faffi

MOTORRAD explained why a bike will try to go straight when the brakes are applied midcorner like this: "Uprighting momentum" comes from the contact patch moving sideways from the tyre's centre line, creating a lever effect. Together with the brake force, this lever will twist the wheel inwards, a phenomenom we tyipcally refer to as counter steering. The result is a bike righting itself unless the rider counters with an equal amount of force. Generally speaking, the wider the tyre, the bigger the righting force. With the brakes on, the testers measured up to 250Nm twisting force at 12 degrees lean.

From the MOTORRAD pamphlet, freely translated: Leaned over 15 degrees, you would normally have to keep some pressure on the inside handlebar. Due to the tyre contact patch being off centre, the resulting force will try to turn the wheel further into the corner. Uncorrected, this will cause the bike to right itself. Leaned over 50 degrees, very little steering torque steering remains and the centrifugal and gravity forces equal each other, hence little or no steering inputs are required to stay on the chose line. The reason this happens first around 50 degrees from vertical and not at 45 degrees is a result of the tyre width moving the patch of contact off the centre line.

I would say that understanding each individual, their needs and how to communicate with them in a manner that both make them understand and also motivates them is the most important thing for a coach - right after actually knowing what you are teaching, of course. That's why there are so few good coaches (and leaders) in the world. Even highly skilled trainers will typically only really be good at coaching one type of people while coping with the majority and failing with the other minority. I'd say fitting brilliantly with about 10%, doing acceptably with about 80% and failing miserably with the remaining 10% of students. Hence being a great instructor of any kind is an extremely difficult job that only a very limited number will ever be able to excel at. I'd be a lousy instructor because I would focus on those showing great determination and/or intelligence/understanding and not be able to encourage those who are shy or not showing sufficient interest. Let me take one concrete example. Peter Mueller was the coach for the Norwegian skating team. He had two good students; brother and sister Bökko. When Peter was sacked for sexual harassment and replaced with new coaches, we noticed a drop in particularly brother Bökko's performance and a big leap in performance for a lot of the other skaters in the team. Why? Mueller was fantastic as a coach - providing the "ideal" student, but incapable of instructing the majority nearly as well. What was motivational for a few was demotivational for the majority.

Most definitely. If you have a way to do that without constantly moving your focus point from close to near to close to - you get it - I'd be highly interested. Because I can only see details within a very narrow "window". For instance, keeping the VW I cannot even make out anything from the instruments or mirrors. I do notice that they are there, but I do not have enough details in the information that I can use it for anything, no matter how hard I try to focus (cannot make out the point needles or whether there is a car etc. in the mirrors, it's all just a blur). Same with minor stuff in the road. Just after the snow went a few weeks back, I made a walk in the park keeping the VW all the time. Very cool to observe birds in the sky while not looking at them, etc. I also stepped in lots of dog turd because I couldn't make it out from the gravel and mud Shifting my view from near to far constantly saves my shoes

I haven't seen the video - I'd be interested to hear how far he's leaned over. I should dig out the article and run the full explanation by you, although it will require me translating it from German. Note that these are things that I am not really qualified to comment on because I do not fully understand all the physical laws involved, so all I can do is repeat what others say/write and combine the information with my own findings. And my own fidnings suggests that most bikes will need some steering input in order to follow a certain trajectory around most corners - for me, at least. The amount required have varied from next to nothing to substantial depending on the machine ridden.

The wide view, as I tried to explain in my own way earlier, makes things slow down dramatically more often than not. You will run a smaller risk of getting surprised by other traffic, obstacles, change of road direction etc. However, as I also mentioned, relying solely on the wide view on public roads is - IMO - a bad idea because it will obscure things like small patches of sand, oil, bumps and dips etc since the peripheral vision isn't sharp enough to notice them, nor are they always visibile from a distance. Hence road riding demands - IMO - a constant alternation between the wide view and glances on the road quite close to the bike. Eyes must move constantly. On a track, with a known surface, scanning the road is of less importance and keeping things "slow" is of greater importance. At least that's my take on it

Try to ride towards a manhole at 40 mph and see how close you can get before swerving to avoid it. I think you will be surprised how close you can get, probably around 20 ft. It will depend heavily upon the bike and the amount of power you use on the handlebars - a chopper will take ages, a nimble 200 lb machine can turn on a dime. I do this all the time when riding on city streets I wait until the last possible moment before swerving to avoid manholes, potholes etc. Not only will it make you more confident when it comes to excerting a lot of force to the handlebars, it will also make it more likely that you will countersteer in an emergency situation. Finally, following cars tend to keep a very safe distance because from their view you look like a lunatic When driving and riding on the road, I try to look past all other traffic as if it wasn't there, seeing as far forward as possible. The worst you can do is look directly at the car in front. You just need to be aware of it at all times, not stare at it. However, when I ride I constantly switch my view between far ahead and real close - I do not want to hit holes or bumps or paint or anything else that can upset the bike. Looking far ahead is great on a race track where the conditions are known, but limiting yourself to the wide view on public roads is not something I would recommend.

I just read an explanation on this. Before this can take place, you will have to have reached a "balanced" state where the centrifugal forces are equal to the forces trying to pull you towards the ground, usually when leaned over about 50 degrees (due to the width of the tyres). When the bike is leaned over less, let's say 20 degrees, you cannot expect to maintain your line if you let go of the handlebars.

Paul Dean wrote a piece on this in the latest issue of Cycle World. He had basically the same concerns as has been voiced by some of us earlier.

When I fitted longer, harder shock absorbers to my VT500FT Ascot (some may be old enough to remember), it became just as you described when dropping the front on your SV. The rear was raised about 40 mm under load, so it was quite a bit. Once I raised the front a similar amount with stiffer springs and more oil, it became its old neutral self again. I also did a very poor and ugly attempt at making an old XL500S into a pure street machine. I fitted an 18" rim instead of the stock 23" thingo. The rear was retained at 18". I fitted road type tyres; BT45s in 100/90 front and 110/90 rear. Furthermore, shocks somewhat shorter and stiffer were fitted. It didn't look too good, as mentioned, and although the smaller front wheel should compensate for the drop in rear height (at least), the bike still rode with its front too high for my taste. However, having experiemented with moving the front end through a full 3 inches (by raising the legs in the triple clamps) I found virtually no influence on how the bike handled. I'm anxious to hear how sensitive (or not) your KLR is!

This is quite typical, I think. A friend of mine had a built in lean limit that made him at least as fast as me on gravel, not unusually slow in the rain and hopelessly slow on dry tarmac. His speed was exactly the same no matter the conditions. He didn't even understand the conditions, he only understood how far he dared to lean. It took many years of street riding before he got his pace up on dry tarmac to a level where caravans stopped passing us

If that is indeed the case, why is it that cruisers generally handle very poorly despite lots of rake and trail? I'm not saying your theory is wrong, I'm just trying to understand it. Perhaps the problem is the rake? The more you rake out the front end, the further the contact patch will move away from the bike's line when the wheel is turned. To make tings even worse, trail is often reduced by raking the forks more than the steering stem, enhancing the tendency for the contact patch to move. Hence you can see cruisers with virtually zero cornering clearance that have worn their front tyres to their edges; when turning sharply at low speed, the front tyre is leaned over a lot even if the bike is upright. Sorry, I guess this only helped to confuse things more

A chain driven bike will raise its rear under acceleration if the rear axle sits below that of the output shaft. OTOH, if the rear axle sits above the output shaft, it will squat under acceleration. Shaft driven bikes will always raise the rear end under acceleration unless you build a system (like BMW and others) that place all of those forces elsewhere. BMW haven't eliminated the climbing tendency (but they could - they could also have reversed them if they so desired), but very little remains.

You're doing good for a man with an exploded head, old chap The CX500 had fairly little rake (26.5 degrees) and trail (100 mm or 3.9 in) and a narrow front tyre (3.25 in or 88 mm), yet it would stand up like the most eager A person on the most exiting day of his life if you touched the front brakes mid-corner. My Daytona-based Triumph has 27 degrees of rake, 105 mm (4.2 in) of trail and a 120 mm (4.7 in) front tyre and has just a gentle tendency to straighten itself under similar conditions. How does that fit with the theories? Oh, sorry, forgot you're head's gone

Common misconception. Most sport bikes will not stand up. It might run wider, but shouldn't stand up. I can buy that. Maybe even with my cruiser, come to think of it. I can see myself getting confused between the tendency to running wide and standing up - because if you do not want to go wide, you have to use more force to increase the lean. Hence it will feel like the bike is standing up a bit because the bike will sort of finish off the turning and you will just naturally let it come back up. Food for thought - and testing. And now that the snow is going, I may even be able to go for a ride and test this soon Also, as has been mentioned, different bikes act differently. For instance, the Intruder had to be "held down" by constant counter steering or it would just stand up at any time. Other bikes will want to fall in and will have to be steered into the corner to prevent it from toppling over. Some bikes will stand up dramatically under the brakes, others are almost oblivious to this. Tyres matters greatly - I've read tests that claim the new Honda VFR1200 (which comes with two brands of tyres, depending on market or luck) are fine with one brand and evil with the other.

My Intruder 1400 had to be fought to be kept on line under acceleration while cornering, or it would just head straight. But in my unskilled opinion, accelerating hard while leaned over will make any bike want to stand up. This isn't equally pronounced between bikes, but I've always used hard acceleration on corner exits to let the bike right itself. Maybe it's just something in my head.

I think you are right - that ugly helmet has bothered me. Nice to have an explanation

Generally speaking, on a race track you would enter wide, clip the inside of the apex and then run wide out again. This is done to keep the corner as straight as possible and speed as high as possible. Using the same technique on the road, however, could quickly lead to trouble. Especially around blind corners, something at least we have in abundance. Clipping the apex, apart from risking that your head hits the mountain wall lining the road, around an inside turn would significantly reduce your view ahead. Clipping the apex around an outside turn would leave significant parts of you hanging into the oncoming lane. Personally, I tend to use 3 different approaches during road riding; pointy, flat and round By pointy I mean that I enter a corner just outside of the middle of my lane, go in deep, turn the bike quickly with relatively low speed and the accelerate out as hard as the conditions allow once I can see far enough ahead. This is mostly used on low speed roads or at least quite short corners. By flat I mean using track-like lines. I reserve this to when I can see really far ahead and there are no obstructions near the road. I still consider this to be the most dangerous way to ride on public roads. Not from a bike control point of view, but from where it places my upper body during cornering. Finally, using round lines basically means more or less following the arch of the road, making the line as long as possible without crossing over into the opposite lane. This style gives me the best visibility ahead and leaves a lot of room to the inside, allowing me to tighten the line should I encounter danger. Yes, I know these examples are an over-simplification, but going into minute details could take all week So, what do the rest of you do or think? Am I wrong or am I right in that you generally have to use significantly different lines during road riding compared to track riding?

I'm pretty sure that pic of Spencer is from 1983 on board his Honda NS500 triple, although it could possibly be late '82. http://world.honda.com/HRC/history/1982_1985/

Am I right, then, when I say Gardner is the one of the old school to come closest to the current standard?

My response was to Dave and his assumption that gearboxes seems almost bullet proof Please note that I didn't mention the word clutch anywhere as I agree that proper technique will not damage the gearbox - be that with or without use of the clutch. Now to your questions Is there any advantage to doing clutchless downshifts? Advantage? It must be that you can retain a full grip on the left side of the handlebars. I honestly cannot think of any other valid reasons. Shifting down at lower rpm isn't valid - you can do that also with the clutch. What are the pros and cons of clutched and clutchless downshifts? Pros: See above. And your race will not be affected if your clutch release fails (which isn't very often). If you find it easier to perform clutchless shifts than clutched shifts, you will find it a pro as well. I'll risk saying those will be in a great minority if you make a study among all riders in the world - just as you are likely to find among car drivers, whose gearboxes are also simple to shift without the use of a clutch if you take care. Cons: It takes time to master for what I personally consider a miniscule return. And many will never master it, but that could naturally be said for a lot of things. It will make you less likely to pull the clutch should the rear wheel lock up due to a mechanical issue (which, admittedly, doesn't happen very often). It will, in my opinion, increase the number of poor shifts for most riders, increasing the risk of gearbox damage. In conclusion, I will say that both pros and cons are very limited and that it is more down to personal preferences than any real benefits. But please feel free to disagree. My words are no more gospel that those of others. What I can say is that I have tried clutchless downshifts many times over the past 30 years and never found any reason to persue the subject into perfection because for me, the clutch is something I can operate well without thinking about it.

Bent or worn shift forks and damaged dogs/slots on the pinions are, if not exactly common, not unusual. Pre-loading the shifter will put bending forces onto the shift forks - too much, and it can bend permanently. Even restricted pressure will increase wear. However, they can usually take quite a bit of wear before they stop functioning. Bending them, though, will usually make it hard to shift or gears to jump out under load. Bending them do take some serious effort, however, and isn't very common. Having the dogs or "claws" break is perhaps a bit more common damage done to motorcycle trannies and is caused by shock loads. Imperfection during production will make this kind of damage more likely. However, elongated slots or rounded off dogs is by far the most common thing to take place, as they wear over time. The result is that the affected gears starts jumping out under load. Here is a picture of a badly broken pinion Rounded dogs

Doohan, under control Schwantz,probably less so Schwantz, now simply a passenger?

Roberts Jr Rossi Hayden Stoner

Lawson Garnder Rainey Schwantz Doohan Criville