Sunday, February 13, 2011

New Project: King Arthur's round vehicle

At least that's the working title I just made up. So named because I chopped up this round outdoor table for a steel donor, besides multiple different bike frame tubes.

I plan for it to have stoker pedals like the Widecar, only centered more and running a chain to an axle that transfers power out to the side and then through another chain to the wheel.

I chose a different bike to pair the car with, and set it up with only three attachment points. Other sidecars I've made have all had at least four points of connection, yet this arrangement is as stiff as any I've made yet, and far easier than the Decidecar to unmount and re-attach. PLUS, this model gives more pedaling room to the driver than any other I've made yet, which is great! No more bumping of the right knee on the front connection or catching of the right heel on the chainstay connection.

Here is the axle/chainstay connection. Originally, it was two parallel seatstay tubes going over to the compression plate, but I realized it would impinge upon the pedaling action somewhat. So I chopped the forward one in the center (well, close anyway) and angled the tubes aft to connect with the other one. There are two bolts on the compression plates holding the chainstay. After a bit of testing, I noticed there was still some play in this area, so I added a bit of angle iron and cut dropouts into it to be held by the axle nut of the donor bike. Super solid hence.

Here's the seatpost connector, fairly easy to connect and remove. It's a recycled chainstay with the dropout fitted between the nut and quick-release cam. The other end is welded to the frame and in the middle is a sleeve tube and hose clamp to be able to adjust the camber of the vehicle. Having a bit of camber makes cornering a little easier, but too much and the wheels will suffer under heavy loads.

The head tube connection. First, I sliced open a piece of 1"x 2" rectangular tubing lengthwise on the 1" side, turned the halves away from each other, and added some oversized oval down tubing to connect them around the front of the head tube. Three bolts hold it on while recycled tire rubber protects the frame. The tube projecting out from it sleeves inside the front attachment bar and is only about 8" long. That way, you can remove the car by sliding it off from the front attachment point and ride the bike itself without the car and not have to hassle with removing the three bolts. ( The Decidecar works this way as well, only that the longer tube is connected to the bike and the shorter one comes off with the car.)
After a little testing, I noticed this connection was a bit flexy, so I added that little piece of 1/2" conduit for stiffening. The slider here allows for tracking adjustment of the sidecar wheel. If the wheel is parallel, it happens to drag one side of the bike enough to make no-hands riding impossible, except for short periods. By giving the car wheel a bit of toe-in, the drag is mitigated to where the vehicle rolls in a straight line when unguided.

Then I made some convoluted attempts to link up the sidecar's drivetrain, which ended up looking like this:
Then, Paint!

Widecar Revamped

It's the new and improved version, Widecar 1.4

Yesterday I went about repairing and revamping this sidecar, in part for and upcoming parade including our strolling minstrel to help Dan Zimmer go to Holland in the name of Love. I also did it because my other sidecars are too small to easily carry three people, although it happens often. But if the car looks large enough to easily fit two passengers, people will hop on more readily. A lot of people would look at the Skruvskar or the Decidecar and say "Oh, no way. It's only a one seater." or advise me to get a 2-seater or a bench seat. Also, I hear a lot of "Where are the pedals? Can I help pedal this thing?" So the Widecar is now pedicab-worthy again to fill those requests. The drawbacks I face in using this sidecar is the heavier weight to chug up hills like Mill Street and also the potential to become overwhelmed with passengers and ruin a set of rims. At the Paw Paw Fest I let a gang of kids run amok with it and they were cornering it real hard and had kids hanging off the back of it to make it ride wheelies in a circle and such...which I'll admit looked fun and it was hard to be mad at them for bending both back rims.

The main difference in this version is the improved stoker seat backrest and armrest with two layers of pipe insulation and fleece blanket wrapped around it. Having the stoker more caged in has eliminated the
awkwardness of trying to pedal while feeling as though about to fall off the side of the machine. Also there is the chain tube I made from some flexible piping, because the chain is held low by an idler wheel on the top side and the bottom side crosses beside it twice.  Besides that, the "BIKE TAXI - rides 4 tips" sign, a saddle pouch up front for the ePod and radio, the slow moving vehicle bag I used on the other car, a Safety Bug rear blinky, and a LED flashlight/laser pointer secured with electrical tape for a headlamp.

Further improvements to make on the Widecar include:
  • a HORN or two
  • a sweet set of beefy rims
  • a super low gear ratio
  • some filler in front of the deck so people don't step inside the frame
  • bottle holder
  • canopy??