cartographe

I'm just posting the final update on this issue since it has been, oh, almost ten years.

It turned out that the noise was in fact caused by the Arai drum brake - I ended removing it entirely. It seemed improbable to me at the time, despite the good advice of the last few posters since the noise didn't really sound like the brake and seemed related more to pedaling than not. But in the end, I suspect that the problem was almost identical to what thebulls described above, which explained why it would be connected to pedaling. After removing the brake, it has been quiet bliss...

Thanks everyone for the advice! Gratefully our marriage is still going strong and now we have 3 kids and I'm in the market for kids tandems

Cyclist0108

That's great news. Congratulations. Be sure to drop in again when you are trying to figure out which grad schools the kids should be applying to.

ksryder

Dang that is impressive. 7 posts total. Five of them in this thread. Followed up 8 years later with an update.

I'm not even being snarky. That is impressive. Chapeau.

loopless

The symptoms you have indicated are similar to what I was facing. the sound was non metallic in nature, somewhat sounding like rubber rubbing against each other and pretty high pitch at times. it comes after 15 mins of riding and especially so when going uphill. Very recently it had started to sound out even through normal riding. note though, sound goes off the moment i stop turning the cranks.

sent it in and turns out it was the rear wheel hub. It had gone dry internally and had to have some oil and grease applied. that was done and the bike is now silent.