Ooops you got me... . The old airhead bearing has the metal cage. 07 11 9 985 005 TAPERED ROLLER BEARING - 40X17X14 (to 01/81) Your bearing has a plastic cage, and it is sealed on one side but does not have the additional dust seal, 33 17 2 311 729 TAPERED ROLLER BEARING - 17X40X13,25 There is a third bearing for the R100GS which is identical but it has a beefed up raised 3mm section outside the race for the additional dust seal. 33 17 1 241 546 TAPERED ROLLER BEARING - 40X17X17 I used parts from all three bearings, so I have a indestructible bearing with a outer dust seal. There are some advantages, but I tend to over think things. I'm sure the stock bearing will be fine as long as it's kept tight.