fooferdoggie 

it is like working on two bikes t once. I knew what I needed as far as setup but my wife is blind and has not ridden a bike in 40 years that was real fun. but playing with gearing so we can climb steep hills (even a e tandem is work climbing. getting around that our cranks are not locked together I put cadence sensors on both cranks and found she is peddling 10 rpms faster then me (thats why we were spinning out at 22mph or so. so I ask how to change it and get the right chainring for the back and put it on and add some chain links (I found the chain is a 9 speed Shimano chain not the 8 speed I expected) but I had a couple Quicklinks to only find the chain is too loose. I was thinking I needed a pin so I could take one link off. so I get it today and nope wont work. I had noticed the bottom bracket looks like it would rotate and I see the bolts on the bottom and check YouTube and yep it rotates. when I changed the back changing to a smaller one I ran into the problem of the chains touching. They sued a combo of ramped chain ring on the outside and straight on the inside but I could only find a ramped inside so I had to get washers. but I think thats why they used a 9 speed chain to help get clearance too.
we did a short test ride before dinner to make sure it works before we we go out tonight and it seems good. got to get a 6mm Allen wrench to take with us to loosen that chain if needed. I may be able to get the quick link off but it is a close thing and needs the tool to do it.

JanMM

Yes, tandem stuff can be more complicated. Removing a quick link is usually much easier with a tool. For me, anyway. A free tool that can help the removal and reattachment process be easier is a piece of hanger wire (or similar) a few inches long with both ends bent down at right angles. That can be used to hook the chain in front of and behind the quick link to take tension off that section.
No, there is no quick link in the pic. ........yes, it is in the picture at the right end of wire tool! Quick link should be in middle of the relaxed section to remove/install.

bobh123

Even easier (no extra tool needed), but messier – Rotate the pedals until the quick link is on the bottom side of the chain loop and the chain is on the small chainring. With the left hand push the rear derailleur forward to release chain tension and with the right hand remove the chain from the small chainring and let the chain lay loosely on the bottom bracket shell. The rear derailleur can be released. The chain is now fully untensioned and the quick link can be removed easily with a tool. Reverse the process to get the chain back on the small chainring after reinstalling the quick link. Not necessarily a better way, just a different way.

fooferdoggie 

talking about the timing chain (I think thats what its called) not much slack at all.

JanMM

Ah....the timing chain or sync chain. Should have just a little bit of sag.
Our recumbent tandem has an idler setup for the timing chain - instead of an eccentric - that is very quick and easy to adjust for loose or snug.

Darth Lefty 

It's a few new things but fortunately it all makes sense once you figure it out.

The last time I needed a timing ring I found it from Origin8, it was a combination 130/110 BCD. Some tandem people now like using narrow-wide rings for their timing chains if you can find one in the right BCD and care to pay it.