Got my new Avon AV45 front put on today. Bike feels new again! My Z4 was cupped and worn a bit off center. This was causing the handlebars to shimmy when cornering and when coming to a stop I could actually see/feel the bars shimmy left/right. Felt like I had to muscle the bike in the twisties. Now it's smooth as butter and falls right into the corners without having to force it.