Very cool, but a sachs dual drive does not alloy you to run a thicker chain. You can run a 3x8 with the same width chain (24 speeds). 1.5cm is a lot to spread that frame. My opinion is to not do that.
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1 Super Record bike, 1 Nuovo Record bike, 1 Pista, 1 Road, 1 Cyclocross/Allrounder, 1 MTB, 1 Touring, 1 Fixed gear