The session, based at the Louth Cycle Centre in Newbridge Hill, will run from 10am until 1pm.
Bicycles will be UV-marked and safety checked for free (any required new parts are not included).
All cycles marked on the day will also be entered into a free prize draw to win a £20 gift voucher at the Louth Cycle Centre.
The scheme is in support of National Bike Week - find out more at www.bikeweek.org.uk.