How hot should discs get?

[damz]

i was riding my bike earlier and when i pulled in the clutch i could hear a kind of whistling sound and thought maybe the brakes are binding. anyway when i stopped and checked the discs they were all quite warm and was wonderinf if they should even be warm at all.
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Current Bikes RVF400 - 94
Cars: RX7 FD, Eunos Roadster
Former Bikes: FZR 250R 89, ZX7R 98

[doggone]

It's not unusual, if you weren't using them beforehand you might want to clean out the calipers so the pads get more clearance.
If there's no noticeable resistance when pushing it about, nothing too worrying going on.

Rally cars will sometimes get the brake discs so hot they glow red at night.

[damz]

calipers, pads,hoses and fluids are all new as i replaced the entire brake system two months ago and the weather has been pretty good lately so only a few rainy day uses so i hope it isnt binding. i will give it a check later on today. sadly my front padock stand is keeping the fzr up while im working on it so cant do the spin the wheel test and the rear padock wont work as it holds it by the axle.
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Current Bikes RVF400 - 94
Cars: RX7 FD, Eunos Roadster
Former Bikes: FZR 250R 89, ZX7R 98

[Wafer_Thin_Ham]

Don't worry too much about it. They get pretty warm.

The spin test is a far better gauge then a touch it and feel test.

Up to a given point the warmer they get the better the pads work anyway, kind of like tyres. (They do overheat after a certain point though)
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[MattEMulsion]

They do get pretty warm with just normal usage, warm enough to burn your hand when you touch them.
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Yamaha YZF-R6

[MarkJ]

Heavy braking will definitely get them so hot they'll burn your hand.

If the noise was a sort of whistling/buzzing sound then that sounds to me like the sound you get from drilled discs

[damz]