PC fan thermally controlled too slow. Convert to non-thermally controlled or extend sensor?

Hi

I have an Antec Smartcool 120mm, thermally controlled case fan.

It's supposed to spin from around 800 to 1900+.

I can only get an average 1050 to 1300rpm out of it.

Can I extend the thermal sensor with a bit of wire?

Or perhaps just replace the temperature sensor, (thermistor? which I take it means thermally variable resistor etc.), with a resistor. Would I use a hair dryer and multimeter to determine correct resistance?

I'm not sure on the gauge of wire and solder I'd use. I've got 60/40 Rosin core .8mm (about 1/32 inch).

Laughing at the newbie but no eye-rolling permitted thankyou.

Thanks

Darren