Jeld Wen Rollers

hi, I bought 4 JeldWen 142x96" sliding glass full unit 4 panel doors (W4500 series) for a new construction project and have a problem with the doors being very hard to open and close. We believe that it is the patio roller assembly mechanism (1 1/4"). What roller system do think will work best for this unit? We would need 16 rollers.

Please let me know what other information you might need.