on my quest to find out more about my 1927 Sunbeam model 9 and it's original owner RT Green who was a keen amateur motorsport motorcyclist who entered many events from 1927 onwards on the Sunbeam I came across a fantastic Website that has many many pre war motorsport event images including Brooklands you can type in a year and up come the images hundreds of them I typed in "1930 Trial" with the hope that images of the Southern Trial would come up many photos did although not sure what trial it/they are but the photos are fantastic of many different bikes and cars off road trialling.....the women didn't get left out either.......I type in the the reg of the bikes in some of the photos into check an MOT and found only one bike still on the road a Douglas sprint bike.....amazing.......anyway grab a cuppa and have a look and amuse yourself you never know you might actually see your bike in one of them.....LOL
https://www.motorsportimages.com/photos/?race_type_id=&search=1930+Trial
the link might not work anymore as the site etc has been bought by Getty images so try this instead
1920's motorcycle trials (https://www.gettyimages.co.uk/search/2/image?phrase=motorcycle%20trials%201920%27s&sort=)
if you hover your mouse pointer over the picture and hit the control button bottom left on your keyboard 2x in quick succession you'll get a nice blown up image of the photo which you can zoom into specific parts of the photo.....also in the search box you can type for something specific.....like 1920's Brighton beer run or Brookland's.......or a name of someone....like Jack Brabham........have fun