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Old 04-14-2016, 11:15 AM
phatcruiser phatcruiser is offline
Motorized Bicycle Senior Member
Join Date: Sep 2013
Location: San Diego
Posts: 96
Default Re: what did you do to your motorized bicycle today?

Originally Posted by bluegoatwoods View Post
Welll....only a bit of this was done today. But if the question were, "what have I done to my motored bike in the last month or so", then this would be it.

The bike is on my 'service rack' in this photo because I've got an egg shaped tire on the rear and I'm trying to get it more round. I failed, by the way. I've taken it out for a test run since and it's just as bad as it was. My last tire purchase was a real loser. Very bad Indonesian tires.
Attachment 82250

I've experimented, in the past, with 'better' tires. Continentals and Panaracers and such. And --yes-- they're nice tires. But I've not been impressed with their life spans. If an eight and a half dollar Kenda or Cheng Shin is going to last as long, then I don't see the point in spending thirty dollars plus for a name brand.

This last purchase came folded in half like bike tires often do. I unfolded them and parts of them stayed flat as though they'd been through a hydraulic press. Figuring this was trouble, I mounted them on rims --they were so distorted that even this wasn't easy-- and partially inflated them and simply stored them like that for eventual use. But even that didn't help. Also, the ones I've used so far seem to have no lifespan at all. Cracks are showing up quickly. These are garbage. I know I've got tires that are better than this one. Tomorrow one of them will have to take it's place. And when I buy more I'll be careful to check that the brand is trustworthy. This is pretty disappointing.

But, anyway, some recent innovations. Note the proper exhaust system. The sound of the bike is so much better. It sounds almost like a respectable Honda or something like that. Maybe I'm overdoing it there. But it doesn't sound any worse than an old VW Beetle or Karmann Ghia. And their sound was kinda likeable, for that matter. And it's a lot better than "Zinnggg! Zing!"

And I put some good turn signals on the bike. These are highly recommended. They actually only worked for about a week. When I ran into my first rain with them, the flasher relay quit working. It was instantly clear to me why that should be; that thing was designed to ride in the cab of a car. There's no water-proofing at all. It died as soon as it got wet.

But this wasn't as disastrous as it might seem. The turn signals gave me a much better 'presence' on the road. Losing the flasher relay gave me the opportunity to simply turn on these lights in steady mode after dark. Now I've got good running lights. Red in back and amber up front. And the cars on the road do, in fact, seem to treat me more as a vehicle than as a toy.

Plus I can still signal a turn by merely reaching over with my thumb and flipping the toggle switch back and forth a few times. Granted it's a bit clumsy since, when preparing for a turn, there are other things that my hands need to be doing. But it can be done.

Future improvements to this design will include wiring that's better hidden. But I've also got a by-pass circuit in mind that ought to allow me to run these lights steady when wanted and then switch one side over to a flasher relay circuit for an actual turn signal. I think it'll work with one switch. It might require two. But that'd be a small price to pay. I'll also need to weather-proof the flasher relay. But that won't be any big problem.

I've got a new saddle on the bike which I built yesterday and today. Two test runs on it felt pretty good and I think this is a saddle I can live with. The heart of it is a bicycle saddle with bee-hive rear springs and a hair-pin spring up front. I took the beehives out a long time ago and replaced with some springs that are better suited to this task. And it was a pretty good seat. But not quite good enough. To be close to comfortable I had to slide back so far that my butt was over the edge.

For the last month or so I've been trying to make another saddle work. This one is an actual motorcycle solo seat. One that's pretty small by motorcycle standards, but fairly large for a bicycle. I had a good spring setup under it. But I had trouble getting it mounted really well to the bike. When it was good it was quite good. With the exception that it was just a bit wide for comfortable pedaling. But I had a hard time getting it to stay put. No doubt I'll work with it again sometime and see if I can get it dialed in just right. But not right now. So I resurrected the older saddle.

The older saddle needed a larger 'footprint'. So I cut out a thin plywood 'pan' with a narrow horn, widening out to a wide and deep seat. For cushioning, aside from the springs themselves, I put in two layers of some under-layment I had left over from a flooring project. Before that, though, I took some of this under-layment and rolled it up into a 'sausage' that's a bit over an inch across. I laced this onto the plywood seat-pan right at the back edge. In order to give this seat a bit of 'lift' at the rear. Put the other padding over this and then covered with a cover made of cheap plastic tarp laced onto the whole thing through the undercarriage of the saddle. On my test runs I noticed that I could definitely feel the rigidity of the seat pan right in the center of the seat. But I'm not sure this will be all that uncomfortable since the springs in the undercarriage are softening the road. But even if I find this to be a bit hard, adding a bit more padding with be a simple matter.
Attachment 82251

I've also been experimenting with engine drive-train gearing. The 44 tooth sprocket was not too bad. But to get moving with any speed at all, say about 15 mph, I had to listen to that engine scream. It gets tiresome. So I changed to a 36 tooth. I figured this would give me about 10% more speed at a given engine rpm. This would have seemed like only a moderate change. Yet the difference was, maybe, a bit too much.

It certainly had one advantage. I could get moving to a speed that would get me out of congested traffic spots quickly and would allow me to eat up some miles on the open road at an engine rpm that sounded really nice. But it also made it too easy to go faster than is wise. My wife and I took a ride one day. I led and had her clock our speeds on her scooter. We were going in the low 20s in those places where stop signs and such weren't getting in our way. And my bike handled that quite well. But I'm not comfortable with sustained speeds in that range. It doesn't really feel as though I'm beating my bike to the breaking point. But I can't help the feeling that sustained 20 plus will result in accelerated wear and tear. The risk of wheel bearing failure or frame fatigue and breakage might be greater. Probably enough that I just don't want to do it.

This gearing also had one disadvantage. The greater speed was gained at the price of correspondingly less torque, of course. The bike was definitely a bit weak getting rolling from a stop. Even on level ground. I could have lived with that except that hills really defeated the bike. There's a hill on my commute that was too much when there was a headwind. The bike couldn't pull me up by itself. I don't mind helping with the pedal drive-train, of course. But my pedal gearing is very low, for the sake of start-ups and pulling away from a stop. This meant that I'd have to get down to a very, very low speed in order to allow pedaling to make any contribution at all. And then I'd have to pedal like a mad man. Not impossible, but clumsy. There was one night when I had a good, strong tailwind and the bike pulled me up that hill pretty well. I found myself wondering if the bike weren't suddenly stronger for some reason. But that wasn't it. The difference between a strong headwind and a strong tailwind is quite a bit, after all. It's enough to make that sort of difference and I had to conclude that that gearing was just a bit high.

So I went with a 40 tooth sprocket. I've only had one work commute and a couple of local test runs with this. But I can tell that this will be a satisfactory compromise. I'll be able to travel at the speeds I like with an engine that's purring like a kitten. I'll be able to kick it up a few notches when needed. But I won't be tempted to over-do that because I won't like the noise that's involved.

One of those work commutes with the current gearing was last week. I was also still working with that motorcycle seat I mentioned above. I had a hard time keeping it adjusted right. As a result I got home so exhausted and with a back so sore that I drove to work for the next few days.

Mostly I don't have to drive on four wheels very much at all and life is good. But these bikes, though very sweet and more fun than a barrel of monkeys, can beat you half to death if you don't watch out.

Bluegoatwoods. Have you tried continental gatorskins? I've got a couple thousand miles out of a tire on my commuter with little sign of wear. There are reports of gatorskins going 4-5k miles before being replaced.
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