High or low frame - what is the particular difference?

[Bela]

In some threads I have read about low and high frame. Searching the forum I got some threads with that expression but no explanation about how to identify.  Do I have to die stupid?

[Charles Levien]

Could start by asking what Austin Seven you have?

[Peter Clayton]

Look on the old forum site under "high frame" there is a explaination on it . http://pub25.bravenet.com/forum/static/s...=5&msgid=0

[Mike Costigan]

From the photos you have posted in the thread about your car, it looks like it has been built on a Ruby-style chassis, which is often referred to as a 'low frame'. This is because, in standard form, the Ruby used flatter road springs, and so the chassis frame sat lower and nearer to the ground.  Once an original car has been modified into a special, the term becomes less appropriate as, for instance, a Ruby frame could be used in a trials special with cambered springs, and has effectively been converted to 'high frame' configuration. Alternatively a 'high frame' chassis is often fitted with flattened springs (usually even flatter than standard Ruby springs) and so becomes as low, or lower, than a standard 'low frame' car.

["Slack Alice" Simon]

The difference that causes problems is that when the chassis frame went from "high" to "low", the position of the mounting feet on the engine crankcase changed.

If you have a standard car this usually means you cannot easily use a high frame engine in a low frame car - or a low frame engine in a high frame car.

(I am simplifying it a bit)

If you have a special, you can usually make one fit the other.

[Bela]

Thanks for all the hints.

I'm not a native speaker and as far as I understood it is more the suspension than the frame itself? But there are two different frames in the spare part list - LOW Frame BR132 and BR100. Is BR100 the high frame?

[Mike Costigan]

Yes, that's basically it; the 'low frame' is the term given to the new frame (BR132) introduced in 1934 for the Ruby and Pearl models, identified by the up-swept rear extensions. It is referred to as the 'low frame' because the suspension was set lower. At the same time the 2-seater and 4-seater tourers (and the vans) continued with the old style chassis frame with straight rear extensions and the higher suspension, hence the 'high frame' designation. This 'high frame' was also used for the Nippy sports car when it was fitted with even lower suspension than the Ruby frame, but the chassis frame itself is still the 'high frame' BR100.

[Bela]

Thank you - learned this lesson!

[Ian Williams]

for completeness a Nippy chassis although essentially a high frame chassis has a number of detail differences so they are not identical.

[Mike Costigan]

I was trying to keep it simple, Ian! So, to add to the complications, what is the difference between the high chassis frame BR100 listed in the first 'Ruby' parts list, and the BR121 frame listed in the preceding 1934 parts list?