I thought it was coming from the bottom bracket but that may be just vibration from the rear wheel.
It's intermittent but more frequent once it has started. I wondered if it was the freewheel but I can't replicate it on the bike stand.
Yesterday it happened while freewheeling down hill and didn't occur again while doing 10 miles on a track. If I put the slightest pressure down on the cranks it stops it temporarily.
The sound is similar to a playing card flicking the spokes.
It's intermittent but more frequent once it has started. I wondered if it was the freewheel but I can't replicate it on the bike stand.
Yesterday it happened while freewheeling down hill and didn't occur again while doing 10 miles on a track. If I put the slightest pressure down on the cranks it stops it temporarily.
The sound is similar to a playing card flicking the spokes.