Grappling Hooks and Spiderman weapons not working properly

[ThatDesire]

Alright, so, I am using this swep [url]http://steamcommunity.com/sharedfiles/filedetails/?id=355431607[/url] , now, it works fine in sandbox, but when I add it to darkrp it barely lifts me off the ground. After trying it on darkrp, it doesn't work in sandbox unless I restart my gmod. There are no errors in console. I can't understand what is wrong with this.. is it an option in darkrp?