William's brother Joe won a silver medal at New Zealand Schools over 800 metres in 2018 when in year 12 but did not better that position in his final year, although he was part of the Whanganui Collegiate School medal-winning senior boys' cross-country team.
Their sister, Ruby, may not have achieved the accolades of her brothers but she was an invaluable part of Whanganui Collegiate and Athletics Whanganui. She brought a cheerful and dedicated presence to all her teams. Ruby was the first to offer assistance at club events and has been missed this summer. She is now attending Canterbury University.
Daniel, the next Sinclair sibling, had a difficult summer as, under the Covid regulations in place for most of the summer he was unable to run In the Classic Meets and the Athletics New Zealand Championships in March. He was able to run at Whanganui Schools, where he won the 1500m with a slick performance in his first competitive race since November. He defeated his cousin and teammate James Hercus, who won the 800 metres at Whanganui Schools and had finished sixth in the New Zealand under-18s championship with his first sub two-minute performance.
A week after the Whanganui Schools victory, Daniel Sinclair won a special 1500 metres at the conclusion of the penultimate Club Night of the season. His winning time of 3:58.74 propelled him to second in the New Zealand under-18s rankings for 1500 metres.
Subsequent training was interrupted after contracting Covid-19. He has, however, started the cross-country season in excellent fashion. He ran the fastest leg at the Wellington Scottish College Relays at Karori in early May and was part of the first Whanganui Collegiate Boys' team to win this long-established relay.
Last week at Whanganui Secondary Schools he won the Senior Boys title over 6km (six laps of the Victoria Park circuit). He should be pleased with both the time (19 minutes 20 seconds) and the manner of his win.
He can clearly run under 19 minutes in Nelson, a course very similar to Victoria Park, which is always competitive at New Zealand Schools. He was eighth in his senior boys' debut in Hāwera last year. This gave him a place in the New Zealand Secondary Schools paper team, and in a normal non-Covid year would have run as part of the annual New Zealand Schools tour to Australia.
Sinclair would love to repeat or better last year's effort at the head of a strong Whanganui Collegiate Senior Boys team. A position in the top 10 would give him an automatic place in the proposed New Zealand Schools' team to run at the Australian Championships in Adelaide in late August.
Daniel will be joined by his younger brother Matthew in Nelson. Matthew was the winner of the junior (under -16s) title at last week's Whanganui Secondary Schools Championships. Sinclair moved up a grade to be a part of the aforementioned winning Whanganui Collegiate Senior Boys team at Karori, where there were six members in each team and will be a key member of his junior (under-16s) team in Nelson.
The Sinclair brothers are favourites to win the Senior and Intermediate Whanganui Collegiate titles on Friday on the Whanganui Golf Course circuit. The races are all over 3000 metres, and although there is likely to be more rain this week, they both look likely to better their performances of last year.
The good news is that there are still more Sinclair siblings to come.
Racing at the Whanganui Collegiate School Cross-Country starts with the junior (under 14.5 years) for girls and boys at 12.15pm and 12.40pm respectively, with the Intermediate and Senior races after a lunch break from 2.10pm until 3.35pm.