Forestry England said it expected the 2028 works to last for six months and it would not be “safe or practical” to keep the bike park trails open during them.
It said Hamsterley was a “working forest”, providing sustainable, home-grown timber alongside opportunities for recreation and wildlife.
“Commercial leases across the nation’s forests are evaluated to ensure they continue to meet our objectives and deliver the best experience,” a statement from the organisation read.
“As leases expire, any future opportunities are considered through Forestry England’s normal procurement processes.”
Nick McCarthy, from Shotley Bridge, who has been going to the park with his daughter for seven years, said: “It’s become such a regular part of what we do as a father and daughter.
“It will just create a huge gap in our lives.”
He said downhill bike trials were “so few and far between”.
“We’re often talking about how children don’t get out and participate in outdoors activities and we’re going to be it taking away.
“I just think that’s wrong.”
Bishop Auckland MP Sam Rushworth, who has written to the Forestry Commission about the “real loss” of the bike trail, said: “Facilities like this are incredibly important to give people something positive to focus on and creates opportunities for them to develop skills, confidence and friendships.”
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