Lawrence08648

Cannondale 2010 Road Tandem 3 with Tiagra shifters and 200 miles on it. Something is making an irregular taping or banging noise when pedaling. It seems it's making more of a noise when pressing hard on the pedals, it's almost as if the frame is flexing and something then is making noise. It's coming from the drivetrain and I don't think it's coming from the Captain's bb. I haven't ridden it as a stoker and the person I ride with may not be capable of determining the location of the noise. Any suggestions?

TandemGeek

The very same EBB that you've posted about in your other two threads probably needs to be tightened.

bikeriderdave

Sounds like a symptom I once experienced on a new tandem. Is the stoker BB sufficiently tight in the frame?

ReedCycle

I had a problem with a clunking noise in the drivetrain of my Calfee tandem after 1,000 miles. It has the Tandems East modified Cannondale bottom bracket, DaVinci cranks and a titanium cartridge bottom bracket. The noise was only when pedaling, and it wasn’t clear if it was from the captain or stoker. It turned out that the adjustable retaining ring on the captain’s bottom bracket has worked its way a little loose. I tightened it up and the noise is gone. The last 200 miles have been noise free.

I was helped in diagnosing this problem by Sheldon Brown’s web site: https://www.sheldonbrown.com/creaks.html. It suggested, under Bottom Bracket Cups/Retaining Rings Loose?: “Turn the cranks so that the left crank is alongside the seat tube, wrap both hands around the crank and seat tube and squeeze the crank hard toward the seat tube. Then turn the cranks so that the right crank is alongside the seat tube and repeat this. Listen for a creak/click.” I did this on the captain’s crank and got the clunk that I had been hearing while pedaling.