If you have the money - CK If not, Profile From my experiance with front freewheels, they work well (I had an ACS) surprisingly enough, it didn't come loose for me (loose when I got bike back), and skipped a few times, but nothing major. Only bad thing is, is that they're always hungry and love eating jeans, work trousers, school trousers etc. Just got my profile on today, and it is looovvvvveeeeellllllyyyy. It's second hand, so it's already bedded in. But from brand new they do skip, but once they've made themselves at home, they're fine But if you go for a frontfreewheel, go for the Trials ENO. 72ep reverse thread lockring ACS's are ok, as long as you coat it in WD40 etc, and locktite the lockring It's your choice.