StephenRC45 wrote:The gear box ratio's were altered to over come the '28 lack of zip wasn't it?

That's the story.
A '28 has got a more spread out gearbox and a lower final drive, they could have achieved almost identical results by just running 15/43 gearing and retaining the entire mc21 box.

If you run a '28 box, to get as near as possible to '21 top speed gearing you want to run 15/41.
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