Dulwich Hill Bicycle Club

Just blew up two tubes and have traumatised HAB & cat as a result. I think the problem is that the track pump is reading considerably below actual pressure. I have triangulated results of the reading from the track pump with the following result:

Track pump - 60 psi
Thumb method - feels like 110 psi
Tried recently pumped tyre with track pump - read 60psi yet I know it should be about 100 psi.

So - how do I fix this problem? or is it terminal. The pump is a Serfas FP 200

Hi Eleri,

from my instrumentation background - it's probably a throwout, unless you keep it for emergencies, but with the gauge texta-ed (spelling?) over to avoid confusion.

Others might have more idea about that particular pump & if you are likely to get replacement gauges for it, but I suspect if you had to pay someone to fit it, it would be uneconomic to repair.

My method to confirm that it's stuffed, which you've pretty much already done, would be to pump up a tyre to (say) 100psi with a pump that you trust, then use the dodgy one to add a couple more pumps and seeing what reading it shows.

If you're really brave &/+ desperate, you could put a mark on the gauge where you've established that 110psi actually is, and only pump up to that mark, but if the gauge has deteriorated as much as it seems that it has, you really don't know when & by how much it's going to go further out.

Andrew

Hi Eleri,
That's a bugger - they are a real good pump and seem to last very well. Bob at Stanmore had them, might be worth a call.
Andrew's Texta calibration is a great idea.
Will await possible further explosions in the night.

Others might have more idea about that particular pump & if you are likely to get replacement gauges for it, but I suspect if you had to pay someone to fit it, it would be uneconomic to repair.

You can get a replacement dial for it and it's $8 (unknown currency). I wasn't sure if that was where the measurement actually happens or if it happens somewhere else and the dial is just a display. They call it a gauge though.

You can get a replacement dial for it and it's $8 (unknown currency). I wasn't sure if that was where the measurement actually happens or if it happens somewhere else and the dial is just a display. They call it a gauge though.

If they call it the gauge then it's likely (99%) to have the measuring bit in it. Also, the manufacturer would have been unlikely to want the complication of measuring the pressure in one place and displaying it somewhere else.

At $8 I'm not surprised it failed, but at that price how could one resist the temptation to try to fix it???