Dylan Code

I don't think we will ever see a motorcycle pull 1.96 lateral G's on flat ground this lifetime. For comparison a Superkart on the skidpad did 1.39g in one test. In the same test a Williams F1 car with 0.5G downforce was able to do 2.0G on a track in a fast, banked corner aided by the wings for road holding. An Ariel Atom, known for its cornering, can only mange 1.12G, a Ferrari LaFerrari comes in a 1.16G. I think your calculations may be based off of some assumptions regarding the contact patch and it's location for the effective lean angle figure vs frame lean angle. I'm looking at a datalog of a moto2 bike at Aragon ridden by a world level rider, fastest lap, banked turn, and coming up with a max lateral acceleration of 1.42G as a momentary peak. The key point being that it's a banked turn.

So if a MotoGP rider is leaned over in a corner on flat ground at 63 degrees of lean, what do you think the lateral acceleration is?

Regarding the graphic of lean angle and G-force above: that would only hold true if the motorcycle had a theoretical "zero width tire". The apparent lean angle and the effective lean angle are different on a motorcycle due to the contact patch being off to the side versus straight down the center line of the motorcycle. For example a MotoGP bike at 62 degrees of lean is going to be more like 1.2G. That can also be skewed by the amount of banking. So the question would be how are we measuring the lean angle: against vertical or in relation to the road's camber? You can be perpendicular to the road in a steeply banked turn and register 20 degrees of lean from vertical...

Recently Joe Roberts did a day of practice on one of our school bikes which he is familiar with. He had always rode it with a 200/55 rear but this time he used the new 200/60. As suspected the bike turned in very well due to the higher rear. The 200/60 is 10mm taller than the 200/55.

Riding with one hand forces the rider to both push and pull on the bar... The push is in my opinion more accurate but the pull can help overcome the resistance for higher speed turns. Less necessary for a light responsive bike.

I think this topic is simple enough to where someone can just go out and try it. In my experience I have seen every combination of rider with regard to preference on bar pressure but it does make sense that using both a push and a pull will give the most control.

The schedule is up but the Laguna dates are not finalized yet. Should be up in 24-48 hours hopefully.

Regarding ease of steering: you can push the inside bar (push right bar to go right...) but you can and should also pull the opposite bar. Some people have a hard time coordinating this if they have not done so before.

Generally speaking you would want to apex it where it is the most off-camber.

Sure if it's cold the Q4 would probably be a better choice than the slicks but the slicks will grip better when they have warmed up. Yes if someone wants to upgrade to the Q4 that's no problem.

No we are going to be sticking with the Q3+ on the fleet bikes due to its all around versatility, durability, etc.

I can't tell if you are serious or joking with this post. Tensing your gut to steer the motorcycle? Turning your head to steer it? Pull the inside bar outwards? Regarding you comment about the No BS bike, the further you are from the center of mass of an object, the more leverage one has on it. The No BS bars are quite high, therefore have more leverage and still can't get the bike steered with any efficiency.

Bottom line up front: the bike is extraordinary, awesome, phenomenal. Why: It is build bottom up as a track-specific bike. Different from a World Superbike that started out as a street bike, this was built as a track bike from the bottom up. Somehow it was incredibly user-friendly. Any intermediate level and up rider will love it. Handling: Zero changes on the suspension, the bike would not only hold a line, it went anywhere you wanted it to go. Very easy to set it on a line. Rough pavement (at Willow Springs) was no problem. At our race school I was able to make passes over a bumpy outside section where other riders would avoid. Power: Super linear. Never really hit hard suddenly. The mapping it came with is very manageable and a perfect balance of outright power and user-friendly delivery. 3rd and 4th gear power wheelies are easy and very progressive--not sudden. It definitely is far more powerful than a stock S1000RR. Gearbox: This was something that surprised me. Super-smooth and positive shifts. The stock gearbox is just fine but this one was even better with a very positive feel and great travel. Electronics: The traction control is audible; you can hear it coming in with a fluttering sound which is very helpful to get the immediate feedback on what the bike is doing on that. The dash is a race dash with a very simple interface and easy to control and change settings. Launch control: just like the GP bikes! So cool. Used it today at our Race School. Took off like a scalded cat. Finish: Every thing is so tidy under the seat where the battery and datalogger are. Nothing missing, nothing extra. Most bolts are drilled titanium. Wiring harness is custom with nothing xtra, but there are jacks for additional sensors like brake pressure and suspension travel. Brakes: Zero fade. Excellent feel. Some travel but not too much, very linear. Weight: Holy sheet. It's 6lbs lighter than a 300 Ninja when it's fully wet. Wow so easy to transition. I have video of two women lifting the bike completely off the ground. HP4R Price: $78,000. Engine replacement at 3,100 miles. Yoshimura superbike: $300,000. Engine rebuild at 700 miles. Graves Superbike: +/- $150,000 estimated. Engine rebuild at 1,200 +/-. BMW World Superbike: $120,000. Engine rebuild/replacement at 1,000 +/- Privateer MotoAmerica Yamaha Superbike: $60,000. Engine rebuild/replacement at 1,000 +/- and lots of bugs to fix and iron out, lower spec brakes and components. Any true superbike price is very hard to nail down because the development is the real cost. The parts are reflected above, but double, triple, quadruple is spent in development and testing at the track. Just one weekend testing is serious dollars. What you get with the HP4R is significantly more that you could ever get if you started with a stock S1000RR and tried to build a superbike from there. It's really a totally dialed in and balanced package. I had the owner of a local performance shop ride the bike from Motorsports Exotica, who said after getting off the bike: "I've ridden bikes with twice the money into them that don't even come close to this bike."

Most discussions of steering and "weight shift", "loading" and "helps it to steer" are riddled with illogic, and the people discussing will not reach a conclusion predicated on so many errors in thought. Rather, going to the basics of logic is the best way forward lest they get entangled permanently in confusions. Forums have become a popular platform to air ones flawed thought process, while other visitors try in vain to overhaul their whole logical approach to problem solving. Not saying I've got logic down myself, but some statements and articles have so many flaws, it's like: "where do we start?..." and just skip it. Remember when you have contrary facts, one or both are false. Some things to consider: https://en.wikipedia.org/wiki/Consistency https://en.wikipedia.org/wiki/Validity

Well I think you've read enough data here and there to have plenty of food for thought. Really the rest is up to you to experiment with. It seems to me that a person like you is all about the journey vs the destination so enjoy your journey!

The section of the bike that the seat is connected to is also the one with the pegs. If you put weight on one versus the other, the bike can't tell any difference. You still weigh the same as far as the bike is concerned. Try sitting on the seat as that's what it's for. We know racers don't hover over the seat while cornering, and even if they did, the bike would not know any difference. You said you wanted to understand bike dynamics more. So start with steering and read the article. Also the wiki article on countersteering: https://en.wikipedia.org/wiki/Countersteering

You sound hurt... Anyway what I'm saying is that your approach is flawed and there may be some fundamental flaw in your research process. Looking over some basics on logic and the scientific method may help. Not saying I have those subjects covered, but I see a lot of circular conversations coming up with no resolution. Fully understanding something as complex as motorcycle dynamics is not possible with today's depth of understanding of the physics and mechanics. We can't even easily explain how a bicycle steers with math: https://www.scientificamerican.com/article/the-bicycle-problem-that-nearly-broke-mathematics/ Maybe you should start with steering if you want to understand these topics; read the article. The other thing you have to realize is that this all must help you get through a corner better. Maybe you don't need to know exactly how a brain works in order to think...

It seems like you are trying to take everything you have heard on the subject and get them all to agree. Or maybe just stimulate an interesting dialog. Judging by your response it seems like this could be a circular conversation for some time, but if you really do want to actually know, I'd suggest you do some more of your own experiments, but read the definition of "confirmation bias" each time before you do any of the experiments. Also, remember that if you have contrary facts, it means that one or both are false. noun: confirmation bias the tendency to interpret new evidence as confirmation of one's existing beliefs or theories.

Peg weighting is pretty much a joke among physicists. If you put weight on the peg versus the seat, does the shock know any difference? Does the contact patch know any difference? If you are in a row boat and press down on the bottom of the boat, does it sink further into the water? If you sit in a car seat and push on the dashboard, does it move the car forward? How effective is putting weight on the pegs? Have a look at the video:

That the surfaces the bike was rolling across were not completely flat, coupled with a profiled tire, would be a big clue. Add to that what happens with front tire friction when a bike is leaned over and what that in turn does to the bars and you have more clues.

Any of them. Just see the Off-Track coach for the day and schedule a time to ride it.

Here's a short TV spot about CSS. Courtesy of Superbike Planet

The slip % should be between 5% and 15%, which it is, and the traction control will keep it in that range. It looks like you are getting a lot of slip % at steep lean, which would suggest that your entry speeds are a little low for your liking and are being compensated for with somewhat aggressive throttle while leaned over far mid turn. I have no clue about Michelins, but would follow the suggestions of the local distributor for that tire.

I call BS on that link. Schuberth has been in the head protection business for 70 years. Practically, there is no effective way to test a helmet for all types of impacts. What's good for a light impact is bad for a heavy one and vice versa. Anyone's testing system is going to be seriously flawed regardless of how you do it. Current SNELL and DOT regulations are also criticized heavily on their outdated testing criteria. The same could be said for ECE or this UK government site. Schuberth makes helmets for bomb defusal, cars, motorcycles, police, firemen, etc. and has been doing so for decades. Here's some serious criticism on their methods: A LEADING safety engineer from Birmingham University* has spoken out against the SHARP helmet rating scheme, believing the system should be scrapped following the results of a recent scientific study. Dr Nigel Mills, who has worked on helmet testing and design for 30 years, believes the European helmet testing system is flawed. During an intensive six-month study, Dr Mills found areas of concern, which has prompted the scientist to ask for SHARP ratings to be scrapped. Dr Mills has pointed out three major factors within SHARP that are of serious concern. Speaking exclusively to Visordown earlier today, Dr Mills said: "First, the impact velocities in oblique impact tests must be realistic; gentle impacts used to determine helmet friction coefficients differ from more severe impacts in which the helmet starts to roll on the road. "Second, the test headform must simulate the human scalp and hair which allow significant helmet rotation. A test headform without scalp or hair responds differently and may overemphasise the friction of the helmet shell. The rotational acceleration of the test headform must be measured. "Third, the pass/fail criterion must be set. Only ballpark figures for human tolerance to rotational acceleration are known. You might imagine that independent researchers had agreed on the details, and the industry was convinced of the benefits of these radical new tests. However the SHARP scheme was developed by the government Transport Research Lab for the DfT without public debate." Dr. Mills criticises the oblique impacts in the SHARP scheme, as they don’t measure rotational head acceleration. Presumably to save money, they use a mechanics model, a friction coefficient and a direct impact test result to estimate the oblique impact performance. Mills’ study shows the model is too simple, so the estimated performance parameter (a linear head acceleration multiplied by a function of the friction coefficient) is meaningless. They weight test results from different sites in a complex way to estimate how many lives would be saved by a particular helmet design. This overemphasises test ‘results’ at the sides of the helmet, and totally ignores impacts on the chin bar region. Hence he concludes that the estimates are meaningless. Dr Mills feels that the British and European helmet standards could be amended to include tests for oblique impact protection, based on scientific consensus, with the design consequences considered.