Cooking Ribs on top and bottom grates in WSM??? Have to rotate?

Hey Nick, I have a 18.5 as well and have smoked quite a few multi racks. I run with a full water pan so it may be different if you run dry. I will rotate as a matter of operational ease but I've never noticed any real difference. It's just faster to foil the top rack slabs and then throw them on the bottom rack when I pull those slabs. If that makes sense. With baby backs, most people seem to do 2,2,1. Currently, I'm partial to 4,1, Sear for spares so I guess I would adapt that to 3,1,Sear for backs. Rib racks could alter this a little so if you want to smoke more than 3-4 slabs you might have to play with it a little. Of course, dialing in Your perfect rib is half the fun and definitely what drives me. Happy hunting!
Lance

I have a WSM 22 and i have done spares on top and bottom same time no problem. i run with the water pan covered in foil and find the air pocket makes a nice heat shield for the whole smoker. My ribs come out juicy and tender using 3-2-1 or a modified version. I do not rotate the ribs but if you did i don't think it would hurt them any might cook little more even. if i am doing a lot of ribs i have a rib/roast rack that you can put 4 racks of ribs on and they cook good on the bottom or top rack either way.

here is the rack


the rack is in roast mode with a foil pan underneath but you get the idea

its made by weber and its about $25 on amazon


 Here are some ribs after the foil with some sauce you can see i have ribs foiled underneath i leave them foil  a little longer because the lower rack runs a touch cooler.

Experiment and get to know your smoker and how you like to make your food. have fun with it enjoy!

Happy Smoking,
phatbac(Aaron)

I run ribs on both racks no problem on my 22.5" WSM, for big parties I even have rib racks for both top and bottom and have had up to 12 racks going a one time. Only drawback is the ribs at the end of the rib racks can git a tad crisped on the ends because the heat is coming up the sides of the smoker, but other than that it works fine. I personally run around 250° and leave the ribs unfoiled for the entire cook. Then right at the end I sauce them and toss them onto my Weber Kettle to caramelize the sauce a bit - plus it puts a nice crust on the ribs.

For the 18" WSM you may have to cut your racks in half to fit them on the rib rack and still have them fit in the smoker. But I have seen a shot or two where folks kind of wove them in the rack to get them to fit: