The BOB COZ is a bicycle trailer made by BOB. It is designed for touring and utility use, unlike most bicycle trailers which are designed for carrying children (BOB also makes trailers for children, but I've never used one). The COZ is the lesser known of their two utility trailers, the more popular one being the YAK. I chose the COZ over the YAK for a couple of reasons:
It has a more useful storage area then the YAK. As you can see in the picture above it uses a Rubbermaid Action Packer as its storage area. This is nice because it means that you can put a lid on the trailer, and the Rubbermaid box is mostly weather proof.
The box can be removed and replaced with another larger box or a different type of cargo holder. I haven't tried using it, but Rubbermaid makes a taller box that should fit onto the trailer. The frame of the trailer is small and simple.
The trailer is designed to come apart with two bolts and 4 hand tightened nuts. When taken apart it easily fits into the Rubbermaid box.
I have made three modifications to the stock trailer. The first was to replace the wheel. The stock wheel was a very cheap nylon wheel and I did not feel comfortable using it (although others have told me that they've had no problem using this wheel). The wheel that I am using is built around a Shimano XT hub with 32 15 gauge spokes and a 349mm Sun M14A rim. It has a 37-349 Primo slick tire which replaced the low quality, knobby tire that comes with the trailer. If I were doing this again I would use a 305mm rim because the 349mm rim doesn't leave a lot of room between the tire and fender. The 2001 BOB COZ trailers use the same spoked wheel as the BOB COZ. It still uses a cheap rim and hub, but is a much better wheel than the old plastic one.
Another modification that I have made was to replace the stock BOB flag with a small windsock. No real reason to do this other than to make it look better and get rid of one of the BOB logos.
A final modification was to change the trailer over to use the new (2000+ model) BOB locking pins. My trailer came with cotter pins to secure the trailer to the hitch. These are easy to lose and it is hard to tell when they are fully inserted. The new pins ($15 for 10 from a BOB dealer) are tied to the trailer so that they can't be lost, and use a new retention system which is easier to use and more secure. BOB will sell you a $50 new front fork that is designed around the new pins, but it is really easy to convert the older fork to use them too. You just need to drill and tap a hole for a flat-head screw where the corner of the new pin will rest. The flat-head screw holds the pin in place. I just ziptied the pin's rubber tie to the trailer so that the pin can no longer be lost. Here is a picture of the converted fork:
There are a couple of problems that I've run into with the BOB COZ trailer:
- Single wheeled trailers don't handle well on many bicycles. As the bicycle leans left or right the trailer puts twisting pressure on the bicycle's rear axle. Most bicycles aren't designed to have high loads at this point. On some bikes (every road bicycle that I've owned) the trailer can make the bicycle handle very poorly even with a light load. On bicycles with a stiff rear end (my recumbent and tandem) the trailer handles a lot better.
- The hitch interferes with the Tubus racks that I use on a couple of my bikes. Blackburn and Bruce Gordon racks don't seem to have this problem.
- The trailer is hard to connect to the bicycle when it is loaded. BOB suggests only connecting it or disconnecting it when it is empty. It can be hard to load when it is connected though, because you need to find a place to lean the bicycle and trailer so that they remain upright.
I would recommend this trailer for anyone who uses their bicycle for touring and can't use panniers for some reason. The trailer handles pretty well when lightly loaded, and the locking and waterproof box is very handy when on outr. It was also fairly inexpensive at roughly $200 from Zach Kaplan Cycles. I also ordered the rim and spokes from him. The hub was purchased used from Recycled Cycles. The total cost of the trailer with the new wheel came in at about $300 with shipping. Zach was very useful in helping me select wheel building components and in helping me decide between the COZ and YAK trailers.
Another good shop to purchase the BOB Coz from is OlyBikes in Olympia, WA (they also do mail order). Contact Larry Leveen at leveen@olywa.net. Their price is $170 for the trailer, and $50 to upgrade to a spoked wheel (using the wheel from the BOB Yak, and the $50 includes tire and tube). A great price compared to other offerings.
Since I don't tour with a trailer and this trailer handled poorly with some of my bicycles I have traded it for a Burley Nomad.