This is part of a compilation of MIY and DIY that came out of my “dusting off” the exercise bikes and looking at them from a renewed commitment standpoint. I had already done most of the modifications to the Airdyne over the last 20 or so years. However, in documenting the saddle replacement, I decided to address all of the modifications. I started out to make this a single Instructable, but broke it up into more manageable segments.

Shelf Assembly

There isn’t anywhere to set anything down on a Schwinn Airdyne AD4. An add-on reading stand exists but it sits high up and doesn’t look particularly accessible.

This is a really old modification originally done to hold my cassette player, then CD player, then MP3 player, and then mini keyboard / MCE remote. It also provides a place to hang heart rate “watches”. It has continued to be useful for a couple of decades now. I decided to write it up as I updated the edge shielding. The adhesive backed felt originally used was looking really ratty.

Step 1: Parts and Tools

Parts

1 ea - 1/2 inch x 12 inch x 24 inch, 14 gauge, expanded metal

3 feet - universal rubber edge trim, 10mm x 14.5mm (1.2 to 5.8 mm opening)

1 ea - 3/4 inch x 1/2 inch PVC Compression x FIPT Irrigation Tee

1ea - 1/4 inch x 20 x 3 inch machine screw

2 ea - 1/4 inch washer

1 ea - 1/4 inch lock nut

4 ea - small cable ties

1 ea - Mighty Bright XtraFlex2 Book Light

Notes:

12 by 24 inches is usually the smallest size of expanded metal available.

I bought an extra foot of edge trim just in case (added less than $2.00).

I went with stainless on the machine screw, washer, and nut.

Tools

Hacksaw or other metal cutting tool (e.g. rotary tool cutoff wheels, metal cutting snips)

Metal file or other grinding tool (e.g. rotary tool stones)

Wood boards

Clamps

Rubber mallet

Utility knife and several extra blades

Electric drill

Step drill bit (unibit) with 1/4 inch step

Adjustable wrench

Screwdriver that matches machine screw head (Phillips or slot)

Cable tie tensioner (optional)

Gloves

Eye protection

Disclaimer

I like this disclaimer from the author Samuel M. Goldwasser (http://www.repairfaq.org/sam/captest.htm) - “We will not be responsible for damage to equipment, your ego, blown parts, county wide power outages, spontaneously generated mini (or larger) black holes, planetary disruptions, or personal injury that may result from the use of this material.”

Add to that the usual admonitions to use safety equipment, be careful of hot, sharp, or rotating parts and equipment, and be cautious around electricity. Also, if you change it, and they can tell, it probably voids your warranty.

Step 2: Cut Metal

1. Mark a piece of expanded metal at 6 inches by 12 inches. A 6 x 12 inches piece works well because you can just cut the end off of the larger piece. You can make a longer shelf, 6 x 15 inches, but not a wider one. Also, you have to adjust the length of the trim pieces to correspond to the change in dimensions

2. Cut the piece, preserving the “welds” so there are no open “eyes”. File off any burrs.

Step 3: Bend

1. Mark the bends at 1-1/2 and 5 inches from one end. Clamp the piece between two boards with the 1-1/2 inch marks parallel to and about 3/16 inches away from one of the boards.

2. Use the mallet to bump fold the metal to 90 degrees. Multiple small bumps are better than a big bash.

3. Clamp the piece between two boards with the 5 inch marks parallel to and about 3/16 inches away from one of the boards.

4. Use the mallet to bump fold the metal to 90 degrees in the opposite direction. Multiple small bumps are better than a big bash.

5. Clamp the boards further back. Put the piece on a flat surface and press down to close the angle to 50 degrees.

Step 4: Hanger

1. Use a step drill (unibit) for drilling thin plastic and metal. It results in a cleaner hole and the bit doesn’t wander. A split tip bit may work but a standard twist bit can wander off center and can result in a ragged hole. The hole in the photo is slightly ragged. It was done before I discovered using step drill bits.

2. Drill 1/4 inch hole centered between the end caps and at the crown of the body (the top of the “T”).

3. I found the crown by stacking magazines and paper beside the “T” until a fine point felt tipped pen jut touched the top of the “T”.

Step 5: Cut Trim

1. The trim has metal “horseshoes” under the rubber. You have to cut between the “horseshoes”, which is challenging. Examine the inside channel of the trim to see the imprint of the “horseshoes”

2. Using the utility knife, cut the lengths. Change the blade frequently because the steel horseshoes dull the blade quickly. You can cut one extra horseshoe long, remove the horseshoe, and cut a clean end. If you do it this way, buy 4 feet of trim.

a. 2 ea – 6-1/8 inches

b. 2 ea– 1-1/ 8inches

c. 2 ea– 5 inches

d. 2 ea– 4-7/8 inches

Step 6: Assemble

Note: A Mighty Bright XtraFlex2 Book Light is used for lighting the display.

1. Slip on the trim pieces and press to fully seat them.

2. Attach the holder

a. Slip the washer over the machine screw.

b. Feed the machine screw through the mesh, the open end of the fitting, and the drilled hole.

c. Slip a washer over the machine screw and thread on nut.

d. Tighten the nut.

3. Attach the shelf to the AirDyne computer supports with cable ties. The bottom cable ties go over the trim and the upper cable ties go inside the trim. Be aware that the supports are closer together at the top. Snug the cable ties with a cable tie tensioner.