What is the best method to get correct chain length for full sus? Is it bottom out the travel and run the chain over the big ring in the front and the big cog in the back plus one link or two links ? One link equals one inner and one outer? Or run the chain around the big in front , big cog in back and through the derailer and then bottom the trave plus one or two? Seen both on the interwebs. Confused as to which is best? Going to a 1X10 setup and want to get it right.

I advise the use of a small cage rear d.

Fully compressed and in the biggest rear cog will tell you the required max length. You have to be spot on. The proof of your work will be revealed in the position of your rear d cage when on the largest cog.

-If the cage is parallel to the chainstay in the largest rear cog your chain length is too short. Add links as necessary. The rear d should look relaxed and not laid out flat. Pay close attention to where the upper pulley cage sits in relation to the cassette. If it is super close to the cassette and you have your chain length proper, adjust the b point screw. This will help fine tune the fit.

I got an SLX long cage clutch derailer I want to install. I plan on getting the Wolftooth 30 up front and get the 42 for the back. So your saying big ,big thru the derailer and get cage at about 4 to 5 o'clock with the upper pully on the cage a few millimeters from the 42 adjusted by the B screw.

There are multiple ways to do it. i dont know if you already checked this, but I find the Park Tools site nearly always has the best instructions:

http://www.parktool.com/blog/repair-help/chain-length-sizing

.. .and, to answer your question, "one link" is the distance between two rivets, whether inner or outer link. If in doubt, cut it long by a link, check again, and cut shorter if necessary.

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Thus, if we are to understand the world, we should live somewhere between judgement and amazement — Alfredo Lopez Austin

Thanks for your help guys. Dan's suggestion to go long and check and adjust is what I'll do. I've seen the info on the web and it can get a little confusing.

Trevor, one of these homemade chain tools will make it easier.

_________________
Thus, if we are to understand the world, we should live somewhere between judgement and amazement — Alfredo Lopez Austin

Thanks Dan, got an old coat hanger ready to go.

Mitch hits the nail on the head, extra emphasis needed on the FULLY COMPRESSED part. Best bet is to detach your shock and compress the suspension fully to make sure you have enough chain when you bottom out.

Yes, but easier to just let almost all the air out, cycle up & down (because fully compressed is not always the tightest point depending on design) and then pump back up (assuming it's not a coil shock).

_________________
Thus, if we are to understand the world, we should live somewhere between judgement and amazement — Alfredo Lopez Austin

ODD is right about variations in pivot geometry...
To paraphrase Shimano technical service instructions: Find the max. distance possible between bottom-bracket centerline and rear axle centerline during suspension travel; With chain around Lg. chain ring and Lg. sprocket at that max. distance, and pulled tight (shortest possible length), add two links.

Don't mean to be redundant redundant...

How about a picture of a proper length chain when a large/large chain ring and cog combo is selected? The last two times I replaced my chain (including tonight) I used the two extra links large/large method to determine chain length. The rear DR is a little more laid out than the original set up, but I have to say that the shifting has been better than before and I'm not dropping my chain, even without a clutch DR.

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A bicycle is a splendid thing.
~Ernest Hemingway

What do you plan on climbing . . . telephone poles? [insert smiley here]

_________________
A bicycle is a splendid thing.
~Ernest Hemingway

There are pictures -- right & wrong examples -- on the Park Tools link given earlier. I agree with you, the first time I used this method I thought the chain would be too tight, and I thought it looked tighter than original, but it worked great. Just to be sure, I'd say go three links, then thread through dérailleur and check it (don't need to fully press the Shimano rivet or seat the SRAM link tight until done checking). Then when you're convinced two is gonna work, take out that third link and cinch it up tight!

_________________
Thus, if we are to understand the world, we should live somewhere between judgement and amazement — Alfredo Lopez Austin

^^^ According to the Park Tools pictures, mine is spot on. Good thing too, since I don't feel like getting greasy again adding a link.

_________________
A bicycle is a splendid thing.
~Ernest Hemingway

Yeah, guilty... I've been using a coil shock for the past few years.