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There are generally two big specialties for pumps. High Pressure (HP) or High Volume (HV). I ride Fat bikes, mountain bikes and road bikes, so I'm confused about buying a new pump to carry while on rides and whether I could find one pump to rule them all?

I know there are good pumps that do high pressure and others that do high volume. However, there are several that claim to be switchable between HP or HV.

How effective is this?

Will it be as effective as a dedicated HV pump on my fat bike tires? Will it also be able to put 110 lbs of pressure in my road bike tires as efficiently as a HP pump? Or are these a compromise that kind of works, but less than a purpose made HV or HP pump?

Examples of switchable pumps:

  • Giant Control Mini Combo Pump
  • Blackburn Mammoth Mini Pump
  • Raleigh RMJ604 2 Stage Switchable Pump

    • Seriously doubt it is going to be more efficient than a dedicated. – paparazzo Nov 11 '15 at 17:26
    • If it can reach the highest pressure you use it can do the bigger softer tyre but it might take a while. For taking with me I rather like my road morph, which is designed for thin hard tyres, but I've tried it out on 26x2 from flat and didn't think it took too long. – Chris H Nov 11 '15 at 20:02
    • I used a road morph (mine) and a mountain morph (my friend's) fixing a flat on my fat bike tire in the woods. The mountain morph was much faster at inflating the fat bike tire 26x4.5 to 10psi. The road morph is totally serviceable for use on a mountain bike tire, but less efficient due to a lot more pumps needed. For a fat bike tire, the volume is much larger and I'm not considering using my road morph ever for that again. I'm wondering where a switchable pump fits in here... does it work as well as say, my mountain morph? or does it require another hundred+ or more pumps like my road morph? – Benzo Nov 11 '15 at 20:13
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      As I understand it, the "switchable" pumps work by having two different diameter cylinders, one inside the other. As such, with proper design and sizing of the components, it should be nearly as efficient as the corresponding single-purpose pumps of the same overall size. However, a "mini" pump is already a pretty poor compromise, functionally, and making it switchable doesn't improve things. A better choice, for on-road use, is a "frame pump", and a "floor pump" is far and away a better choice for use at trail's end. – Daniel R Hicks Nov 11 '15 at 20:51
    • My guess is that the ergonomics of a pump also weigh in a decent amount for how hard it is (is the handle crap, is the base unstable for these mini frame pumps, etc.). Also, note that Genuine Innovations sells 20g and 45g CO2 cartridges, which will be faster and easier than either pump (albeit pricier in the long run and less environmentally friendly) -- you can do the math based on the tire volume to figure out how many grams of CO2 you need for your tire. – Batman Nov 11 '15 at 21:10
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    Answer: No. Any tool intended for a specific job will always be better at that specific job than a multi-purpose tool.

    That said, pricing may mean that a single pump is sufficient for your needs.

    Fat bike tyres have a lot of volume to fill, but generally they don't go to high pressures - I'd be surprised if you're running them at anything above 40 psi.

    Note I assume you're not talking about shock pumps when you say high pressure - they are used on higher end shock dampers and not tyres/tires.

    You said "less work" but from a wording point of view, the work remains the same, your input multiplied by the efficiency of the pump will approach the total work required but never equal it. So a 50% efficient pump will feel like you're doing more work than a 75% efficient pump.

    • Have you actually used one of these switchable pumps or is this just generalizing? By less work, I mean fewer pumps. A HP pump on a fat bike tire would really take a long time and require hundreds more pumps. Would a switchable pump be the same number of pumps as an HV pump or require many more pumps? – Benzo Nov 11 '15 at 20:08
    • @benzo I've used one. You do the first 40-60 PSI in high volume mode then switch over to high pressure mode. Its kinda like using a crowbar to pull a nail out - at some point you have to reset your "leverage" Given OP was asking specifically about fat tyres, which don't run a lot of pressure, a high-pressure pump may be unnecessary. – Criggie Nov 11 '15 at 21:25
    • Wondering how many pumps it would take to fill a fat bike tire with one of these versus a leyzene HV micro floor drive or a Topeak mountain morph? If it was comparable to either of these, then I would say it's effective. It takes about 216 to 255 pumps with these two high volume mini pumps to fill a vee bulldozer 26×4.7 tire to 7 psi. fat-bike.com/2015/05/trail-pump-shootout – Benzo Nov 11 '15 at 21:33
    • Though it's interesting to note that the pump you used forced you to switch modes to fill a road tire. That's definitely a consideration. What pump have you used? – Benzo Nov 11 '15 at 21:35
    • 40 PSI for a fat bike is a lot. I'd think you'd be around 15 PSI on the high end. – Batman Nov 11 '15 at 22:34

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