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.