Extended swing arm chain calculator

[Yamada]

Found this on a quad forum. Really easy to use. Did not tried with real world number. Probably works if you are using the stock gearing. I remember a lot a people asking on the forums.

http://www.metaltechproducts.com/Chain_Calculator.htm

[somekidwithanm4]

I'm sure that'll be helpfull for people who want to extend their bigger bore trikes.