Eccentric chain adjuster vs DIY idler
 

Been considering giving a frankenstein tandem a go for touring. Might change my mind the more i actually learn about it.

Most modern/decent tandems seem to be fitted with eccentric chain adjusters right?? Would it be easy to fit one of those on some random cut down MTB frame. Grub srews etc? What sort of cost do most go for?

I've seen that alot of DIY back yard built tandems use a basic idler pulley to tighten the chain. How do they compare to the eccentric hub type? Any issues for long tours?

Cheers

I have built some tandem frames and can tell you a few inherently difficult issues you will be faced with: 1) the position of an essentric is a really exact calculation. You should have it positioned to where the bottom bracket is exactly aligned with the seat tube when finished. You have to allow for what size timing chainrings are to be used, it can be pretty tricky to get it right. 2) The essentric cannot be crocked or the chain will keep falling off. The problem with idler wheels is that they tend to be really noisy.

Honest chances of putting together used frames into a tandem, and it turning out right in my opinion is extremely small. there are other considerations like: frame alignment and crank height and the angles. Should be noted that most forks are not rated for tandem use.