Hey Bolt91, Sorry about the customer service dis-connect, what email address did you use [we didn't see one]? We have looked into both sizes and there is only about a 3mm difference in width and 4mm difference in length. The JR should work well with these slight differences, the only change in placement may be to pull it pack from the front of the skate about 4mm [so just shy of the front of the skate]. Let me know how it feels. If you have any issues will work with you to get you what you need. Feel free to email me directly if you need anything else taken care of. michael@adrenalinedesign.ca Cheers!