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Best Bike Locks Under $50 for Adult Tricycles
This tier finally buys real hardened steel, so the choice becomes shackle size, chain thickness and how it fits a trike frame.
Updated · 4 min read · 6 products evaluated
Move from cable to hardened steel and a lock starts to matter. At this tier you can buy a U-lock with an 18mm shackle or an 8mm square-link chain, and both resist the cheap cutters that defeat cable in seconds. The catch for trike owners is geometry: a trike frame and its wide rear axle need more room inside the shackle than a standard bike.
This guide compares U-lock combos, plain chains and an alarm chain. It is a step up from the cable-focused under 25 guide, and it complements our full U-lock and chain lock pillar guides, which cover the heaviest options.
Short answer
The NDakter 18mm U-lock with a 4 ft chain is the pick for most trike owners because the large shackle and the chain together cover frame and wheel. The Kryptonite Keeper 712 is the best straight chain, the INTEKIN 8mm chain is a thicker link, and the eMjollRay adds an alarm. The Sportneer pairs a smaller U-lock with a 5 ft cable.
Quick Picks
Our 6 recommendations at a glance. Tap a pick for the full verdict.
Our Picks
Best Overall1 of 6
NDakter 18mm U-Lock with 4 ft Chain
A large U-lock plus a chain gives a trike the reach and the steel to be locked properly.
Best for
Most trike owners
Why we like it
This set pairs an 18mm hardened steel U-lock with a 4 ft chain and a mount bracket, and includes three keys. The inside opening is 8.66 by 4.12 inches, large enough to pass through many frame tubes and a post.
Compared with the Sportneer, the shackle is thicker and the opening bigger, which matters on a trike with wider tubing. The weight is nearly 4 pounds, so it is not light to carry. For daily outdoor parking it is a reasonable budget choice, and it is the one to start with unless you want a second NDakter variant.
Key specs
| Size | 8.66 x 4.12 in opening, 18mm shackle |
|---|---|
| Fit and mounting | Bracket for 0.98 to 1.37 in tubing |
| Features | 4 ft chain, 3 keys |
Specs can change between model years; confirm the exact version before buying.
Strengths
- Large 18mm shackle
- Wide inside opening
- Chain adds reach
- Three keys included
Limitations
- Nearly four pounds to carry
- Bracket may not fit every frame tube
Consider it if
- Daily outdoor parking
- Locking frame and wheel together
Skip it if
- Riders who need a light lock
Best for Multiple Trikes2 of 6
NDakter 18mm U-Lock with 6mm Chain
A similar U-lock and a chain long enough for several trikes.
Best for
Locking a group
Why we like it
This NDakter set uses an 18mm U-lock and a 120cm by 6mm chain with a nylon protector, and the maker says the chain is long enough for three to four tricycles. The cylinder is zinc alloy and it comes with three keys.
It has a thinner chain than the other NDakter set above and weighs 4.4 pounds as a package. Choose it if you lock more than one trike at a shared rack or garage. For a single trike, the other NDakter set has the larger opening and is the better fit.
Key specs
| Size | 18mm shackle, 120cm x 6mm chain |
|---|---|
| Weight | 4.4 lb set |
| Features | Nylon chain cover, silicone shackle cover, 3 keys |
Specs can change between model years; confirm the exact version before buying.
Strengths
- Chain reaches several trikes
- Silicone and nylon covers protect paint
- Three keys included
- 18mm shackle
Limitations
- 6mm chain is lighter than the 8mm options
- Heavier package
Consider it if
- Couples or families with two trikes
- Shared garages
Skip it if
- Solo riders wanting the thickest chain
Best Straight Chain3 of 6
Kryptonite Keeper 712 Chain Lock
A known-brand 4 ft chain with a deadbolt head for riders who want chain only.
Best for
Simple chain locking
Why we like it
The Keeper 712 uses 7mm four-sided hardened manganese links, a deadbolt lock head and a nylon sleeve, at around 3.75 pounds with two keys. It includes access to the maker's key replacement program, useful if keys get lost.
It is a little thinner than the INTEKIN 8mm chain but is lighter and from an established lock brand. Choose it when you want a straightforward chain with a good lock head. A 4 ft length is workable for a trike, though it can be short if the rear rack is far away.
Key specs
| Size | 4 ft long, 7mm links |
|---|---|
| Features | Deadbolt head, nylon sleeve, 2 keys, key program |
Specs can change between model years; confirm the exact version before buying.
Strengths
- Hardened manganese links
- Deadbolt lock head
- Key replacement program
- Nylon sleeve protects the frame
Limitations
- 7mm links are thinner than the INTEKIN
- Four feet can be short on a trike
Consider it if
- Riders wanting a name-brand chain
- Standard outdoor racks
Skip it if
- Heavy-theft areas
Best Thick Chain4 of 6
INTEKIN 8mm Bike Chain Lock
The thickest chain links in this tier, with a deadbolt core, in a shorter package.
Best for
Cut resistance
Why we like it
The INTEKIN has 8mm square links, a solid metal deadbolt and blade core, a fabric sleeve and three keys, at 2.87 pounds. The thick links resist small bolt cutters better than 6 or 7mm chain.
The trade is length. At 2.6 feet it is the shortest lock here and often too short to wrap a trike frame and a post. Choose it if you mainly lock to a nearby rail, or as a second lock combined with a longer one.
Key specs
| Size | 2.6 ft long, 8mm links |
|---|---|
| Weight | 2.87 lb |
| Features | Deadbolt and blade core, fabric sleeve, 3 keys |
Specs can change between model years; confirm the exact version before buying.
Strengths
- 8mm square links
- Deadbolt core
- Three keys included
- Light for a chain this thick
Limitations
- Short for a wide trike
- No U-lock option
Consider it if
- Locking next to a close post
- A second lock layer
Skip it if
- Reaching distant racks
Best Lighter Combo5 of 6
Sportneer U-Lock with 5 ft Cable
A lighter U-lock with a long cable for the frame and a wheel.
Best for
Lighter loads
Why we like it
The Sportneer is a 17mm shackle U-lock measuring about 7.76 by 5.02 inches, weighing around 1.6 pounds, with a 5 ft steel cable and a bracket. It ships with two keys.
It is much lighter than the NDakter sets and the cable lets you secure a wheel along with the frame. The smaller shackle and cable mean less resistance to cutting, so it is the choice for shorter stops. If you park outside overnight, go with the NDakter 18mm set.
Key specs
| Size | 7.76 x 5.02 in, 17mm shackle |
|---|---|
| Features | 5 ft cable, bracket, 2 keys |
Specs can change between model years; confirm the exact version before buying.
Strengths
- Lighter than the other U-locks
- Cable reaches a wheel
- Bracket included
- Two keys included
Limitations
- Smaller shackle opening
- Cable portion is easy to cut
Consider it if
- Daytime stops
- Riders who dislike heavy locks
Skip it if
- Overnight outdoor parking
Best With Alarm6 of 6
eMjollRay 4 ft Chain Lock with Alarm
An 8mm chain that also sounds a siren, but the alarm does not replace a stronger lock.
Best for
Noisy deterrent
Why we like it
The eMjollRay combines an 8mm, 4 ft chain with a vibration sensor that sounds a 110dB siren. It has two remote controls, USB-C charging and three keys, and a fabric sleeve.
The alarm gives a thief a reason to leave, but a rechargeable alarm only works if you keep it charged. Compared with the Kryptonite Keeper, you pay for noise rather than a better lock head. It suits riders who park in public view and want an audible warning.
Key specs
| Size | 4 ft long, 8mm chain |
|---|---|
| Features | 110dB alarm, 2 remotes, 3 keys |
Specs can change between model years; confirm the exact version before buying.
Strengths
- 110dB siren on movement
- Two remotes included
- 8mm chain
- USB-C rechargeable
Limitations
- Alarm needs regular charging
- False alarms in wind or bumps
Consider it if
- Public parking spots
- Riders who want audible deterrence
Skip it if
- Riders who forget to charge devices
Spec Comparison
Key figures side by side. A dash means the brand gives no figure, so ask before you buy if it matters to you.
| Model | Size | Weight | Features | Link |
|---|---|---|---|---|
| NDakter 18mm U-Lock with 4 ft Chain Best Overall | 8.66 x 4.12 in opening, 18mm shackle | — | 4 ft chain, 3 keys | Check price |
| NDakter 18mm U-Lock with 6mm Chain Best for Multiple Trikes | 18mm shackle, 120cm x 6mm chain | 4.4 lb set | Nylon chain cover, silicone shackle cover, 3 keys | Check price |
| Kryptonite Keeper 712 Chain Lock Best Straight Chain | 4 ft long, 7mm links | — | Deadbolt head, nylon sleeve, 2 keys, key program | Check price |
| INTEKIN 8mm Bike Chain Lock Best Thick Chain | 2.6 ft long, 8mm links | 2.87 lb | Deadbolt and blade core, fabric sleeve, 3 keys | Check price |
| Sportneer U-Lock with 5 ft Cable Best Lighter Combo | 7.76 x 5.02 in, 17mm shackle | — | 5 ft cable, bracket, 2 keys | Check price |
| eMjollRay 4 ft Chain Lock with Alarm Best With Alarm | 4 ft long, 8mm chain | — | 110dB alarm, 2 remotes, 3 keys | Check price |
How We Chose These Bike Locks Under $50
- Shackle size and trike fit
- We compared the inside opening and shackle diameter, since a trike frame needs more room than a standard bike.
- Steel and link thickness
- Chain thickness from 6 to 8mm and 17 to 18mm shackles were compared as the real measure of cutting resistance.
- Reach and weight
- Chain length and total weight were balanced, since a lock that is too heavy gets left at home.
- Distinct from cable-only locks
- Cable-only locks belong in our under 25 guide, so this one covers hardened steel and alarm options.
What to Look for in a Bike Lock Under $50
Shackle diameter and opening
A thicker shackle takes longer to cut, and a bigger opening lets the lock pass through a trike frame and a post.
Look for 17 to 18mm on a shackle, and check the inside dimensions in the product details before ordering.
Chain link thickness
Thicker links need larger cutters, so each millimeter adds real time. Six millimeter chain is a light deterrent, while 8mm is a stronger budget choice.
Compare the link size on the title, not marketing words like heavy duty.
Chain length against trike length
A 2.6 ft chain may only reach a close post, while 4 ft covers most racks.
Walk to where you park and measure. If it is more than a few inches short, you will end up locking only a wheel.
Alarm trade-offs
An alarm adds noise but also a battery you must maintain and false alarms in wind.
Choose it for exposed public parking and keep the chain itself as the main security.
How to Choose
By How You Park
| Situation | Our pick | Why |
|---|---|---|
| Daily outdoor rack | NDakter 18mm U-Lock with 4 ft Chain | Large shackle plus chain |
| Two or more trikes together | NDakter 18mm U-Lock with 6mm Chain | Chain long enough for several |
| Nearby post only | INTEKIN 8mm Chain | Thickest links, shortest length |
| Daytime stops, light carry | Sportneer U-Lock with Cable | Lightest U-lock here |
| Public view parking | eMjollRay Chain with Alarm | Siren adds a warning |
U-Lock vs Chain
- U-lock
- The NDakter sets and the Sportneer are U-locks. The rigid shackle is hard to cut, but the opening limits what it can wrap around.
- Chain
- The Kryptonite Keeper, INTEKIN and eMjollRay are chains. They reach awkward spots and wrap a trike easily, but links are thinner than a shackle.
Most trike owners should choose the NDakter U-lock and chain set for the combination of both.
For Shared Garages Specifically
- Look for
- A chain long enough for more than one trike and a sleeve that will not scratch neighbors' paint.
- In this comparison
- The NDakter 18mm U-Lock with 6mm Chain is built for this, since the chain reaches three to four trikes.
When to Spend More
- Spend more if
- You own an electric trike or park in a city. Look at the heavy locks in our U-lock and chain lock pillar guides instead of the Sportneer.
- Save if
- You ride locally and lock up only for short stops. The Kryptonite Keeper 712 or INTEKIN is enough.
Frequently Asked Questions
What does a lock in this tier give me over a cheap cable?
Hardened steel shackles and thicker chain links that resist small cutters much longer than cable. It is a clear step up, though not equal to the heaviest locks.
Will a U-lock fit around a trike?
Only if the opening is large enough for the tube and post together. Check the inside dimensions, since a small shackle may only secure a wheel.
Is an alarm lock worth it?
It helps in busy public places because the noise draws attention, but the alarm needs charging and can false trigger. It does not make the steel stronger.
Should I carry two locks?
Using a U-lock and a chain together forces a thief to carry two tools, and it is a sensible plan for overnight parking.
How heavy are these locks?
The U-lock sets weigh around four pounds, while the INTEKIN chain is under three. Plan on carrying the weight in a rear basket, not on the handlebar.
Bottom Line
Under 50 is where a lock begins to offer real resistance. The NDakter 18mm U-lock with a 4 ft chain is the best fit for most trikes, and the Kryptonite Keeper is the best simple chain. For the heaviest security, see our full U-lock and chain lock pillar guides.