To complete this we had a two kid in-step brand bike trailer. This is nothing fancy and costs way less than most brands out there.
List of materials:
Bike trailer (if different might require different pole attachment)
Old skis (found mine at thrift store for $8)
(6) 2" wood screws
(2) locking pins
(1) 1/2" dia x10' electrical conduit
(2) rated load bearing carabiners
(2) scrap pieces of 2x6 about 16" long
(4) 1/4" x 2" carriage bolts and nuts
One coil plumbing pipe strapping
Any backpack with waist strap or heavy duty fanny pack
First cut wood to contour wheels of trailer. Trace wheels and cut using a jig saw. Remove bindings from skis and attach wood block to skis using 2" wood screws from bottom of skis. Make sure to countersink the screws. You can fill in the holes with ski wax or candle wax if you choose. Next deflate the tires a little and place in cradle. Determine where you want the attachment to be and drill (2) 9/16" holes through the wood about and inch down from where the wheel sits. Cut the plumbers strapping long enough to go over the wheel rim and back down to the holes that you just drilled. Attach strapping with 1/4" carriage bolts. Make sure and attach two connection points to each wheel. Use a bike pump to reinflate the tires. SEE NOTES BELOW ON HOW MUCH THE METAL STRAPS SUCK!!!
Note your wheel should be centered over where the ski bindings are supposed to go. This is the thickest part of the ski and there should be some markings indicating where they go.
On to the attachment to the work horse... I mean the loving parent. This bike trailer was made of square tubing about 1" outside measure. This allowed for a 1/2" electrical pipe to fit inside perfectly. I removed the plastic end caps so that I could slide the new harness in.
I cut the pipe in half using a hack saw so each section is 5' long. I measured 5" back on the trailer and started drilling a hole 9/16" diameter all the way through the square tubing. Next I inserted the sharp end of the conduit pipe into the trailer 6" and drilled a hole into the conduit. Connect the two pieces with the locking pin.
Do this for the other side as well.
Use a piece of scrap wood and a hammer to flatten the person end of the conduit pipe. Use 3/8" drill bit to make holes in the flat part and then insert carabiners.
Now you have a completed trailer ready to haul the kiddos around. Just attach the carabiners to either a backpack with waist strap or heavy duty fanny pack. Wait for snow and have fun. I will report back on how well this works dragged behind both snowshoes and cross country skis.
I had the opportunity to try out my contraption. I unfortunately have some bad news. The ski attachment to the bike was a total bust. The ski to wood block attachment remained intact but the ski is we're too long and twisted on the wheels. The metal strapping was too flimsy and twisted and split at the connection points.
On the bright side however the harness contraption worked great!!!! I bent the pipes slightly by standing on them while we were out. This let the trailer be at more of a parallel to the earth. The carabiners attached easily to my backpack waist strap and was easy to pull. I had three kids in the trailer and it was minimal work to pull them all. BTW I was pulling them all on the snow with just the wheels in my snowshoes. I also pulled them on the sidewalk this way. I really want to try it out this summer as well for walks around the neighborhood. We have a lot of hills and it would be nice to not have to push a double stroller to go jogging. There is the update. I will write back again if I try some different configuration with the skiis.