Improving eight frame Langstroth spacing with wider end bars

This post really follows up from my previous post discussing bee space with the eight from Langstroth hive dimensions here:

The following discussion isn’t to specifically discuss the merits or issues with modifying frame widths (ie. narrow vs. wide), but is to provide a method of spacing eight frames evenly in an eight frame super without modifying the super dimensions. This also removes the need to manually space frames and uses the Hoffman frame design for the purpose it was originally intended… keeping frames evenly spaced.

I have spent some time recently with Kim, a local from Gundaroo ( with a laser cutter, that has assisted in cutting several R&D hive component designs for me.

The first of these components is a 37mm end bar. This end bar design still maintains the standard Hoffman end bar profile with wider 37mm ‘shoulders’. It has been developed to interface with standard Alliance top and bottom bars from New Zealand. The gallery space between the narrower section of the end bars is also maintained in line with the original 35mm end bar gallery dimension.

The following photos show a standard eight frame Australian wooden hive with a 310mm internal width.

Eight frame hive box with 8 x 35mm Hoffman frames displaying remaining space. The end bar shoulder width measurements vary slightly between end bars.

Close up of remaining space when all frame are compressed to one side

The minor discrepancy in frame width can be seen when measuring the overall 8 frame space

The 37mm end bars were placed on the same top and bottom bars from Alliance and then placed in the same wooden eight frame super.

Comparison of 37mm end bar width to 35mm end bar

37mm frames compressed to one side showing remaining space

Showing minor increase in top bar spacing from increase to 37mm

Gallery space remains unchanged from the 35mm end bar

Resultant free space to edge of super (14.5mm) is now much closer to originally designed 15.3mm measurement discussed in the linked forum post

IAQ (Infrequently Asked Questions)

Can’t I just manually space the frames?
You can, but this introduces minor inconsistency in the comb spacing. When manually spacing you may find that the arc of honey above the brood is drawn closer together between frames, and if the distance between frames isn’t maintained exactly when removing/reinserting the frame for inspection, this gap may close below bee space. Having these frames ‘pressed’ together after being manually spaced also has the potential to trap bees between the two comb faces.

Why not just modify the size of the box/super?
Unfortunately, modifying the box only solves part of the problem. Other components such as bases, lids, queen excluders would also require modification to the narrower dimension. Modifying dimensions of hives/supers made from modern hive materials such as polystyrene and plastic is also problematic.

Isn’t 37mm too wide?
37mm sits right between the comb center widths advocated by Abbe Warre (36mm) and Charles Dadant (1 1/2 inch, or 38.1mm). Whether this makes them impractical, i’m happy to determine by running the frames in hives.

Can’t you use nine 33mm end bars?
This post is really about maintaining the number of frames for the eight frame hive rather than modifying the frame count. Using nine 33mm frames will result in a total frame width of 297mm, compared to 296mm for the eight 37mm end bars, so almost identical spacing to internal walls. 33mm end bars are used and actively promoted in New Zealand, so may be readily available in your region.

Would 37mm end bars work in a Flow hive?
The Flow hive has an even wider internal eight frame width of 315mm. This results in a total empty cavity space of 35mm, which is enough to insert another frame. Even though a ninth frame will physically fit, this doesn’t provide adequate space to the edge of the hive. Eight frames with 37mm end bars will reduce the distance to the side of the box in a Flow hive to approximately 20mm (10mm each side).