The Doodle bug , or it's Canadian cousin the Dirt bug is by no means a masterpiece of modern engineering , however the major thing it has going for it is availability.
It does have some good points such as size , decent steering head and wheel bearings also the balloon tires help the ride.
The biggest drawback is the small engine , the welding on the frame looks like it was done by a kid (likley a chinese one) the brakes work marginaly but watch out if you upgrade the engine.
I am not slamming the DB's , I have two myself and find them to be a great starting point for a build to make them into a great little bike.
Rob