1. Lowering the bike (especially two inches) will greatly reduce your cornering clearance. If you are only going for the cafe racer "look", and not the actual function of a racer (getting there faster), it won't really matter.
2. Brace yourself to start buying driveline parts. The u-joint is a simple joint, meaning that when it is not directly inline (because the suspension has been lowered), the output of the u-joint (the shaft between the engine and rear wheel) will change rotational speed twice for every revolution. The more you increase the offset angle, the more the speed changes. That will wreak havoc on the final drive system and wear out parts long before their normal life expectancy.
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