Which Way Do Bike Pedals Undo? | Loosen Direction Fast

Baffled by a stuck pedal and a wrench that seems to make things worse? You’re in the right spot. This guide gives you the exact turning direction for each side, plus simple checks, tools, torque numbers, and stuck-pedal fixes. You’ll also pick up a couple of memory tricks so the next time someone asks “which way do bike pedals undo?” you’ll answer in seconds.

Which Way Do Bike Pedals Undo?

Here’s the plain answer: the right pedal uses a standard thread and loosens counterclockwise; the left pedal uses a reverse thread and loosens clockwise. A neat way to picture the rule is this: both pedals tighten toward the front wheel and loosen toward the rear wheel. The sections below show what that looks like in real wrench turns, with notes for flats vs. hex fittings and typical torque values.

Quick Reference Table: Directions, Sizes, And Torque

Bookmark this table if you want the answer at a glance. It fits most modern bikes and common pedal styles.

Item	Right Pedal	Left Pedal
Loosening Direction	Turn counterclockwise	Turn clockwise
Tightening Direction	Turn clockwise	Turn counterclockwise
Thread Type	Right-hand thread	Left-hand thread
Common Wrench Flats	15 mm pedal wrench	15 mm pedal wrench
Common Hex In Axle	6–8 mm hex (often 8 mm)	6–8 mm hex (often 8 mm)
Typical Install Torque	35–55 Nm (brand-specific)	35–55 Nm (brand-specific)
Removal Memory Aid	Back toward the rear wheel	Back toward the rear wheel
Markings On Axle	“R” stamped/etched	“L” stamped/etched

Bike Pedals Undo Direction By Side And Tool

You’ll see two common tool interfaces: thin wrench flats on the pedal axle, or a hex socket inside the axle at the crank side. The turning rule never changes, but your hand position does. Stand on the drive side for the right pedal and the non-drive side for the left pedal. Place the tool so you can push down with body weight while turning toward the rear wheel to loosen.

Right Pedal: Step-By-Step Removal

1. Shift the chain onto the big ring to protect your knuckles.
2. Set the crank arm forward and horizontal. This gives room for the tool.
3. Fit a 15 mm pedal wrench on the flats or an 8 mm hex in the axle.
4. Pull the tool counterclockwise to loosen. Aim the effort toward the rear wheel.
5. Spin the pedal off by hand once the threads break free.

Left Pedal: Step-By-Step Removal

1. Move to the left side of the bike.
2. Set the left crank forward and horizontal.
3. Seat the same size tool on the flats or hex socket.
4. Pull the tool clockwise to loosen. Again, think “back toward the rear wheel.”
5. Finish by hand to protect the crank threads.

Why The Left Side Feels Backwards

Pedals are threaded this way to resist “precession,” a tiny rolling motion between the pedal axle and the crank hole that would nudge a standard thread loose on the left side. Reverse thread on the left counters that effect. The right side uses a normal thread without issue.

Which Way Do Bike Pedals Undo? (Memory Tricks You’ll Keep)

Plenty of riders type “which way do bike pedals undo?” right before a home repair. Here are two quick mental cues that stick:

• Back-off rule: to loosen either side, turn the wrench toward the rear wheel.
• Front-tighten rule: both pedals tighten toward the front wheel.

Say those lines as you set the tool. In a pinch, glance for “L” or “R” on the pedal axle and match the side before you pull.

Tools, Torque, And Prep That Save Threads

Use a thin 15 mm pedal wrench with a long handle or an 8 mm hex that seats fully in the axle. A short multi-tool works for roadside swaps, but a long lever makes stuck parts budge with less risk. Before installation, add a light film of grease or anti-seize on the threads. That prevents galling and helps the next removal.

Recommended Torque And Grease Steps

• Torque range: 35–55 Nm for many flat and clip-in pedals. Stainless or alloy cranks like similar numbers; check your brand’s spec.
• Grease: thin smear across the full thread length. Wipe any squeeze-out after tightening.
• Re-check: after the first ride, give each pedal a quick snug toward the front.

Want the official word on directions and torque? See the Park Tool guide to pedal installation and removal and Shimano’s dealer manuals for wide ranges like 35–55 Nm on many models (sample torque sheet). These pages also show part markings and tool interfaces.

Fit Checks Before You Turn A Wrench

A quick pre-flight stops the classic “wrong side” move and protects the crank threads:

• Side check: match “R” to the chainring side, “L” to the opposite side.
• Thread start: always start by hand. The first two turns should feel smooth.
• Tool seating: if using an 8 mm hex, push it fully into the axle before loading it.
• Wrench angle: set the crank arm at 3 o’clock so you can push the handle down.

Stuck Pedal Playbook

When a pedal won’t budge, don’t force a shallow tool or smack the wrench at a weird angle. Work through this sequence to free it cleanly.

Step 1: Add Leverage

Use a long pedal wrench or slide a pipe over a short handle. Keep the tool in plane with the axle so the flats don’t round.

Step 2: Break The Bond

Apply penetrating oil at the crank face and let it wick along the threads. Hold the opposite crank for support, then pull in the correct loosening direction (rear-ward). A steady load beats a quick jerk.

Step 3: Heat Or Chill (If Needed)

Targeted heat on the crank (not the pedal body) can expand the female threads a touch. A bag of ice on the pedal afterward can add a small differential. Keep the effort smooth and controlled.

Step 4: Last-Resort Moves

If the hex socket strips, move to the 15 mm flats. If the flats round, stop before damage spreads to the crank. A shop can remove the axle body and work the spindle with a tighter-fitting tool or a bench setup.

Reinstall The Right Way

Clean the threads in both parts. Add a light film of grease. Start the pedal by hand for at least three turns. Set the tool and tighten toward the front wheel: clockwise on the right, counterclockwise on the left. Hit the torque target. Wipe any extra grease. Spin by hand to confirm free rotation without play.

Thread Standards, Sizes, And Oddballs

Most modern cranks use 9/16" × 20 tpi pedal threads. Older kids’ bikes and some one-piece cranks may use 1/2" pedals. If a pedal seems to start crooked or bind early, stop and confirm the size. Never force an adapter or wrong thread into an aluminum crank.

Hex Size Notes

Plenty of clip-in models take an 8 mm hex; some road models use 6 mm. If the hex feels sloppy, try the next size up. On flats-only pedal axles, use the 15 mm pedal wrench; a standard 15 mm open-end can be too thick and ride high on the flats.

Common Mistakes That Strip Cranks

• Wrong direction: turning both sides the same way. Remember: back toward the rear wheel to loosen.
• Cross-threading: starting with a wrench instead of fingers.
• Dry install: skipping grease, which invites corrosion and seized parts.
• Short handle: cranking on a stubby multi-tool until something snaps.
• Angle load: pulling at a tilt that rounds the flats or the internal hex.

Troubleshooting Table: Symptom, Likely Cause, Fix

If a pedal won’t start, won’t loosen, or creaks under load, match it here and knock it out fast.

Symptom	Likely Cause	Fix
Threads won’t start	Wrong side or angle	Hand-start straight; confirm “L/R” marks
Pedal won’t loosen	Wrong direction or corrosion	Turn toward the rear wheel; add penetrating oil
Hex slips in axle	Shallow seating or wrong size	Seat tool fully; switch to 15 mm flats
Flats rounding	Thin open-end wrench	Use a pedal wrench with full contact
Creaks while pedaling	Dry threads or low torque	Remove, grease, reinstall to spec
Play at the pedal body	Cone/locknut out of adjustment	Service bearings per brand guide
Stuck after rain rides	Galvanic bond in crank	Penetrant soak; heat on the crank; steady load
Wrong thread size	1/2" pedal in 9/16" crank	Match sizes; never force an adapter

Safety Notes Worth Heeding

Wear eye protection when you add lube or use heat. Keep hands clear of the chain and ring teeth. If the pedal or crank shows damaged threads, stop and get a thread-chasing tap or a shop assist. Fresh threads and correct torque beat an ugly repair later.

One More Time For Memory

Say this out loud while you set the tool: both pedals loosen back toward the rear wheel and tighten forward toward the front. If a friend asks “which way do bike pedals undo?” you can answer without thinking: right pedal counterclockwise, left pedal clockwise.