Pokémon GO Trade Distance will increased temporarily for Community Day Machop. Machop's evolved form Machoke can be traded to evolve in Machamp without the need for Candy, so to make Community Day Machop go as smooth as possible the trade distance will be increased.
Pokémon GO Trade Distance Increased for Community Day Machop
From Jan. 15-18, the trading distance will be increased to 40km, or about 25 miles. You should be able to find a partner to work with in this range to evolve your Machokes during the event more easily.
Machoke doesn't necessarily need to be traded to evolve, but you will save 100 Candy for evolving it with the trading method. Machoke evolved (with or without candy) during the event and for up to two hours after will learn the event-exclusive move Payback. You can save the Candy to evolve more Machop and trade them for more Machamps.
This trade distance increase isn't limited to Machop's family. Community Day Machop doesn't start until Jan. 16, so you have a full weekend to take advantage of the trade distance increase. If you need to get your hands on some rare Pokémon, you may have some more luck during this weekend trading with other players.