Sad to see Jack has died , remember seeing him ride for Bristol when I was a kid. Despite what the records say I am certain I saw him ride for Bristol
You probably did Rodders but there's no evidence that he rode for them that I can find:
JACK GERAN, born in Melbourne, Australia in 1929 first arrived in the UK in 1952 finding his way into the Exeter Speedway Team where he stayed for four years. Settling in and doing well right from the start he gained a full international cap in 1953 riding for Australia. During 1955 and still riding for Exeter Falcons he topped the National League averages, perhaps more remarkable is the fact that during that year he did not miss a league match and did not score less than 11 points at any one of those matches.
Moving to Poole Pirates for a year in 1956 when the Exeter County Ground Closed, then leaving the south coast and moving inland to Leicester Lions in 1957 and from there to Oxford Cheaters in 1961. Following the retirement of Exeter’s Tim Bungy, Jack Geran returned to Exeter in May 1965 scoring well for them during that year and the next two and holding a good average throughout.
Jack seems to have been able to hold his form throughout his riding career until just before his retirement in 1967, then following his retirement as a rider he continued his relationship with Exeter Falcons by becoming the coach for their juniors in the late 1970s.
In 2005 Jack Geran was the President Elect for 2006 duly taking up his presidency at the World Speedway Riders’ Association in 2006. He was in 1957 & 1958 a World Finalist and has been capped 11 times by Australia.
source speedway museum online
And
wwosbackup.proboards.com/thread/1058/jack-geran is usually accurate.
20 September 1958 - Speedway Individual World Final - Wembley, London - Barry Briggs (New Zealand)
1. Barry Briggs (New Zealand) - 15 (3,3,3,3,3)
2. Ove Fundin (Sweden) - 13 (3,3,2,3,2)
3. Aub Lawson (Australia) - 11+3 (1,3,3,1,3) +3
4. Peter Craven (Great Britain) - 11+2 (2,3,0,3,3) +2
5. Ken McKinlay (Scotland) - 11+1 (2,2,3,2,2) +1
6. Ronnie Moore (New Zealand) - 9 (3,2,0,1,3)
7. Olle Nygren (Sweden) - 9 (3,2,2,2,0)
8. Ron Johnston (New Zealand) - 8 (1,1,1,3,2)
9. Gerry Hussey (Great Britain) - 7 (2,0,2,2,1)
10. Ron How (Great Britain) - 7 (1,1,2,2,1)
11. Peter Moore (Australia) - 15 (0,1,3,1,0)
12. Mike Broadbanks (Great Britain) - 5 (2,0,1,0,2)
13. Rune Sörmander (Sweden) - 4 (0,2,1,0,1)
14. Jack Geran (Australia) - 13 (0,1,1,0,1) 15. Josef Hofmeister (West Germany) - 2 (1,0,0,1,0)
16. Joel Jansson (Sweden) - 0 (0,0,0,0,0)