Tandem Cycling - sync chain tension help

Can someone tell me the proper tension for the sync chain, I bought a new tandem today and it seems very tight to me no play. Is this correct adjustment or should I back off the eccentric a little.
The rear axle was very tight also and when freewheeling the cassette would want to turn, so I took it all apart lubed everything and made a little adjustment on the axle now its fine but the sync chain seems way to tight to me.

The sync chain should have about 1/2" to 3/4" of play (or about 1/4" to 3/8" of sag). Under no circumstances should a sync chain be so tight that it's binding. It's also worthwhile to note that a new tandem's sync chain (or a new sync chain made up from new chains) will loosen up quite a bit on the first several rides as the OEM grease is squeezed out of the rollers and pins. Keep an eye on the chain for when a slight adjustment is needed.

You can find several articles on sync chains in the archives linked from this post that will be helpful as you work on your tandem's crossover crankset:
http://www.bikeforums.net/showpost.php?p=3896976&postcount=7

Thanks for the quick reply so would you recommend me giving it the 1/2 play now before I take it for a serious ride its really tight 0 play! now.

Thanks for the quick reply so would you recommend me giving it the 1/2 play now before I take it for a serious ride its really tight 0 play! now.

If the cranks rotate freely, but the chain is a bit tight, you should be OK as is. If, on the other hand, it feels "notchy" as you turn the cranks I'd go ahead a loosen the eccentric, back it off a degree or two, and cinch it back up for the first ride. Be sure to check it when you get home.

FWIW, I run my sync chains on both road and off-road tandems with enough slack (3/4") to allow me to derail the chain by hand, if needed. Then again, we're not churning out 1000's of watts of sprinting power so no worries about throwing a chain during a massive effort.

Thanks its not notchy filling so I will leave it for now thanks.
I tend to go tru my bikes before each ride checking everything so I will be keeping a close eye on things.
A question when you run allot of slack what better Out of Phase or In-Phase cranks? Just curious as to the effect is of having a lot of slack in the sync chain.

I think there may have been some cut and paste errors in your last post. However, I'll take a wag at the actual question: it doesn't matter. The key is not having so much slack that the chain can swing far enough off-center from the rear timing ring to either be caught by the end of the stoker's crank arm or unintentionally derailled at the stoker's rear timing ring: either one of these are what are referred to as a "bad thing".

Bear in mind, in addition to the slack that you intentionally leave in the static sync chain, once it's under load that amount of slack will increase quite a bit for a variety of reasons. Most of it has to do with the top run of the chain being held in suspension while the lower run is completely slack and it's that combined amount of slack (or slop) that determines just how far from side-to-side the chain will swing as you ride, noting that when many teams sprint or climb out of the saddle they tend to throw the bike from left to right under their bodies. The more the bike moves left to right, the more the chain swings. Now, back to your question about in-phase vs. out-of-phase, a team who rides OOP will be far less likely to be bike throwers so, in that regard, having a lot of chain slop may pose less of a risk of a crank catch or being derailled vs. a IP team that throws their bike around. Oh yeah, having a lot of slop in the chain can also bite you if you encounter a bumpy road as the rumbles, etc... can cause the lower run of the chain to "jump" and that too can put it off center.

By the way, if you want to get a sense of just how much slop collects along the bottom run of a sync chain, next time you're riding with another tandem team check out what their sync chain looks like while the bike is propped before the ride and then check it out while they're riding. Actually, if you ride alone you can check your own chain on a bright sunny morning or in the late afternoon by looking at the shadow your tandem casts along side your bike as you ride. Note: don't look too long as that could lead to another one of those "bad things".

Hay thanks for the detailed answer it helps allot!
I will see what works best for us.

Thanks Again and I'll see what the chain looks like tomorrow after my ride if weather permits.

While tandem is on the repair stand, run the pedals s-l-o-w-l-y backward. Chainrings are not perfectly round and you'll see that at times sync chain looks tighter/looser. Set you eccentric accordingly . . . have only snapped/broken 2 cross over chains in 32+ years of tandeming. No fun having the stoker pedal you 'home alone'! It pays to carry chaintool, snaplink or extra links 'just in case.'

Thanks for the response zonatandem
It's tight all the way around I did 50 mi loop today and its still about the same really snug, I may back off the eccentric just a bit to relieve some of the tension and keep a close eye on it.