This was requested back in the forums at simsasylum.com. Intrigued, I found the iTUN and modified the fun increase for using a hover board. The "clumsy fail" is the additional chance that a sim will fail to use the hoverboard if they have the clumsy trait. From what I can tell, the mod works as it should but please report anything to me if you have problems.
The default fun value is 2. I have a more fun package here (Increases the value to 10) that doesn't mess with the default clumsy failure chance.
Double fun increases the fun value to 20.
I have hover board fun, less clumsy (Hoverboard fun value: 10 and Clumsy value is 5%) and double the fun (Increases value to 20) with regular clumsy chance (Regular clumsy chance is 15%). And a package for Hoverboard double fun (20%) and less Clumsy 5%. Lastly, there's a package for double fun increase and no clumsy chance (0%)
If you want to request a flavor, please do so in the comments.