If you’ve ever suffered from knee pain, numb hands, or a sore back on long rides, it’s very likely the problem is your position on the bike.
After 800+ Retul bike fittings, I can say with certainty: 90% of cyclists make the same mistakes.
Here are the 5 most common ones — and how to fix them.
1. Saddle too high = destroyed knees
Symptom:
- Pain at the back of the knee
- “Locked out” knee at the bottom of the pedal stroke
- Unstable pelvic movement (rocking side to side)
Why it happens: Most cyclists think: “Higher saddle = more power, because you get a longer stroke.”
Wrong.
A saddle that’s too high means you can’t activate your glutes — the most powerful muscles you have. Instead, you overload the hamstrings and the knee.
How to fix it: Basic rule: at the bottom of the pedal stroke, your knee should be slightly bent (25-35 degrees of flexion).
Test: Sit on the bike, put your heel on the pedal (no shoe). Your leg should be almost, but not fully extended at the bottom. When you clip back in, you’ll have roughly the right height.
My approach: The Retul system shows me the exact knee angle in real time. Target: 30-35 degrees at the cleats position you’re using.
2. Handlebars too far away = back and neck pain
Symptom:
- Lower back pain
- Tension in the neck and shoulders
- Numb hands (especially on long rides)
Why it happens: Two reasons:
- You bought a “race” geometry (because it looks cool), but you don’t have the flexibility for that position
- The stem is too long (common with online purchases where you pick the wrong size)
How to fix it: If you can’t hold the position without pain, the position is wrong. Period.
It’s not about “developing” flexibility. Race position is for pros who have 4 hours a day for mobility work.
Practical test: Hold the aero position for 10 minutes. If you can’t do it without pain, shorten the stem or raise the handlebars.
My approach: For most amateurs, I recommend endurance geometry. You’ll put out more power when you’re comfortable than when you’re in an “aero” position but can’t breathe.
3. Cleat position = #1 cause of knee pain
Symptom:
- Pain at the front of the knee (patella)
- Pain on the inner/outer side of the knee
- Burning sensation in the foot (“hot foot”)
Why it happens: 90% of cyclists never set up their cleats properly. They just bolt them on roughly in the middle of the shoe and hope for the best.
The problem: Your feet aren’t symmetrical. If you set cleats “by eye,” you’re creating lateral stress on the knee with every rotation.
How to fix it: Basic rule: the metatarsal head (the bone behind the big toe) should be directly over the pedal axle.
This isn’t the same spot for everyone! Some people have longer toes, others shorter. You need to set cleats individually.
My approach: I use laser alignment to determine the exact fore-aft and lateral position. Sometimes the difference between left and right foot is 5-8mm — enough to cause pain.
4. Handlebars too narrow or too wide = numb hands
Symptom:
- Numb hands/palms
- Wrist pain
- Difficulty holding position on the drops
Why it happens: Handlebar width should match your shoulder width (akromion-to-akromion distance).
If the bars are too wide: you overload your hands/wrists If the bars are too narrow: worse aerodynamics, harder to breathe
How to fix it: Measure the distance between your shoulders (bone to bone, not muscle).
- 36-38cm shoulders = 40cm bars
- 38-40cm shoulders = 42cm bars
- 40-42cm shoulders = 44cm bars
Important: These are center-to-center measurements! Not the outer edge of the bars.
My approach: We test multiple bar widths and monitor hand pressure. I often recommend swapping the bars — a 50 EUR investment that fixes months of pain.
5. Ignoring stack & reach = buying the wrong frame size
Symptom:
- The bike “just doesn’t feel right”
- You need an extreme stem (super short or super long)
- You can’t find a comfortable position no matter what you adjust
Why it happens: You bought the bike based on top tube length or “size M/L.”
The problem: That tells you nothing about how the bike actually fits.
Stack (vertical distance) and reach (horizontal distance) are the only parameters that actually determine whether the bike fits you.
How to fix it (preventively): Before you buy a new bike:
- Get a bike fitting on your current bike
- Calculate your ideal stack & reach
- Buy a bike that matches those measurements
You can’t fix the wrong frame with a long/short stem. A 2cm stack difference is a problem no stem will solve.
My approach: Before buying a new bike, we do a fitting on the current one, calculate the target stack/reach, and then I recommend models that match.
Bonus mistake: “I’ll just wait until I ‘get used to it’”
No. If it hurts after 100km, it won’t stop hurting after 1000km.
Pain is not normal. If it hurts, something is wrong.
Ignore it long enough, and pain turns into injury (ITB syndrome, patellar tendonitis, lower back issues).
Why bike fitting isn’t optional
I ask people: “How much did you pay for your bike?”
“3000 EUR.”
“How much did you pay for a fitting?”
“I didn’t… I thought I could set it up myself.”
The problem: You have a 3000 EUR bike that doesn’t fit you. You’ve essentially bought a 3000 EUR pain-generating machine.
250 EUR for a professional bike fitting is the best ROI investment you can make in cycling.
What to do next
If you have any of the symptoms above, don’t ignore them. Don’t “wait for it to pass.” Don’t “hope you’ll get used to it.”
Get a bike fitting from someone who:
- Uses 3D motion capture (not “eyeball” fitting)
- Understands biomechanics, not just rules of thumb
- Has done 500+ fittings (experience counts)
Your knees, back, and backside will thank you.
Once your position on the bike is dialed in, the next step is structured training — so you can make the most of every watt that a proper position unlocks.
Want to fix the pain? Book a Retul bike fitting — 2.5 hours that will change every ride after.