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Saturday, February 7, 2009

First Ride A Success, Learned From Steering Failure


I forgot to post these pics yesterday of the modifications to the frame, necessitated by where the seat will have to go to give me the correct angles and lengths to the pedals, primarily.

The whole bike, above. Below, the seattube (cut an inch or so above the frame lug that joins the top tube to the seattube, so I can still put a clamp for seatposts if needed), as it now connects to the seat stays, which now connect to the ex-front-fork (white), that used to connect to the back of the seattube.

This is how the seatstays look at the dropout end now:

Bending the stays took patient careful bending, and I still think I have too tight a radios on it, but I didn't think of making a jig for it until too late. I also don't have a torch to heat it up with, so it's possible there is damage to the tubing there which could fail later. I see no problems visually, but they could be microscopic cracks now, just waiting to come out and snap off the stays during a ride. ;-)



In pretty much the above configuration, except without the motor attached, today I finally got to ride my crazybike on the road, just around the block a few times. No motor power, just pedals, to see if I could steer it properly at higher speeds, since in the yard there's not enough room to go very fast, especially with the dogs chasing me (why do dogs love to chase bikes so much?).

I got used to the non-1:1 steering pretty quickly, even with the slop in it from the imperfect mounting method I have on the tie-rod (yet to be fixed), and managed to get up to the highest gears on the short streets around my house, with no traffic around.

I don't yet have the real seat made, so it's just got the bike saddle mounted on the top tube as pictured in the previous post, and because of the way the pedals and seat are arranged, I had to actually pull on both handlebars to hold myself on the seat as I pedalled. Even so, it was more comfortable to ride like that for a few minutes than it is to ride the same length of time on my regular bike, in an upright position. The real seat is almost finished, and is essentially almost a normal chair seat, leaned back some, so the back is resting against it with support, and the butt is fully supported by the bottom of the seat. The back is actually involved in pushing with this style of bike, which makes it a new thing for my body to learn, thus it will be very helpful to have the motor working during the learning process, for when my body tires out from the new ways of working muscles.

I forgot to take pics of the real seat during the marking and cutting of wood, and the construction process, but I'll describe it later, and post pics of the seat as it is now (almost done) and as it will be then. It's incredibly simple to build.

Front brake worked fine to stop it as just me and the frame, without the motor and batteries, but I will need the rear brake once I add the other parts' mass. Still have to install the mounting tabs/pivot points for the rear brakes.

Shifters need adjustment, and I don't really like these gripshifters nearly as much as I do the ones on my regular bike (Columbia)--they feel different in operation, and the left shifter (for front derailer) has about 8 or 9 clicks to it for the 3 gears it controls, and so are all the other gripshifters I have. The one on the Columbia is just three clicks for three gears. I'll have to open one up to see about fixing that, but still I don't like the way they feel. I might end up using thumbshifters, since I have a set of Shimanos that are SIS, so they'll click into each gear, no guessing about where I am in the range (as with older types of thumbshifters). I would have used them on the USS of the original recumbent, as gripshifters could not be installed on those handlebars the way I made them. I suspect I wouldn't be able to fit the gripshifters on with the ex-Honda scooter grip/control assemblies on the handlebars anyway, or if I did, not be able to use them effectively.


Eventually I did fall over during a turn, because the stupid knobby tires I had to use (only ones I have in 24" size right now) caught the edge of the front wheel on the rough spots in the pavement as I was turning around in the street in a hard-full turn at speed, and the torque forced the wheel to turn farther than the tie-rod should allow, so the tie-rod's eyelet stem bent. :(

Now at least I know it *can* fail, and how, so I can work out a better solution before I put it on the road as a regular bike, and be safer as a result. It was easy enough to bend back in shape that I wonder how I did not notice how easy it bent in the first place, with all the abuse I laid on it during aligning it and making sure it wouldn't just fall apart from handling. So it's still usable the way it is, if I'm careful to never let the front wheel turn so far as to allow such a problem to happen, or always be slow enough before such a turn that it can't grab like that.

Or I could just get better tires--this last is a problem because all the 24" bikes I ever run across have knobby tires of one persuasion or another. Only the 26" and 700C bikes seem to ever have smoother road-type tires. I do need different tires as soon as possible, as these are not efficient on smooth roads and are going to give me a vibrating ride from the bumps, but finding good tires to recycle is tough enough without having to find 24" road slicks. :-\ Still, coincidence has been my ally in all of these projects, so I will probably run across what I need soon enough. ;-)


I also know that because of the way the bike falls in a skid, I can't leave the motor down below (where I wanted it because of it's weight, among other reasons for it being down there like frame spacing and belt length), since it could be damaged severely in a crash involving a left-side skid--and I have no spare motor to replace it with. So I have to go buy a longer belt, and move it up higher in the frame (directly under the seat, where if it falls over the side of the wider plywood-based seat will take the impact, not the motor). I could also just weld together a frame around the motor to protect it, but that would add several pounds to the bike, and moving it adds very little (just the extra belt weight, which is negligible).

On the bright side, I was able to easily step off the bike as it fell, because it's so low to the ground, which is something that is possible but difficult to do on a regular bike in most skid-crashes I've been in.

Since I still can't get anyone to hold the camera, I can't get a video of me riding it. I tried the tripod, but the dogs wouldnt' leave it alone, and as soon as I put them inside and started to take the bike out to ride and be recorded, someone came out and let the dogs out again. Then they wouldn't all go in, so I took the tripod outside the fence, set it up in my front yard to ride past, and then some little kids came running up to the yard and wanted to mess with it, so I just gave up the whole idea of recording the historic first ride. :(

To make up for it, here's another video of the motor in operation using the drivetrain as it was just before the ride (it'll be similar after I move the motor, except the motor position and belt length, and the pedal chainline won't be as long since it will not have to run around the motor anymore).

video

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