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Categories: all aviation bicycle gadgets misc motorcycle theater
Thu, 31 Jul 2008
CL175 rebuilding part 7. Finally.
Hey, it's only six months late, right? I finally sat down yesterday and logged some more footage for the next episode of rebuilding the CL175. From December. But I finally did it, and the next episode shouldn't be too much further behind.
Look for Part 8 within a month. Really. Probably. Posted at 14:42 permanent link category: /motorcycle Mon, 28 Jul 2008Jesse finally talked me into going out and riding in the dirt a bit, and today was the day. We loaded up and headed out to Tahuya, which is near Tacoma, on the Kitsap Peninsula. It's a little state park that's been set up for offroad vehicles, and seems to be mostly used by dirtbikes and quads. We had Jesse's WR250 and his friend's XR200R in the truck, and I was wearing a hodgepodge of my, Jesse's and the friend's gear. Now, this was a significant day, and I should explain why. When I was growing up in Woodinville, my parents absolutely forbade motorcycles of any kind. There were other kids I knew who were allowed to ride dirtbikes, and it seemed horribly unfair to me that I wasn't given the same opportunity. Unfortunately, most of the kids I knew who rode dirbikes were also, to be blunt, assholes. They seem, through the gathering mists of time, to have been characterized by awful mullet-like haircuts, husky voices, a certain fantastic boastfulness ("I'm a black-belt in karate" sort of thing), and a smug, superior attitude. Between the attitudes (despite all present evidence, I was a scrawny and unpopular kid when I was growing up) and the bike-envy, I essentially grew up hating dirtbikes. In early adulthood, I came to view dirtbikes, and by extension their riders, as these awful noisy things that went around destroying natural areas. It's a classic capital-L Liberal reaction. It was supported by the evidence, though, and it never even crossed my mind that I might one day try riding one offroad. Then, a few years ago, Jesse got a dirtbike. I made the requisite inbred-hick jokes and didn't think much more about it. He seemed to be having a good time with it, but I wasn't interested. After I got into racing this year, I heard an awful lot of people say, "Dirtbike riding really improves your track riding skills." Ok, sure. Still not interested. Finally they got through to me, and last week we made plans to go out. I agreed to go attempt this form of riding that I'd been completely against less than a week earlier. Jesse's friend Eric had a bike to lend in exchange for some much-needed maintenance. So Jesse and I replaced bearings and brake shoes, and adjusted and cleaned and did all the things you really have to do every so often on motorcycles. Once we finally got on the trail, riding Eric's undersprung XR200R, pretty much the first thing I did was crash on the first corner. I saw this seemingly huge vertical wall looming, and stared it down, crashing as surely as if I'd target-fixated on a concrete wall on the freeway. Fortunately, I crashed at about 4 MPH, and the worst damage was to my pride. Heaving and sweating (it wasn't a hot day, but I was already soaked from working muscles I didn't know I had, and I was wearing my effectively non-ventilated road helmet), I picked up the bike, and declared to Jesse as he rode back to investigate, "This isn't fun." He laughed it off, and we kept going. He told me about how he'd had much the same reactions at first, as well. I realized that my mistake on the first crash was that I wasn't looking where I wanted to go, so I worked on that. It got better, but my second crash was basically the same thing. After that, I didn't have any more trouble with crashing due to looking in the wrong place. So, a bit more background here. In street riding, you're working on the assumption that the road surface is solid, and any impediment to traction (such as oil, gravel, rain, snow, etc.) is a call for utmost caution. You train yourself that if you see these things, mental alarm bells go off, and you back way off and go gingerly. Gravel in particular is one of those things that sets off the alarms. Now, on the trail we were riding, there was about 50% coverage with what I will graciously term "gravel." This wasn't your nice, jagged, unlikely-to-roll roadside gravel. No, this was deep puddles of rounded stones that looked to me like gigantic mineralic ball bearings. In other words, exactly the sort of thing that makes my brain flash red strobelights and engages every nerve that will lead to stopping and getting away from this foolish road condition. So, for the entire hour or two we were out, I was fighting deeply ingrained impulses to STOP because I was ABOUT TO DIE. The trails we were following were between 3 and 5 feet wide, and typically involved a sharp curve every 10-20 feet. The curves were massively banked, so it was possible to fly through them quite quickly, although I was going at a grandma's pace. Jesse was very good about stopping and checking that I was still upright, and he wasn't going too fast (although I found that if I let him get ahead of me, I wasn't consuming quite so much dust). However, in addition to being massively banked, they were also covered with these seemingly colossal swamps of overgrown pea gravel ("orange gravel," if you will). Fortunately, it didn't take me too long to figure out that the bike wasn't going to freak out about this stuff if I wasn't. It would slide around a little bit, but in a very controllable way. It would go over little rocks and roots and such without any drama, although the 1991 motorcycle's apparently-original rear shock wasn't doing its job particularly well any more. Unfortunately, my brain wasn't so quick to shut down the alarm bells. On top of all this, despite my book-larnin' about how you're supposed to ride in the dirt, my natural instincts were to adopt street-riding techniques. I stood up over the heavy bumps, but I stood in such a way as I might on a street bike -- as if I was going to sit down again immediately, putting a huge strain on my arms to pull me forward just for a moment. Only I held that position for minutes at a time. Not so good. I put my feet on the pegs with the balls of my feet taking the weight. When dirt riding, you want the weight in the middle of your foot. When I could actually convince myself to do this (or more like remember to do it), things were easier, but that amounted to about 5% of the time. In order to ride correctly, I had to consciously override years of training and instinct, and that just didn't happen very often. Among the kit I had on, the one piece of my own gear I was using was my helmet. I tried Eric's helmet, but it was definitely too small, and adding a headache into the mix seemed like a terrible idea. The goggles I had didn't really fit in the cutout of my road helmet, but it was a better system than trying to use my faceshield, and at least the helmet wasn't attempting to compress my skull. The problem is, offroad helmets are positively breezy compared to road helmets, so my head was swaddled in its own steambath within a few minutes of setting off. Now perhaps, you can imagine me, sweating my way down the trail, turning sharp curves every few seconds (we might have hit 15 MPH in one of the straight sections, so at least we weren't going too fast), brain screaming, "GRAVEL! YOU'RE GOING TO FALL!" the whole time, arms and chest trembling with unaccustomed effort, sucking in clouds of dust as I attempt to tame this sliding, slithering, wobbling motorbike. It was... passable. I made it. My last fall resulted in a banged-up leg, but nothing broken. But at no point did I even approach near the thought, "This is kinda fun." No, it was just work. I was working to make sure I didn't fall so I could get back to the truck, get off this bucking hellbeast, and breathe some air that had much less of a mineral component. It was not enjoyable. And in a very important way, I was horribly disappointed by that. I had really hoped that this would be an activity where I could just let loose, and have a really good time. Stop worrying about everything. Just have fun. Instead, I was thrust into a situation where there was literally a small but solid (6-8" diameter) tree directly in my path much of the time. Every turn was composed of a traction situation designed to induce panic. Working with the bike was a chore to be endured. I did learn (or at least re-learn) things. Looking where you want to go is vitally important. Traction is not an absolute thing, and some traction is good enough. Armor is good. (If I weren't wearing very substantial boots and shin armor, I'd have more damage than a big bruise on my leg.) And, there were cool parts. Once I enforced the rigid discipline of "look where you want to go," it was amazing how easily the bike could ride up these walls in the corners, and over obstacles that looked at first to be completely unsurpassable. I didn't have to think about it at all by the time I was done, the bike was just going where it needed to go. I managed to go the whole ride without bashing anything like a tree or stump (and there were countless opportunities, with a couple close calls). Despite the fact that I'm writing this with my faintly throbbing leg (which inspired the title for this entry) elevated to keep the swelling down, I didn't really come away with any damage. An ex-girlfriend's motto is, "I'll try anything twice." There's a certain logic in that, and I'll stick to it for dirt riding. It's obvious to me how the skills transfer from dirt to track. I don't want to give up on something just because I wasn't immediately skillful at it on the first try. So I'll try it again. Maybe in a few months. After my leg feels a bit better. Posted at 23:28 permanent link category: /motorcycle I took a look at the dyno charts Ducati Seattle sent me home with, and all the runs that look reasonable (ie, real runs instead of "riding at road pace" warmup runs) run up past 16 HP. That's definitely not my bike: we saw a lot of 12.x HP, and 14.0 peak. I'll have to check in with Ducati Seattle again to see whose files I actually have... Posted at 08:21 permanent link category: /motorcycle Sun, 27 Jul 2008At the last race, a few folks got together and started plotting for an event they've wanted for a while: a dyno day. Cogs, one of the racers, works at Ducati Seattle, who have a very nice dyno. He proposed the idea to his manager, who readily agreed, and the Vintage 160 dyno day was born. It occurred yesterday, and Jesse and I both brought our racebikes down. We'd picked up these shiny new carburetors from Bateman early this month, and we were anxious to use the dyno time to tune them up. So this week was spent somewhat feverishly making the intake runners we'd use to hook up the carbs. I ended up standing in front of the lathe and mill for many hours, but it worked out well: we now have six complete runners, with four installed on bikes, and two spare. Anyway, we showed up at Ducati Seattle around noon, to find a moderate crowd of vintage racers milling around, talking, and working on bikes. I don't think anyone was on the dyno at that point, but it wasn't long before the room was filled with the subdued roar of a bike revving towards redline. I should say a word about the Ducati Seattle dyno. It's a different brand than the one at Twinline (which I wrote about at the time, and posted a video about), and apparently reads horsepower numbers differently by about 2 HP -- the 11.8 HP we saw at Twinline is equivalent to about 9.8 on the DS dyno. The DS dyno is also beautifully enclosed in a little sound damping room, so that when a run is happening, it's still possible to hold coversations outside. Saturday morning, I was waiting for intake runners, since the timing had worked out that we only had one set finished by Friday. That set was then installed on Jesse's bike, which was successfully test-run. But it left me with a bunch of machined-but-not-welded runners until Saturday morning after Jesse had time to weld them. So, my new carbs were installed mere hours before they were put to the test on the dyno. In fact, all we had time for before departing for the Ducati dealership was to get the carbs bolted on, not even attached to the control cables or the fuel lines. Jesse had the foresight to check the length of my fuel lines (not long enough) so we brought along some clear PVC tubing I had in my stores. We got there, and essentially the first thing I did was set to work, getting my carbs hooked up. No real problems until I turned on the gas the first time. For some reason, the new (clear) fuel line was weeping gas. I thought it must not be sealing properly, so I bummed some zipties off Mark Etheridge, who had graciously opened his shop (rented from Ducati Seattle, and literally a dozen feet from the dyno room) for us. One didn't seem to do it, so I put on a second. I turned on the gas, and instead of a weep, it was shooting a stream of gasoline at my face! I shut off the petcock, as I realized that the stupid tube must have split. Exercising my excellent "sponge" skills, I asked Etheridge if he had any fuel line. He did, and let me use enough of it to get my carbs hooked up. It was nice Motion Pro line, much higher quality than what had been on the bike before. I owe Mark a cigar. But that solved the problem, and the bike was finally looking ready to try starting. It took forever to get all this done -- I had several people come over and ask me if I was rebuilding the engine or something. So, I rolled the bike off the table (Mark has both a lift and a table with a ramp in his shop -- very nice!), and up into the alley. I spent the next ten minutes unsuccessfully running the bike up and down the alley behind Ducati Seattle, trying to get it to run. Finally, sweating profusely in the mild Seattle sun, I got it to fire off, although it didn't run that well, cutting out at full throttle. Even though it had problems, when it was running correctly (ie, when I wasn't too aggressive on the throttle) it was shocking how much more power the bike plainly had. It tugged me back unexpectedly in first gear, with a much sharper pull than I'd ever felt before. I was entirely unprepared for it. Etheridge later said it looked like I was close to lifting the front wheel off the ground. I rolled the bike back, and sat back in one of the provided chairs, glad of the cool warehouse air and the shade. Tamra and I and several others chatted for a while, and watched dyno runs through the soundproof windows. It was informative to watch the other bikes being put through their paces. I saw peak HP numbers anywhere from 11 to 16 that day. I watched with particular interest as Jesse's bike was rolled up onto the dyno. His bike and mine are so nearly identical that his results (in particular his air/fuel mixture) would indicate the path I should take with setting up my new carbs. He ended up posting 14.4 HP peak, and no real problems with mixture, which was a relief. He was running size 98 main jets, which are the primary determinant of mixture. I had the size 100s in (we bought an assortment of jets for tuning purposes), which looked to be close enough to be worth a try. It'd be interesting to see what the difference was. Finally, it was my turn to roll up on the dyno. We had some initial problems with the mixture reading, which may have been the position of the sensor (a long copper tube that's shoved unceremoniously up the bike's exhaust pipe). However, after a few tweaks, we started getting real-looking numbers, and things looked good. We saw a peak of 14.0 HP on one run, after tweaking the timing. However, further tweaks dropped the power back down to 12, so we ended up seeing 12 most of the time. By the end, the engine was radiating heat pretty fiercely despite the copious flow of air over it, so we rolled it off to cool down while someone else ran their bike. As long as I was waiting, I pestered Bateman to see if he had spare 98 jets -- my sparkplugs were on the dark side after the dyno run, so I figured I might be able to go leaner for a bit more power. He had them, so I swapped the jets out. I have to say, swapping jets on the new carbs is remarkably easy compared to the old stock carbs. The day was wearing on, and by the time it was my turn, Robert, our valiant dyno operator, had a certain limp-rag nature about him. He'd been up there, running puny-horsepower bikes on the dyno, for a full 8 hours, and asked if I could come back some other time. I still had dyno time coming, but he was wiped out. No problem, of course. A bit disappointing that I didn't get to see what the slightly smaller jets did, but that's alright. With my schedule, I probably won't be able to get back to the dyno for a couple weeks. I have to say, one of the highlights of the day was near the end, when Bateman was in the dyno room with Tom Deem's bike. I had been casually watching the numbers scroll up, when I saw them approaching, then passing 15 HP, and keep going. A cheer went up from the crowd, and the bike topped out around 15.8, I think. Someone explained what was happening: Bateman was adjusting the timing on the fly, as the bike ran! That's a good way to do it, if you know what you're doing. It was impressive to see the peak power he got that way. Overall, I can only call the day a success. The dyno was running a lot of the time, and lots of people came away with printouts of their bikes' power curve. I had a USB flash drive with me, so I actually have all the data files with me, although it requires a Windows computer to run, so you'll have to wait to see my charts (I know, you can't wait). I may be able to get those charts figured out today, though. As usual, it was great fun to hang out with the vintage crowd; they're a group of excellent, kind people. It was also interesting to see the power other people's bikes were making in comparison to my own. Particularly with the new carbs, I don't feel too bad about my bike's ability to hold its own. If you're keeping track at home, the peak HP we saw at Twinline was 11.81 HP. Subtract two to get the equivalent HP on the Ducati Seattle dyno, so 9.81 HP. The peak I saw on Saturday was 14.0, or more than 4 HP gain (over 40%!). I'd say those carbs were a fine investment! Maybe my lap times will reflect the change. We'll see on August 9th and 10th, the weekend of the next race. Posted at 11:14 permanent link category: /motorcycle Tue, 22 Jul 2008First things first: I got back from Alaska on Sunday. It was neat. I have a great deal more to say about it than that, but let's call that good for the moment. I took around 1200 pictures. Look for them to go up soon, but you can see some of them on svsequoia.com (my parents' website; click on Trip Journals and Alaska). I got a new milling machine just before I left for Alaska (and the end mills -- the cutting tools -- hadn't arrived before I left, so all I could do was admire it). Jesse and I are working on new intakes to mate up to our new carburetors for the race bikes, and I'm doing the machine work. He did the design, and will be doing the welding. So, these intake tubes were the first project I did on the mill. It wasn't anything too special, just cutting off the ends of four little sections of tube to 8°. These tubes will thus be angled outward from the centerline of the bike, allowing the carbs to clear the central frame section. See?
Beautiful! (Please ignore the banding on the tubes, these are definitely "prototype" quality, not "production" quality.) Posted at 21:27 permanent link category: /misc Sun, 06 Jul 2008
The First Annual Formula 160 Vintage Invitational
That's a fancy name for what happened this weekend, but it's also pretty accurate. Bradford Duval of Portland put together a really neat day of riding for Vintage 160 riders, and invited everyone to show up. We had racers from California, Oregon and Washington, that I know of. It was held at Pat's Acres, a little go-kart track in Canby, Oregon, just south of Portland. Check out the track. According to the surveyor's document they had posted, the track was .59 miles long along its centerline, but the whole thing was contained in a square about 300 or 400 yards on a side. Very very twisty. I never got beyond third gear, and that only for about 5 seconds down the straight. The rest of the track was second-gear-only, and I even dropped to first for a couple of the hairpins. Of course, being this twisty and convoluted meant that one lap consisted of about 8 changes of direction, and therefore changes of hanging-off side. It was a constant barrage of gas-brake-gas-brake. The end result is that my arms are protesting from resisting the braking force, and my legs are protesting from all the side-to-side. I think the only time I actually rested on the seat was on the straight, and that lasted all of 5-10 seconds. It took between a minute and three seconds, and a minute and 15 seconds, of the people I timed, to go around the track. That makes the fastest average speed around 25 MPH. I'll have more on it later, including a ton of pictures and video (the GoPro worked every time, so maybe my little copper shim in the battery compartment works). It was great. It was tiring. Let's do it again! (But let me rest first, I need to get feeling back in my legs!) Update: The video's done and posted. This is among my final laps on the track, so I was both tired (thus slower) and more experienced (thus faster):
Posted at 20:08 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. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
