Thinking about going 1x9 on my yeti and would need a chain guide. I'd probably switch out my 22/34/bash for a single ring, something like a 26/bash. After looking at guides briefly online, seems some use pullies/rollers at both the top and bottom of the chain ring, some only on the bottom, some run the chain through a "channel" (similar to a derailleur) to hold/guide the chain... Pros and cons to them all? Reliability? Ease of setup? Is chain drag ever an issue?