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How to fit a bike alarm

Updated: 20.10.2026

The puck is out of the packet and it either screams at nothing or will not arm. Both failures show up in the UK reviews of these amazon.co.uk vibration alarms, and both are usually fitting. This is how to fit a bike alarm so the body stays on the bike, the remote is paired before you hide it, and only a deliberate push sets it off. Rankings are on the [bike alarm comparison](/hub/burglar-protection/bike-alarm). Button names differ, so follow the card in the box. A qualifying purchase through our links can earn a commission at no extra cost to you.

The puck is out of the packet and it either screams at nothing or will not arm. Both failures show up in the UK reviews of these amazon.co.uk vibration alarms, and both are usually fitting.

Our top picks

Cruxer Cruxer 110 dB USB-C alarm

Best overall

Cruxer Cruxer 110 dB USB-C alarm
8.9/10about £19.99
View offer
Wsdcam Wsdcam 113 dB remote alarm

Rank 2

Wsdcam Wsdcam 113 dB remote alarm
9.1/10about £16.99
View offer
Fosmon Fosmon 113 dB SOS alarm

Alternative

Fosmon Fosmon 113 dB SOS alarm
8.6/10about £17.99
View offer
On this page
  1. 1.Fix the body so it stays put
  2. 2.Pair the remote before you hide it
  3. 3.Set sensitivity while it is disarmed
  4. 4.The first night

Fix the body so it stays put

Tape alone is the fit reviewers watch fail. A Fosmon reviewer says to use adhesive and cable ties together. The Qumox box includes two ties and two stickers, and the Cruxer 22R includes a strap and tape. Put the body on a tube that does not flex. The USB-C Cruxer adds a nylon bracket a reviewer twisted off without screws. Screw it. Under a cover is fine only after sensitivity is low. The REAPP is a different shape. The geometry stays on bike alarm vs disc lock. Loop the 1.5 m reminder cable where you will see it, so you do not ride off with the pin in the rotor.

Pair the remote before you hide it

Wsdcam reviewers say the remote does nothing until it is paired. Pair it in the hall before the puck goes under a saddle. The card in the box is the sequence. A dead fob looks like a dead siren. A Cruxer 22R owner replaced the AAA cells and then the remote cell before it responded. If the siren still chirps, change the fob cell first. If there is no chirp, change the siren cells or charge the USB-C pack. The Fosmon battery screw is very small. The Cruxer 22R listing says 20 m in the details and 50 m in the bullets. Test from the bike to your front door, not at the longer printed figure.
Cruxer Cruxer 110 dB USB-C alarm

Testsieger

Cruxer Cruxer 110 dB USB-C alarm
8.9/10about £19.99
View offer

Set sensitivity while it is disarmed

Set the seven steps while the alarm is disarmed, then arm it and push the bike with your palm. You want that push to start the sound, not wind on a cover. Left high, a Cruxer 22R went off during a jet wash, a Mengshen went off for a broom, and a Wsdcam went off in rain under a bumper. If the lowest step still screams at weather, the limits are on the bike alarm buying guide. The Mengshen disarm chirp is loud, with no quiet option in that review. SOS tilt, on the Fosmon and the Cruxer 22R, sounds past about 45 degrees. On the Cruxer it is off by default. Leave it off unless you want a fallen bike to scream.

The first night

Arm it only after an evening test outside. Push the bike, walk to the door you care about, and disarm. GOV.UK explains how councils deal with neighbour noise. A siren that runs because a cover flapped is that complaint. These listings do not state a cut-off you can rely on. Do not leave a new unit at maximum against a party wall. If you wire a siren into a motorcycle loom, stop and use the alarm the bike’s policy already specifies. A strap-on puck is not that job. For an e-bike or mobility scooter, the extra limits are on the e-bike alarm page. Who each one suits is on the best bike alarm page.

Common questions

Should I use tape, ties, or both?
Both, unless a screwed bracket is holding it. Tape on its own is what reviewers say a thief can peel. The Fosmon note in the saved listing is adhesive plus cable ties. The Qumox includes two of each. On the USB-C Cruxer, screw the nylon bracket. A bracket that only clips can be twisted off, which is the failure one reviewer described.
How do I stop it screaming at the wind?
Disarm it, lower sensitivity with the remote control on the card, then arm it and test with a deliberate push. Do not hunt for a dial. None of these twelve listings shows one. Keep the body off anything that flaps. If rain still sets it off at the lowest step, as one Wsdcam did under a bumper, that spot is wrong.
When do I change the fob battery?
Change the fob cell when the alarm still chirps or shows a light and the remote has stopped controlling it. A Cruxer owner replaced the alarm cells and then the remote cell. Change or recharge the siren when it is silent. The Fosmon cover screw is tiny, so do that indoors. Charging a USB-C puck does not refill the fob. The fob is a separate cell.
Can I hide it under a saddle or a cover?
Yes, after it arms reliably and after sensitivity survives a cover being lifted. Hiding it first means you strip the fitting when pairing fails. A cover lift triggered a sensitive Mengshen. Under the saddle works if you can still reach the cells. Do not park the speaker where rain pools if you have already heard weather false alarms.
What changes with a disc lock?
You pass a pin through the brake disc instead of strapping a puck, and you use the REAPP’s 1.5 m reminder cable so you cannot ride off locked. There is no radio remote to pair and no sensitivity step on a fob. The lock still needs a second, rated lock if the bike can be lifted. That limit stays on the disc-lock page.

Related pages

Bike alarm

Best bike alarm: known siren, USB-C, or a disc lock

Bike alarm buying guide: type, power, then the lock

E-bike alarm: siren for a shove, not GPS or a lock

Bike alarm vs disc lock: noise, or a pin in the disc

Sources

Public UK sources listed in the research digest. Listing prices, stars, and review counts are from the amazon.co.uk extracts for this category, checked on 19 October 2026.

  1. ONS nature of crime: bicycle theft (retrieved 20 October 2026)
  2. Quotezone: police-recorded bicycle theft in England (retrieved 20 October 2026)
  3. Sold Secure pedal-cycle lock grades (retrieved 20 October 2026)
  4. Sold Secure: ABUS 8077 disc lock (retrieved 20 October 2026)
  5. Environmental Protection Act 1990, section 79 (retrieved 20 October 2026)
  6. Road Vehicles (Construction and Use) Regulations 1986, regulation 37 (retrieved 20 October 2026)
  7. Merseyside Police: how safe is your bike? (retrieved 20 October 2026)