I use Google to search BF, because BF searches don't always give the results I seek. Just include "site:bikeforums.net" in your search terms.

For your search, I would google something like:
[site:bikeforums.net Schwinn Traveler "chain size"], which gives these results:
http://www.google.com/search?hl=en&h...=&oq=&gs_rfai=

(This isn't a "use the f'ing search" reply; just trying to save you a little time next time!).