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Among the track pumps (floor pumps) on the market, I see one advertised with the following feature:

foot-activated high-pressure/high-volume switch

I'm interpreting this to mean that the pump has two modes:

  1. High pressure and low volume, suitable for pressures between 80psi and 160psi.
  2. High volume and low pressure, suitable for pressures between atmospheric and 80psi.

Is this interpretation about right, and does this feature make it more attractive than other models for someone who'll use it mainly for road bike tires, but also occasionally for mountain bike tires?

I'm intrigued by how they achieve this, since a first guess of how to build it would involve changing the diameter of the tubular air compartment, not exactly something that can be obtained by a switch. But that's for another question (perhaps on some mechanical site).

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    These pumps have 2 cylinders, since pressure equals work, a thin cylinder produces a higher pressure than a wide cylinder with the same amount of work or force. The switch selects the cylinder that will fill your tyre while the second cylinder runs empty. To fill a bigger MTB tyre that needs more air at a lower pressure, you choose the large cylinder that does the job faster. You could of course use the high pressure cylinder but you'd need more pump strokes – Carel Apr 4 at 14:22
  • It would be useful in many situations. Whether it's worth the extra cost, complexity, and weight is a separate question. – Daniel R Hicks Apr 4 at 14:32
  • @DanielRHicks: It may be useful if you have a roadbike with high pressure tyres and a fat bike with high volume low pressure tyres. With a pump aimed at high pressure tyres it will take ages to pump up the fat tyres because each stroke will only deliver a small amount of air. – Carel Apr 4 at 19:23
  • @Carel But the track pumps in the "competition" all consist of just one setting. That setting likely uses the full volume of the rather large air chamber. Yet they are meant for road bikes, and so I don't see your point. – Sam Apr 4 at 20:10
  • @Sam: Switchable track pumps are quite rare. The type that is emerging on the market is the one with a reservoir for seating and inflating tubeless tyres that are hard to seat with a standard stroke by stroke pump and need a single high pressure pop. – Carel Apr 4 at 21:19
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That interpretation is about right, I found some more explanation and a positive review of one here: https://off.road.cc/content/review/pumps-and-co2-inflators/crankbrothers-gem-floor-pump-review-2759. Interesting!

I see a couple of use cases

  1. Two bikes one pump; if you have high volume tyres on one bike and high pressure ones on another, you can just have the one pump. However, with inner tubes, there's not a huge penalty for inflating high volume with a conventional pump anyway and the reviews I've seen don't mention how well it performs on tubeless.

  2. Mid-sized and up tubeless tyres where you want to fill the tyre with rapid volume to seat the bead or save time, then top up to a medium to high pressure where a high volume pump won't cut it.

Whether or not any of the attributes are beneficial will depend on your own 'stable' of bikes, and even then how those wheels and tyres behave if you're using tubeless. Sometimes seating tubeless is no trouble with just a conventional high pressure pump, other times they won't even seat with a mains air compressor.

You might want to suck it and see - it's not that expensive. Think of it as a good track pump with a bonus feature that will be helpful some of the time, but not solve every problem.

For people who already own a pump to suit their bikes, it's not something to rush out and buy, though I am intrigued and interested to try one. It certainly looks like a reasonable option for a first pump, with a little future proofing for the bikes you might come to own (n+1 where n is the number of bikes you currently own).

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Are you riding on Tubeless tyres? If so, the high-volume pump can help to "seat" a tyre to the rim.

Some tubeless-focused track pumps have a reservoir which can be charged with air, and then released in one fast PHSSSSST to "pop" the bead out to the rim and establish a seal.

enter image description here

Note they should not be stored charged, so its not like a portable air tank or a CO2 cannister.

I've never personally seen a track pump with a switch like you describe, but guessing its trying to be more things for more people. A conventional floor pump will probably work fine for your bike maintenance needs. Get an entry-level track/floor pump and go from there.

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    This is the booster mode, but I do not beleive that is the HP/HV exchanagble modes the OP is asking about. These are something different. They do not get the air go from a pre-pumped container in one go, they just change the regular pumping operation. – Vladimir F Apr 6 at 7:26
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This switch is a feature of my shock pump (which also works as a normal pump) and is very useful to be able to pump larger tyres and still be able to achieve high pressures. You start your pumping with the high volume setring until you are able to do so. With more pressure in the tyre or in the shock (or whatever) the pumping becomes harder and harder.

You then have to switch to the high pressure mode and continue pumping with a smaller amount of air per every push to achieve high pressures (in my case above 50 PSI, it is a small pump on can carry around). It requires much smaller force for each push. If you use this mode for small pressures you would have a very large number of pushes.


Note: In my case it has nothing to do with tubeless. But it could be useful for tubeless on a big floor pump, if it pumped more air than normally possible, to have a higher chance to seat the tyre. In that case, the size of the pump's cylinder will be the limiting factor. The larger, the more air you can get there at once.

But sometimes one might get out of luck anyway, yesterday I did not get my tyre seated. It had been seated around five times before without any issue but with time the ends became closer and closer. So the air from a floor pump escapes too quickly. I had to order a tyre booster and will see. I believe these boosters (giving a lot of air by opening a large pre-pumped cylinder), no matter if included in a pump or separate, have a higher chance to seat a stubborn tyre.

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