Has anyone seen or tried these before? http://www.gnarlyparts.ca/product_in...ducts_id=12106

They seem like a good idea to see what height suits the individual best however, I'm not sure how they'd work in the real world. Would there be much movement/fretting between the spacers if you used the maximum height/number of spacers. Also would they be legal in the uk for road use?

Any thoughts??
Gory