Originally Posted by
gregf83
If my tubulars were heating up to the point where the resin might soften I'd be more worried about the glue holding the tubes to the rims.
Well, the flip side of the resin softening from heat is its poor thermal conductivity. That's why it heats so badly compared to alloy (heat is not wicked away off the brake track). So the brake track gets hot, but the spot where the tube is glued to the rim remains much cooler.
But you are right, this is one additional concern.
In clinchers, the tube sits directly opposite the brake track and there's a higher risk of heating the tube itself.