I'm currently reading an article in RC on a SQ4 into PRF frame conversion and whilst I wouldn't dream of such a crazy idea myself (or would I? Should I?) it made me think.
Question is, the frame top tube is usually (I believe) extended for this conversion, which also makes it higher relative to the bottom tubes. If you do this, surely you have to extend the forks, or reduce the ground clearance? Doesn't the steering rake and trail change as well?