This loop is a pleasant tour around the most scenic parts of Delta, with much of it on gravel dykes or trails interspersed with sections of pavement, but even these are on fairly quiet roads (at least on weekends). It is about as close as you will get to a flat route although there is one prominant hill at about the midway point, just to keep you on your toes.  As an added bonus, being on a river delta and surrounded by wetlands, you will likely see a wide variety of birds at this time of the year.

I did the preride on a road bike with 28mm slicks (Gatorskins to be precise) and did just fine, but I would definately not use high end lightweight road tires. It is more comfortable to go wider and preferably have a bit of tread. Both my riding partners during the preride were on gravel bikes with wider tires. But generally the trails are in good shape--similar to the trails in Stanley Park or the Endowment Lands.

A few notes on the route:

The first section through a forested greenway can be a bit slick in places if it has rained, but the majority of it is on hard packed gravel and is fairly fast rolling. 

There is maintenance work being done to the Mud Bay dyke trail. At km 34.5 there is signage warning of the work and the route detours around this section. As tempting as it may be to continue straight through, follow the detour route around the airport.

The bridge to Westham island is now open (after being damaged by an errant barge). The surface is still a bit wonky in places, so use caution, especially if it is wet.

There is a short section of trail at km 92, just past the Deas Island pedestrian underpass, that is under construction. What used to be a pleasant tree lined trail is now a clearcut with a temporary trail of lumpy mulch. It's short though, and totally rideable.

One of the best things about this route is the lack of car traffic. There are however plenty of pedestrians and dogwalkers to be found, particularly close to trailheads. Please pass wide and slow to avoid startling people and dogs (a bell is very handy). If you feel the need to hammer, do it on quiet sections of the trail, or on the roads. Colebrook Road and River Road are great time trial segments.

A few logistics notes:

If arriving by car, park at the north end of the Planet Ice lot--furthest from the building. There are no washrooms available at the start (unless you dare going into the Planet Ice hockey rink wearing lycra); the nearest ones are at a Tim Hortons a couple of blocks away, or on the route there are portapotties at Mud Bay and other places as well. There are washrooms as well as food/water at the midpoint staffed control.

Make sure to check back here in the few days before the event as there will be minor route changes needed after the pre-ride.