They put tar down, then chippings, and no asphalt on top, so the surface wears into very rough patches for bikes.
https://one-diz.3dn.ru/forum/12-13827-1#20082
http://sharecovid19story.com/viewtopic.php?t=2688258
https://one-diz.3dn.ru/forum/12-12841-1#19096
http://horsecity.ru/phpBB3/viewtopic.php?f=8&t=264738
http://ewmen.com/viewtopic.php?p=1159891#p1159891
http://www.prepody.ru/topic67805.html
viewtopic.php?t=84240
https://mmomakemoneyonline.net/threads/ ... ze.495005/
http://horsecity.ru/phpBB3/viewtopic.php?f=33&t=275852
http://ewmen.com/viewtopic.php?t=741644
http://www.prepody.ru/topic94794.html
http://sharecovid19story.com/viewtopic.php?t=2749449