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Bike Shop 3-5 / Week 11 / Wednesday
3/6
Week 11 · The Quick Check

Wednesday

B is for Brakes
// A, B, C before every ride
⏱ about 15 min

Wednesday: B Is for Brakes

Rocket squeezes his brake lever. It slides almost all the way to the handlebar.

"It still squeezes," he says. "So it is fine, right?"

Raven looks closely. "What do you notice about the space left?"

Nova hovers by the lever. "Brakes need room to squeeze," she says. "How much room is enough?"

Rocket grabs a ruler. "Let's measure!"

Brakes: the B check

Remember the brake lessons from earlier in the course.

Squeezing the lever makes the brakes press and slow the wheel.

One quick check guide gives a simple brake test.

Squeeze the lever. There should be at least 1 inch between the lever and the handlebar.

The brake pads should not rub the tire.

If something looks wrong, a grown-up fixes it before any ride.

BikeSpace left when squeezed (made-up practice numbers)
Bike A2 inches
Bike Bhalf an inch
Bike C1 inch
Bike Dnone, lever touches the bar
Made-up practice bikePasses the 1 inch lever test?
Bike A: 2 inches?
Bike B: half an inch?
Bike C: 1 inch?
Bike D: lever touches the bar?
WHY THIS EXERCISEAt least 1 inch of space passes. Less than that needs a grown-up fix.
Using the made-up practice numbers, how many bikes need a grown-up fix?
WHY THIS EXERCISEBike B and Bike D have less than 1 inch. That makes 2.
BRAKE CHECK QUESTIONS
  • Read the question.
  • Tap your answer.
The brake pads rub the tire as the wheel turns. What should happen?
Why does Rocket use a ruler?
Try it
With a grown-up, stand by a bike that is held still.
A grown-up squeezes the brake lever and holds it.
Hold a ruler near the lever. Look at the space to the handlebar.
No bike? On paper, draw a handlebar and lever with 1 inch of space.
Safety first
The bike stays standing still. A grown-up holds it and squeezes the lever.
Keep fingers away from the brake parts and spokes.
Nothing turns while you measure.
For a grown-up
If the lever touches the bar or pads rub, fix the brakes before riding.
Ask a bike mechanic for help if you are unsure.
LeverSpace I sawPass or needs a grown-up?
Left lever
Right lever
BRAKE CHECK STEPS
  • ?A grown-up squeezes the brake lever.
  • ?Look at the space to the handlebar.
  • ?Look at the pads. Do they rub the tire?
  • ?Write what you saw in your shop notebook.
  • ?A grown-up holds the bike still.
WHY THIS EXERCISEHold still, squeeze, look at the space, look at the pads, then record.
Squeezed lever space should be at least ____ inch.
The brake pads should not ____ the tire.

Brakes checked! Tomorrow we look at C and Quick: chain, cranks and quick releases.

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