Pulling up beside him, I asked, “What’s up, Ry?”

“My shoulders are killing me,” he said, taking both hands off the handlebars and stretching them behind his back.

Ryan is a triathlete. The dude spends more time in the contorted aero position required by his time trial bike than most people spend sleeping, so I was surprised to hear him complain about a comparatively comfortable road bike ride.

We took his bike to our local shop the next day. Turns out, the handlebars on his road bike were too narrow. All that swim training for triathlons gave him a little more girth in the shoulders than your average spaghetti-armed cyclist. According to James Keller, service manager at Full Cycle in Boulder, Colo., your handlebar width should approximate your shoulder width. Handlebars that are too narrow can cause extra tension in the neck and shoulder muscles. Too wide can cause hypertension in the elbows.

You can get an accurate reading by measuring the distance between the bony “points” of each of your shoulders; this is the place from which your arms radiate. Translating that into the proper handlebar measurement is the tricky part because there is no standard way that handlebars are measured.

Most are measured from the center of one drop to the center of the other. In that case, add two centimeters to your shoulder measurement to find the right size. If the points of your shoulders are 40 cm, for example, you’ll want a 42 cm handlebar. Some bars are measured from the outside edges of each side. For those, add four centimeters to your shoulder measurement. So a 44 cm bar would fit 40 cm shoulders.

According to a report published on Bicycling.com, the following brands are measured center to center (add 2 cm): Cinelli, Terry, Profile Design, Ritchey, Dimension, Salsa. The brands measured outside edge to outside edge (add 4cm) are: ITM, TTT, Deda. Note that it makes no difference whether the handlebars are regular drop handlebars or the ergo (also called anatomical) handlebars; the measurement is based on brand, not style.

Since we were on the subject of handlebars, I wanted to get into the fun.

“So how come when we’re climbing up Sunshine Canyon and we get to the dirt section, my hands get tingly and numb?” I asked James.

James peered at me through his dirty blonde hair. “That’s pretty serious,” he said. “How long has it been going on?”

“Ever since I started taking my road bike on dirt,” I said, starting to get nervous. Stupid Boulder, where everyone is a freak and has to ride their road bike up canyons where the pavement doesn’t go.

James called it handlebar palsy. According to SportsInjuryBulletin.com, this condition is also known as ulnar neuropathy. It results from an inflammation of the ulnar nerve that runs along the entire length of the arm to the hand, providing for both movement and feeling in the arm and hand.

If left untreated, handlebar palsy causes compression of the ulnar nerve due to swelling of surrounding muscles and connective tissues. The nerve’s ability to transmit messages to the muscles of the forearm may be significantly reduced. The result is a loss of strength in the muscles of the hand, often first reflected in an inability to spread the fingers, followed by a decrease in grip strength.

In my case, the rough dirt terrain had increased the amount of shock and vibration passing through my handlebars, putting extra stress on my ulnar nerve. But there are other causes of handlebar palsy, too. The lower your handlebars are relative to the height of the saddle, the more likely you are to experience symptoms (basically anyone who races a road bike). If the front of your saddle is tilted downward, putting your body weight onto the hands and arms, the risk of handlebar palsy increases significantly.

My bike position was already dialed-in, and I wasn’t going to raise my handlebars, so James suggested new, thicker gloves and double-wrapping my handlebars. I did both. Ryan ordered new handlebars, one size up. As we walked out, Ryan pointed out that thanks to his griping, we were now better equipped to ride our next century. Hard to argue with that.