I have two questions,
1. How often does fork oil need to be changed?
2. I took the front derailer off and am currently running a truvativ boxguide on my 06 norco six. Would it be beneficial to have a regular non ramped chainring instead of the current ramped one that's on there now? I've been told that it would help to keep the chain on more so then a ramped ring due to the different "tooth profiles". Been looking at these http://www.blackspire.com/qs/product/83/5948/263228/0/0[
](http://www.blackspire.com/qs/product/83/5948/263228/0/0)
Current pic of my setup:
Question #1- Each fork manufacturer has a recommended fork maintanence schedule. Marzocchi for example recommends an oil change every 50 hours for intense use and 100 hour under normal use.
Question #2- Due to the fact you aren't using a top guide on your box guide it would be advisable to put on your front derailleur and lock the set screws to hold the chain from falling in. The bottom pulley on your guide will tension the chain but doesn't stop it from falling off the top. A non ramped chain ring may work better with the top piece of the chainguide because it would give you more clearance to center the chainring in the top guide. However if you are going to use your front derailleur as a top guide then your ramped ring isn't an issue.