixie riders, only way to go!
  What are you sporting kilofox?
2. by ricosalomar on 4/03/06
  
  + 2 diggs
  
  Way. Just put my fixie together this week, and had to skip school on Thursday cuz it was so fun.
3. by recursive on 4/03/06
  
  + 2 diggs
  
  My commuter's a Raleigh Rush Hour. With fenders.
  
  The freewheel side of the flip flop hub has yet to see any use. Fixed is too fun.
by WaterDragon on 4/03/06

+ 1 digg

Why not just add a heavy flywheel to the crank, if you want to avoid the lapse of power at the top of the stroke?
I know, I know...y'all are preoccupied with lightweight bikes.
But a heavy flywheel can be useful.

It just might make it harder to stop though, unless you can disengage the flywheel, and let it keep spinning, while you stop...but then we are no longer talking about an ordinary bike.

...and a spinning flywheel certainly would help you start up again faster.
Hey...maybeeee......Naaah!
[reply]
1. by steveoa3d on 4/03/06
  
  + 1 digg
  
  The spinning flywheel is a better idea than this. That is if it can store energy and then kick in slowly to bring the bike back up to speed after it slows down. More of a personal transport thing than a race bike of coarse.....
by FishyJoe on 4/03/06

+ 1 digg

Rotor also makes elliptical chainrings that give much of the benefits of the rotorcranks without the weight or complexity. They've been on a few pro bikes this year.
[reply]
by zaskie on 4/03/06

+ 1 digg

whats next, neon colored jerseys, anodized bike parts and sharkfins ... dug for the memories =)
[reply]
by databasecowboy on 4/03/06

+ 2 diggs

Like elliptical chainrings, funny saddles and other hoo-ha that comes out in the bike world, these sort of "innovations" come out every ten or twenty years as something new and revolutionary and have been since the late 1800's.

As other folks have pointed out here, you need to learn how t

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Offset Bike Crank Eliminates Power Vacuum

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