How to use a folding bike lock comes down to one closed loop around an immovable anchor, a closed frame section and, where reach allows, a wheel. The overview in Folding Bike Locks Explained summarises the format itself; this article covers the lock-up itself, step by step. Technique carries real weight: in observations of around 8,500 London bicycle-locking events, researchers rated just 20 percent as locked in a secure way1. A folding lock's rigid links raise the stakes further, because the loop can't be lengthened at the rack.
Quick Answer
What is the correct way to use a folding bike lock?
Unfold the links and pass the loop around an immovable anchor and a closed section of the frame, then add a wheel if the loop still closes. Keep the bicycle tight against the anchor and the lock body off the ground. The wheel deserves the effort: in a survey of Montreal cyclists published in 2015, wheels made up 20.1% of reported parts thefts2.
Key Takeaways
- Partial lock-ups are common: in the same London observations, only the frame was locked to the stand in 19 percent of locking events1, which leaves both wheels free.
- The anchor spends part of a fixed loop. By Seatylock's estimate, going once around a streetlight pole with a 7-inch base3 takes about two thirds of an 85 cm folding lock's circumference.
- A folding lock that can't reach the rear wheel can follow half of a police two-lock setup. Avon and Somerset Police describe one D lock through the front wheel and down tube4.
- Slack is working room for a thief. A policing guide describes tools pushed into the gap left by a loosely fitted lock to lever it apart1.
- A stronger lock can't fix a weak lock-up, because steel grade doesn't correct poor routing.
How to Use a Folding Bike Lock: What to Check First
A folding bike lock is a set of flat hardened-steel links, joined by rivets, that folds into a compact bundle and opens into a rigid loop. Locking circumference is the full perimeter of that loop once the lock body closes it, the figure quoted as a folding lock's length. Unlike a chain, the loop can't be wrapped twice or shortened, so its size has to suit the cyclist's usual anchors.
- Circumference against real anchors: the loop has to enclose the anchor, a frame tube and ideally a wheel simultaneously.
- Lock body access: the key has to turn with the loop closed tight, so practise the closing movement at home first.
- The usual anchors: note the rack or post at work, at home and at the shops, because anchor thickness decides how much loop remains.
Anchor thickness is easy to underestimate. The Association of Pedestrian and Bicycle Professionals warns that rack tubes with a cross section larger than 2 inches can complicate the use of smaller U-locks5. Portland's rack permit allows tubing up to a 3-inch outside diameter6, and by Seatylock's estimate, going once around a tube that size equals approximately 24 cm of loop. Iowa's road specification sets round steel sign posts at a minimum of 2 3/8 inch diameter7, approximately 19 cm by the same estimate.
| Folding lock | Locking circumference | Weight | Left after a 2 3/8-inch sign post | Left after a 3-inch rack tube | Left after a 7-inch pole base |
|---|---|---|---|---|---|
| Foldylock Mini | 75 cm | 0.89 kg | about 56 cm | about 51 cm | about 19 cm |
| Foldylock Compact and Pride | 85 cm | 1 kg | about 66 cm | about 61 cm | about 29 cm |
| Foldylock Forever | 90 cm | 1.76 kg | about 71 cm | about 66 cm | about 34 cm |
| Foldylock Classic | 100 cm | 1.6 kg | about 81 cm | about 76 cm | about 44 cm |
| Foldylock Elite | 110 cm | 1.9 kg | about 91 cm | about 86 cm | about 54 cm |
Seatylock's simplified estimate subtracts the anchor's circumference, pi times its diameter, from the lock's locking circumference. Treat the figures as a rough guide, because real lock-ups vary. A loop pressed against the frame wraps only part of the anchor, and straight links can't hug a round tube.
For a cyclist whose usual anchors are thick municipal tubes, locking circumference is a security feature, because a short loop forces the wheel out of the lock-up.
Folded size versus reach is weighed in compact folding lock sizing, and everyday carry in folding lock frame mounting. A lock riding in its holster on the frame is available at every destination, which is where this sequence starts.
Step 1: Pick an Anchor the Lock Can Close Around
An immovable anchor is a fixed object, such as a bolted steel hoop rack or a sign post set in concrete, that resists lifting, unbolting and sliding. Without one, the lock only prevents the bicycle rolling away. In a survey of Montreal cyclists published in 2015, 20.5% of theft victims reported that the bicycle was simply picked up and moved2. That share covers all surveyed victims, including those who didn't know how the theft happened.
Some anchors only look fixed. The policing guide on bicycle theft describes thieves lifting the bicycle and lock over the top of the post, and notes that the post itself is sometimes not anchored securely1. Sheldon Brown's lock notes add that some posts can be lifted out of the ground, and that thieves have cut racks and taped over the cuts8.
A folding lock adds a further requirement: the anchor has to be slender enough. Montgomery County's streetlight specification calls for a pole with an outside base diameter of 7 inches3. By Seatylock's estimate, going once around that base equals approximately 56 cm, roughly two thirds of an 85 cm loop.
Purpose-built racks are specified around a U-lock, a rigid loop like a folding lock's. The professionals' guide says a closed loop of the rack should allow a single U-lock to capture one wheel and a closed section of the frame5. Portland's permit sets the same bar: the frame and at least one wheel can be locked to the rack with a standard U-type lock6.
- Shake it: grip the anchor and pull hard; any movement at the base eliminates it.
- Check the top: a post with a removable sign or an open end lets the whole loop slide off. A closed hoop has no top to clear.
- Match the section to the loop: a short lock needs the slimmest solid leg of the rack, while a longer one can take a thicker section and still close tight.
- Pick a visible spot: Avon and Somerset Police advise recognised cycle parking that's well lit and covered by CCTV4.
Verification is immediate: if the anchor survives the shake, has a closed top and leaves room in the loop for a frame tube, it passes. Wooden rails, thin fences and small trees fail, because cutting them takes less effort than cutting hardened links.
The anchor sets the ceiling for the whole lock-up. With a folding lock it also decides how much loop is left, and a thick pole can leave the wheel no room at all.
Step 2: Capture a Closed Section of the Frame
The loop must pass around a tube belonging to a closed triangle of the frame, so it can't slide off an open end. That's the closed frame section the parking professionals' guide refers to5.
The rear triangle is the part of the frame formed by the seat tube, the seat stays and the chainstays, which together hold the rear wheel. The front triangle is formed by the top tube, the down tube and the seat tube. A loop around the seat tube or the down tube is trapped by the junctions at both ends.
- Roll in close: bring the bicycle alongside the anchor, right side toward the rack, which makes removing drivetrain components harder8.
- Pick the tube by wheel: use the seat tube if the rear wheel will join the loop, and the down tube if the front wheel will.
- Avoid bolt-on parts: never loop only the seat post, the saddle rails, a carrier rack or the handlebars, because each one unbolts.
- Seat the lock body against a tube: close the last link into the lock body so the body rests on the frame, not out in the open.
To verify, push the closed loop along the tube in both directions. It should stop at a junction each way. A loop that slides past an open end is holding a component, not the frame.
The Foldylock Pride shows why a covered link matters here. Its protective link covers sit between the steel and the paintwork while the loop is pulled tight.
The frame is the one part a thief can't replace on the spot, so a closed frame section is the non-negotiable half of every folding lock-up.
Step 3: Add a Wheel Where the Reach Allows
With the anchor and a frame tube inside the loop, the rear wheel comes next, threaded inside the rear triangle, provided the lock still closes. When it doesn't, the front wheel with the down tube is the fallback route. Avon and Somerset Police advise locking the frame and both wheels to the parking stand where possible4.
Leaving the wheel out has a known cost. The policing guide warns that locking only the frame may cost a wheel or wheels, while locking the wheel alone may leave only that wheel1. The rear wheel is the bigger prize of the two.
"It would be a lot of work to steal a frame without a usable rear wheel, the most expensive part of a bike after the frame."
Sheldon Brown, bicycle mechanic and technical writer, Lock Strategy, revised by John Allen8
Route A: rear wheel and seat tube
Thread the open loop through the rear rim just behind the seat tube, inside the rear triangle, then around the seat tube and the anchor. Sheldon Brown explains why the spot works: a lock around the rear rim inside the rear triangle holds a wheel that can't be pulled back through the frame8.
Route B: front wheel and down tube
Where the rack only reaches the front of the bicycle, pass the loop through the front rim beside the fork, around the down tube and around the anchor. This is the same route Avon and Somerset Police give for one of two D locks: through the front wheel and down tube4. It holds the frame and the front wheel, and the rear wheel then needs its own protection.
Verification takes one sideways pull on the captured wheel: the loop should catch the rim and the frame tube simultaneously. A loop that catches only the tire can slip off once the tire is cut or deflated. The Foldylock Forever in the photo, an ART 3 Star certified lock, shows the finished front route, with the lock body held high beside the down tube.
The rear wheel is worth a few seconds of threading, and when the reach runs out, the front route still beats a frame-only loop.
Step 4: Fill the Loop to Cut Slack and Tool Space
Slack is the empty space left inside the closed loop once the anchor, frame and wheel are in place, and it is the working room an attacker needs. A chain can take up slack with an extra wrap, but a folding lock can't. Its fixed loop is filled by what goes inside it and by how close the bicycle stands to the anchor.
"Thieves will use the gap between the stand and the bike left by a loosely fitted lock to insert tools such as jacks or bars to lever the lock apart."
Shane D. Johnson, Aiden Sidebottom and Adam Thorpe, Bicycle Theft, Problem-Specific Guides Series No. 52, ASU Center for Problem-Oriented Policing1
The same guide notes that thieves will rotate the frame itself against the stand as a lever1. In the Montreal survey, 2.3% of theft victims named crowbars as the method2, a small share, but one that a loose loop makes easier.
- Close the gap first: Avon and Somerset Police advise securing the bicycle as close to the stand as possible, to give thieves little room to manoeuvre4.
- Fill the loop with the wheel: a captured rim takes up space a pry bar would otherwise use, so Step 3 also serves Step 4.
- Lock where frame and anchor meet: slide the loop to the point where the frame tube touches the rack, not where they diverge.
- Put the lock body in the narrow part: rotate the closed loop so the body sits in the tight space between frame and anchor.
Verification is a lifting test: grip the loop between the frame and the anchor and pull it outward. A well-filled loop moves no more than a few fingers' width, and the bicycle stays pressed against the anchor.
A tight loop also restricts cutting tools, which need operating room. In the Montreal survey, 10.3% of theft victims named bolt cutters2. By Seatylock's reading, a loop pressed against the frame gives a cutter's jaws fewer exposed links and its handles less space to swing. How long a cut takes still depends on plate steel, rivets and joints, which folding lock construction explains part by part.
Slack is the one weakness a cyclist removes for free, so a tight, well-filled loop is worth more than any later upgrade.
Step 5: Keep the Lock Body and Joints Off the Ground
Every link and joint, and the lock body, should rest on the frame, the wheel or the anchor, never on the pavement. The bicycle theft guide warns that a chain or lock left touching the ground lets thieves use a hammer and chisel to split it1. Avon and Somerset Police give the same advice in five words: keep locks off the floor4.
The lock body is the housing that holds the cylinder and receives the last link when the loop closes. A joint is the riveted pivot where two links meet. A folding lock carries several joints, and on a rear-wheel lock-up the lowest one can end up hanging below the chainstay.
- Lift the low point: rotate the closed loop until the lowest joint rests on the rim or the chainstay instead of hanging free.
- Raise the lock body: settle it against a frame tube at or above the height of the hub.
- Face the keyhole down: Sheldon Brown's advice is to face the keyhole down so water doesn't run into it8.
The visual inspection is a walk-around, looking along the ground on both sides of the bicycle for any link or joint touching the pavement.
Height costs nothing and eliminates an entire attack method, so a lock body resting on the pavement is a lock-up that isn't finished.
Step 6: Cover the Wheel the Lock Can't Reach
One folding lock holds the frame and, at best, one wheel, so the other wheel needs its own layer whenever the bicycle stays out for hours. The policing guide notes that thieves know how to undo bolts and quick-release mechanisms1, and a free wheel on a quick release is the easiest part to take.
A quick-release skewer is a hub clamp with a cam lever that lets a wheel come off without tools. Sheldon Brown notes that quick releases are great for fast wheel changes during races, and also great for thieves8.
Option A: secure the wheel fixings
Replacing a quick release with a keyed fastener prevents removal by hand. Avon and Somerset Police list security skewers or nuts among the measures that make front wheels harder to steal4.
Option B: a cable through the free wheel
A looped steel cable runs through the uncovered wheel and returns to the folding lock, extending the lock-up without a second key. The Cable Loop 120 is built for that job, with looped ends that close into a folding lock or a U-lock. Avon and Somerset Police advise avoiding cable-style locks because thieves can remove them in seconds, so a cable only adds a light deterrent beside the main lock4.
Option C: a second lock of a different type
The policing guide's advice for maximum security is two locks of different types, because a thief then needs two different tools1. Avon and Somerset Police describe the full version: one D lock through the front wheel and down tube, the other through the back wheel and seat tube4. A folding lock can take either of those two routes.
Second locks were rare in the London observations. That study found that in 87 percent of locking events, cyclists used only one lock1. When the parking risk calls for more than one layer is weighed in folding lock security trade-offs.
A wheel on a quick release comes off without tools8, so the second layer earns its place on any stay longer than a short stop.
Common Folding Lock Mistakes to Avoid
A common mistake is a lock-up that holds only part of the bicycle, and it's an easy one to make. Research on 180 possible ways to lock a two-wheeled bicycle to a standard stand rated just 23 of them as good or secure1.
| Mistake | What it allows | Fix |
|---|---|---|
| Loop through a quick-release wheel only | Wheel opened, frame taken; the wheel may be all that is left | Capture a closed frame section first (Step 2) |
| Frame locked to its own wheel, no anchor | Whole bicycle lifted and carried away | Close the loop around an immovable anchor (Step 1) |
| Loop around a thick pole with no room left | Frame tube forced out of the loop, or a loose fit around a component | Use a slimmer anchor or a rack leg (Step 1) |
| Loop around the seat post or saddle rails | Loop freed by unbolting a clamped part | Use the seat tube or the down tube (Step 2) |
| Bicycle parked a loop's length from the anchor | Room for a bar or jack; frame used as a lever | Press the frame against the anchor and fill the loop (Step 4) |
| Lock body or a joint on the pavement | Hammer and chisel against a hard surface | Rotate the loop and raise the lock body (Step 5) |
Most of these mistakes share a cause: the cyclist locks to whatever is nearest instead of following the sequence. Running the six steps in order every time turns them into a habit that takes seconds.
Every mistake in the table costs time to correct at the rack and nothing to avoid at home, so one practice run is worth more than any accessory.
What a Correctly Used Folding Lock Looks Like
A correctly used folding lock passes four inspections in one walk-around. The anchor doesn't move, the loop traps a closed frame section and a rim, it lifts no more than a few fingers' width, and nothing touches the ground. Those inspections answer four of the attack methods the policing guide describes: lifting, unbolting, levering and striking1.
Technique and lock grade work together, and neither substitutes for the other. For a high-value bicycle, Avon and Somerset Police say it is worth buying Sold Secure diamond-grade locks4. Matching the certification to the bicycle and the parking spot is covered in choosing a folding lock.
The finished lock-up is a set of independent defences, and its strength comes from completing all six steps, not from perfecting one.
Frequently Asked Questions
Where should a folding bike lock go on a bike?
Around the seat tube and through the rear wheel inside the rear triangle, then around an immovable anchor. When the loop won't stretch that far, use the front wheel and the down tube instead. The wheel is worth including: in a Montreal survey published in 2015, wheels made up 20.1% of reported parts thefts2.
Is a folding lock long enough for the frame and a wheel?
At a standard rack, generally yes. By Seatylock's estimate, going once around a 3-inch rack tube6 leaves an 85 cm loop approximately 61 cm for the frame and a wheel. A thick pole changes that: a 7-inch base3 leaves the same lock approximately 29 cm, enough for the frame alone.
Can a folding bike lock go around a lamp post?
Only a slender one. Montgomery County specifies streetlight poles with a 7-inch outside base diameter3, and by Seatylock's estimate one pass around that base equals approximately 56 cm of loop. A 75 cm lock keeps approximately 19 cm, too little for a wheel, so a hoop rack or sign post is the better anchor.
Should the keyhole of a folding lock face up or down?
Downward. Sheldon Brown's lock notes advise facing the keyhole down so water doesn't run into it8. Keep the lock body off the pavement too: the policing guide warns that a lock touching the ground can be split with a hammer and chisel1.
Is one folding lock enough to secure a bicycle?
By Seatylock's reading, one folding lock around an anchor, the frame and a wheel is a reasonable minimum for a short stop in a busy, well-lit place. For maximum security, the policing guide advises two locks of different types, and London observations found that 87 percent of locking events used only one lock1.
Limitations and Edge Cases
- Step-through, cargo and small-wheel frames move the tubes away from the anchor, so a rigid loop may hold only the frame. A cable or a second lock then protects the wheels.
- The anchor sizes come from three US specifications and the theft figures from a Montreal survey and a policing guide's UK studies; local racks and theft methods vary. Whether a U-lock suits a given rack better is compared in folding lock versus U-lock.
References
Methodology: every third-party figure was checked against its live source page on October 27, 2026. The anchor-share and loop-left figures are Seatylock calculations from those sources, and folding lock circumferences and weights come from Seatylock's product pages on the same date. Michael Shenkerman holds editorial responsibility, and Shahaf Levavi, Head of Product, reviewed the article.
- ASU Center for Problem-Oriented Policing - Bicycle Theft, Problem-Specific Guides Series No. 52, by Shane D. Johnson, Aiden Sidebottom and Adam Thorpe, 2008.
- Transportation Research at McGill (TRAM) - Breaking into bicycle theft: Insights from Montreal, Canada, by Dea van Lierop, Michael Grimsrud and Ahmed El-Geneidy, International Journal of Sustainable Transportation, 2015.
- Montgomery County Department of Transportation - Specifications for Streetlight Hardware, IFB 1063092, Poles and Footings, PDF dated May 2019.
- Avon and Somerset Police - Protect your bike from thieves, crime prevention advice, accessed October 2026.
- Association of Pedestrian and Bicycle Professionals - Essentials of Bike Parking: Selecting and installing bicycle parking that works, 2015.
- City of Portland, Bureau of Transportation - TRN-10.09 Bicycle Rack Permit, rack design requirements, accessed October 2026.
- Iowa Department of Transportation - Electronic Reference Library, Section 8040: Traffic Signs and Posts, materials for round steel posts, accessed October 2026.
- Sheldon Brown - Lock Strategy, by Sheldon Brown, revised by John Allen, accessed October 2026.
Conclusion
A folding lock does its best work when one fixed loop holds an immovable anchor, a closed frame section and a wheel, pressed tight and lifted off the ground. Because the loop can't grow, the anchor choice and the wheel choice are made together, and a slim rack leg usually beats a thick pole. The six steps cover different attack routes, so finishing all of them matters more than any single upgrade.
For how folding locks compare as a format, see the short overview in the folding bike locks guide, which summarises where they fit in daily riding.
