mugget

Not quite in the same league, but you might find this interesting. A reasonably powerful car (480bhp) which usually has 255 section tyres, running on 125 section space savers. edited to add: yes the tyres did eventually delaminate, check here for more discussion about that (skip ahead to around 2:40):

Yes, I think that's still accurate to say that rolling on the throttle causes a transition that makes use of the rear tyre's larger contact patch. If you don't roll on, you won't have as much weight on the rear tyre, therefore it won't be as 'squashed' and won't have as large a contact patch on the ground. Right? As discussed, there are a lot of factors that determine how a tyre will work. It's not just about the technical aspect that we've touched on here... Have a think about this: how many times have you seen a motorcycle and rider (racing, or maybe just showing off) exiting a turn and they are still leaned over and the front wheel is off the ground? Compare that with the number of times you've seen someone braking into a corner and the rear wheel is off the ground... while the bike is leaning in?

On the subject of electronic aids like TC and ABS, I think a good way to look at it is that they don't protect you if you're greedy with the throttle or sloppy with the controls. Some magazine reviews I've read seem to indicate that the S1000RR is an almost 'idiot proof' bike, that you could give it as much throttle as you want at full lean and the TC will save you, or that you could brake late and deep into a turn with increasing lean and the ABS would save you. But I find that really hard to believe... I wouldn't be worried about it 'spoiling' you as a rider, or not enabling you to learn proper throttle and brake control. The way I look at it is that modern sportbikes are really way too powerful for the average rider, but TC and ABS gives you a larger safety net and makes more of the bikes performance safely accessible. That equals more fun!

Great info, Timmer! The below especially makes sense, never thought about it that way before.

Ah, this is an interesting topic. Now that it's mentioned - I do recall seeing lots of racers with their chins very prominently showing out the bottom of the helmet... (helmet tilted backwards on their heads). It's something I've always been mindful of, so I've never had a problem with the helmet... But how far does everyone tuck down? How close is your chin to the top of the tank, does your helmet go down into the little cutout area on the top of the tank? I don't usually tuck down as far as possible because I found it was just a lot of effort! Add to that the fact that the bottom half (or more) of my vision would be obscured by the bottom of the screen - made things kinda scary. So I just stick with a 'comfortable tuck' most of the time now, chin/bottom of helmet maybe 10-15cm from the tank. I never even considered tilting my head while tucked (thank goodness!) - that would be a bit confusing wouldn't it!? I bet the people who were doing that sure were glad to find a fix for their vision.

Is it also true that it can be called "pinking"? Well maybe not in other parts of the world, but apparently in Australia. No idea why it's called that, but I only learnt about that in the last couple of years. Just going back to the topic of fuel octane ratings - a bit of a myth that you can hopefully clear up... does using a higher octane fuel increase performance (power)? I have looked into this briefly myself and found that really it shouldn't make a difference to power - that a higher octane fuel is only needed to control detonation issues? The recommendation that I came across was to save your money and used the minimum recommended octane fuel (mostly 95 for modern sportsbikes? Or my bike at least.) But ask some different people and I bet they'd swear that they get better power from higher octane fuels. It seems to me like there's alot of people using inaccurate and defective 'seat of the pants' dynos. I never knew that Japan has 102 octane fuel available as their Premium (Aussie Premium is 98, which is the Japanese 'Regular'). I guess that explains why some places have such an abundance of vehicles with built engines?

I'm running the Bazzaz gear with TC and quickshift on my K6 GSX-R1000. It's a bit of a mystery brand out here in Australia - I think it is actually banned from the local/national race series, so practically no one bothers with it. But I wanted it because I didn't want to feel left out riding a bike with no traction control and no quickshift. It's worked so far - I stopped lusting over any new bikes... for now... Only other mods are a BMC road/street air filter and an M4 GP exhaust. That exhaust ended up being a real hassle to tune, from what I can gather. There was alot of dyno time (more than one day), but I'm glad that I got it done by a reliable shop, and they spent the time to get it right. The difference after I picked it up was night and day - the first thing I noticed was that it was just so so much smoother, even compared to the OEM fuel map with the stock exhaust fitted. After that I decided that a dyno tune would be one of the very first things to have done to any other bike I own. All that wiring was a real mess to install though, had one connector plugged into the wrong spot and was going out of my mind. Lesson learnt, double check each plug against the instructions. I think I managed to keep it all fairly neat though: I also have the Bazzaz TC trim & map switches - I had planned to get two dyno maps done, one for the open exhaust and another for use with the quiet baffle. Turns out the quiet baffle was really not so good to use... the guy at the shop mentioned that I was just ridiculous how much it restricted the exhaust flow, and that it could cause problems with additional heat etc. So that plan was ditched. The below dyno graph shows before the tune, with the quiet baffle fitted - compared with afterwards and the open exhaust: The exhaust is hella loud - the poor guys working at the shop were nearly deafened even though they were outside the dyno booth. So now whenever I see people asking about the M4 GP exhaust I warn them off the baffle. Sounds awesome, I just ride very sedately around town and I haven't got any tickets yet... I did get a bung welded in the exhaust for the O2 sensor to be used with the AFM module. I went out one night and started to tune that, but found it to be very tedious, which is when I just decided to go with the dyno tune.But now that I've got a good base map it's handy to have the AFM sitting in the shed in case I change any other parts and want to make a tweak. (Although everything around the exhaust and fairings was really tight, with the O2 sensor it doesn't all fit ideally, but that's another story.) A question about the O2 sensor that comes with the PC5 - do you advise people to remove it after tuning, or just to leave them in? I read a bit about problems with water fouling the sensor and even the sensor just getting 'used up' after a period of time? That's one of the problems I have - no room to put the bung on the top half of the exhaust so it's practically on the bottom... which is why I didn't want to leave it sitting installed for too long.

I have a WooHoo!/Photo of myself from the last couple of weeks, a bit different to the other photos here - but I thought I'd post because I don't think many people get the chance to sit on a MotoGP bike! All the times I've seen the previous years bike at the Phillip Island GP or in some other show, they're always locked up and there's no chance you'd be allowed to touch it, let alone sit on it. But thankfully, Japan is a pretty awesome place. This was taken at Tokyo Auto Salon in January which is mainly a car show. But Honda had their bikes on display, and it made sense to bring out Stoners machine since they'd just won the championship. But rather than having it sit there by itself they were letting everyone line up for a chance to sit on it themselves. No way I was going to pass that up! L1010344 by mugget, on Flickr L1010349 by mugget, on Flickr I consider myself a fairly average height (5'11") and maybe a bit heavier than average (83kg), so I was taking note of how everything fit. We keep hearing people mention how small the MotoGP bikes are - I'll confirm that! In the tuck position my backside was firmly up against the rear seat pad, I was trying to fit my elbows and knees together somehow but there's just no room to move. My mate is a bit shorter and looked like a much better fit, probably alot closer to Stoners size. L1010352 by mugget, on Flickr L1010351 by mugget, on Flickr I think he had the better idea of moving his head closer to the screen. I looked up some pictures of Stoner and that's exactly how he seems to ride (with his head closer to the screen, that is). Now a semi-related photo that popped up on Facebook over the holidays. Matt Mingay (Aussie stunt rider) post this pic, I've seen him around a few times and he's pretty much the same height as me, I'd say an average size guy as well. I'm not sure about anyone else, but I always thought of MotoGP in terms of relating it to my own bike - but the size and weight difference just shows how extreme it is compared to anything else I'm used to.

Hi Steve, good to see you here helping us understand this! I have a habit of opening forum threads and letting them sit for hours or days before I get a chance to reply, so I didn't see your earlier reply before I commented. I just read 'friction topics' and that helped me to get a better idea of the whole thing and started to bring in some real-world applications. If only there was a link at the bottom of the 'friction' page that took me straight to the followup... it should be mandatory to continue with reading that second page. Yep, that does help thanks. I think I understand all of that now, I can't argue with the facts, but it's still doing my head in... I keep thinking up different scenarios that just confuse me. Say for example we were playing tug-of-war. Now that's something I'm not recently familiar with, but thinking back on my childhood experiences I'm fairly sure that I'd start having trouble if I tried to stand on one foot. But if I had both feet on the ground my chances would improve greatly. But according to the rules of friction it shouldn't be so? What I meant was - sure I learnt about friction, but then what? I'll just go on riding the same as I always do and not give it a second thought... But if there was a direct application to everyday riding, that would be something really great. Maybe just a summary at the end, even if it was just to correct myths (like riders thinking that there's less grip available on the edge of the tyre because of reduced contact patch). And people sometimes just like to skip to the end and find out what it's all about. Anything that helps riders to get a more accurate understanding of motorcycling and increases their confidence... well just about the only thing better than that would be being able to surgically implant riding skill. There's some interesting things up there though, I'm still making my way through the motorcycling pages. Going a bit of topic... but dark-sider?! I'm going to assume that you ride alot of straight roads... right? Is it just because of cost (or to reduce your costs)?

Oh, didn't you know that you can corner with 2G? I do it all the time, you ought to see it! I just picked a number for the sake of illustrating a point. But I think I misunderstood what you're getting at. Now I'm just starting to get confused...

Eirik, I think I know what you're getting at when you say that both types of bikes seem to be limited to just over 1G. But don't forget that a 125GP bike cornering at 1G is exerting a very different force to a 1000cc bike at 1G. Let's say the 125GP bike weighs 100kg, therefore at 1G it is supporting 100kg + rider. At 2G it would be supporting 200kg (plus the equivalent of two riders!) If we say a 1000cc sportbike weighs 200kg, then at 1G it is supporting a force of 200kg + rider. The 1000cc bike at 2G would be supporting 400kg (plus the equivalent of two riders again). So when we're talking about the cornering forces of 1G, it's all relative to the type of bike (and rider).

Hmmm... an interesting article at the link there. Although I'm not sure if I learnt anything, I do have some questions... Firstly - starting with the microscopic texture of surfaces, even two flat surfaces do not truly have a 100% contact area. There are microscopic peaks and valleys, no problem - I can understand that and it makes sense. But then it goes on to say that if you double the surface area the true contact area of the peaks will not change. Please explain? Let's say a certain piece of rubber has 100 true 'contact peaks' at the microscopic level. Assuming a certain level of surface uniformity we could reasonably say that another piece of the same rubber, at the same size would also have 100 true 'contact peaks'. Correct? But then if we cut one single piece that equalled the area of the two single pieces we would still only have 100 contact points?? That just seems illogical to me... or am I missing the point or reading this wrong: But the example of the pie graph is really interesting - so we have the exact same amount of available traction at full upright position as well as at full lean. Just that at full lean the majority of available capacity is used in turning. So in theory, if the bike is upright and accelerating hard enough that the tire is not slipping or sliding (let's say 95% of available capacity is used in acceleration), then the rear tyre should be able to support just the same type of force in a turn, as a cornering force rather than an acceleration force? So if I go ahead and apply it literally... thinking of the feeling of the rear tyre digging in and gripping the road when the bike is upright and the throttle is at the stop... then cornering at 95% would feel just the same, but with a lateral load? If I'm understanding it right, that's pretty amazing. That could really give someone the confidence and trust to push their tires. fossilfuel, that visualisation of the rim going into the pavement seems really extreme! But judging from my own experience (I'm still surprising myself with how much speed I can carry into turns and how quick I can turn in, yet the front tire still feels completely solid), and if I have the correct understanding of what I've written above then it seems like your example of pushing the rim into the pavement may not be so extreme after all! If the purpose of the linked article was to increase riders confidence in the ability and performance of tires then there may be something to it, although I wish it was continued through to that conclusion because as it is now it just seems like it's unfinished...

Hey CSarge, MotoGP is a whole different level to what anyone else is riding at. I think it was Cal Crutchlow who said that it's basically twice as hard to ride MotoGP as it is to ride World Superbike. So back to the question - I think the reason they hang their leg off is just for balance, and you'd better believe that they're braking hard! (It's not likely you'll see them hang a leg off on the warm up lap or if they're just cruising.) It's hard to be sure without asking a MotoGP rider, but you're right that it seems that it would be difficult to grip the tank with only one leg/knee. I'm thinking that they are using the handlebars alot more to hold themselves up, which is why every now and then we hear of a rider who is suffering with arm pump (aside from the fact that MotoGP bikes are just much more physical to ride). It wouldn't really be surprising to imagine that the carbon brakes and those tyres require an entirely different approach to riding. It's probably like trying to grip the tank on a motard. Which is just impossible since the tank is miniature, using the 'bars to support your body is just the way you ride it.

I'm a two finger braker as well. I started off using 4 fingers, which is probably a good thing for learners but then pretty soon I just found myself unconsciously using 2 fingers. It was around this time I was starting to practice blipping the throttle as well. I'm curious - how to people who use 4 fingers for braking blip the throttle? Or do you just not do it at all? Or do you have a fancy bike that automatically blips for you and allows clutch-less downshifts? Gorecki, it's funny that you mentioned about the MSF trainers telling you to use 4 fingers. I experienced a similar thing here in Australia at couple of basic roadcraft/street training courses that I've attended. No matter how fast and controlled you could stop with 2 fingers on the brake, you could do rolling stoppies and they would still insist that 4 fingers is the proper way to do it. Which to me just seems silly. Motorcycle technology has come a long way, bikes don't use disk brakes anymore - so riding technique needs to catch up as well. 2 fingers are plenty for me to lift the rear wheel off the ground, modern braking systems are not short on power. I did an advance riding course with a different provider and he couldn't believe that some people still advocate 4 finger braking as the absolute only 'proper' way to do it. Anyway he stopped himself before he went off on a rant... I had a quick look over that article linked above and I feel the same when they mention about 2 finger braking being better to be able to control steering. I am trying to imagine trail braking with 4 fingers and it just seems really awkward... Just a note on street riding - I don't even cover the front brake lever. I've read a good reason for not doing so - and it is that in an emergency/panic situation the split second that it takes to move your fingers to the lever will give you an extra chance just to asses the situation and avoid making a panic reaction. If you ride with the brakes covered you may be less able or inclined to make a quick steering input etc. (it may be better to avoid the obstacle rather than stopping). About smooth throttle movement, is the 'screwdriver method' where you just twist the throttle without moving your hand/wrist/arm? If so - that really helped me to ride alot smoother when I was learning. I don't consciously think about using the throttle too much, but I guess it's still a technique that I use. Also I think wheelies, stoppies and burnouts are cool. No reason they should 'hurt' your bike if you do it properly.