After 22 years in charge, Bartlett will take on a new position at the Vanarama National League South club.
A new manager will be appointed as the club made a slow start to the new season.
In charge since 1995, he is one of the game's most respected figures.
Legend Bartlett said tonight: “Despite my huge disappointment to step aside after 22 years, I genuinely believe that the club will benefit from a new approach and a fresh start is what it craves.
“I have become increasingly frustrated and I can honestly say I have not been managing with a smile on my face recently. In the past, we have overcome some very difficult times and remained upbeat and with the help of many others, always managed to steer the ship to calmer waters.
“I am a positive person by nature and last seasons so called ‘crisis’ proved a point, when despite the doom and gloom merchants, we finished the season with one defeat in our last twenty games.
“This pre-season had been encouraging and the majority of performances have seen us better than the opposition, but it’s a results business and they haven’t been good enough.
“Sometimes you need to be a lucky manager and that certainly cannot be said for the numerous things that have occurred this season, so when you add everything up, the time is right!”
He continued: “Looking back, I have a huge amount of pride on the success and progress we have made since my arrival in 1995.
“I move on with some brilliant memories and the knowledge the club is in a far better place than when I took over. This is a unique football club which has been a privilege to manage over the years and I must acknowledge the fans for their hard graft, passion and undying support in throughout my time.
“My ambition was to take the club back to the top of Non-League football and although we may have finished one short of the objective, I can’t really say I haven’t had a fair crack at it.”