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Categories: all aviation bicycle gadgets misc motorcycle theater Mon, 24 May 2010I was pondering a phenomenon on the way in to work today. When I swerve around an obstacle on my bicycle (or motorcycle), I've noticed that I never perform a nice sine-wave curve, with the obstacle at the peak of the wave. Instead I end up making a kind of stretched wave, with the obstacle at the front shoulder of the wave. In thinking about it, I realized that of course this makes sense: turning a cycle is a multi-step process, which is one of the reasons they're harder to pilot than a car. Step one: decide to turn. This isn't the meaningless distinction it may initially seem. You need to choose to turn before you can start the turn, and there is necessarily some delay between deciding to take the action, and actually taking it. In particular, when swerving around an obstacle, you have to decide it's safe before you're willing to turn back into your original path of travel. Step two: initiate the turn. This includes a bunch of sub-steps, which you may or may not take, but which I do. The first is to turn my head and look at where I want to go. If you're not already doing this, it's a simple but astoundingly effective way of guiding a cycle with confidence. The next step is to actually lean the bike over, a step I've actually spent hours and hours considering, filming, talking about, and writing about, using a method called countersteering. Finally, once the bike is leaned over, you're actually in the turn. Step three: roll through the turn. This is the simplest part: you've set yourself on a path, and you continue along it. Interestingly, there's a kind of inertia to turning a cycle, so that deviating from a curved path takes more energy and thought than just staying on it. Newton might not be happy with it, but it's true. Step four through whatever: recover to your original path. This is essentially the reverse of the curve you just took, but without the decision-making step about whether or not the obstacle is a further factor. The key thing in all of this is that in order to describe a nice curving path around an object, and place it at the peak of the curve, you have to decide to turn back, and actually be in a turn, before you can pass the obstacle. As I've just outlined, it takes time to follow through with those actions, and particularly with obstacles (and double-particularly with live obstacles like animals or humans, who are prone to doing stupid things like move toward you), you don't really want to decide to swerve back until after you're past the obstruction. Thus, the too-long curve back to your original path. This all actually plays heavily into racing. If you're running as fast as possible, and you decide you want to turn, you have to have made the decision and gone through all the steps to actually get you into the turn well before you reach the turn. It's kind of counter-intuitive, and is one of the reasons that inexperienced racers end up running wide through turns, or having to dramatically slow down: you've got to be looking at the next turn, not the one you're in. I'm still working on that, myself, mostly through turns 3 and 4 at Pacific Raceways, but that's a discussion for a different time. Posted at 11:31 permanent link category: /bicycle Tue, 18 May 2010I was on my way home this evening, and (the sun being out so late these days), noticed quite a sight. I had to stop, and pulled out the camera. This was the result.
I was pretty pleased. This may become a habit. Posted at 22:46 permanent link category: /misc Sat, 15 May 2010I finally took some time to do to do a couple of minor tasks on my commuter bike, and looked down to note the mileage (I keep a maintenance log, and that probably tells you more about me than I could in ten times as many words). There it was, in bold letters on the little display. 7003. That's a lotta miles, y'all. Posted at 15:40 permanent link category: /bicycle Tue, 11 May 2010I tried taking the street CL175 for its inaugural break-in ride yesterday (seems like I've done a lot of those rides in the last few months), but was thwarted out of the gate. It would idle, but that's about it. Any more gas than that, and it would have enough power to spin up the motor with no load, but nothing more. When I put it in gear and tried to head out, it just bogged and nearly died until I turned around and gave up for the day. I spent some time pondering the problem. It was doing this odd coughing/backfiring routine whenever I cracked the throttle, and I started entertaining gloomy thoughts of having messed up the cam timing -- something that wouldn't be disasterous, but would mean I'd have to pull the engine out of the bike yet again. I also considered crud in the carbs, water in the gas, and dead sparkplugs. The obvious first step (that's a lot less obvious when faced with these problems, for some reason) is to replace the sparkplugs. Once fouled, it's effectively impossible to get a plug back to a functional state, and these sparkplugs had been through a fair number of first-runs without being replaced. So this morning, I replaced both plugs, carefully retaining the ridiculous double-washer I have to run with my too-large sparkplugs (it's a long story involving miscommunication and Helicoils). Although it hesitated at bit at first, after a few minutes of idling and warming up, the engine came to life, and I was able to ride off for a fairly satisfying first ride. It's so nice when the first and simplest attempt at problem resolution completely solves the problem. There are still a few tiny issues to deal with (timing could probably be adjusted; jetting could probably be adjusted; an indicator light needs to be replace), but it's looking likely that the street CL is finally healthy and back on the street. Posted at 10:13 permanent link category: /motorcycle Sun, 09 May 2010It all started, as they say, much earlier than the actual events. Without getting ridiculous about it, I can safely start with a few weeks ago, when I noticed that my wristwatch's band had broken. I took it off, and eventually brought it to a repair shop, where it's even now awaiting a new band. Thus, when I set off for the track yesterday, I didn't have a watch on. It was a fairly standard departure, made slightly less stardard by the fact that I'd had a theatrical event the night before, which kept me out until 1, and my plan was to be at the track around 7 am. So my alarm was set for 5:30, and I went to bed at 2. Grand. As I pulled the bike off the truck, I noticed that it seemed a bit tough to move, but I put it down to deflated tires, since both tires were low on pressure. I got my pit area set up, and after I'd pumped up the tires, something made me check the bike again -- it was still tough to move. Something wasn't right. So, I spun the rear tire (conveniently suspended above the ground by the bike's stand) -- no problem. I lifted the front of the bike with some effort, and tried to spin the front -- yep, that's not right. The front brake was sticking. I messed around with it a bit, and discovered that the rear of the two brake levers was actually sticking in the engaged position, and then as soon as the tire was rolled backwards any amount, it would snap to the disengaged position. Seeing that we had nearly an hour until our practice session (the only time we'd be on the track that day), I decided to pull apart the front wheel and grease up the various bits and pieces, something I'd never done before (so it was probably long overdue). Sure enough, the actuating shafts were bone-dry, as were all the other moving parts inside the brake. I applied careful smears of grease in the appropriate spots, and put it back together. Of course, what I'd forgotten to factor in was the "not at home" time multiplier. Any time you try to do anything like this at home, it takes X amount of time. Any time you try to do it away from home, ie without all the normal setup and tools and work areas, it takes longer because of that change. I think it was about 1.5x on this job, which isn't bad, but of course ate into that hour I'd thought I had. Added onto this (I realized part-way through the job that the time factor was hitting me), I didn't have a watch, and I'd forgotten to bring the little battery clock I usually have hanging from the shelter. So the only way I had to check the time was to check my cell phone (which I didn't want to smear with my greasy gloves), or call out, "What time is it? Anyone?" I had no idea how fast or slow time was progressing. So I started to panic a bit. Naturally, when you start to panic a bit, things do not get better. But I didn't want to miss this practice. If I did, then it was a huge mistake to even come down for Saturday, when we only had one practice instead of the normal two. I'd considered, very late Friday night, just not coming down for Saturday, but figured I should probably make it if I could. Now, I was up to my elbows in disassembled front brake. Not a thing you want to have go missing while railing into turn 2. So I was under double pressure to do it quickly, but do it well. As it happens, I did manage to get it done, and in enough time to head out for practice with everyone else, but the story doesn't end there. As we were sitting at the mouth of the track entrance, I realized that I'd forgotten to safety-wire my belly pan bolt, a bolt which will vibrate itself out within a minute or two of riding. Indeed, I leaned over to check it, and it was halfway backed out. I reluctantly turned my bike up onto the gravel return road and went back to my pit to hurriedly wire the bolt and get back out. Thus, I was able to get into the practice having only wasted a couple minutes of track time. But, of course, it doesn't end there, either. I have this routine I go through before a track session. I think everyone has a variation on this. I put on my suit about 30 minutes before we're supposed to start. I check the gas. I check the tire pressure. I look over the bike to see if there's anything I've missed. And so on, but the key fact here is that it starts about 45 minutes before we ride. What was I doing 45 minutes before we were to start? Well, the same thing I was doing 20 minutes before we were to start -- putting my front brake together. Even with all that, I didn't manage to get it adjusted correctly, so that it was both dragging and working at about half power. So, about 2 laps in, I finally remembered: I'd pumped up my tires with too much pressure (like I always do), preparatory to using the tire gauge to carefully set them. Tire pressure is terribly important, and too much or too little can cause serious problems, including crashing. And here I was, running with way more pressure than I wanted to. Afterward, after the tires had cooled down, I measured 27 PSI front and 35 PSI rear. I normally run 23 and 29. One pound of difference is the usual increment of change when you're tuning tire pressure. Needless to say, I backed off a bit, and had a generally unsatisfying practice, firm in the knowledge that if I pushed it, my tires would probably slide, potentially dumping me off in the process. So, although I did actually get out on the track, and nothing really bad happened, it was a completely unsatisfying time, and the rush-rush-rush pressure I'd felt before riding left me fairly exhausted and unhappy. The consolation prize for this story is that, because we didn't have any more events in the day, I was able to take a much more leisurely approach to rectifying the remaining front brake issues, and I was able to come away from the day with a much more calm and zen feeling than what the morning had produced. Posted at 20:39 permanent link category: /motorcycle Sat, 01 May 2010Although it's been over a relatively long period of time, I've had some interesting developments in the Land of the Bikes (aka, my garage). The big one is the CL175 street bike. I think I've had that damn motor out of the bike about 5 times in the last 6 months, most of those occurring in the last month or two. Last year, in the fall, I took it apart to track down an odd clattering noise in the head. I found absolutely nothing in the head that should be causing a clattering noise, but in the process, I had so thoroughly cleaned and burnished the head that it seemed a real shame to put it back on the awful, oily rest of the engine. So I proceeded taking it apart, until I had the whole thing all the way apart, down to the transmission being out of the case. It cleaned up beautifully. I only really found one problem in doing all that -- there are these little flat pieces of metal under the crankshaft, which I think serve as oil baffles, and they're held in by spring tension against a pin. It's not clear to me exactly why they're there, but they are, and one of them was loose. So I bent it a couple of degrees, and now it's not loose any more. There's more than that, of course. As long as I had the engine apart, I figured, I might as well replace all the oil seals, and the piston rings. These are things that just wear out and get old, so it was worth replacing them. So I did. When I was putting the new rings in, though, they didn't match the diagram in the manual, so I kind of guessed at the order they should go in. It happens that I guessed wrong. I put the engine back together after a very long period of being in pieces on the bench (from November last year to something like early March of this year). I did a little break-in process. After all that, it was still smoking like Groucho Marx on a bad day, so I took it apart to swap the rings around (having figured out that I'd done it wrong the first time). So that was cool and all, but it didn't actually solve the problem. Still blowing a ton of smoke, and it was around here that I busted out the leakdown tester, a tool that can help you isolate where leaks are happening. I quickly determined that there was a comparative torrent of a leak around the piston rings in the left cylinder. Apart it all came again, and I checked things out. Thing is, everything looked good. I did careful measurements, I checked ring end-gap; everything I could figure out how to check, I did. Eventually (and about three more engine dismantlings later), I threw up my hands and took the cylinders in to Autosport Seattle to be bored (Autosport did the same service on my racebike engine, and I've been very happy with the results). The cylinders will probably be ready early next week, and I'll be able to update you as to whether the haunted left cylinder is finally working right. Hopefully, that's the last time I have to pull that engine for a while. It'd be nice to actually be able to ride the damn bike instead of looking at it forlornly sitting, denuded of tank and engine, like a sopping wet kitten who's suddenly half the size you thought it was. The race bike also received some love lately. I had the first race of the season a few weeks ago, and managed to get what I was hoping would be significant work done before that point -- I degreed the cam. This is a terrifying-sounding but surprisingly easy process that brings the engine into a theoretically better state of tune. I finished it in plenty of time for the first race, but not in enough time to get it back on the dyno before the race. At the same time, I swapped cylinder heads between the race bike and the street bike (I really like this "having two of the same bike" thing), to get the race bike back to a closer-to-stock condition. With all these changes, it was worth getting the bike to a dyno, which I finally did last week. I have results ready to set up, but haven't had a time to actually get them generated yet. The short story on the race bike is that I was hoping for a couple of HP from the degreed cam, and I would have been satisfied with one. I got .5, so that all felt like kind of a failure. However, we cleaned up the power curve a lot, and actually made a quite noticeable difference as far as area-under-the-curve, and that's actually pretty important. I also discovered that with the new head and degreed cam, the engine was running noticeably lean, so in went the 100 jets (I was on 98s before). We saw a peak of 14.9 HP, with the aforementioned increase in area-under-curve. So, I'll have to see how that works out. Hopefully it'll make a little bit of difference in times around a lap, although I'm pretty sure I'll notice no difference whatsoever in how the bike feels. There's also been news on the pedal-powered bikey front. The big news is two-fold: first, I got the new headlight from Supernova, and while it's not the night-into-day HID terror I'd been secretly hoping for, it's much better than the old one with its shaped beam and massive hotspot right in front of the front tire. The second bit of news, which impinges a bit more on my daily riding, is that I finally broke down and got myself a rear rack and a set of panniers. I'm not 100% convinced on this as a change, but it's pretty cool to not have the weight on my back (and therefore on my butt). The obvious negative is that I'm now putting that stress much more directly onto the rear subframe, particularly as I normally only run one bag. Asymmetrical loads bother my engineer's mind, and I can definitely feel that the bike is a bit wonkier over bumps now. The Ninja 250 and the Xtracycle don't really have any exciting news to impart (as much as news about an inanimate object can be considered exciting). The Ninja just keeps on keepin' on, and the Xtracycle hasn't been out much lately, particularly with the panniers on the commuter bike. Still, no news is good news, so I'll take it. Posted at 17:31 permanent link category: /motorcycle Categories: all aviation gadgets misc motorcycle theater Written by Ian Johnston. Software is Blosxom. Questions? Please mail me at reaper at obairlann dot net. |
