Strange Noises

[MementoMori]

Twice, months apart from each other, when riding my bike, it's suddenly started making a strange noise, like sand, or if you let your disc brakes get rusty and you push the bike then brake, it makes a kind of hissing/slight scraping sound. Obviously it would in that situation, but this is whilst I have been out riding it.

The first time it happened, I was in about 4th so I slowed down and it stopped. The second time, I was in 6th, slowed down - nowt happened. Changed down to 5th and the noise stopped.

Does anyone know what this could be? It's up for MOT soon I think anyway but it'd be nice to have an idea.

Thanks.
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The tiger who came for a pint

[BFG]

Flares caught in rear wheel?

This could be anything at all - even a stone being thrown up and getting caught in the mudguard. How loud was the noise?


Which bike, how old, any history etc.

[Gazdaman]

Quite possibly a stone getting caught between the pad and the disk, being held there by the friction of the wheel turning, slowing down dislodges it?

Had it happen in the car once.

Other than that, no idea.

Gaz