Captain's pedals
 

It's my understanding (meaning I haven't removed them yet to verify) that both of the captain's pedals have left handed threads. If so, is there a source for pairs of pedals that have left handed threads? I want to put SPD's on my tandem but the idea of buying two pair and using just one pedal from each pair seems so wasteful.

If the captain's crank is tandem-captain-specific, as it should have come from the factory, or been built up correctly, then the pedal threads on the crankarms, and the pedals, will be "normal". If the captain's crank is a flip-flopped single bike crank, then the pedal threads on both crankarms will be reversed from what they should be. And, loctite and diligence will be required. This is assuming that the synchornizer chain is on the left side.

As noted already, it shouldn't be as most contemporary tandems use cross-over tandem cranksets.

What year/make/model of tandem do you have and/or what make/model of cranks are on your tandem?

If the peddals are on the bike see if you can find any labels on either the crank or the peddals to see which way the thread is going before you put a wrench to them, crank arms are usually marked L or R. I have mangled a thread on a crank arm by insisting on going the wrong way.

Thanks for all the replies.

The bike is a late 90's Univega mountain tandem. It's pretty low end but for the price (<100) it was hard to pass up. It only needed a stoker bar and saddle. It does have a left-side timing chain and it doesn't have any brand markings on any of the cranks. I'll have to look at the pedals closer and see if they have any thread markings. Now I'm getting excited. If they ARE standard threads, or even if they've just been flipped, I've got a pair of pedals ready to pop on.

You might look for a tiny L or R on the pedal. You might also look for marks on the crankarms that say "Tandem" or something similar. Another sure bet is that all the crank arms and chainrings will look like they come from the same molding.

Anyway, I'm 90% sure that they are low end maybe, but still the typical tandem crankset you have on modern tandems. Therefore each rider has a right pedal that is threaded the normal way and a left pedal which is left-threaded.

In other words, you'll need ONE set of (normal) pedals.

Sorry if this is obvious, but grab any set of pedals (maybe off of a different bike, or out of your parts bin) and see how they go on. This should make the situation clear.

As mentioned tandem cranks are reverse threaded (that is to say that if they were mounted with the chainring on the right, they would be reverse). When mounted on a tandem with the chainring on the left, everything is normal. You can you use any set of pedals and put them on the same way you would put them on anything.

I'm fairly confident that they used a tandem-specific cross-over crankset on those particular tandems.

I finally had the chance to go out and look. After scraping at the rust on the ends of the pedals I was rewarded with one R and one L. So this is good news. Interesting that everyone here was so confident there would be one left and one right. Got to see if I can find where I read that about them having two lefts....

Oh yeah, on the Blayleys site, http://www.blayleys.com/articles/tandem/index.htm

Well I'm glad they were wrong and you all were right. Thanks.