I have two rear wheels for CCM Mustang's. One is stamped "V160 MADE IN CANADA-20A", the other is "V160 MADE IN CANADA-18x1 3/8 E4J". What's the difference? They appear to be the same size.
The EJ4 is an old British rim designation. The 20A sounds like a bastardization of European sizing systems. In the European system 20 would designate the rim width between the flanges in millimetres, which for a typical 1-3/8" rim would fall between 16-23mm. The letter suffix defines the bead seat diameter for a particular nominal tire diameter. For an 18" (450mm) nominal tire the A suffix would indicate a 400mm bead seat diameter. This just happens to be the bead seat diameter for a 18 x 1-3/8" rim. However, on a rim the distance between the flanges would normally be paired with the bead seat diameter (i.e., 20-400). It's a bit of bastardizationin in that it's combining tire and rim sizing practices and I have no reason why CCM would be using such a system. Perhaps it is just a coincidence.
The EJ4 is an old British rim designation. The 20A sounds like a bastardization of European sizing systems. In the European system 20 would designate the rim width between the flanges in millimetres, which for a typical 1-3/8" rim would fall between 16-23mm. The letter suffix defines the bead seat diameter for a particular nominal tire diameter. For an 18" (450mm) nominal tire the A suffix would indicate a 400mm bead seat diameter. This just happens to be the bead seat diameter for a 18 x 1-3/8" rim. However, on a rim the distance between the flanges would normally be paired with the bead seat diameter (i.e., 20-400). It's a bit of bastardizationin in that it's combining tire and rim sizing practices and I have no reason why CCM would be using such a system. Perhaps it is just a coincidence.