The big advantage of toe straps is they offer a positive engagement on the pedals. Occasionally the foot slips out; after awhile there might be a loss of circulation from the tight strap, and possibly a rash on the top of the foot from constant rubbing. Nevertheless, for many, the benefits outweigh the alternative of going strapless.
I started working on heel straps for someone with edema who had trouble holding his feet on the pedals and ended up liking them so much I switched over to them exclusively about 18 months ago. Very relaxing, stress free on the knees and quite efficient, I even use them for racing.
There are many ways to make successful straps. Here are some, for example using plastic, string, nylon webbing and fin straps:
After trying all these, I eventually settled on sheet neoprene -- it flexes with the foot, can be cut to any length, holds its position on the heel, is quickly adjustable for length, is durable and has good strength. It is commonly available through gasket suppliers.
This next picture shows the material, preferable tools and slot jig,General notes:
1. The material is cut on a bias to accommodate the length of the strap. I use 20" finished length for up to size 11 (US) shoe.
2. Slot intervals are 1.5" on the inboard side and 1" on the outboard side. The more slots, the more adjustable the strap.
3. These straps are cut 1.5" wide, trimmed down to 1 1/8" width plus 3/8" for the heel cup. As an alternative, the straps can be cut straight without heel cups.
4. Get enough material to practice on, make mistakes on and make an extra pair or two. I used 1/8" sheet neoprene.Procedure:
1. Lay-out the desired length and width using a white (pencil or comparable).
2. Cut the gross strap size with a straight edge and box knife.
3. Trim to create heel cup (optional).
4. Round off corners with round chisel and mallet (optional)
5. Make jig for slots as shown above using Hobie toe strap for slot template, centered on strap and angled at about 20 degrees.
5. Use a leather punch to create appropriate size hole at each end of slot; use box knife to remove remaining material. Trial fit each slot on pedal tab; adjust as necessary.
Here's what the straps look like finished:
This is a close-up showing fitment on the inboard pedal tab:
Note that the angle on the slot allows it to: 1) to clear the pedal shaft and 2) allow the heel to drop straight in without slipping off (like the raised back of a sandal). Note also, the pedal now hangs correctly without the need for counterbalancing weights or bungees.
Here they are in use:
Heel straps are a great alternative to the factory toe straps for many users. Note, heel and toe straps should not be used together, as they can trap the foot in case of capsize.