Riders need to keep a look out for steel plates in the Mt Dandenong Tourist Road and The Crescent through Olinda and Sassafras.
The plates are not necessarily hazardous, but swerving across the road to avoid them could be.
These roads see many bikes at this time of the year, and it can be an exhilarating place to ride.
Right now, Yarra Valley Water is bringing a piped sewerage service to most properties in Sassafras.
New sewerage pipelines will be constructed along road reserves and easements requiring excavation on the road, and holes temporarily covered with steel plates.
Plates always need to be ridden over with care as sometime the road can be uneven, there can be a lip where the plate joins the road, and sometimes the holding pins are prominent.
Avoiding them altogether is not always the right option as the road can be narrow twisting in the Dandenongs and oncoming traffic not easy to detect.
The project will move from this major roads in the near future when work will move to local streets.
In the meantime, Yarra Valley Water would like to see everyone remain upright and intact.