Cycling UK Forum

I want to use an old Blackburn track pump at a community bike project. It is in good condition except the head seems to blow air on both sides regardless of which way round it is twisted. It grips Presta and Schrader valves, but air will come out of the opposite side in each case.


I can buy a new head, but I’m asking in case there’s a simple part missing that could be repaired with something in the bits box. When I remove the head, there’s a central pivot with two O-ring seals, and then there seems to be a hole up the middle and then a hole at right-angles that goes right across, so both sides will get air regardless of which way the head is twisted. I am assuming one of these holes was blanked off for it to work, but with what?

There’s a photo of each side of the central piece below with a red background to show that you can see right through it. On one side there’s just a small hole, but on the other, there’s a recess as if something that may have blanked the hole has popped out. The side with the small hole has a mark on it where something that was in the hole might have been dragged along the surface.


I could try stopping up one or other side with epoxy and see if that works, but it would be good to know what state I am trying to re-create.

As above, a new head of a different design is an option (this design is no longer available), so it’s as much curiosity about what’s missing / what it will have been like when it was new.

Thanks for any insights.

If you don't get an answer here I recommend asking Blackburn directly for a diagram and about which rebuild kit you should use:
https://www.blackburndesign.com/contact-us

Jonathan

I wonder if there should be an O ring sat in the larger of the two holes? It might then seal up the side it’s not meant to be blowing to.

Jdsk wrote: ↑6 Sep 2023, 5:29pm If you don't get an answer here I recommend asking Blackburn directly for a diagram and about which rebuild kit you should use:
https://www.blackburndesign.com/contact-us

Jonathan

Thanks Jonathan,

I'm asking here because I'd asked there a while back and they had been unable to help. The pump is old, and probably pre-dates the internet. They sent me some diagrams, but these are strangely silent about what goes on inside the the twist grip assembly. The diagrams seem to have come out of a loose-leaf binder and pre-date all of the electronic versions on the Blackburn Design website. I'd forgotten I had these - thanks for the prompt. The blocky resolution is what I received.

And, the Lifetime Warranty seems to be a Limited Lifetime Warranty in the sense that it works well if you are in the US, or possibly if the UK retailer it was bought from is still trading.

backnotes wrote: ↑6 Sep 2023, 7:59pm And, the Lifetime Warranty seems to be a Limited Lifetime Warranty in the sense that it works well if you are in the US, or possibly if the UK retailer it was bought from is still trading.

My experience of the warranty is that any Blackburn dealer will do the swap for you - they just return the item to their Blackburn rep. I had no purchase receipt and wasn’t even the original owner. Though I may have omitted to mention that bit.

Thanks, I can certainly give that another try at a different shop.

Thanks also for the O ring suggestion above. I think the opposite side needs to be blanked off in some way, so I think whatever is missing won't have a hole in the middle, unless I have misunderstood the suggestion - which is quite possible. An O ring would stop air from coming round the sides of the central pivot, but wouldn't it still be able to go through the aperture in the middle if the O ring if it is located in the recess above the hole?

You can buy a complete new head I think from BBB. I did a few years ago. They are better because they have a compression lever - not just push on. Yes, found it: https://www.sprocketandgear.co.uk/produ ... mps-bfp-93.

I had another think about this. The recessed hole very likely had a round rubber bung in it which stops up the hole of the unused connector. The part you turn is likely very simple: just two opposed connectors with holes open on the inside of a smooth tube of a diameter you can push over the o-rings. Friction and wear would destroy the rubber bung. To stop it shearing out of the hole, it might have been stepped, looking like a very flattened mushroom. It could even have had a thickened stepped plug to hold it in place in the hole. Whatever - the rotation and sliding would wear it away. A poor design.

The BBB replacement I mentioned has some kind of pressure-operated change-over valve. It doesn't always flip when you want, but does eventually. We have the same type on the ends of our compressor hoses at the bike workshop.