Fork rebounds ok. Not sure about a "leak". There is oil left on the fork after riding but haven’t really noticed any leak. Not sure it is supposed to have oil or lubricant visible on fork after riding. None of my previous Treks have shown this. Preload is definitely a bust. If it works, I can’t tell. Fork claims 100mm of travel but seriously doubt it gets that. Not sure I necessarily need true 100mm of travel but that is what the fork claims to get. Everything I have read and compared it to points to fact that fork is pretty much a bust, but I’m thinking just ride it ’til it quits then look at a better one.