Main Frame

We are often asked why our main frame does not have a ‘swan neck’, to replicate the original. This is because, despite being very heavy, the swan neck is a serious point of weakness and is a major reason for frame distortion on standard Tiger Cub frames. The original swan neck frame was designed to use the fuel tank as a stressed member of the frame, theoretically to give a higher fuel capacity. But do we now need a 3 gallon tank on a Tiger Cub?! To create the swan neck shape, the down tube, which should be one of the strongest tubes in a frame, is flattened so that it fits inside the headstock casting, alongside the curved top tube. This dramatically reduces its strength.

With Armac frames, we have refused to compromise strength and frame rigidity. They are lighter,straighter and with jig-accurate geometry. As well as staying ‘true’, Armac main frames allow the cylinder head to be removed without removing the engine.

- Improved steering geometry

- Taper roller bearings in steering head

- Integral 1/4” 6082 T6 alloy sump shield

- Improved ground clearance

- Lockstops with replaceable nylon heads for Armac yokes (these are only for Armac/billet yokes and do not work with standard yokes)

- Oil in frame

- Improved geometry between gearbox sprocket, swinging arm spindle and rear wheel

- Fully TIG welded from seamless Trumech/CF53 tube

- Stainless steel fasteners

- Laser cut brackets

- Engine plates

- CNC machined components

- Accepts standard yokes, swinging arm and sub frame

- Fully jig built for maximum accuracy

- 5.2kg total weight



- main frame

- taper roller head bearings

- oil filler plug (screw cap)

- sump shield + bolts, nuts, washers

- front engine plates + bolts, nuts, washers

- bottom engine mount + bolts, nuts, washers

- new bottom engine mount

- counter sunk bolt for oil union


- welding new engine mount to gearbox

- removing bottom engine mount

- counter sinking oil union

- mounting point for Armac tank, if required

- coil mounting bracket beneath the top tube

PRICE: £850


STOCK: We are making 5 frames for late summer 2019. These are currently all reserved, but we will run a short waiting list in case anyone's circumstances change.


Armac frames are eligible for Pre-65 Scottish Pre-65

2-day trial with addition of our Tube Kit (limited number, with serial numbers).

The Pre65 Scottish 2019 has been won by Dan Thorpe on a full Armac Cub, with REH Forks. Third place went to Gary Macdonald, also on a full Armac Cub with REH Forks, owned by Dave Stewart. Congratulations all.

bare-frame kit-parts