Problems pumping up tyres!

As 2 omegas said a track pump with a skinny barrel like the Rennkompressor will be much easier to use for those who are lighter in weight.

You are tring to compress a column of air from 15 PSI to >100 PSI and the larger the volume of the column, the more force would be required. Two pumps 60 cm tall but one 2cm barrel and other 4cm would need double the force to get the same pressure in each.
Would need half as many pump strokes with larger pump but each requiring a larger force
per stroke.

I have Crank Bros hand pump that has two chambers inside which you can select; large volume (hard to pump) to get started then a small volume (high pressure) that is easier to pump but compresses a smaller amount of air to a higher pressure per stroke.

Thanks for the physics lesson Steve, we have a Rennkompressor, doesn't work for the slighter in build...
see previous posts.