There I was enjoying my run around Scotland when I had a minor niggle. The TPS was solid on the front, but the rear was 0.1 bar low, most, but not all the time. That poked a stick at my OCD nature, so I thought I'd stop at a filling station and sort it. Simple. Or it should have been.
I found one but it demanded a 20p fee. OK. In went the 20p. On went the connector. Lever pressed. Hiss. But instead of air going into the tyre, air was escaping from the valve. I tried to make a more secure connection, but only succeeded in losing yet more pressure. The more I tried the worse it got.
The staff did what they could. Gave me another 20p to try again. Same result. One went to get a foot pump from her car. That seemed to add a bit of pressure, but as soon as the noise of my furious pumping stopped, the hiss of rapidly escaping air could be heard. 350 strokes of the pump later, I gave up. I moved the bike round the corner, red triangle flashing, 1.1 bar on the TPS.
At that point I might have had only the option of calling out the recovery service. But there was a Plan B.
Out came my 12v air pump. I hadn't used that in the first place because it is a faff to set up. It lives in the bottom of a pannier. The seat has to come off to get a secure access to the battery terminals, and getting the cable back in the space it came from is an art that can waste 10 minutes. (Clearly the makers employ specially trained elves to get the 12v connector and cable into the undersized space in the pump). But that pump had a screw-on connector which I knew was good (as is the foot pump I've always used at home). After a while the tyre pressure was back where it should be. The pump was now very hot, but I had remembered to keep the engine running while using the pump just in case.
Looking at the cause of the problem, the K valve stem is *very* short (and perhaps is on other BMW models where the connector is sideways on, coming out from the spoke rather than the well of the wheel). If a garage connector has to sit deeply on the stem - as was the case at this garage - it is not going to seat properly and all you do is let air out.
The solution was, of course, at home. Aren’t they always! A short tyre valve extension which screws onto the bike valve and has a long reach threaded section for the pump to mate to. It is now carried on the bike.
I found one but it demanded a 20p fee. OK. In went the 20p. On went the connector. Lever pressed. Hiss. But instead of air going into the tyre, air was escaping from the valve. I tried to make a more secure connection, but only succeeded in losing yet more pressure. The more I tried the worse it got.
The staff did what they could. Gave me another 20p to try again. Same result. One went to get a foot pump from her car. That seemed to add a bit of pressure, but as soon as the noise of my furious pumping stopped, the hiss of rapidly escaping air could be heard. 350 strokes of the pump later, I gave up. I moved the bike round the corner, red triangle flashing, 1.1 bar on the TPS.
At that point I might have had only the option of calling out the recovery service. But there was a Plan B.
Out came my 12v air pump. I hadn't used that in the first place because it is a faff to set up. It lives in the bottom of a pannier. The seat has to come off to get a secure access to the battery terminals, and getting the cable back in the space it came from is an art that can waste 10 minutes. (Clearly the makers employ specially trained elves to get the 12v connector and cable into the undersized space in the pump). But that pump had a screw-on connector which I knew was good (as is the foot pump I've always used at home). After a while the tyre pressure was back where it should be. The pump was now very hot, but I had remembered to keep the engine running while using the pump just in case.
Looking at the cause of the problem, the K valve stem is *very* short (and perhaps is on other BMW models where the connector is sideways on, coming out from the spoke rather than the well of the wheel). If a garage connector has to sit deeply on the stem - as was the case at this garage - it is not going to seat properly and all you do is let air out.
The solution was, of course, at home. Aren’t they always! A short tyre valve extension which screws onto the bike valve and has a long reach threaded section for the pump to mate to. It is now carried on the bike.
~ i'll stick to kicking me tyres. 
