Jason Williams’s resume includes study and certifications with SICI, SBCU, Retül, and Slowtwitch Fit Institute. He’s been fitting bikes to riders for more than 12 years, almost a decade of which has been at University Bicycles (known affectionately by most locals as “UBikes”) in downtown Boulder, Colorado, where he’s now Head of the Fit Department. Because of its location, UBikes is busy year-round with a steady supply of die-hard loyalists and first-time shoppers alike. And with that foot traffic come a lot of bike fits.
When I asked Jason to identify the most common aches and pains mountain bikers can solve through getting a bike fit, he draws not only on years of specialized (and Specialized) education, but on the literally thousands of bike fits he’s performed over the years.
“Probably a reason a lot of mountain bikers don’t seek out bike fits is that the position is inherently a lot more comfortable [than road biking],” Jason said. “That doesn’t mean that mountain bikers don’t need fits, though. The way I phrase it on the floor is this: Your body doesn’t care what you’re riding. Your knee wants a certain angle, and it’s looking for neutral biomechanics. It doesn’t care if you’re on a road bike or mountain bike.”
Which brings us to the first item on the list:
1. Knee Pain
Knee Pain is perhaps the most common ailment riders experience on the bike. That’s because it can be caused by any number of issues, which makes finding the solution more than a simple if-this-then-that equation. For Jason, the first place to look for a problem is the foot—the shoes, cleats, and pedals.
“Cleat misplacement is huge. If your cleats are crooked, and that’s holding your foot in an odd position, then the knee is where the symptom is going to show up,” said Jason.
But that’s not all.
“Worn out equipment may also be the culprit,” Jason said. “It’s not uncommon to have to tell somebody, ‘I know you love these shoes, but they’re used up. Let’s get you some new ones.’ At least we’ll start there. It may not totally resolve things, but it does give us a blank slate and a fresh start.”
2. Back Pain
Back Pain is often attributed to a problem with reach, the horizontal distance between the bottom bracket and the handlebar. But there are myriad other potential causes for a sore lower back. Chief among them? Hamstring tension and sit bone width.
“If you’re overextending, you’re pulling on the hamstrings,” said Jason. “And if you’re hunched on the bike, a tight hamstring will pull on the lower back.”
That’s why a physical assessment of flexibility and range of motion precedes most comprehensive fits, a practice elevated by Andy Pruitt and standardized by the Specialized fit school. Your body plays an enormous part in your comfort on the bike.
“If the seat is too narrow and you’re avoiding pressure on the front of the saddle, you’re going to roll back to take that pressure off. You’ll think the seat is fine, but if your back was neutral, the saddle would be taking more of that pressure. So that’s my other suspicion; let’s see if the seat is too narrow.”
In other cases, the problem may be another you might not expect in the age of dropper posts and an on-the-bike position that’s changing with every berm and pedal stroke: your saddle may just be too high.
“To overgeneralize, if I did nothing else during a fit but lowered the seat by just 2mm, that can eliminate a lot of problem areas,” said Jason.
Of course, if everything with the lower body checks out, the problem could be the reach, after all.
3. Neck Pain
Neck Pain? Stop me if you’ve heard this one already: there may be any number of potential root causes.
“When I hear neck pain, I think about how stretched out or low the front is,” Jason said. “The obvious one is if you’re too stretched out and too low, or [your bars] could be too wide or too narrow. We’ve got to make sure the seat is in the right place. The pain is in the neck, but if the seat is 3mm too high, then lowering the seat may take care of it. And again, width of the saddle is a big issue. If we’re rolling back with the spine to avoid the seat, we have to strain the neck to look ahead. It’s counterintuitive, but again, it’s a pretty distinct connection. If you’re avoiding the seat, the problems are going to show remotely.”
4. Wrist Pain
“Knees I can measure, seat [position] fore and aft, I can measure. But there’s nothing about bar width that’s like, ‘Here’s where your bars need to be,'” said Jason.
For years, bar width has been trending wider and wider, with many riders opting for the control of a wider bar over the more natural reach of a narrower bar.
“The front end of mountain bikes does pose a bit of a problem because of where things have evolved. There’s nothing fit-wise that makes sense about short stems and wide bars. It feels awesome, and it rides great, but that’s whack. I like it—most people do—but as a fitter, I just have to say, ‘Yeah, that’s what it is.’”
In the case of wrist pain, the fix has less to do with equipment and more to do with consciousness and intention on the bike.
“An 800mm bar and a short stem feels great when you’re rallying, but when you’re riding for three hours, wrist pain can be an issue because we’re way out here.”
You can imagine what he’s doing with his arms.
“On a mountain bike, you have to engage the core, broaden the chest, get the elbows out wide, and the wrist will be a lot happier. You can see it visually. If the wrist is kinked, it’s not going to be happy. It does take significant core engagement—it takes calories burned to sustain that position, and it’s not natural. It’s a cultivated posture that we have to develop.”
5. Pain in the Butt
Friends less fortunate than you and I—friends who haven’t yet discovered the joy full days on a bike can bring—have asked me how I can spend so many hours on the bike: Isn’t that uncomfortable on your… well… you know?
Before I found the perfect saddle, I’m sure I asked the same question.
“A lot of people expect a bike seat to be miserable—that [discomfort] comes with the territory—but it doesn’t have to be. It’s never going to be the couch, but it shouldn’t be intrusive. It shouldn’t significantly compress soft tissue. You shouldn’t have numbness. You shouldn’t have friction or saddle sores. A lot of people expect these as a part of biking.”
“Most shops have a way to measure sit bone width. It doesn’t always tell the whole story, but it does give us a starting point,” Jason says.
From there, it’s a matter of trial (and probably error) until you’ve narrowed the literally hundreds of saddles on the market down to the few that fit your body and your preference. Bonus points if your local shop has a fleet of test saddles on hand to make the process a little less painful.
If there’s one takeaway, it’s this: finding your fit can be a complicated process, one that can require years of training and years more of experience. More often than not, the path from cause to effect looks more like a toddler’s scribbled “doodle” than an uncooked spaghetti noodle.
But there’s good news, too.
Chances are there’s a fantastic fitter not far from you, and he or she would be ecstatic to help you make the most of your time on the bike, whether you’re looking to minimize injury, increase efficiency, or get faster—or all three.
As Jason puts it, “It’s all connected. A comfortable fit is a fast fit, and an efficient fit is comfortable. They shouldn’t be separate. If you’re comfortable, you can focus on pushing hard. If you’re in a fit that’s too aggressive, it’s not going to be fast because you’re uncomfortable, and that undermines your potential power. So comfort and performance, comfort and efficiency, do go hand-in-hand for sure.”