You sit third wheel on a steady cafe ride, watching the rider ahead. Every stroke swings both knees wide, like saloon doors opening and closing.
That rolling style is why so many riders end up searching why older cyclists pedal with wide knees.
Maybe that’s simply what aging looks like on a bike. Maybe your own knees have already started drifting out on climbs.
It’s rarely the knee itself that’s at fault. Most of the causes are fixable, and a few are best left alone.
Below are the five usual reasons older riders flare, with a quick check for each and a simple rule for when to act.
Your Knees Are Just Following Orders
The knee is a hinge, not a steering wheel.
It goes where the hip above and the foot below send it. The top of the stroke is the tightest point, where hip and knee fold the most, so any shortage of room there pushes the knee sideways to find space.
That’s good news, because you can win that room back. Start with the hip.
A Stiffer Hip Needs Somewhere to Go
The motion that tends to fade is one you never think about, turning the thigh inward.
Sit on a chair and swing your lower leg outward without moving your knee. That twist at the hip is internal rotation, and hip rotation shrinks with age, with lower averages seen in men and in heavier adults.
Losing that inward turn is also a classic sign of hip arthritis. Think of a door that won’t swing fully open anymore, so you slip through at an angle.
Clinicians who study bike fit note that when bone blocks hip motion, no stretch program forces it open and the bike has to give instead.
It’s one more example of how age affects cycling, where small losses add up over the years.
If your hip cannot turn in, your knee will turn out.
The Saddle That Got Lowered to Touch the Ground
Plenty of us have done it. The saddle creeps down until both feet can go flat at a stoplight.
That feels safer in traffic. It also folds the hip and knee tighter at the top, so the knees escape outward to complete the turn.
A review of saddle-height research found kneecap compression rises as the saddle drops, and height changes shift how the knee moves. Lower isn’t kinder to knees.
A saddle set for stops is usually too low for pedaling.
Check yours with the heel method. Put your heel on the pedal at the bottom of the stroke with the crank at six o’clock.
Your leg should be straight without rocking your hips, which leaves a slight bend when you clip in with the ball of the foot.
Raise a low saddle in small steps over several rides. Practice sliding forward off the saddle at stops instead of reaching for the ground, so the saddle can stay at the right height.
Some older riders on stop-start routes like a dropper post for the same reason.
Riders coming back to cycling on an old bike should check this first, because that setup was dialed in years ago for a younger body.
Sometimes It’s Just the Belly
This one needs saying kindly, because it’s about space, not effort.
As the thighs rise at the top of the stroke, a larger midsection leaves less room between leg and torso. So the knees go around it.
You’ll see it most when riding low in the drops with elbows bent. The lower front end closes the gap and the flare grows.
Give the thighs somewhere to go.
Ride on the hoods more, or raise the bars slightly with a spacer or a shorter stem. No lecture here, just geometry.
Cranks Built for a Younger Hip
Most likely, you’ve never given crank length a thought. A bike bought years ago may have long ones fitted as standard.
A longer crank lifts the foot higher at the top, which demands more hip and knee bend in exactly the spot older hips like least. According to a clinical bike-fit review, overly long cranks can push the knee outward to compensate, and riders with stiff hips may need shorter cranks.
Lab tests on amateur riders found a 5 mm longer crank added about 2 to 3 degrees of hip and knee bend, with no gain in efficiency.
Shorter cranks open the top of the stroke without lowering the saddle.
Swapping from 175 mm to 165 mm is one option for tighter hips. Raise the saddle about 5 mm for every 5 mm you shorten, since the foot no longer reaches as far at the bottom.
Feet Too Close Together for Your Hips
Road bikes assume a narrow stance. Your hips may not.
Q-factor is the industry term for the distance between the pedals. When the pedals sit well inside the natural width of the hips, the knees point outward to bridge the gap.
Do the standing check in socks. Walk a few steps, stop relaxed, and look down.
If your feet rest noticeably wider than your pedals, stance may be part of your flare.
Fix it in order. First move each cleat inward on the shoe, which pushes the foot outward.
If the knees still splay, shops sell 1.5 mm washers and longer spacers, such as 20 mm (about 0.8 inches).
Research shows pedal spacers widen knee tracking in a measurable way. More width isn’t always better, though. Lab work found that going far wider raises load on the inside of the knee, so add width only until the stroke looks smooth.
Leave It or Fix It? Let Pain Decide
Knees that track wide aren’t automatically broken.
Use this rule. Smooth and pain-free means leave it alone, especially if you have ridden that way for years.
Act when there is pain at the knee or hip, one knee flares much more than the other, or the change appears suddenly.
Don’t force a laser-straight stroke for looks. Squeezing the knees inward can create the very knee pain you hoped to prevent.
Riders with diagnosed hip or knee arthritis, or with a joint replacement, should check with a surgeon or physio before changing cleats, spacers, or saddle height. Bring bike photos and note which side flares, since one-sided flare can point to a joint issue. There’s more on sore knees in our guide to avoiding knee pain.
Work in this order:
- Saddle height with the heel check, raised in small steps
- Front end height and more time on the hoods
- Stance with cleats first, then washers or spacers
- Shorter cranks if the top of the stroke still feels jammed
- Hip mobility, starting with common mistakes over 50
- Hip and glute strength, starting with lifting weights over 50
- A professional fit if pain persists after the basics
This short video walks through the space problem, a quick squat test you can copy at home, and the main fixes.
Do the heel check on your next ride before touching anything else. It tells you whether the saddle is behind your flare.
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