Frank X said:Quoted message said:The better the pump, the easier it will be with whatever
strength you have, definitely. I don't know the Blackburn
but, whatever, I recommend going for something that is
"rated" /well/ beyond what you need to make sure that it
can manage what you actually need /comfortably/. I use a
240 psi Silca Super Pista* for my 130 psi tyres. Easy!
Eh? The difficulty will be proportional to the diameter of
the piston (inverse square).
Yes I know that.........
Quoted message said:If the diameter were 1.5 inches you need over12 1/2 stone
on top of the piston to get to100 psi.
If the diameter were 1 inch you only need 5 1/2 stone for
the same 100 psi.
Of course with a small diameter you need to pump more
times to get the same volume of air in. It's not better or
worse, it's just a choice.
Pumping fewer times but having to use more force *is* worse
if the required force is uncomfortable or impossible to
manage. Or do you think you can reach any pressure with any
pump if you just go on pumping long enough?
You don't mention the length of the piston. Eh, why not, eh?
:-) That is another factor, I believe--a rather important
one. This, as well as diameter, varies from pump to pump.
The fact remains that in practice, some pumps manage high
pressures easier than others. The "easy" ones tend to be the
ones that are "rated" higher. These "ratings" often being
somewhat bogus anyway, so therefore it is sensible to get
one that's supposed to be better than you actually need.
~PB