FAQ. All you need to know

Hello. I'm Boo9's CEO, David White.  I hope that the following will answer any questions that you might have about WiCaps or regarding tyre safety. If not, please use the contact page on this site and I'll be ready to help.  Please do not contact by phone: it isn't feasible to offer that service as a small company.

This page isn't as easy to use as I'd like. ASAP, I'll make it easier to find the information you need . . .

Before anything else, you might reasonably ask "why is there  so much to read on in this section? I thought your products are fit-and-forget".


Our products are indeed very easy to fit and use. WiCaps have a user guide that explain everything very clearly.  BUT, tyres are a big safety issue and that topic is unfortunately a very complicated one and our mission is to promote tyre safety. Also, you might like to have in-depth information about how our product works.  So this section is intended as a source that you can refer to if you need to. Don't feel you have to read every word before using our product!

Q. Can your product help prevent tyre blow-outs on my vehicle?

A.  Yes. Both under-inflation and over-inflation of tyres is the most common cause of blow-outs. The damage that leads to a blow-out can sometimes occur over days or weeks of the tyre being running at the wrong pressures.

The solution is to prevent internal tyre damage happening by checking tyre pressures constantly. WiCaps let you do just that with no effort.


Q. What causes a blow-out and what is a blow-out?

A. Under-inflation is one cause: the rim starts to run on the inner liner of the tyre, progressively destroying it. This eventually causes further loss of pressure.

   Also, when a tyre is-under inflated, all the components of the tyre – rubber, fabric, steel, composites – flex more. When the pressure gets too low and the tyre is running under load, these components get flexed beyond their design limits. What happens then is much like the effect of bending a length of steel wire: manipulate the metal long and far enough and it will become very hot and fracture.

In the same way, tyre cords (which effectively hold the tyre together) progressively break until a point where the tyre explosively splits. 

   When under-inflation is accompanied by over-loading of the vehicle or trailer (more common with the latter), this destructive process is accelerated.

   The message here is not only to check and correct pressures frequently but also to ensure that loadings are not exceeded for the particular tyres being used. My other message is don't hesitate to talk to the manufacturer of your tyres if you have any doubts or concerns.

Q. What should I do if I discover that I have been driving with an under-inflated tyre for some time?

A. Reduced / reducing pressure is generally an indicator of a slow puncture if tyre, wheel and valve appertains to be in good condition. Take a good look to see if you have a damaged wheel, valve or tyre wall. Check the tyre rubber is not showing signs of perishing. As best you can, check for a puncturing object in the tyre tread (easier said than done).

   Also, I suggest you take the opportunity to check the date of manufacture of the tyre (it's on the tyre wall). There are mixed opinions on whether tyres should be replaced every five years or so, regardless of tread wear.

   If all looks OK, inflate the tyre to its normal cold inflation pressure (only when the tyre is cold). Then drive with caution. After a while, check the pressure readout on your app if you have WiCaps fitted (or  a gauge if you don't have WiCaps..

   If you are worried about anything with regard to your tyres, I recommend you call a mobile tyre service or the manufacturer for guidance.

   Finally – and this is critical –if your tyre has been run 10% or more under-inflated for a significant time, it could have unseen internal damage – a possible precursor to a blow-out later. In this case, you should have the tyre internally inspected by a tyre professional as soon as possible.


Q. I know your products are about safety and avoiding under-inflation but can they save me money?

A. Yes. Comparing a correctly-inflated tyre with one that's 25% under-inflated*, it will cost you up to 4% in extra fuel and 25 to 30% more in tyre wear. Plus your chance of a tyre-related accident increase by a factor of 3*. That could add up to an incalculable cost, of course. If your tyres are 40% under-inflated (which is very, very dangerous), tyre life is reduced by 65%. Message: WiCaps can save you a significant amount of money – as well as time and grief. * Source: NHTSA research

Q. For what vehicles can I use your products?

A.  In two words: 'any vehicle'. However, our speciality is vehicles that are used for recreation, namely, motorhomes, caravans, boat trailers, horse trailers, horse boxes, motorbikes, even e-bikes. For many of these applications, high pressure tyres are needed. WiCaps are accurate to 180 psi  (12.4 bar).

  Anything that's towed carries extra risk with tyres. Simply because you generally can't see, hear, feel something going wrong with tyres on something you're towing. Also, there's the issue of loading: it varies a lot with recreational vehicles. We're finding it's all too common to find that caravans and motorhomes have the wrong pressures or even tyres for their laden weight. Because WiCaps  monitor your tyre pressures on the move, you can see if pressures are changing abnormally. In particular, you can see if pressures are increasing significantly because your pressures started too high, too low or because you have the wrong tyres.

Q.  Are your products suitable for bikes?

A.  For motorbikes, most certainly. For regular bikes, our products are probably a bit 'over the top'. Notwithstanding, e-bikes are an exception. They are heavy and therefore difficult to push and very difficult to carry over the shoulder if they end up with a flat tyre. If you get prior warning of reducing pressure, you have more options to deal with the problem. Also, it's easy to start a journey not realising a tyre is a bit soft – which generally indicates a slow puncture. If your bike has Presta valves you need a Schrader adapter. Contact us if you need an adapter.

Q. Are there particular vehicles where you see your products as a 'must have'.

A. Yes. Obviously, I'd suggest – wouldn't I? – that our products should be fitted to ALL vehicles other than those that don't already have TPMS fitted as standard (a legal requirement for cars since 2014 in many countries). However, I strongly feel TPMS is a ‘must-have’ for all caravans and trailers because it is virtually impossible to tell when a tyre has gone soft on a trailer while you are towing it. (In contrast, with a car, the change in handling due to a soft tyre is generally noticeable). 

   The consequences of a trailer tyre failing can be catastrophic and this is particularly so if the trailer is a valuable caravan, or you are moving horses or towing an expensive boat.

   The big risk with a trailer tyre failure is that the trailer causes the tow vehicle to swerve or over-turn.

    I also recommend TPMS for motorhomes because, with heavier vehicles, it's also more difficult to detect a soft tyre by noticing a change in handling. 

   Wheelchairs are 'vehicles' where we don't tend to consider tyres to be an issue. In fact, it is an issue because wheelchair tyres are easily punctured. And it's essential that a puncture (as indicated by lower than normal pressure) be addressed before the wheelchair is used.


Q. Can WiCaps be used on vehicles that have original equipment TPMS?

A.  This is a question I never thought I'd be asked. However, increasingly drivers are getting fed up with systems that often have just a red light that warns of major under-inflation. And often the system needs resetting if it triggers.

What you see of a TPMS valve looks very similar to a normal Schrader valve. As a result, WiCaps can screw straight on to a TPMS valve stem.


There's another reason to fit WiCaps. They detect if tyres are INCREASING in pressure more than normal. That's something that often goes unnoticed, even with standard TPMS fitted. High pressure increases result from tyres overheating. And the cause for that can be the wrong tyres fitted, wrong recommended pressures or vehicle overloading.


Q. Can your products cause tyre imbalance?

A.  This is a a somewhat difficult question to answer. A WiCap weighs 9 grams. We've only experienced slight front-wheel vibration issues when track-testing higher than the legal limit with some cars. Personally, I would take the fitting of WiCaps as an opportunity to have your vehicle or trailer tyres professionally checked and balanced. To be clear, don't waste money on having our products professionally fitted – it's a quick and easy DIY job. 

Q. Before fitting a WiCap, I've realised there is not enough space for it to fit on the valve. What do I do?

A.  As long as the product hasn't been used, you can return it for full refund. However, often there is a solution: have your tyre professional fit longer valves. You can also use a valve extender – which doesn't involve demounting the tyre. Only use an extender if a tyre professional agrees it's OK for your wheels. I suggest that if an extender is used, it is essential that it be fitted using liquid thread lock.  In some cases, hub caps can make fitting difficult. Temporary or even permanent removal of the hub caps may be a solution.

Q. Before fitting a WiCap, I've realised that it will extend the tyre valve beyond the outer wall of the tyre. What do I do?

A.  As long as the product hasn't been used, you can return it to us for a full refund. However, often there is a solution: have your tyre professional fit a shorter valve (which involves demounting the tyre).

Q. What is the wireless range of a WiCap?

A. We've tested WiCaps with various recreational vehicles and have found the app works reliably and accurately in all normal situations. In short, the range is adequate for use with caravans, trailers and motorhomes. 

   In technical terms . . . WiCaps use an international wireless standard called Bluetooth (BLE). The transmitted power is regulated to a fixed strength. The signal received varies, of course, with range as well as a number of other factors.

  Objects between receiver and transmitter reduce signal strength depending on their consistency and size. For instance, a brick wall may totally block out a signal.

I mention this because it's often possible to see your tyre pressures from inside your house with the WiCap system. 

I don't promise that however!

   If a transmitter and receiver are very close, yet blocked or partly-blocked by a human body, the signal can be reduced significantly, even at this short range. A typical example is when Bluetooth headphones work intermittently.

   At longer ranges, the omni-directional radio waves from the WiCap can generally go round the side of an object between it and the receiver (your mobile device). Hence, our tests demonstrated that a WiCap fitted to a wheel can successfully communicate with a mobile device hand-held in the passenger seat of a van – when the range is up to 28 metres. Clearly, this is not an absolute figure – it's influenced by many factors such as rain and radio interference. 

Q. How does the WiCap system work?

A. In simple terms, the WiCap, when fitted to a tyre valve, radios information from the various sensors it incorporates to a mobile device such as a smart phone or tablet. This information is then translated by an app, running on the mobile device, so that tyre pressures etc can be displayed on screen.

   In technical terms . . . WiCap incorporates a pressure sensor which sends pressure information to the WiCap's microprocessor. 

   This processor is incorporated within a large chip that also integrates a radio transmitter/receiver and other electronics that turn information from the pressure sensor into digital data that can be transmitted and error-checked.

   Once fitted, the WiCap communicates, wirelessly, with an app running on smartphone or tablet.

   The communication method is low energy Bluetooth (BLE), a wireless standard used by  smartphones and tablets.

   The communication is  one-way, from WiCap to app as digital data, eg pressure, which is passed to the app for display on the mobile device's screen. 

   WiCaps use state-of-the art technology to pack a lot of electronics into a very small and light package to deliver very accurate information. The package works with high pressures, can cope with high temperatures and is waterproof to the IP67 standard.  

   WiCaps are designed to use minimal power such that the (non-replaceable) battery can last two to three years. WiCaps switch on when they are pressurised and sense pressure or temperature changes.

Q. What is pairing?

A. Pairing is a process you only have to do ONCE. WiCaps need to associate themselves with the app such that the app can permanently  'memorise' their IDs. This means the app only searches for and listens to the intended WiCaps. It can then ignore the dozens, even hundreds, of other Bluetooth devices that may be in range at any given time. The app can then also ignore any other WiCaps that might come within range. This process of association is called 'pairing' or sometimes 'binding'. It's a one-time process.

   Once achieved – it's a near instant process – the app will be able to associate wheel positions (as displayed on-screen) with the particular ID of the WiCap on that wheel.      Pairing process is a one-time process  . . . removing a WiCap from its valve never affects the pairing. 

Q. How is pairing achieved?

A. Our user guide, supplied with the WiCap kit explains this in detail. However, here's an overview . . .

Our kit comes with a printed QR code on the box (the code is a different version of the well-known barcode).

The app allows you to use your phone's camera to scan this code to gain the identity of each WiCap supplied.

WiCaps have a number printed on their caps  (1 to 4).

If you order two WiCaps, you may receive numbers 1 & 2 or

3 & 4. It makes no difference and we generate the QR code so that it allows for this.

   When a WiCap is fitted to the tyre, it becomes pressurised, which in turn switches on its electronics. It then immediately transmits a  signal to the smartphone. Within seconds, pairing is achieved and then you repeat the process for the remaining cap/s.

   Once pressurised, WiCaps transmit every three minutes to 'advertise' their presence to the app. Transmissions are kept minutely short so that power consumption is minimal – thus allowing WiCap batteries to last for several years. 


Q. Why does the app offer several means of pairing?

A. The app is third-party software which is multi-purpose: I only recommend you use the method that uses the QR code.


Q. I think I've followed the user guide but I haven't achieved pairing. Why?

A. If you follow the steps given in the printed user guide supplied with the WiCap kit, it will be unusual if you have a problem. 


Here are reasons why pairing fails first time:

• You initiated pairing for, say, wheel 1 but did not fit

WiCap 1. (If you have been supplied with WiCaps numbered 3 and 4, you'd start with 3).


• You didn't pair / fit the WiCaps in numeric order.


• You didn't fully screw the WiCap on to the valve stem (THIS IS THE BIGGEST CAUSE). You need to screw them on very tightly.


• The tyre wasn't inflated.


We all know that phone apps can sometimes not do what the programmer intended. So if pairing still is not

achieved, here are some things to try  . . .

1. Unscrew the WiCap slightly and then tighten it back.

This causes the WiCap to transmit automatically and instantly to the app.

2. Close the app, restart it and repeat the pairing process.

3. Turn your smartphone off and back on again.

4. Delete the app and download it again.

5. If you have an Android phone, Google have released updates recently that have affected many apps. The problem should be sorted by now because customers are reporting the app now works OK.


If you still have a problem, email me via this site.

Q. The WiCaps don't seem to be transmitting to the app Why?

A. The range of WiCaps is exceptionally good, so that factor shouldn't be an issue. Remember that the WiCaps only transmit every 3 minutes (to save power), so you may have to wait 3 minutes or more for all WiCaps to have transmitted to your mobile device.


Q. What does the rotation of the dials (on the smartphone's screen), when the app is running, signify?

A. The dials rotate only when the app has  received a transmission from any one of its paired WiCaps – typically this will be when the WiCaps come within range of your smartphone.

Unfortunately, all the dials rotate when just one app's transmission has been received.So it may take a few minutes for the app to update for all dials, even if they are rotating. 


You may find it more convenient to start driving your vehicle and have your 'co-pilot' check pressures when all the WiCaps 'wake up'. Thereafter, you can check the pressures inside your vehicle whenever it is safe to do so. As the driver, don't use your phone while driving.  

Q. Why does the app indicate that tyre pressures have increased once I have been driving a while ?

A. As tyres warm up, pressures increase.

Q. Sometimes pressures appear higher on one side of the vehicle to the other. Why?

A. Particularly with caravans and trailers, the nearside or kerbside tyres can heat up if the edge of the road is uneven. The nearside tyres then flex more than the offside ones and heat up more, thus increasing the pressure.

Q. I don't get an alarm, visual or audible, when the tyre pressure has dropped significantly. Why?

A. The dials turn red and a speech message is given when pressure drops to the level set in the Settings page of the app. The threshold for the app to warn of low pressure has a maximum of 36 psi (this adjusted in the Settings page of the app). As a result, for example, with a 60 psi tyre, the alarm trigger point is lower than I like. However, your tyre pressures are always on display  – that's way better than having no idea what's going on. It's not ideal but something that we address in the app we are coding ourselves. Please be patient: we are working hard on this. 

Q. The dials on the app are permanently red. Why?

A. This means either that your tyre pressures are below the low threshold you have set in the app or the pressures are above the the maximum threshold you have set in the app. The maximum threshold is 93 psi. 


Q. How do I turn off the audible warning?

A. Tap the speaker symbol top right of the screen.


Q. Are WiCap batteries replaceable?

A. No. We've made them sealed because we were finding that some users were damaging the radio antenna inside the device when looking inside. We discard batteries supplied from China and fit European-sourced high-capacity batteries. When it gets closer to battery replacement time, we intend to launch a low-cost WiCap replacement service.

Q. Can WiCaps corrode or can their threads jam on the valve stem?

A. WiCap electronics are protected by seals conforming to the IP67 standard. The only metal component of the WiCap is the valve thread, which is brass – the metal used for virtually all valve stems. Whilst corrosion can occur with different metals in contact, brass on brass is generally OK. Notwithstanding, it's not a bad idea to lubricate the valve stem with a light oil or silicone spray before fitting the WiCap.

Q. Can I use WiCaps with boat trailers that get immersed in water?

A. Yes. WiCaps are totally sealed when fitted to the valve stem. They are rated to IP67, which means they can be immersed in up to 1.5 metres of water for up to half an hour if necessary. However, do watch out for your wheels if they get immersed in water, especially salt water. Wash them thoroughly after immersion.


Q. Where's the best place to get information on tyres and tyre safety? Here are two good sources:


www.theAA.com/tyres     (click 'tyre advice' on the AA page)

Also, always read the user manual supplied with your vehicle, trailer or caravan.

More questions?

Use the contact page and ask away. We're here to help!


Stay safe