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Mister Speaker posted:Can someone explain to me the phenomenon of mild fishtailing when downshifting into a corner? Seat of the pants, I think I know what it is, but I'd like to see it laid out. You see this all the time in MotoGP, before they enter the corner on braking and downshifting the back end wiggles around a bit. My guess is on weight transfer to the front, the rear gets light and the contact patch shrinks, so in slippery conditions it starts to lose traction and slide around.
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Sep 23, 2019 19:59
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Yeah, I'd say weight transfer on deceleration is part of it, but also if you don't rev-match perfectly there's going to be some mismatch between engine speed and wheel speed and if the rear is light enough then the engine wins.
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Sep 23, 2019 23:05
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Sagebrush posted:Yeah, I'd say weight transfer on deceleration is part of it, but also if you don't rev-match perfectly there's going to be some mismatch between engine speed and wheel speed and if the rear is light enough then the engine wins. Seconding this. I think it was all engine braking by down shifting too soon. Couple that with a slick surface and you lost traction.
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Sep 24, 2019 03:11
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 College day 2 was more electrical theory, and the practical was changing the battery and multimetering different things when the bike was on/off. At least in theory; the bike didn't start and I took apart the fuel pump, sprayed in WD40 and manually worked the gears loose with a screwdriver. Went back together fine and worked first time. Extremely satisfying. Also the course tutor has ok'd me parking my bike in there to strip down over the winter which is a boon since I don't have a garage. Nice guy. Shelvocke fucked around with this message at 17:24 on Sep 24, 2019 |
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Sep 24, 2019 17:20
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Question: so what's the deal with copper headgaskets? They seem like a really attractive option, especially if you want compression to the moon. Are there a bunch of drawbacks to them, or do people just not use them because they're expensive?
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Sep 27, 2019 00:02
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Mirconium posted:Question: so what's the deal with copper headgaskets? They seem like a really attractive option, especially if you want compression to the moon. Are there a bunch of drawbacks to them, or do people just not use them because they're expensive? It’s the latter.
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Sep 27, 2019 01:37
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Any headgasket worth its salt has some soft metal in the center, don't they?
Ola fucked around with this message at 08:17 on Sep 27, 2019 |
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Sep 27, 2019 06:55
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Mirconium posted:Question: so what's the deal with copper headgaskets? They seem like a really attractive option, especially if you want compression to the moon. Are there a bunch of drawbacks to them, or do people just not use them because they're expensive? Further answer: they’re not used in vehicles from the factory because of the expense. If you have to replace a head/base gasket, you’ll never have a leak there again (as long as you don’t have to take the head off). So I’ve read on the Internets anyway.
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Sep 27, 2019 15:13
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HenryJLittlefinger posted:Further answer: they’re not used in vehicles from the factory because of the expense. If you have to replace a head/base gasket, you’ll never have a leak there again (as long as you don’t have to take the head off). So I’ve read on the Internets anyway. So disclaiming that I am definitely 100% NOT doing this, but if you are bumping compression on an engine is that a good thing to do to prevent issues down the line? (Also what other kind of stuff do you need to do in that situation? Something to mitigate blowby and stronger connecting rods/crank I'm guessing?)
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Sep 27, 2019 20:33
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That's beyond my knowledge, but I'd expect you'd want stronger valves, new valve springs, new valve seals, new valve cover gasket, cam chain tensioner gasket, and whatever other gaskets are feeling an increase in pressure. Assuming that bumping compression means a new piston, I'd expect it would come with rings and maybe new sleeve? If not, I'd probably want a brand new sleeve or at least a professional hone on the existing one. Depending on the engine in question, it wouldn't surprise me if that required a bit of timing adjustment as well.
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Sep 27, 2019 20:41
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Who do we got up in regular AI who knows old-school hot-rodding like that?
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Sep 27, 2019 22:14
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cursedshitbox has done a bunch of that kind of work on bikes and trucks, I think.
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Sep 27, 2019 22:27
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Mirconium posted:So disclaiming that I am definitely 100% NOT doing this, but if you are bumping compression on an engine is that a good thing to do to prevent issues down the line? (Also what other kind of stuff do you need to do in that situation? Something to mitigate blowby and stronger connecting rods/crank I'm guessing?) This is really very dependant on what particular engine you have and what your goals are. Unlike cars, there isn't really much point in building a bike engine with the goal of just making number bigger, you build bike engines with a particular use in mind, on Japanese bikes 95% of the potential is there from factory and you're just moving the point of optimisation around. A fraction raise in compression from shaving down the head/barrel won't necessitate any big changes. The bigger the changes you make, the greater the knock-on effects elsewhere. Part of what makes an engine 'good' or popular with tuners is the ability to accept modifications that give a decent gain without revealing lots of other weaknesses. Also have to remember power is just rpm x torque. Raising compression will theoretically gain you a small torque increase everywhere, but unless you're racing or you've got something super old/a Harley, the big gains are generally elsewhere. Like you don't just increase compression by itself because it's a lot of work for a very small gain, normally that stuff is accompanied by other more elaborate poo poo like more capacity, bigger cams, porting etc.
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Sep 27, 2019 23:57
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Slavvy posted:This is really very dependant on what particular engine you have and what your goals are. Unlike cars, there isn't really much point in building a bike engine with the goal of just making number bigger, you build bike engines with a particular use in mind, on Japanese bikes 95% of the potential is there from factory and you're just moving the point of optimisation around. A fraction raise in compression from shaving down the head/barrel won't necessitate any big changes. The bigger the changes you make, the greater the knock-on effects elsewhere. Part of what makes an engine 'good' or popular with tuners is the ability to accept modifications that give a decent gain without revealing lots of other weaknesses. Oh hey, glad you're back! And yeah, makes sense. I was just reading rantings and ravings on the topic of increasing compression elsewhere. I keep telling myself that at some point I'll pull a GY6 or a 125cc Honda single out of a scrap yard to mess with it. One of the things that I've always been curious about with them is that rather than altering a lot of the actual cylinder/piston properties, teeny-tiny engines like that are like the perfect candidate for electrical supercharging. Normally electrical superchargers are wildly impractical because you could easily need to build a 10-20 kw power delivery system to run them, which is no loving joke, especially if you have to run it off of 70 VAC magneto output. But a supercharger that only needs to flow a couple hundred CFM wouldn't draw that much power, and in a sensible 3 conductor wye configuration, you could transmit enough power straight off the magneto if you mod it a little bit, and you probably wouldn't even need anything much heavier than 10 gauge wiring. The added load on the crank might be an issue, but vOv. It would be fairly simple to mate a small supercharger like the AMR300 to an electric motor, with the added advantage that you wouldn't need to run it at very high RPM, since it's designed for something like a 600CC engine. But then if you start shoving a bunch of air in the intakes presumably the engine then promptly blows up. This is just a pipe dream for now though, so I could just be talking out of my rear end
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Sep 28, 2019 02:13
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Electrical supercharging seems like a good use case for lithium batteries. Size the battery up a few times, keep normal charging but add easy external charging, so no power loss from extra charging. You should be able to get quite a few boosts from 1 kWh, which you can get from two e-bike batteries.
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Sep 28, 2019 02:27
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Mirconium posted:Oh hey, glad you're back! Supercharging gy6's and similar is very much A Thing, you can buy little electric superchargers cheaply off eBay, I believe they're originally intended for power equipment. I don't know the specifics of boost etc you get with such a setup but IMO the first thing to fail on a blown gy6 (jetted correctly with adequate cooling) would probably be the rod or wrist pin area as those are very weak and flimsy and there is no oil jet or other means of preventing gudgeon scuffing.
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Sep 28, 2019 02:37
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How terrible an idea would it be to get some crash bars like this: and bolt some acrylic/aluminium/something to the front to try and get some more weather protection for my legs/feet? e/ obviously accounting for wheel clearance and such. Renaissance Robot fucked around with this message at 10:36 on Sep 28, 2019 |
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Sep 28, 2019 10:31
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Renaissance Robot posted:How terrible an idea would it be to get some crash bars like this: Fairly terrible. It will catch the wind, it will worsen your fuel economy and it will look less attractive than dog's vomit on a Gordon Brown tribute plate. I'd rather spend money on better gear.
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Sep 28, 2019 10:57
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if you're wearing the correct boots, you can ride through pools of battery acid with occasional lava sprays and nothing below your knee will notice.
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Sep 28, 2019 17:53
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If the bike is air- cooled like that one you could cause it top over heat as well.
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Sep 28, 2019 18:02
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Elviscat posted:If the bike is air- cooled like that one you could cause it top over heat as well. I'd be genuinely worried about this yeah. Some Harleys have a setup like what's being described and they have to have special ECU behavior to prevent overheating in traffic.
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Sep 28, 2019 19:06
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Renaissance Robot posted:How terrible an idea would it be to get some crash bars like this: According to every courier in the 80s and 90s, an estate agent board works perfectly in that application. I'd be concerned about cooling etc though.
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Sep 28, 2019 19:17
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Renaissance Robot posted:How terrible an idea would it be to get some crash bars like this: HD makes soft "lower fairings" that go over the crash bars.
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Sep 28, 2019 20:23
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Renaissance Robot posted:How terrible an idea would it be to get some crash bars like this: It’s a good idea. Leave some air to cool the engine obviously.
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Sep 28, 2019 20:29
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Slavvy posted:I'd be genuinely worried about this yeah. Some Harleys have a setup like what's being described and they have to have special ECU behavior to prevent overheating in traffic. Lol traffic what's that? Obviously I'd prefer boots that just don't leak, but the time to shell out for another pair of forma adventures was last month, before I bought a pair of very well-rated hipora lined Richa boots that can handle heavy rain but apparently don't like being ridden through huge pools of standing water for 30 miles. ¯\_(ツ)_/¯
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Sep 28, 2019 22:14
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Renaissance Robot posted:Lol traffic what's that? If it ain't Gore-Tex, it ain't poo poo. There are other waterproof breathable membranes out there that work extremely well but none of them have made it into motorcycle gear, particularly boots. F9 did a video comparing several of the house brand waterproof membranes, and the results were laughable for pretty much anything that wasn't Gore-Tex.
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Sep 28, 2019 23:39
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I haven't ridden my bike in a long time (spending all my time and money on home remodeling) and I plan to do a track day at the end of November. Someone give me tips on how to refresh my skills. Traffic in Austin feels like it has gotten really bad and I just don't enjoy riding around a bunch of inattentive drivers. I guess I should buy a phone mount so I can have some semblance of navigation and go out really early on some weekends, but otherwise what skills should I go practice in a parking lot? I always sucked at the figure eight test from the msf course
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Sep 29, 2019 02:29
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MetaJew posted:I haven't ridden my bike in a long time (spending all my time and money on home remodeling) and I plan to do a track day at the end of November. Go buy a dozen or two mini cones from amazon and set yourself up a baby MSF course!
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Sep 29, 2019 03:35
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What bike? Rigid phone mounts on vibey singles / v-twins are eating phone cameras.
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Sep 29, 2019 04:51
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I put 25,000 miles on a crappy $10 phone mount from amazon holding my iPhone 6S to the bars of my
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Sep 29, 2019 05:01
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Revvik posted:What bike? Rigid phone mounts on vibey singles / v-twins are eating phone cameras.
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Sep 29, 2019 05:43
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RadioPassive posted:I put 25,000 miles on a crappy $10 phone mount from amazon holding my iPhone 6S to the bars of my I have the quad lock system and it holds firm but that means it transfers vibrations right to the phone. The damage seems to occur as a usually gradual buildup from rattling components related to optical image stabilization. The iPhone 6S does not have OIS.
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Sep 29, 2019 14:46
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No complaints about my ram x-mount a month in. Cheap-ish and sturdy. I always use the rubber retainer they included though. I’m a trusting fellow but the resale value of my bike is approaching the value of my phone, let’s say, so I’m not taking chances.
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Sep 29, 2019 15:54
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When did they stop putting those little corner cutouts on phones for you to tie a wrist strap/lanyard to? If they were still a thing I'd say put a karabiner in there and snap it to your handlebars (while in the mount) for extra peace of mind.
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Sep 29, 2019 17:09
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Renaissance Robot posted:When did they stop putting those little corner cutouts on phones for you to tie a wrist strap/lanyard to? More than a decade ago.
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Sep 29, 2019 18:42
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I only got a smartphone like five years ago, and before that I had a nokia brick that I'd had since 2007 or something
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Sep 29, 2019 18:49
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I only trust ram mounts now, so i picked up a bar mount and the x-grip thingy that comes with the rubber retainer thingy. the retainer is far too small to hit all four corners of my iphone 8, but I just put it on diagonal corners and it locks it down well.
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Sep 29, 2019 19:07
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Renaissance Robot posted:When did they stop putting those little corner cutouts on phones for you to tie a wrist strap/lanyard to? Sony phones still have those because attaching 20 tiny kawaii dongles to your phone is a thing in Japan.
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Sep 29, 2019 20:00
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Renaissance Robot posted:How terrible an idea would it be to get some crash bars like this: I used to run crash bars on an original model fazer1000, and to those I zip tied cutouts from an A3 drawing folder. That with the combats, mesh jacket and cracked fairings made me look the part of the courier I always wanted to be. I'll see if I can find some pictures a bit later. Oh and it worked fine for probably 3 years of poo poo weather commuting, as long as you're covering your legs and not the engine, no airflow issues.
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Sep 29, 2019 22:53
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Do any of y'all have experience on mounting a ram mount to the SV650S? It looks like you can just about squeeze the mount to the left clip-on/handle bar. Is this the best option?
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Sep 29, 2019 23:14
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