Originally Posted by
twocicle
I would like to hear from some math whizes if it is possible to use a combination of the smaller single bike rings (5 arm, 130mm BCD) and single belts listed in the pdf above, to achieve the same "chainstay" (bottom tube) length as the gear designated for tandems. I am looking for an equivalent setup for a 71.5-72cm bottom tube length. I was unable to use the Gates calculator (
http://www.carbondrivesystems.com/fo...rs.php?lang=us) to find the answer.
Any takers?
Definitely not a math whiz, but I'll take a swing --
Smallest "sprocket" (chainring) I see on the Gates PDF in 5-arm/130 is a 46 tooth. The longest belt is 125 teeth. Since we're using two chainrings and the belt covers half of each, that's 46 teeth that are in contact with the chainrings at any moment. 125-46=79 teeth left to span the distance between the chainrings. Divide by two since the belt is a circle -- 79/2= 39.5 teeth. 39.5 *11mm per tooth = 434.5mm separation between the contact points on the chainrings, which should be equal to the separation between the bottom bracket axles. Convert to inches 434.5/25.4 = ~17.11"
So.... not on any normal tandem.