How Do I Safely Brush Debris Off a Rear Bike Tire While Riding?

Question: I’m an old roadie, accustomed to brushing off my tires with my fingers or gloved palm whenever I ride through debris. The habit comes from riding with sew-ups back in the day.

Now, after a long absence from cycling, I’m back in the saddle on a new (and incredibly lightweight!) bike with clincher tires. But the seat tube has an aero shape, and there’s so little clearance between it and the tire that I can get only one finger in there to brush the rear tire. What’s the solution? — Tom D.

Coach Fred Matheny Replies: Brushing tires was standard procedure when most people rode tubulars, also called sew-ups because their tube is stitched inside the casing.

(For newbies, you can imagine why tubular punctures are a huge hassle — you have to open and re-sew the tire when patching the tube. Brushing is a way to knock off something that’s stuck to the tread before it can work through and cause a flat.)

Like for Tom, brushing is a habit I can’t break, even though I’ve ridden clinchers forever. It’s obvious that clinchers are far more puncture-resistant than sew-ups, so I’m not sure that brushing them is worth the effort. When a clincher does pop, replacing the tube or patching it is quick and easy.

Here’s the key point about brushing: It’s dangerous to stick your hand between the rotating rear tire and the seat tube. On almost all bikes, your hand can get pulled down and wedged tight. The resulting crash is about as bad as a crash can be. When there’s limited clearance — the situation with many modern frames — the danger is even greater.

It may be better to suffer an occasional puncture than to take the risk.

But if you are going to brush the rear tire, hook your thumb around the seatstay before you contact the spinning rubber. That could prevent your hand from getting caught.

Now if I could just break that habit….!