Saturday, January 17, 2009

Cold Weather and Adhesives: A tale in 3 chapters

Chapter 1: Late last fall when it was quite cold, I had an "interesting" experience. My helmet (a Giro Atlas) delaminated—the shell peeled right away from the foam core of the thing. Strangely and excitingly, it happened while I was riding. I made a quick decision to not stop (it was cold, after all) and try and recover the shell on my morning ride to work, which I did.

I wrote the customer service wing of Giro and they kindly sent me replacement tape (adhesive tape around the perimeter is what holds the standard vacuum-plastic-foam helmet together) with instructions on how to repair it.

I was surprised (stunned, really) about how the thing just let go all at once. Clearly (it seemed to me at the time) this was a temperature-related occurence. I'm now using (for extreme cold weather riding) a Bern helmet using their "Zip-mold" technology, quite a different thing from the vacuum-plastic-foam approach.

Chapter 2: Cycling in to work about 6 weeks ago, when I was about a mile from the office, I experienced a sudden flat. Since I was so close, I just got off and walked the bike in. When I got the tube out of the tire, I was surprised to find that the cause of the flat was a Slime Skab peel-and-stick patch that had just let go. I immediately thought of my helmet and began to wonder about how cold weather affects adhesives. (I also began a more philosophical rumination about how our lives depend on adhesives, but that's for a different time.)

When I was fixing the tire that day, I was concerned about the "wrinkly" appearance of the Skabs (I had several on this particular tube). I compared them to the appearance of a Park peel-and-stick that I also had on this tube. (This is, admittedly, a rather "road-weary" tube.) The Park patch was more rigid, but perfectly flat, while the Skabs were thin and pliable, but all wrinkled.

Chapter 3: Earlier this week, a second Skab developed a leak. I replaced it, but I must say the cold weather reliability (or lack thereof) of the Skabs has me concerned. At the moment, I would not recommend the use of Skabs if you're going to be cycling in significantly cold (below freezing) weather. Reliability of your cycling system needs to be high in extreme weather conditions. I'm not calling it a matter of life and death, but a flat at the wrong time (for no good reason) can be a matter of significant discomfort.

Epilogue: If you're going to be cycling in cold weather and you use peel-and-stick tire repair, go with Parks.

1 comment:

Joe D said...

That happened to my helmet the other day. We don't get the really cold weather here, and the helmet is four or five years old, so I figured it was just fatigue, and glued it back on.

Then the other day, I saw this on Instructables: All-Weather Bike Helmet. How to convert a regular helmet into something that's wearable and warm on cold and wet days.