The Straight-Through Block

- Kevin Raymond

You might think that when derailleur gears became popular, cyclists would have worked out the highest and lowest sprockets they needed, fitted them at the extremes, and then filled in the gaps with evenly spaced intermediate gears.

It didn’t work out that way.

Partly that was because early systems only had three gears — riders in hilly areas would have ended up with huge gaps between those three gears — and partly because early derailleur systems couldn’t cope with that sort of range anyway.