YellowDuck
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Posts posted by YellowDuck
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Please refer to Eirik's new thread "Coordination", and just count your blessings...
Speaking as one of the "nannies"....I am actually a bit skeptical about how many people who claim to be expert blippers / downshifters under braking can actually pull it off under truly high-effort near-threshold front braking. That is a pretty difficult trick. Sure, with moderate braking as on the street maybe you can be all fancy and rev-match your downshifts, nice and pretty. But what about when you have to bang out three downshifts quickly in the braking zone when you have come in a bit hot for a tight corner with the back wheel nearly in the air? Maybe you can do it...but I am skeptical that it is a common talent. There is a reason that most serious race bikes run slippers.
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I hear you brother. I too am a spaz. Perhaps we should start a support group.
Still, I can ride well enough to beat a bunch of other people on the race track. Smarts, experience, composure, skill, etc. can make up for a lot. But if I come up against someone with as much experience as me, who works as hard as me, and who also happens to be athletically gifted....yeah, he's going to kick my ass.
There's always a bigger gorilla in the jungle....
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Dave Moss is a guru in his own way. Some people say suspension tuning is as much art as science, and in my opinion Moss is more artist that scientist. Yes he will get your bike working great, but the technical explanation you will get about why it worked might be a little confusing. For example, in his videos he constantly claims that when you add spring preload to the forks you will likely need to add rebound damping as well because the preload has added "energy" to the springs and so you need to control that better. Right action (maybe), but wrong reasoning. I think he has actually been called out on his comments about preload because one of his videos has this soliloquy in it where he explains that sometimes he has to use "simpler ideas that riders can understand even if they are not exactly technically correct".
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Ha ha! You really have to plan ahead for those hairpin turns don't you?
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The info in Andrew Trevitt's book Sportbike Suspension Tuning is probably all any of us mortals will ever need. Highly recommended.
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Mine is a Ducati Performance unit (made by Bucci) and is not adjustable, but it works perfectly. There is practically no engine braking at all until the bike slows down - it slips very freely - then at some bike speed you will see the tach needle rise as the clutch engages again. At that point you can feel the engine baking return but it does it progressively and doesnt upset the bike.
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I can't be bothered to learn how to blip on downshifts because my slipper works perfectly (1000-cc V-twin). No rear wheel hop ever even if I dump the clutch. A bit of rear squirm maybe if I am braking hard but that's it. It's a sweet setup for a spaz like me who has little chance of maintaining constant brake pressure during a throttle blip.
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Ha ha...yeah "decent save".
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Very interested in this topic. I will not offer advice because there are others here much better equipped to do so. I just wanted to mention that I had a very similar type of crash at a very similar stage of development as a track rider. Already in the corner, just decided to crank it over more, rear end went away. I was nowhere near the lean angles I now achieve on the same bike with similar tires. The major changes I made in my riding since then were: 1. getting WAY more comfortable and therefore relaxed on the bars while leaned over, and 2. setting my lean angle with one quick steering input then not adding more lean while in the corner and rolling on. If I get it wrong and don't think I will make the exit I will just hold steady throttle (which actually produces deceleration) a bit longer before rolling on. Rolling on + adding lean = bad juju.
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Wow, this is a super-interesting question now that I understand exactly what is being asked. I wish my physics and understanding of bike geometry and steering were good enough to offer something useful. There are a few very math-minded folks on the forum here so hopefully one of them can think it through.
It seems though that what you experiencing is a geometry change that occurs when the fork compresses as you hit the uphill section. Normally what happens on flat ground when the fork compresses as you are leaned over (say, because you applied some front brake) is that the bike will want to stand up a bit. This happens because as the fork compresses the center of gravity of the bike / rider moves downwards and towards the outside of the corner. So, to compensate and stay on the same line through the corner you would need to lean more.
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The reason I ask this, is because when I approach tight turns that have a sharp upward hill, I feel the front forks compress and this feels really weird to me when I'm leaned over on the bike. Feels like the front wheel will wash out.
Also, in that same token, when I approach tight turns with a sharp downward hill (like a corkscrew), I feel like my front end is at the top of its range and that also doesn't feel very comfortable.
So just for clarity, we are talking about what happens just at the beginning of an elevation change? Not when you are actually on the hill, but at the beginning of the hill, right? Because once you are on an uphill, your forks would normally be extended, not compressed, and when you are on a downhill your forks would be compressed, not extended. I am trying to get a clear picture here because a sharp transition to a steep uphill or downhill that occurs *in* a corner is a pretty rare thing, even on mountain roads.
In other words, are we talking about a hill in a corner (rare) or a corner on a hill (common)?
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you will usually experience understeer for uphill corners and the exact opposite for downhill corners (understeer)
I read this several times and then something in my brain went "dzzzzt"......
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I've never been on slicks at the track, always a soft compound street tire. Something I've always been really curious about is the level of grip when you contrast, say the Dunlop Q3 vs. the slicks the coaches run at CSS. What kind of pace must you keep up to keep the slicks performing better than the Q3? What criteria would I use to decide that it's time to think about slicks and tire warmers for a track day vs. running the Q3s I have on my S1000RR.
I am not saying that the information I have to offer here is scientific, but I do have some experience with this comparison. I am just a first-year racer with about 5 years track experience. I am fast enough to be competitive in the less-hotly-contested novice classes, but nowhere near expert racer level, nor even a podium contender in a very competitive novice class like 600 supersport. So, red group at a track day, but not amongst the very fastest in that group. Get the picture?
At that skill level I can out ride Q3s. We run the Dunlops on our endurance bike (an 11-year-old Suzuki 600), and they do get a bit overheated if I ride that bike at my sprint-race pace 5 or 6 laps. They get slightly greasy under hard braking and have less corner grip as well - it is easily noticeable by someone at my skill level.
Compare that to my sprint race tires (Bridgestone V01-R slicks). At race pace I am able to keep enough heat in those tires that they work properly, but I simply can't out ride them to the point that they overheat and get greasy. I can (and do) still crash, but if I do it is not because I overheated the tires.
I say this is not "scientific" because it is not as if I have tried every possible pressure setup to try to regulate temperatures. Maybe the Q3s could be kept cooler. But my general impressions seem to be in line with what you would expect, comparing race tires to upper level street tires. I think the difference is real.
When I was an upper-intermediate group track day rider, I was never over-riding the Dunlops (Q2s at the time) until they were worn out. Even at my current faster pace, if I was only doing track days for fun I would probably just run Q3s and accept the minor limitation to all-out pace - they are way more practical than slicks. But if I was going to the track day to try to beat my personal best laptime, I would use the slicks and warmers.
Hope that helps. YMMV.
Edit: Here's a thread I started last winter on a similar subject: http://forums.superbikeschool.com/index.php?showtopic=4045
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I've done about 140 on my bike (calculated based on gearing and rpm, not reading speedo), and personally, even while on the bike it seems totally mad to me. Don't enjoy it at all. But if you are going to record lap times then there is hardly any point if you don't pin it all the way down the straight....so I hold it WOT...but honestly I prefer slower tracks. Sitting on 400 lbs of metal getting pushed through the atmosphere at over 100 mph just seems a tad unnatural...
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Thanks everyone. I really enjoy getting feedback from all of you on these blog posts, and very much appreciate the encouragement.
Nic that sounds like a painful injury! Sorry to hear about that. What happened to me was kind of gross and unfortunately permanent, but at least it didn't hurt that much. Take it easy as you get back into it, and hopefully you will find as I did that the effects on your riding are minimal.
Thanks for the kind words as you have called it exactly right. It is still swollen and painful going back to May 20, 2014... about five months ago but I don't feel a thing when I'm on the bike! Tougher souls like you are pure inspiration.
Well, I might be tough but my wife isn't. She pulled the plug on the final round. Probably did me a favour because it was pretty cold and rainy, but still I would have liked to have completed the endurance racing season. Now I have until May to negotiate with her as to the extent of my involvement next season. It kinda sucks to have your spouse be the biggest impediment to your racing (given all of the other substantial hurdles one must overcome), but I know that I am not the only person in that situation.
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Hard to criticize someone who is blowing by every other rider like they are standing still....
If you want "brutally honest" (i.e., nitpicking)....
1) that series of two corners at 1:15, you seem to be missing both apexes there every lap. If you see yourself doing it constantly, why not experiment with moving your turn in points, sighting the apex better, turning it harder, etc.?
2) I am not really seeing sharp "quick turns". This may be because of the tack layout to some extent - it seems to be mostly fast corners, which tend to require more gradual turn in.
3) The corner at the end of the long straight you do not seem to have figured out to the extent that you can make one single, clean steering motion. You seem to set your lean angle in multiple stages there. That corner seems to have poor visuals but when you get it sorted you should be able to clean it up quite a bit.
Nice riding! Having a zillion horsepower is great fun but also hides mistakes to some extent....when you get a corner wrong and lose momentum it doesn't matter much because you just twist the throttle and pass everyone anyway. It can make it harder to identify where you are weak.
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Air-cooled 2-valver. Beats the pants off any 1200cc air-cooled Harley.
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The zen like state will evaporate pretty quickly and be replaced by stampeding butterflies in your stomach if you get even a tiny bit off line. The track gets very narrow at that speed....
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My answer is always the same:
http://www.ncrfactory.com/eng/html/18.00.shtml
I am not saying it would be comfy, but it sure would be cool.
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Thanks everyone. I really enjoy getting feedback from all of you on these blog posts, and very much appreciate the encouragement.
Nic that sounds like a painful injury! Sorry to hear about that. What happened to me was kind of gross and unfortunately permanent, but at least it didn't hurt that much. Take it easy as you get back into it, and hopefully you will find as I did that the effects on your riding are minimal.
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Holy cow Eirik...you are like a computer with this stuff.
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I guess that leaves me wondering if you have also had some planned ones?
This was my very first unplanned flying dismount of my distinguished riding career.
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That's what the physics say. Larger effective tire circumference = less rear wheel torque = less acceleration.
Blip, Downshift With Brake Applied
in Cornering and Techniques
Posted
I'd really love to learn how to do this, but have never managed it. I don't even understand the physics.
Clutchless upshifts no problem. You back off the throttle a smidge and that "floats" the dogs gears in the transmission so there is no pressure on them and they can slip apart, allowing you to rotate the drum with the shift lever.
But how, physically, is one revving the engine on a clutchless downshift? Before the dogs disengaged, if the engine was revved the bike would surge forward. So is the the blip revving the engine between the time (0.2 s maybe) that one set of dogs disengages and the next set engages, as the shift drum is rotating from one position to the next? So you are pressing down on the shift lever and twisting the throttle simultaneously? It seems like you must momentarily be in a false neutral of sorts if the engine can rev without the bike jumping forward.