# Talk To Me About Timing Chains and Cranks



## mtnbikej (Sep 6, 2001)

New to this whole tandem deal.

Our tandem currently has 34t Surly Steel rings on the timing side. What effect will it have to drop to say 32t?


Next question is on cranks.....

We have Middleburn R7? ISIS cranks all around. We have 4 x 104 BCD on the timing side, 5 x 94 on the drive side. We are gonna go 1x. Now it is easier to find 104 NW rings, and the timing chains should last longer. Surly 34t 5 arm rings are still available. So theoretically I could just swap the spiders from one side to the other?

I know I could just get a new spider, but the only place selling them is from over the pond, and I don't wanna deal with possibly getting the wrong one.


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## mactweek (Oct 3, 2011)

Why change the Surly rings? they should last forever! Middleburn cranks have direct mount chainrings available, so you won't need to use any spider on either side. The company was sold last year and some products may not be very available yet. I would talk to Alex at mtbtandems.com. He is a dealer for Middleburn and would know what is available, and what will work on your set-up without having any trial and error.


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## Jbull (Jan 17, 2017)

I will take a stab at the first question. The timing chainrings need to be the same size in orser to maintain synchronized pedaling so dropping 2 teeth from 34 to 32 should gain you... maybe a 1/16" ground clearance but not much else will be noted. Second question needs to be answered by someone more knowledgeable than i. 


Sent from my iPhone using Tapatalk


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## Okayfine (Sep 7, 2010)

Spiders should swap side-to-side. You don't state which side of the pond you're on, but in the US Alex at mtbtandems.com distributes Middleburn stuff.

32 to 34T sync rings just makes the seller a little richer and your wallet a little ligther. Perhaps a bit more wear to the sync chain, but not much benefit. I guess it's a little lighter, too:thumbsup:


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## Anthem1 (Feb 9, 2008)

I built our Fandango up 1x10 on the cheap, bought 2 close out deore triples, installed 36T rings in the outer position and a 32T narrow wide in the middle.
Just food for thought.


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