bradvanhorn
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Posts posted by bradvanhorn
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Dunlop Q2. Fantastic performance in wide variety of conditions - street or track, dry or wet. Probably the least expensive tire choice among comparable tires. They might ("might") not last as long as some comparable tires, but the fact they usually are cheaper offsets the potentially shorter life.
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Next weekend I have 3 track days back to back at chuckwalla. I put the best tires I could find on both my bikes - 2011 ninja zx6r and 2012 s1000rr. I got pirelli diablo supercorsa SC. Apparently they have alot of grip where I can trust that I can explore steeper lean angles.
Again - by steep I mean relative to what I do now, which is not very much at all.
Once I can relax a bit during a lean and get more confident, I think i'll go back to less sticky tires in the far future and explore the limits of traction.
Something to keep in mind... if you're changing tire type/brand then you should be verifying your suspension still is setup correctly. Frequently changing tire type/brand could even trigger/sustain your apparent distrust because you likely will face constant changes in tire/suspension feedback with each variation. Also, there are a lot of very fast track-day riders using "street" tires (something like Dunlop Q2's) and never having issues with or being concerned about tire traction.
My last immediate thought... good technique is for more deserving of your attention than your tires. If you're giving attention to tire concerns then you have limited attention left over for everything else. As Keith might say, your $10 worth of attention can only buy so much...
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Nice write-up. Certainly sounds like it was quite an adventure for all involved.
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Since you are working on visual skills, I invite you to give a thread I started a read. http://www.ninjette....ad.php?t=109933 It gets pretty deep if you haven't taken level 1 but Misti (a CSS coach) ensures that the basics are covered.
I enjoyed your video, thanks for sharing.
Thanks for posting the link - that is an interesting thread. I found I was doing a lot of head nodding while reading. I could totally visualize many of those things discussed and how many of them could (did) lead to danger (disaster). I am almost continually amazed at how critical good visual skills are to this game.
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The following formulas were used for getting lateral G's:
acceleration in m/s = velocity² / radius (all in m/s)
to convert to G's: accelleration in m/s² / 9.80m/s² = G's
The following formulas were used for lean angles:
tana = .067*mph²/radius in feet
Then you have to inverse tangent of tana and you get degrees of lean angle.
This is why I left the engineering program in college
One of the school coaches posts here under the alias "tzrider". I think he has the math/physics background for this question so hopefully he'll spot this thread.
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Awesome! I asked Keith about this over a year ago and I've been anxiously waiting ever since
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Adding to my post from yesterday...
AMOS starts with intro and tech briefs by Dylan. The riders are assigned to coaches (typically 1 coach to 5 students) and begin a series of steering drills. A couple additional tech briefs are given during the day, often by Dylan, but sometimes by other senior CSS coaches. Mid-day the focus moves from steering to braking. Students do a series of braking drills to establish baseline braking distances, then they get to ride the CSS brake rig. If time permits, the students do the braking drills again; otherwise the next morning is the second round of braking drills. Dramatic braking distance improvements are the norm. Students typically get a chance to ride the no-BS bike and the lean bike, either later on day one or else on day two. Day two then is 5-6 tech briefs and each brief is followed by a riding session on a small road course. Tech briefs generally follow the CSS Level 1 topics but with street themes. The road course is designed to present a few different challenges to the students (esses, decreasing radius, double apex, etc). CSS coaches observe the students ride the road course and flag-in riders as necessary to coach them on their riding.
ARTD is a similar but lesser version of day two of AMOS. Typically Pete Castanik supervises ARTDs (in NC at least), but the coaching all is done by CSS certified volunteer military coaches (such as myself). Riders get 3-4 riding sessions and with some briefs in between. Similar to AMOS, during the riding sessions the coaches observe the students ride the road course and flag-in riders as necessary to coach them on their riding. (ARTD coaches have a specific training program to follow, but often we would pair with CSS coaches at AMOS and it was a tremendous experience working with them in this manner.)
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The CSS material is intended to educate riders who have the misconception (as many do) that the rear suspension will compress under acceleration on a sportbike and that is generally not true. Sportbikes are built with anti squat properties and generally rise (both ends) under acceleration, increasing ground clearance - which is the part that is important to know for throttle control in a corner!
This is point on increasing ground clearance is very observable. When we do our ARTD/AMOS training (both CSS developed programs) for the Marines, they ride a small road course we setup for them. At the beginning of the day you can see riders who have reduced ground clearance in large part due to being off the gas. Off the gas you can see the bike sagging. Once we work with them and get them using good throttle control you can clearly see the bike lift instead. It is a very noticeable difference in the amount of ground clearance they have. The most dramatic examples usually are the big cruiser guys who begin the day dragging just about everything through the corners. By the end of the day many of them are going faster but without dragging anything at all.
I need to watch some of my recorded races. My recollection is you do not see squatting from pro race bikes (WBSK, MotoGP, etc.) I do recall the front end often gets very light, which I suppose for the unitiated could be construed as the back end squatting. I need to watch for this specifically though, and in the analysis it may/may not be truly relevant. At least it'll be fun watching the races again
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AMOS is completely different from the MSF sportbike rider course. MSRC (it actually has a new title which I can't recall) as I experienced it was mainly a refresher of basic MSF training but with a sportbike theme. AMOS is essentially Level One of California Superbike School and some other elements, but oriented to street vice track riding. More to follow when I'm not typing on the iPhone in the airport.
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I know what you mean about a harsh kick if the throttle isn't rolled off exactly smooth....my 675 is like that, the triples do not like anything other then the most gentle roll off possible. On my CBR600RR the roll off with the same output is much more relaxed, you really have to mess up throttle control to get that action. However the 675 is the complete opposite and of course the lower the gear you are in the worse it is too.
Remember this according to Keith, "bikes only do two things, change speed and turn. Riders do 7 different things" Along with evaluating your riding in a positive manner and not making yourself feel unable to "ride" also I would do as suggested and make sure everything is mechanically sound with the front suspension also. If you know your bike is as close to 100% as possible (no bike is perfect IMO) then you don't have to worry about all of the other factors, you know that the mistake was your input and go from there on evaluating how to fix it.
I ride the 1050 triple (2012 Speed Triple) and I have no issue with roll offs whatsoever. The older Speed Triples had a reputation for heavily diving on the brakes but that was corrected in the 2011 redesign. I can't speak directly to the 675 triples but the few guys I know who track ride them never mentioned this as a problem in any way. Perhaps it is a suspension tuning problem?
Or it could also be the quick turn throttle I forgot to mention that I am not 100% used to also lol.....
Interesting. I'll have to see what the local 675 guys think about this problem.
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I know what you mean about a harsh kick if the throttle isn't rolled off exactly smooth....my 675 is like that, the triples do not like anything other then the most gentle roll off possible. On my CBR600RR the roll off with the same output is much more relaxed, you really have to mess up throttle control to get that action. However the 675 is the complete opposite and of course the lower the gear you are in the worse it is too.
Remember this according to Keith, "bikes only do two things, change speed and turn. Riders do 7 different things" Along with evaluating your riding in a positive manner and not making yourself feel unable to "ride" also I would do as suggested and make sure everything is mechanically sound with the front suspension also. If you know your bike is as close to 100% as possible (no bike is perfect IMO) then you don't have to worry about all of the other factors, you know that the mistake was your input and go from there on evaluating how to fix it.
I ride the 1050 triple (2012 Speed Triple) and I have no issue with roll offs whatsoever. The older Speed Triples had a reputation for heavily diving on the brakes but that was corrected in the 2011 redesign. I can't speak directly to the 675 triples but the few guys I know who track ride them never mentioned this as a problem in any way. Perhaps it is a suspension tuning problem?
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From all I have read about the CBR1000RR, and I've read a lot, it has no reputation for front end dive. In fact it often is praised for its confidence inspiring handling and stability. If you're having that much trouble then I suggest you get the forks refreshed and setup to your specs.
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I think I'm missing part of the point here: is more throttle and more lean angle always bad?
There are three long corners I come across on a regular basis:
1. double apex RH. Entry is over a crest, first apex is early, run out wide accelerating all the while, 2nd apex whilst still accelerating, picking the bike up and driving
2. very long (210degree) very fast RH. narrow entry, treated as double apex. entry fast, closed throttle slowing to mid corner 2/3 of the way out then accelerating towards 2nd apex, pick up and drive.
3.long LH (170deg). carry lots of speed in using engine braking to tighten line. hug curb. accelerate. pick up bike on exit pick up and lay onto rhs for rh bend sequence
All of these corners (for me) are characterised by the same thing - at some point well before the 'apex' I am accelerating and this generates more lean angle.
Is this bad?
Turn the bike, get it to lean angle you want, then roll-on, pick up the bike when appropriate, all is well. If you roll-on at the same time you are steering the bike (adding throttle and adding lean simultaneously) then you're taking a bigger risk. Adding throttle and picking up the bike generally is ok.
Roll-on before the apex shouldn't have any effect on lean angle. If you have the bike at desired lean, regardless of where the apex is, and you start your roll-on, then you shouldn't generate more lean angle unless you also add pressure to the inside bar.
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For the track, I really like the RC8
Two RC8's showed up this past weekend at NOLA for the track days. That bike looks and sounds great, plus it appears more comfortable than the Panigale (which there actually are quite a few around here). A nearby dealer has an RC8R production racer for sale but my wife won't go for the $18k price tag.
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Monday I asked Cobie this same question. He replied, "should be out in a couple days."
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The Marine Corps contracts with CSS to deliver a program called Advanced Motorcycle Operator School (AMOS) which definitely does much of what was described. I'll assume for the moment that the quote is referring to AMOS. AMOS was unquestionably the best street riding training I ever received. I in fact did AMOS twice because it's that good. However, I don't believe this training is available other than through the military connection.
CSS also developed a second program used by the Marine Corps, called Advanced Rider Track Day (ARTD). ARTD is great but is just a piece of what is delivered in AMOS. CSS trains volunteer coaches - military members and a few retirees and civilians - to run the ARTD program under the supervision of a CSS Coach, usually Pete Castanik and sometimes Dylan Code.
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You might consider NOLA. The track is great and the French Quarter is roughly 30 minutes away. One downside to the track is it's totally flat so if you want elevation changes you'd best look elsewhere.
Barber also is a great track, and it has some fun elevation changes if that's your interest. Birmingham is roughly 15 minutes away, although I don't know first-hand about what they have to offer.
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1st: Ducati Multistrada 1200 S Pikes Peak (for most everything)
2nd: Aprilia Tuono V4R APRC (for track use)
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Hey, I noticed that Plexus (a great bike cleaner) has skyrocketed in price to something like $21 per can. Anybody know of a more reasonable alternative that works just as well, on paint, windshields and helmet shields?
I like Windex and a microfiber towel (or old fashioned, clean cotton diapers).
Never use Windex on helmet shields, ever. It makes the material brittle and hence, more likely to shatter. Helmet manufacturers will back this up, it's not just some urban myth.
(I used to do the same thing.)
We can politely disagree on this point. There is no published data to credibly confirm or deny this issue; merely lots of anecdotes from people who do or don't use this product. The general focus of the debate is whether the trace amounts of ammonia in Windex will cause damage to the Lexan of the face shield when used to clean the surface. There are many people like me who've used Windex for decades and never had any issue. I will continue to use it without concern; everyone else is free research, read, and make their own decision.
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Hey, I noticed that Plexus (a great bike cleaner) has skyrocketed in price to something like $21 per can. Anybody know of a more reasonable alternative that works just as well, on paint, windshields and helmet shields?
I like Windex and a microfiber towel (or old fashioned, clean cotton diapers).
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What do I wish I had known sooner? Well, I don't recall any small tips or advice but I am sure of a few things I wish I'd known.
* How much fun it is to ride on the racetrack. I seem to recall every few years someone would tell me I should go to the track but I just never did. When I finally did get on the track I then realized why people had been telling me to try it and how much fun I had been missing.
* Even a basic suspension baseline setup can make a tremendous difference. Until I started riding the track no one really ever emphasized the benefits of a good suspension setup. Even after I got on the track I still undervalued the idea. Once I rode my own bike on the track a few times, then took time to adjust the suspension, then went to the track again, at that time I really understood why I should've made suspension changes one of my first priorities.
* California Superbike School will completely change your riding for the better, forever. I think this speaks for itself
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Not to hijack your thread but are you coming to NOLA this weekend? Would be happy to chat with you if you'll be around. I'm usually easy to find since few people are on the track on a Speed Triple - and going slow as molasses in winter
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...just need to understand braking points and procedures better.
If you haven't already read the orgininal Twist of the Wrist, there is some very interesting material on braking. It up-ends the whole idea of having a specific starting point for your braking.
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I think that is what's messing me up is I am setting my braking points as if I am coming to a stop when I only need to set my entry speed.
I don't want to lead you astray but I think you should practice the "no brakes" drill. Set your entry speed using only the throttle (obviously use the brakes if you must to avoid blowing the corner). This drill helps you develop your sense of speed. As you better understand what speed you want to enter a given corner it then should help you better understand where/when/how much braking must take place.
Chicanes And Wot
in Cornering and Techniques
Posted
I may be off the mark but I keep thinking... Have you been able to verify through measurable data you're drive is not as good if you briefly roll off for the transition in the chicane? (Presumably by telemetry data or something similar.) Sometimes our sensations or perceptions are deceptive. If you haven't verified the data then maybe the roll-off is benefiting you more than you realize (or maybe not...)
This is not a direct situational comparison... During a recent track day I followed a friend through the fast esses at NOLA. Our lap to lap pace was roughly the same but I noticed he wasn't changing speed throughout the early esses and then would gradually slow as he went through. He also seemed to run increasingly wide with each transition. When we got in the pits I asked him what was bothering him. He thought it simply was his bike was big, heavy and harder to turn (it's a TL1000R). I asked if he was rolling off slightly for each transition. He was in fact trying to stay on the gas the whole time. This was making it very difficult to get the bike to transition, thus pushing him wide and eventually forcing him to slow and make bigger corrections. Those esses are pretty fast and he thought staying on the gas was the key to being fast going through. I convinced him to make a slight roll-off before each transition, turn the bike, then go back to the gas. He followed me for a couple laps to see what I was doing and then I followed him the rest of the session and I could see him making the roll-offs each time. I had previously been running up on him and having to slow-up slightly in this section but now I had to work a little harder myself to keep him from pulling away. Also, his line was much tighter and more consistent; no more running wide. Afterwards he was astounded at the improvement. He had thought staying on the gas was the right move but discovered the roll-off was a far greater benefit.