Douglasmotorcycles.net

Hi again, having sorted a taper roller bearing for the bottom of my Model Z headstock I'm now stuck with the top bearing. Could anybody confirm if this bearing is of the cup and cone style with loose balls and if so any further information about this bearing including dimensions will aid in my search.
regards
Chris

If the bearing housing in the steering head is quite deep (say 5/8" or more), it probably takes a taper roller bearing. The cup and cone bearings (or thrust type bearings) with loose balls usually had shallower housings (1/4" to 5/16" deep).

  Hope this helps,

       Eddie.

Thanks Eddie unfortunately only as you say 1/4 - 5/16 deep so looks like the loose ball type

Chris,
         One of the bearings Douglas favoured was a deep track thrust bearing with 2 identical halves (part number 2016). Unfortunately, these have been obsolete for many years, and are very hard to come by. When we were involved with postwar spares, we had a couple of batches remade (as Douglas continued to use them on the T35 model. It might be worth contacting the spares scheme!

   Eddie.