Maitland was born in Birmingham and developed an interest in cycle-racing in his teens. He collected autographs from pre-war riders such as Eddie Larkin and Charles Holland and sometimes cycled out to watch them ride time-trials, which were then the only cycle races held on the road. Spectating persuaded him to race. His first race was the Birmingham Time Trial Association 25-mile event. He finished in 1h 13m 22s, 10 minutes slower than the winner. He won a junior race in Warwickshire, near Birmingham in 1939 and the following year joined the Solihull Cycling Club.He started racing seriously in 1941.
His first road race was over 30 miles near Nottingham in 1943, on a hilly course and in the rain. He gained 40 seconds on the field but another rider caught him with two of the 28 laps to go and he finished second.
Maitland was an engineer, a reserved occupation in Britain during the second world war. That meant he could continue racing, although with a reduced calendar of competitions and restrictions on travel. He rode club events but also set a national tandem record for 50 miles (80 km) with Dick Bowes. He rode his first massed-start event in 1943, finishing sixth after 30 miles (50 km).
In 1944 and 1946 he came third in the NCU's national road championship, then won in 1948. That same year, Maitland won a silver medal as a member of the British road race team at the 1948 Summer Olympics. Other members were Ian Scott and Gordon Thomas. Maitland finished third in the NCU's national road championship once more in 1949.
By 1952, Maitland had joined the British League of Racing Cyclists. He came second in its independent road championship in 1952 and the champion in 1953. But as a member of the BLRC and an independent or semi-professional, he was no longer eligible to compete at the Olympics.
In 1958, Maitland rode for his own cycling team, Maitland Cycles. Arthur Ilsley was also a member.
The Olympics Games in 1948 were in London, the cycling road race held at Windsor. Maitland was best-placed of the British team. He said:
Maitland finished sixth and won a medal as member of the second team. He finished four seconds behind the winner, José Beyaert of France. The organisers of the Games reported:
[Gordon] Thomas (Great Britain) tried a breakaway on the penultimate lap, between Ascot and Blacknest Gates, and he was chased by L. Delathouiwer (Belgium). The pair held a 15 second lead as they climbed Breakheart Hill and finished the lap. But with five miles still to go, the group were gaining fast, and as they caught the leaders, all the riders eased in readiness for the sprint which seemed certain to decide the race. J. Beyaert made his first real effort at Ascot gate, but, led by J. Hoobin, the group regained contact. The decisive moment was not, however, to be in the final sprint at all. A short distance before the top of Breakheart Hill, and with over half a mile to go, Beyaert again sprinted into the lead and opened up a gap of at least eight lengths which was too much for any of his rivals, all of whom seemed more tired than the winner at the finish... Great Britain had two riders among the leading group, R. Maitland and G. Thomas, and C.S.I. Scott came in sixteenth to gain the second team award.
Maitland rode for Britain in the 1955 Tour de France - the race was then competed by national teams - in a team selected by cycling journalists because the civil war between the National Cyclists Union and the British League of Racing Cyclists made it impossible to leave the job to either. The team was a mixture of full professionals and riders like Maitland, who were independents. It was divided largely between those who normally rode for the Hercules professional team and others like Maitland who rode for the rival BSA. Sending them was not universally seen as a good idea. The journalist Ken Bowden write in Cycling: "We cannot send a team to the Tour unless we are willing to gamble heavily with men's reputations, our future in the race, and Britain's sporting prestige. Any rider we could send in 1955 could know more about the Tour than what he had read, heard, or imagined. It would fall far short of reality, for the Tour is unique in terrain, weather variation, racing technique and a hundred and one other things."
The writer, Tim Hilton, said: "None of the British cyclists had experienced one of the northern spring classics, so they had no idea that the Tour could be so much harder and faster than the races they had known. The early stages were a shock. And then, between Roubaix and Namur, the British had the jolting first experience of the northern French and Belgian roads. One by one they left the race."
The team were numbers 31 to 40 - Dave Bedwell, Tony Hoar, Stan Jones, Fred Krebs, Maitland, Ken Mitchell, Bernard Pusey, Brian Robinson, Ian Steel and Bev Wood. Pusey went on stage two, Wood on stage three with Bedwell. Jones quit on stage seven, Steel on stage eight, Maitland on stage nine, and Krebs and Mitchell in the mountains on stage 11. Just two got to Paris: Robinson 29th at 1h 57m 10s and Hoar as lanterne rouge at 6h 6m 1s.
The author William Fotheringham wrote:
They were, says Maitland, not a happy team, more 'a lot of individuals put together, just a shambles.' Not all the squad would share his opinion, but it is clear that tensions arose from the fact that he and Cozens, a former star of the winter six-day track races, had been brought in from BSA, Hercules' bitter rivals in domestic racing. There were factions within the team: Maitland and Tony Hoar did not see eye to eye, nor did Brian Robinson and Syd Cozens, while Jones and Krebs just did not get on.
Maitland later became a member of the League of Veteran Racing Cyclists and a masters world champion at the 1989 UCI road world championships in the 65–69 category.
The magazine, The Bicycle, said of him: "It is one thing to have a near-perfectly developed body, capable of the highest tests of human endurance, but the brain of that body must be tuned accordingly, able to dictate and control physical behaviour. And who can doubt that, so far as cycling is concerned, Bob Maitland, national mass start champion in 1949, is one of the shrewdest riders in the game?" He died on 26 August 2010 in Metz, France.