Sunday, 15 April 2018

Tommy Bars

Genuine Ariel tommy bars are another rare item, and typically (of the tools at least) are rather confusing - not helped by the aforementioned rarity:
  • 6612-27, Dwg # G1/57 appears in the 1940 singles parts books as a single diameter bar 
  • The W/NG workshop manual shows a dual diameter bar
  • 6612-27, Dwg # G1/57 (yes, the same part number) appears in the 1947 singles parts books as a bar with three diameters. This also appears in several parts books until 1956, so we can assume this tommy bar was now considered a mature design (!)
    • the 1948-1949 twins parts book
    • the 1949 SQ4 parts book
    • the 1953 singles parts book
    • the 1954 Huntmaster parts book
  • The 1956 Huntmaster parts book lists a 'Tyre Lever and Tommy Bar", 6625-55. Parts books (prior to Leader/Arrow) ceased to be illustrated in 1951, so we have no idea what this looks like.
  • Leader/Arrow parts list include tube spanners with tommy-bar holes, but no tommy bar. One assumes that you were intended to use the screwdriver as a tommy bar...
Once again courtesy of a few members of the Ariel clubs around the world, I have these pictures of three examples of the later 6612-27 three-diameter, two step tommy bar, and a W/NG tommy bar from Ray Tolman's genuine W/NG tool kit which has yielded so much interesting information.

Part of Scott Williamson's 1949 SQ4 tool kit

Close up of some of the tools from David Andersen's 1949 VH toolkit
We can see a few interesting points from this last picture:
  • the tommy bar appears to be about 0.375" in diameter and is overall about 7 1/2" long
  • the tommy bar has a section reduced to maybe 5/16", and this is about an inch long. This is to pass through the holes in the various box/tube spanners and the QD wheel nut spanner.
  • the tommy bar has a further section reduced to maybe 1/4", and this is possibly 3/8" long. This is to engage with the smaller box spanners and the hole in the telescopic fork wheel spindle: this is probably the reason this third, smaller diameter was introduced
Ray's pictures give us some proper information. Ray kindly measured these for me and allowed me to share the pictures so we can all use the information.

You'll notice Ray's tommy bars are a little shorter than David Andersen's later tommy bar. Here's a close up of the stepped ends; Ray confirmed that there is a 0.31" section on both bars:

I'm planning to turn each of these up from EN16 steel round bar. First cut two 7" lengths from a bit of 3/8" round bar:

Face and round the ends:

And as if by magic, some tommy bars appear:

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