Originally Posted by
TandemGeek
I Our timing rings cost about $85 per set and because the rings use only 34t, if they get overly worn it becomes problematic to install a new chain. You can rotate them four times to extend their life 4x if they wear a bit too much; however, I'd prefer to not replace them at all vs. replacing a $30 sync chain about once every 5,000 miles. I also tend to dump my drive chain a bit early to help preserve my cassettes and chain rings.
I do the same, though I have not gotten as much as 5,000 miles on the timing chain, I got half of that last time. Maybe a lesser chain, probably not as careful chain maintenace.
Argument could be made that if you keep the same chain three times longer, $ 90 of chain is more than $85 of chain rings. On the drive chain you will start seeing performance problems with the chain worn beyond 1/8" so the economics are different. In any case I know we are not riding tandems for economics.