This is a long running event organised, extremely well, by East London Triathletes.
It is being held on Sunday 29 April. Distances are approx 5 / 20 / 3 miles
It has moved about and is currently based at Redbridge Cycle Track. The track is similar to Hillingdon, but harder and there is a stinging little hill which you have to run up 5 times and cycle up 20 times. These hills make it a very hard early season event.
I have done it numerous times and thoroughly recommend it.