I was searching like crazy to increase the scrollspeed in chrome because it only was 4 lines per scroll which caused my finger to hurt like hell. It’s not really a fix merly a workaround. Remember to put Imwheel into your autostart programms.

$ sudo apt-get install imwheel

place the following in ~/.imwheelrc

“^google-chrome$”
None, Up, Button4, 2
None, Down, Button5, 2
“.*”
None,Thumb1,Alt_L|Left
None,Thumb2,Alt_L|Right

The thumb stuff is because otherwise imwheel breaks your thumb buttons.
Then run imwheel from the command line.
$ imwheel

2 is the value in which will be used to multiply your scrollwheel speed