Yes, the wheels are on bearings, and the sprockets are mounted onto them. I have had sooooooooo many people skip this possibility and post "it can't turn" it's not funny. So don't worry, your'e definitely not the first
.
The axles run through the chassis for reinforcement, and yes there is no frame beyond the wheels (unless you count a plexi-cover a barrier
). The bearings both bolt the frame together (they're 4-bolt flange bearings) and support all the drive axles. In pic 2( I think) there is a closeup of one corner of the frame. (BTW, the bars are 1" aluminum bar extrusion (hollow)) There are 2 pieces of angle holding the edges together. The inside is 1.5x1.5" and the outside is 2.5x2.5" (The extra inch is for the length of the chassis bars).
A bolt runs through each bar from one angle to the next, and a large bolt goes down from the top of the corner through all 4 to the base. This alone in every corner wouln't hold the frame too well, it would hold, but the frame would probably begin to get bent, or fall apart after a while.
So, I added the flanged bearings to bolt the top and bottom sidebars together. This helps (along with the axles) to reinforce and keep it held together properly.
It sounds like we are planning on using this design next year (04), instead of the MultiDrive I designed.
This system actually worked great last year. While our frame was different, the drive setup was 80% the same. We were the fastest at our regional, and we had no problems winning a pushing bout.
The idea was to come up with an improvement to last year's design. A slightly lighter yet stronger frame, easier construction, cheaper cost, etc. I think I've captured all of that.
It was also necessary that it would require less modifying of parts, and more putting things together, thus more of an emphasis on bolting than cutting pieces, etc.
We (in all confidence) also have boldly claimed that we can build it and have it running in one day. I think we can accomplish this goal.
We're taking advantage of pre-design here. Coming up with things that can be designed pre-season and going through them.
At our December meeting (not too long from now) we plan to have a vote for our drive system. It's NOT a definite vote, the vote is "we'll use this unless there's a good reason not to". That way, we can have our drive/chassis defined the day of kickoff, and order the parts. Within the first week, we'll have a driving chassis complete, with 5 weeks to go. I've only heard of a few cases of that occurring. And, it helps.
Anyway....This was just an example for people to show their new folks an example of a not too complicated drive. Hope It helps.