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  1. #1
    Elite Rider Hermes's Avatar
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    Out of Phase Cranks

    Out of phase cranks (“OOP”) versus in phase (“IP”) has been debated previously in this forum, but I thought it may be interesting to start a thread discussing the topic with our recent experience.

    We started riding tandems in San Diego, CA in 1981 and our first tandem was shipped to us with the cranks out of phase at 90 degrees. At the time, both my wife and I were avid road bike cyclists and raced on occasion. We learned to ride OOP (seated and standing) and we did not analyze the pros and cons of IP v OOP. We accepted the configuration as the manufacturer’s recommendation and knew we could change at any time. We road this way for years.

    Upon purchase of our new tandem in August 2006, the cranks were set up IP. Since nearly 99% of the tandems we see on the road are IP, my wife and I decided to try IP to make sure we were not missing anything. We road 660 miles IP. About a month ago, we changed over to OOP 90 degrees. We road our usual course which includes 2000 feet of climbing (per GPS) and our average speed increased about 5% and we increased our climbing rate speeds 10 to 20%. The climbing speed increase is based upon memory going up various hills IP compared to OOP and is subject to error. We have repeated the results on additional rides. We expected the change to feel different but it felt perfectly natural as if we were riding IP. We expected to have to relearn standing – not a problem, it was as easy as it was on our old bike. I know how to position the pedals around corners for max clearance so that is not a problem. And we think that OOP is very stylish especially standing!

    We are back to OOP. We road 42 miles on Saturday with 5100 feet of climbing and we were very pleased with the configuration and results. With respect to standing, I have noted that many believe it is difficult or not desirable to stand OOP. Well, we think it is easy and effective but we may have forgotten how hard it was to learn. I believe that the key to standing is balance and not swaying the bike. For us, we can stand together upon my command. The acceleration and climbing ability is very good standing OOP. However, we generally stay seated and prefer to spin up hills to conserve energy. We stand when we need a butt break and sometimes to chase and catch rabbits.

    Would we go back to IP? Absolutely. If there were a compelling reason or a special situation that favors IP, of course.

  2. #2
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    We ride both IP on the triple and OOP on the tandem. We rode several years IP before we tried OOP after reading zonatandem's comments in this forum. When we first tried OOP it was a bit unnerving but we stick to it on a long ride and after that we were hooked.

    While test ridding a racing tandem a few months back we did find a little odd to ride IP on a tandem at first, but after a few minutes we were fine. We can stand together while climbing OOP, take off after a slow/stop, or catching up with a rider or group; but hard sprinting is not as natural. We are mainly interested in centuries, double centuries and time trials... for those OOP works fine for us.

  3. #3
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    We rode IP for a year or so then went to OOP. You do not specify whether you're OOP 90 degrs advanced from your stoker or 90 ********. We've tried both, and teh stoker can't handle it unless she's 90 degrees ********.

    For her there's no comparing: OOP in this manner is far better. We're not even close when it comes to power output and she has a pretty bad knee. I think the OOP alleviates some of her resultant aches and pains. FOr me, I think we're probably faster IP but we're not racing anymore.

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    On my upright we have IPS but we always gravitate to being IP on the recumbent without IPS we prefer IP we never seemed to generate enough power OOP.

  5. #5
    pan y agua merlinextraligh's Avatar
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    Quote Originally Posted by ElRey
    We rode IP for a year or so then went to OOP. You do not specify whether you're OOP 90 degrs advanced from your stoker or 90 ********. We've tried both, and teh stoker can't handle it unless she's 90 degrees ********.

    For her there's no comparing: OOP in this manner is far better. We're not even close when it comes to power output and she has a pretty bad knee. I think the OOP alleviates some of her resultant aches and pains. FOr me, I think we're probably faster IP but we're not racing anymore.
    My stoker would be pretty po'd if I said she was 90 degrees ********

  6. #6
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    gotta choose yer battles, and battlegrounds. She doesn't read this forum!!!!!!

  7. #7
    Elite Rider Hermes's Avatar
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    Quote Originally Posted by ElRey
    We rode IP for a year or so then went to OOP. You do not specify whether you're OOP 90 degrs advanced from your stoker or 90 ********. We've tried both, and teh stoker can't handle it unless she's 90 degrees ********.
    I have the stoker leading 90 degrees. We are closely matched on our road bikes climbing and she may have more watts per pound at lactate threshold. Mary Ellen was recently tested in the lab at UCLA and produces very little lactate. My hypo is that the toughest part of biking is climbing such that the party with the most watts per pound leads. In reality, I am not sure that it will make any difference for us who leads. I may switch the phasing later to the captain leading.

  8. #8
    Senior Member zonatandem's Avatar
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    We know we cannot convice the whole tandem world into riding OOP . . .
    But it's nice to see folks at least willing to try it!
    Been OOPers for 30+ years now . . .
    Pedal on TWOgether (OOP!)!
    Rudy and Kay/zonatandem

  9. #9
    Senior Member transam's Avatar
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    Count us as another team that rides OOP. We tried it about a year and a half ago and have not returned to IP. We love the increase in average speed (about 5%) and the smoothing out of the hills. Our choice is for the captain to lead by almost 90 degrees (my stoker/wife does read this forum so I'd better not refer to her being 90 degrees ********). We can both stand together to power up hills and cornering is not a problem.
    Just remember, once you're over the hill you begin to pick up speed.

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    As newby's we started OOP right away from our start because in advance, so theoretically, it seemed the best choice to me. What I had expected came out so we even are not going to try for IP. The ONLY setback I discovered, is that, with the absence of any dead point, the front derailleur performance is worse. I resolve this by NOT performing any force/power when I'm changing front gears.

  11. #11
    Senior Member zonatandem's Avatar
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    Hortan:
    It makes shifting easier on a tandem (IP or OOP) if you let up on pedal pressure a tad. In other words, do not be in the 'full stomping mode' climbing a hill and expect a good clean shift on either front or rear derailleur.
    Just our experience/observation.

    Pedl on TWOgether!
    Rudy and Kay/zonatandem

  12. #12
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    We ride our tandem IP - no reason other than that seems to be more popular. I was thinking about IPvsOOP while riding last summer - does anyone think maybe there would be an aerodynamic advantage to using IP. Both sets of legs are drafting each other - rather than doing their own thing out in the breeze. The drafting in general seems to be a major advantage of tandems.

    Tim and Carlina / Schwinn Duosport

  13. #13
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    Quote Originally Posted by timbo157
    We ride our tandem IP - no reason other than that seems to be more popular. I was thinking about IPvsOOP while riding last summer - does anyone think maybe there would be an aerodynamic advantage to using IP. Both sets of legs are drafting each other - rather than doing their own thing out in the breeze. The drafting in general seems to be a major advantage of tandems.

    Tim and Carlina / Schwinn Duosport
    Never thought about that. It would have an impact for sure...

  14. #14
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    clean shifting while going uphill is more a reflection on your gear than anything else. With DuraAce (used SHimano as an example) there's hardly any troubles, even off the saddle. With the leser grupos that cannot be said.

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