Disc Brake Rotor Wear(?)

[MossCommuter]

Hi

Are my rotors worn out? How do I tell?

I have fitted new pads and cleaned the rotors; well, I followed the instructions on a can of spray that I got that essentially said to wipe them, spray and leave to dry, but performance is poo.

I can feel a bit of a ridge from the non-braking area to the braking area if I run my finger nail over them but I don't have any calipers to measure their thickness.

They've done maybe 6 or 7 thousand miles.

Should I replace them or is there some way to revive / resurface them?

Brakes are: Shimano BR-M416 mechanical disc F/R 160mm

ta

 

[lpretro1]

If a ridge like that is starting to show they should be replaced sooner rather than later as they're probably getting a bit thin.

 

[BimblingBee]

Sounds like you have either contaminated the discs/pads or they have not been bedded in. Also what pads did you get? Organic, sintered etc.. they have have different braking qualities.

Rotors will wear out but I'd be surprised if that's the cause. A slight ridge is normal. They normally warp from overheating long before they wear out.

 

[MossCommuter]

Sounds like you have either contaminated the discs/pads or they have not been bedded in. Also what pads did you get? Organic, sintered etc.. they have have different braking qualities.

Rotors will wear out but I'd be surprised if that's the cause. A slight ridge is normal. They normally warp from overheating long before they wear out.

They're organic; I've used them before and they've been fine.

Perhaps they need a few miles on them to bed them in.

 

[Globalti]

Yes they do. Stop worrying about it.

 

[02GF74]

thickness of braking surface, or lack of, should not affect stopping power unless you are braking for long periods e.g. downhills resulting in the discs getting hot due to low mass. there is a minimum thickness stamped on sme discs, forget the number, but you would need vernier calliper or micrometer to measure.

if you have fitted new pads onto an olkd dic, chances are the ridge between the worn and unworn scection will not match exactly the pads so the pads will not make proper contact - so need to be bedded in.

 

[Moodyman]

Shimano say to replace the rotor at 1.5mm thickness but I read that it's okay to leave until they're thinner

 

[Pauluk]

You could take the rotors off and lay them on a flat surface then use emery paper to resurface the disc. There are some vids on youtube to show you how to resurface the rotors.

 

[MossCommuter]

thanks everyone - they have a hundred miles or so on them now and already improved.

I just don't recall needing such bedding in before

thanks again