In reply to David Coley:
You only have to ask!
The sort-of standard grip test for gloves is NFPA 1971 which tested the grippng ability on ropes and gives the result as a percentage of that achieved bare handed. It´s been changed recently so the values nowadays aren´t so relevant (it´s not rope any more and was hawser laid then as well) but the standard required the loss to be not more than 30% if I remember rightly.
There´s probably a Euro standard out there as well.
There´s some other interesting stuff about grip and heat transfer from the US military but fast-rope entry is getting a bit off our scenario.
For a sample of one (me), force in kg.
8mm Bare 16kg Glove 12kg 75%
9mm Bare 20kg Glove 16kg 80%
10mm Bare 28kg Glove 22kg 79%
(the strain guage I used then measures in 2kg increments so there´s a fair amount of leeway for variation).
These aren´t the absolute maximum I can achieve bare-handed since pain is more or less the ultimate criteria, I´ve seen 45kg but that´s not really a useful value!
In reality you can´t hold so much due to the hand position and I used a value of 12kg for comparing belay plate power when abseiling which is about all you can achieve reasonably long-term. For reasonably long abseils this value is still too high as the heat transfer into the hand is going to be excessive especially down near the bottom when the rope weight is less, usually one is going to take a leg wrap or use both hands though.