Repto,

You might want to take a peek at the following links:

http://home.att.net/~thetandemlink/

http://home.att.net/~thetandemlink/Triplets.html

http://www.jacolope.org/familycycling/index.jsp

http://home.att.net/~thetandemlink/hobbes.html

Good luck, and feel free to ask lots more questions.

Get out there, stay out there!

Herhusband