OK, per the request of a couple of people, here's a list of the components and how it was put together. The goal was to build a bike rack that would hold as many bikes as possible along a single, 16 foot section of our garage using bike hooks that would slide along the length of the wall in order to more efficiently store the bikes.
Parts used to build the overhead, sliding base:
(5) Everbilt 12X8 Heavy duty shelf brackets (rated at 1200 lbs per pair)
(5) #2 EMT/electrical conduit hangers for 1" EMT
(5) 1/4 X 3/4" bolts to bolt conduit hangers to shelf brackets
(20) 1/4" washers (4 per bolt that attaches the conduit hangers to the shelf brackets - 2 on top of bracket/2 under head of the bolt with the bolt inserted from underneath)
(5) 1/4" nuts to attach the conduit hangers to the shelf brackets (1 per assembly)
(10) 1/4 X 2.5" lag bolts (2 per shelf) to attach the shelf brackets to the studs
1" EMT Conduit (only sold in 10' lengths locally - (I had to buy two and cut one of them down to fit)
1" EMT female/female coupling
Parts used to build the sliding bike hooks:
Park Tools THREADED bike hooks
#4 (you could also get away with using a #3) Conduit hanger
(4) 1/4" washers
Steps to put it all together:
Assemble the overhead sliding base by attaching a #2 Conduit hanger to the last hole on the horizontal arm of each of the shelf brackets. I attached them by putting two washers over the bolt, pushing it up through the hole in the conduit hanger, through the hole in the shelf bracket, adding two washers and a 1/4 nut on top.
Locate the studs in the wall, determine where you want to place your shelf brackets, and identify the position of the top screw for each bracket and ensure that they're aligned (I used a laser marker). Once the position of the top hole for each shelf bracket is determined, drill a small pilot hole, position the shelf bracket, and screw the self-drilling screw through the bracket (with a washer between the screw and bracket) and into the stud. Do this for each of the brackets.
Once the brackets have all been installed with their 1st top screw, test fit the 1" EMT through the conduit hangers, measure, remove, and cut to size. In my case, I joined the two lengths of of EMT together with the coupler 1st and then did a test fit, measure, and cut (I wanted to have the coupler as close to one of the shelf brackets/conduit hangers as possible for support. Once cut to fit, slide the EMT back into the conduit hangers and bolt them down tight.
Use the EMT to align the brackets, drill pilot holes for the bottom screws, and screw in the bottom anchor screws.
Assemble the bike hook assemblies by sliding the threaded part of the bike hook through the #4 conduit hanger (I put a nut and two washers on EACH side of the conduit hanger for reinforcement. Tighten everything down. Unbolt the top bolt of the #4 conduit hangers, slide them over the 1" EMT cross bar, and tighten the bolts back up.
Voila! Test fit bikes to the hooks and move them back and forth along the conduit to position them as efficiently as possible. I staggered the bikes (thanks for the suggestion Charles) to make it easier and was able to hang 15 bikes/frames along the 16 foot wall with room for additional wheels, etc.
As mentioned previously, I initially started with a set of less heavy-duty shelf brackets that had the rod holder incorporated into the design. However, I didn't like how soft the metal was and how easily the bracket arms would bend . It just didn't seem solid enough to be hanging 350-400 lbs worth of bikes above a motorcycle and an old 911. Plus I wanted to move the conduit closer to the wall so that the bikes were a bit closer. The heavy duty brackets mentioned above (rated at 1200 lbs per pair) with the conduit hangers seemed to be the answer to those concerns. It also allowed the use of a larger diameter lag bolt for a bit more security. I've attached a couple pics of what the shelf bracket and sliding bike hook assemblies look like for reference. I assume you don't need a picture of the conduit.
My biggest regret is not sitting down and figuring this out before selling off my two MX Leaders to make room in the garage.
I hope this helps!
Texbike