I have no trouble changing my tires with my hands, but now and then I
blister my thumbs (and the ears of anyone nearby) because I push on
the sidewall to get the tire bead to come out.
Yes, tricks involving soap, water, varying the tire pressure, and so
forth also pop the tire bead out, but I'm too impatient and always
imagine that my thumbs won't blister. (They do--it just takes about
ten minutes for the blisters to form.)
Anyway,Park Tool makes a tire-bead seater/helper/puller, the PTS-1:
http://stores.channeladvisor.com/ebikestop/items/04-TL8252
But a Park Tire Seater Tool is over $40 with shipping. Besides, I
wanted one right now, before my temper cooled.
Harbor Freight sells a similar tool online. It's for grabbing pipes,
and the store five minutes from my house had it in stock for $6:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=94077
I clamped the Harbor Freight pipe pliers in a vise and spent a few
minutes rounding off their edges with a half-round file:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=36990
(Often on sale for much less--rotating in two planes can be very
helpful.)
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=40207
(whatever's cheapest)
Even with blistered thumbs, the lightly modified pipe pliers work
well. They're very sturdy, and their dimensions seem almost designed
for grabbing 700c tires and pulling reluctant beads out of their
burrows.
Cheers,
Carl Fogel