Topic: Avoid Cold Patch

[Bob Wessner]

I was last out on the bike late last week. Coming home along my favorite road which follows the river, which has some pretty crappy pavement at the near-town end, they were doing some cold patching. I usually try to steer around fresh patches on general principles, but in this instance, the patching was so widespread there was no avoiding it. Myself and a pick-up ahead of me had to stop for a flagman where they were working. We were finally allowed to pass the work area and from there it is just a few minutes to home.

Parked the bike and didn't get out to the garage again until yesterday. I happened to look down at the front tire only to find it thoroughly covered and encrusted with small stones. I immediately recalled the cold patch encounter. What surprised me was how well adhered these were to the tread surface. I can't even describe the amount of effort it took to get them off. They must have been using super glue as a binder.  Given just how much of the tread was covered, I have to believe this would have been a serious problem had this occurred heading out to start a ride. If you are ever confronted with fresh patching, and you can't avoid it, I would pullover asap and check your tires.

[CB750F2]

G/Day Bob. I don't understand the term "cold patching". Is this the process where they repair cracks in the bitumin by filling them with tar? You mention the front tyre but not the rear. Just a comment. Pat

[Bob Wessner]

Pat,

The cold patch used here is generally for pot holes of some magnitude (unfortunately Michigan has many). In my opinion, just a stop-gap measure. They shovel it in off a truck and let traffic tamp it down. It just seemed to me that the binder used to hold the aggregate together has been changed, (maybe to make it hold up better?) use to be just tar-like substance and it easily wore off the tires. This isn't much of a problem on car tires, but when you only have two wheels under you.. different story. I wondered about the difference between front and rear tire also, and my best guess is, that whatever the binder is, it is picked-up by the front tire and the rear, following the same path more or less, picks up little since it all got on the front. Just a guess though.

[Hyseman]

Bob, thanks for the info. I live here on Ohio and we have a great deal of cold patch as well. I will keep it in mind.

[csendker]

Cold patch is a special mix of ashpalt that cures when it is exposed to air.  It doesn't require heating prior to install like the usual stuff.  This makes it real handy to buy a bag and fix your driveway, or fix the roads after the asphalt plants have shut down for the winter. 

If you run over it shortly after it has been laid, it will stick to your tires, because it hasn't cured yet.  And I suspect the compounds that your tires are made of, being petroleum based in one way or another, are just right for the cure process to stick to.  If you catch it right away, it will probably brush off.  If you let it sit, it will cure in place.

You're lucky they even acknowledge potholes around you.  I think I've seen a VW or two in the bottom of some of ours.

[Bob Wessner]

I was curious so I Googled a bit. It seems there are two varieties of the stuff. They stop making cold patch with petroleum based binders during the colder, or winter months since it won't bind to the road surfaces which are cold. Instead they use a patch with latex and polymer binders. During the summer months (May through Sept) they use the more traditional stuff.

This may have been the first time I encountered the material used in the colder months and I would agree, if you happen to ride through some fresh stuff, pull over and brush off what you can. I wish I had taken some pictures, the pebbles/stones aggregate was so evenly distributed and covered the entire tread so well, I doubt very little tire was actually coming in contact with the pavement.

[Raul CB750K1]

But that can't be bad; your tires will last longer...

Raul