I have feet which are wider than average, and like most wide-foot sufferers, I have learned to live with it. When buying footwear, I get it a size or two larger than normal, and just ignore the huge gap between the tips of my toes and the tips of the shoes. With sandals, however, having a huge gap like this should not be necessary, since the velcro straps will allow you to adjust the sandal to fit any size foot, right?
Unfortunately not. The velcro straps on these sandals are typically set for an average foot, and the stingy shoe companies don't give you enough velcro on the straps to deal with a wide foot (and this example is a nice pair of Tevas, supposedly made for wide widths!). This means that, for a wide foot, there are hardly enough velcro hooks on the sandal strap to stick to the velcro loops, which means that the sandal straps can become undone at the slightest provocation, and any kind of fun activity is always interrupted as you stop to "tie your shoes."
I have found an easy way to increase the velcro strap length on your sandals, though - no sewing, gluing, or anything else required.
Step 1: You Will Need -
Home Depot (and probably Amazon.com and others) carry a product called Velcro Brand One-Wrap. Velcro usually comes in a kit with two strips, one with hooks and one with loops. However, One-Wrap comes as a single strip, with hooks on one side and loops on the other, so that you can wrap this strip around things and the strip will stick to itself.
Because it combines both hooks and loops in one product, you can attach the loops on the One-Wrap to the velcro hooks on one of the sandal straps, and then attach the One-Wrap hooks to the velcro loops on the other side of the sandal strap, effectively extending the length of the velcro strap but still keeping its strength.
Unfortunately, they sell One-Wrap in 12-foot lengths, and you will need less than a foot of it to fix your sandals. The roll is usually less than $10 US, but you can use the remainder for all sorts of interesting things (I use it on my backpack straps to hold the straps closer together across my chest). So, fixing the sandals with One-Wrap is not exactly cheap-and-cheerful, especially if the sandals cost less than $20 US to start with, but not exactly a fortune either.
You will also need a good pair of scissors to cut the One-Wrap.
Step 2: Cut the One-Wrap to Fit
Your mileage will vary as to how you attach the One-Wrap to fit your sandals. My Tevas needed to have the toe strap and the ankle strap extended, but other sandals I have worn needed a heel strap extension while the toes were OK, and so forth.
For each strap extension you need, adjust the strap to a comfortable fit, and then note the length of the velcro hooks that are not engaged on one end, and the length of the loops that are not engaged on the other end. The One-Wrap strap extension should be just about as long as these two lengths combined, so that all of the velcro of the sandal is engaged. On mine, however, some of the velcro was looped through the buckles, so I had to extend the strap after that point.
For my Teva sandals, the toe straps needed about a 4-inch extension, and the ankle straps needed about 7 inches added. That may sound like a lot, but the Tevas were probably designed to stay on with a lot less velcro engaged, so I am over-engineering this, but so be it.
Use a good pair of scissors to cut off the lengths of One-Wrap from the reel - it's pretty thick stuff.
Step 3: Install the Strap Extensions to the Sandals
Now, undo the sandal straps completely, and attach the strips of One-Wrap to the sandal straps, so that all (or most) of the velcro on the straps is engaged. Pinch it nice and tight.
Then, wrap the extended straps back over your feet, engaging the One-Wrap with the velcro on the other sandal strap. All (or most) of this velcro should be engaged.
The sandals should now be far less likely to undo themselves.
Step 4: Success!
As the sandals now have a lot more velcro strength in the straps, they will be a lot more effective for you, so go out and start that triathlon you've been putting off.
Incidentally, if One-Wrap's basic black color scheme is not to your liking, they make a product for wrapping up cables and stuff that comes in a rainbow of colors. Again, not too cheap, and you should experiment to make sure the velcro hooks and loops of the One-Wrap will attach properly to the velcro of the sandals, but it looks as though it should work.