Guelph is a great city for commuting by bicycle. To work, to school, for groceries, for coffee; you can go by bicycle... Well for the most part. It depends where you live. Here's my take on cycling in Guelph; the good, the bad, and the ugly.
Guelph has a positive outlook towards cyclists. This is due to many policies City Hall has put in place that either directly, or inadvertently, benefit the cyclist. Let's start with the ample green space. Guelph is covered with green corridors, parks, and trails, that allow a cyclist to stay away from major roads. Most of my bike commuting is done between the downtown core and Clair Road, and it is all readily accessible through parks and roads with bike lanes. On the rare chance I have an errand somewhere near Woodlawn, I am able to take the Royal Recreation Trail north to access the eastern section of Woodlawn (Wal-Mart, Riverside Park, Beer Store etc.), and that is without traveling a road where the speed limit is over 50km per hour!
If you look for the green patches connecting the subdivisions south of Wellington, you can avoid any road that might give you the heebeejeebies and still arrive at your destination on time.
Guelph has excellent resources for cyclists of all types and budgets. There are over 10 bike retailers in the city selling everything from $100 refurbished commuter bikes to $5000 carbon fibre rocket ships. The Bike Centre here at the university is open to everyone... for free. You can purchase discounted parts and use every bike tool imaginable... for free! It is run by the CSA and everyone is encouraged to bring their bike and learn about the basics of repair and maintenance.
Lastly, Guelph somehow manages to breed a collective consciousness that allows motorists and cyclists to co-exist... in most parts of the city. In my experience, motorist are very respectful of cyclists in Guelph. If you don't bike at night, downtown, on in the northwest part of town, you should be good.
The worst part about cycling in Guelph in the northwest. Silvercreek, Dawson, Imperial, Willow, Edinburgh. All these roads have no bike lanes, high speeds, pot holes and at least 4 lanes of traffic. Silvercreek is the worst; the vast parking lots cause several cars to enter and exit traffic, which is not comfortable for cycling. Woodlawn sucks as well; at all cost avoid Woodlawn if you are not comfortable with high speeds and trucks.
Avoid downtown at night. In fact avoid cycling at night anywhere that students live or are known to drink. I have been called names and pestered by many drunks when biking around guelph at night. Everything from, "Hey fagot on the bike!" to having a group of drunks create a human chain across the road, and grab my arm in an attempt to rip me off my bike as I passed. THIS HAS HAPPENED TWICE! All entirely unprovoked, I swear. I only have problems at night when drunk students walk home from parties looking for trouble. Other than that, biking at night is delightful. Downtown becomes more romantic at night, especially during the hot summer nights when patios are full of chatty locals. If you choose to bike at night, make sure your bike has a red light on the back and a white light on the front. I cannot stress this enough. It is a sinking feeling to be biking at night and hear a cars tires screech behind you. It happened to me once when I was riding without bike lights, exiting the university onto Stone rd. Also, be prepared for trouble. Make sure you are constantly looking ahead for people who might be ill intentioned. Be aware of people who might throw things, and cars that have high revving engines... I suggest carrying pepper spray, a whistle, and a cell phone for your protection; it can be that dangerous.
I forgot I mentioned this section in the beginning. I think I listed it all under "bad".