skating

durometer / hardness http://www.skatelog.com/wheels/durometer.htm

pronating: http://www.nettracing.com/step1.htm

double push theory http://home1.gte.net/pjbemail/dpfront.html

http://www.skatejourneys.com/index.php?option=com_content&task=view&id=57&Itemid=69

Cleaning:

• http://www.groupsrv.com/science/about93528.html
• http://www.fasteddiesskateschool.com/Maintenance.html
• http://www.getrolling.com/orbit/bearLeft.html
• http://www.skiroll.it/tecnica/cuscinetti/cuscinetti_sfere-eng.htm