Proper Terminology

[noamkrief]

Hi everyone

A bit of background, I come from the car racing world and I started riding motorcycles for the 1st time 9 months ago.

I learned how to ride from step 1 (didn't even know which lever the clutch was) and within my 1st week of riding, I rode on the highway on the shoulder at 40mph to my first track day. Since then I've done over 60 track days and enjoy bikes much more than cars because the "limit" is alot more dangerous therefore requires alot more skill and finesse.

 

That being said I find alot of flaws in the motorcycle world. I hope I do not offend anyone.

I find the motorcycle racing/track world to be a much more "shoot from the hip" type of sport.

 

1) Data acquisition. Rarely I see anyone using it. How can you tell if the line you are taking is indeed fastest? What feels fast may not necessarily BE fast.

 

2) Ever heard of a torque wrench? I had the tire guy at the track change my tires and 45 minutes later I asked him what he torqued my axles to. He said "I don't have a torque wrench are you kidding me? This is a sport of FAITH son!" I've ran into this multiple times.

 

3) Terminology. This is perhaps the most frustrating thing for me. Motorcycle racers and even suspension tuners don't have a unified terminology and when they do agree on something it's a very unscientific word like "backing it it". Sorry - but that's retarded.

 

Here are some terms and definitions and maybe some of you can shed some light on if these terms are recognized here or what the motorcycle equivalent is.

 

Oversteer = the rear end looses traction, the front is still gripping. (overtseer is broken down to the following 2 categories)

1) power oversteer [you guys say: sliding the rear end] = rear looses traction due to excess in power

2) corner entry oversteer [you guys say: backing it in] = rear end looses traction under trail braking phase due to the initial turning force accompanied by the rear end being light due to weight transfer to the front

3) understeer [you guys say: loosing the front] = occurs when the front tire is overtasked between cornering forces and braking and starts to slide.

4) Threshold braking [you guys say: I brake really hard!] = maximum braking that is capable given the conditions and tires. Braking any harder is NOT possible. This should be the goal for most corners

5) Corner exit speed [getting the drive] = get the maximum exit speed possible. The "getting the drive" term seems to make good sense in this case

 

 

I'm very willing to adapt to the sport and use the terminology that everyone agrees on in the motorcycle world, it's just that I haven't seen consistency as to the terminology. Some say "backing it in" and some say "loosing the rear end" when talking about corner entry oversteer.

 

Can someone clarify please?

Hope I didn't tick someone off because I can see how someone can take this post as insulting, but please, it is not my intention.

 

Thanks

Noam

[ktk_ace]

For starters the place/country you are racing in is still using the imperial measuring system while the rest of the world has gone off to using the metric system

 

Its a culture thing i guess...

[YellowDuck]

The data acquisition thing - I am definitely seeing much more of this as folks start using GPS-based lap timers with all kinds of post-hoc analysis software. It's actually getting the be the norm around here. These days, if I don't show up with the infrared beacon for my timer, chances are no one else will have one either.

 

Torque wrenches - anyone who works on axles, brakes, steering components etc. without one is a hack, plain and simple. Surprised you have encountered that very much.

 

Terminology - I've never been bothered by the differences personally, and I'm actually not as confident as you are that the car world is so "standardized" in the terminology used. I think its fair to say though that the science of driving cars has a better established set of dogma, probably because there are more people doing it and much more has been written about it. Bikes are still a bit of a black art and a lot of riding style elements come into and out of fashion (extreme hanging off, maximum trail braking, backing it in) as do motorcycle design elements (remember the trend towards "tuned chassis flex" in the 1990s, to provide suspension compliance when leaned over, when prior to that it was all about maximizing stiffness?). But the same is true for driving styles. Jackie Stewart claimed he never trail braked at all, and held in disdain the driving schools who were teaching that method. That was in the late 1980s I believe, which isn't so long ago (at least for some of us).

 

Anyway, I think you might be making a mountain out of a mole hill here - do you really have a hard time understanding what the bike guys are talking about? I am more concerned about the persistent errors in actual understanding of how things work, than I am about what we call them. Ask your average track rider (or car driver for that matter) what they think a suspension preload adjustment does. At least 2/3 of them are *sure* it alters tension in the springs, making them stiffer or softer. I think it is those bits of ignorance that impede our progress, not the syntax per se.

[noamkrief]

The data acquisition thing - I am definitely seeing much more of this as folks start using GPS-based lap timers with all kinds of post-hoc analysis software. It's actually getting the be the norm around here. These days, if I don't show up with the infrared beacon for my timer, chances are no one else will have one either.

 

Torque wrenches - anyone who works on axles, brakes, steering components etc. without one is a hack, plain and simple. Surprised you have encountered that very much.

 

Terminology - I've never been bothered by the differences personally, and I'm actually not as confident as you are that the car world is so "standardized" in the terminology used. I think its fair to say though that the science of driving cars has a better established set of dogma, probably because there are more people doing it and much more has been written about it. Bikes are still a bit of a black art and a lot of riding style elements come into and out of fashion (extreme hanging off, maximum trail braking, backing it in) as do motorcycle design elements (remember the trend towards "tuned chassis flex" in the 1990s, to provide suspension compliance when leaned over, when prior to that it was all about maximizing stiffness?). But the same is true for driving styles. Jackie Stewart claimed he never trail braked at all, and held in disdain the driving schools who were teaching that method. That was in the late 1980s I believe, which isn't so long ago (at least for some of us).

 

Anyway, I think you might be making a mountain out of a mole hill here - do you really have a hard time understanding what the bike guys are talking about? I am more concerned about the persistent errors in actual understanding of how things work, than I am about what we call them. Ask your average track rider (or car driver for that matter) what they think a suspension preload adjustment does. At least 2/3 of them are *sure* it alters tension in the springs, making them stiffer or softer. I think it is those bits of ignorance that impede our progress, not the syntax per se.

 

Thanks for your reply. You made very good points.

Yes - on another post I could not use the term "threshold braking" since no one would know what it means, so I said - 100% brakes and half the people thought I meant braking as hard as my hand can squiz.

 

Also terms like flick the bikes vs turn the bike. One of my instructors hates the word "flick" and when he was critiquing my riding he said "you need to turn faster". So I naturally though - "wow, I'm already almost dragging my elbow, if I go any faster in the turn, I might lowside". but what he meant was to FLICK faster. So basically 1/2 the day we were not talking about the same thing. What a waste.

 

Anyway - it's ok. It's just the way it is. I totally get it. most people just want to ride and go as fast as they can without getting scientific about everything. That's fine

[Steve Rutter]

Also terms like flick the bikes vs turn the bike. One of my instructors hates the word "flick" and when he was critiquing my riding he said "you need to turn faster". So I naturally though - "wow, I'm already almost dragging my elbow, if I go any faster in the turn, I might lowside". but what he meant was to FLICK faster. So basically 1/2 the day we were not talking about the same thing. What a waste.

 

I think either flick or turn would work in that scenario, had he said the words 'You need to go through the turn faster', or you need to corner faster then you'd have been on the right track with thinking that your cornering speed needed to increase. By saying that you need to turn the bike faster then I'd understand that to mean your steering input.

 

I can understand why the instructor might not like the word flick, as by it's very definition it means 'a light quick blow' and that's not really what we're after, we don't want to be making the input any faster or lighter, we want to keep it the same speed as any previous input, just make it harder. It's a bit of terminology that has caught on here as the Quick Flick is nice and easy to memorise, but it perhaps isn't the best choice of terminology for the action we're referring to.

[YellowDuck]

"Threshold braking". I have come across this term in plenty of riding instruction books. It is not a foreign term to motorcyclists. I use it regularly.

[Hotfoot]

"Threshold braking". I have come across this term in plenty of riding instruction books. It is not a foreign term to motorcyclists. I use it regularly.

 

Noamkrief - on threshold braking - I didn't really mean that people might interpret that as holding the lever as hard as possible (although they could, I suppose) - more what I meant was that some riders might misunderstand 100% braking to mean - braking exactly the same amount from start to finish, versus modulating your braking to ease it off as the bike slows and you approach your turn point.

 

Maximum or threshold braking seems a little tougher to define on a bike compared to a car. For example, even on identical bikes with identical setups, one rider might slide or stoppie much more easily than another, due to stiff arms or uneven bar pressure.

 

There are lots of different ways to 'mess up' braking on a bike - for example, a rider migh try to also use the rear brake, so for that rider the rear tire would lock up or come around much earlier than someone who isn't trying to use the rear brake. Sliding the front (as mentioned above) can be greatly influenced by rider position, not to mention suspension setup, tire temperature, tire wear, tire profile, lean angle, etc. The rear end can lift, if you brake really hard in the front, but can also do other things BEFORE it would lift - like come around on you!

 

Since there are so many ways to hit the "threshold" of braking, and since the threshold must be perceived by the rider (some don't mind the rear - or even the FRONT - sliding, or the rear coming around, or lifting, while others would immediately back off braking to stop that) I think that "threshold braking" becomes difficult to define.

 

I know once I started racing my perception of maximum possible braking changed dramatically!

[ktk_ace]

"Threshold braking". I have come across this term in plenty of riding instruction books. It is not a foreign term to motorcyclists. I use it regularly.

 

Since there are so many ways to hit the "threshold" of braking, and since the threshold must be perceived by the rider (some don't mind the rear - or even the FRONT - sliding, or the rear coming around, or lifting, while others would immediately back off braking to stop that) I think that "threshold braking" becomes difficult to define.

 

I know once I started racing my perception of maximum possible braking changed dramatically!

 

Mind if i chime in on my own findings as a student? ^^

 

Reminds me that SR's artificially cause the threshold limit to be lowered, as for which sr's and what, id believe the DVD /books goes to great leangths to tell

 

once you know how it goes wrong , you can right it and sometimes play/game on the razor edge (brake drift / power drift / initializing your own controlled slides) if skills and setup allows for it

 

I dare say as a student no part of my 130 points of IQ nor talent will be of any help to my riding if not for the books and dvd's ,

 

its that black of an art by itself if you wander in solo and try to learn it without any aid ... just my 2c

[Hotfoot]

 

Mind if i chime in on my own findings as a student? ^^

 

Reminds me that SR's artificially cause the threshold limit to be lowered, as for which sr's and what, id believe the DVD /books goes to great leangths to tell

 

 

 

Absolutely. Also, as the books clearly describe, focusing on braking to improve laptimes only gains you small improvements, where focusing on corner speed, early throttle applicaiton, and exit drives can make much larger gains much more quickly and with less drama. I have certainly experienced that myself, and also found that when I focus on trying to brake later or harder I often sacrifice entry speed and my laptimes suffer.

[Lnewqban]

1) Data acquisition. Rarely I see anyone using it. How can you tell if the line you are taking is indeed fastest? What feels fast may not necessarily BE fast.

 

Noem,

 

This site shows some graphs that may result interesting to you:

 

http://www.datamc.org/

 

4) Threshold braking [you guys say: I brake really hard!] = maximum braking that is capable given the conditions and tires. Braking any harder is NOT possible. This should be the goal for most corners

 

I don't see how the words threshold and braking can go together in motorcycling.

 

Copied from

http://www.merriam-w...onary/threshold

 

Definition of THRESHOLD

 

1: the plank, stone, or piece of timber that lies under a door : sill

 

2a : gate, door

b (1) : end, boundary; specifically : the end of a runway (2) : the place or point of entering or beginning : outset <on the threshold of a new age>

 

3a : the point at which a physiological or psychological effect begins to be produced <has a high threshold for pain>

b : a level, point, or value above which something is true or will take place and below which it is not or will not

[YellowDuck]

1) Data acquisition. Rarely I see anyone using it. How can you tell if the line you are taking is indeed fastest? What feels fast may not necessarily BE fast.

 

Noem,

 

This site shows some graphs that may result interesting to you:

 

http://www.datamc.org/

 

4) Threshold braking [you guys say: I brake really hard!] = maximum braking that is capable given the conditions and tires. Braking any harder is NOT possible. This should be the goal for most corners

 

I don't see how the words threshold and braking can go together in motorcycling.

 

Copied from

http://www.merriam-w...onary/threshold

 

Definition of THRESHOLD

 

1: the plank, stone, or piece of timber that lies under a door : sill

 

2a : gate, door

b (1) : end, boundary; specifically : the end of a runway (2) : the place or point of entering or beginning : outset <on the threshold of a new age>

 

3a : the point at which a physiological or psychological effect begins to be produced <has a high threshold for pain>

b : a level, point, or value above which something is true or will take place and below which it is not or will not

 

Take definition 3b for "theshold". Threshold braking It is the braking force (deceleration) above which either the bike will endo or the tire will slide (depending on traction and geometry), and below which you are not braking as hard as is currently possible.

 

It is really primarily a concept for emergency braking on the street, when one needs to stop in as short a distance as possible. Threshold braking involves a progressive squeeze at the lever for 0.5 s or so to get the weight transferred onto the front, then additional lever pressure as required *usually* to the point of the rear tire being barely in contact with the road (except in low traction conditions, when you are applying pressure up to the point of skidding the front tire). As speed comes down, you can apply more and more pressure at the lever without skidding the tire or flipping the bike, right up until the point that you come to a stop (at which point you can squeeze as hard as you like!).

 

I used to practice this type of braking from 100 kph or so, every time I rode on the street, if traffic conditions permitted. I got pretty good at it, but for some strange reason could never stop myself from releasing brake pressure right before stopping completely.

[ktk_ace]

1) Data acquisition. Rarely I see anyone using it. How can you tell if the line you are taking is indeed fastest? What feels fast may not necessarily BE fast.

 

Noem,

 

This site shows some graphs that may result interesting to you:

 

http://www.datamc.org/

 

4) Threshold braking [you guys say: I brake really hard!] = maximum braking that is capable given the conditions and tires. Braking any harder is NOT possible. This should be the goal for most corners

 

I don't see how the words threshold and braking can go together in motorcycling.

 

Copied from

http://www.merriam-w...onary/threshold

 

Definition of THRESHOLD

 

1: the plank, stone, or piece of timber that lies under a door : sill

 

2a : gate, door

b (1) : end, boundary; specifically : the end of a runway (2) : the place or point of entering or beginning : outset <on the threshold of a new age>

 

3a : the point at which a physiological or psychological effect begins to be produced <has a high threshold for pain>

b : a level, point, or value above which something is true or will take place and below which it is not or will not

 

Take definition 3b for "theshold". Threshold braking It is the braking force (deceleration) above which either the bike will endo or the tire will slide (depending on traction and geometry), and below which you are not braking as hard as is currently possible.

 

It is really primarily a concept for emergency braking on the street, when one needs to stop in as short a distance as possible. Threshold braking involves a progressive squeeze at the lever for 0.5 s or so to get the weight transferred onto the front, then additional lever pressure as required *usually* to the point of the rear tire being barely in contact with the road (except in low traction conditions, when you are applying pressure up to the point of skidding the front tire). As speed comes down, you can apply more and more pressure at the lever without skidding the tire or flipping the bike, right up until the point that you come to a stop (at which point you can squeeze as hard as you like!).

 

I used to practice this type of braking from 100 kph or so, every time I rode on the street, if traffic conditions permitted. I got pretty good at it, but for some strange reason could never stop myself from releasing brake pressure right before stopping completely.

 

If you use google chrome;'s translation function, this might shed some light on brake pressure:

http://tw.myblog.yahoo.com/k1200r-PAPAGO/article?mid=6877

[Fajita Dave]

DIsclaimer, I didn't mean to make this sound so "deep" but its the only way I can find to explain it!

 

noamkrief, I think you might be to worried about termanology. Every region and sport has its own termanology and I don't nessisarily think it should be the same between motorcyces and cars anyway. With a car your body has no influence on the machine other then the direct steering, shifting and petal inputs. I think things get viewed more from a mechanical "matter-a-fact" kind of way because its entirely up to the car's setup.

 

On a motorcycle the rider is an integrated part of the system and you become one with the bike . With such a direct and important role that you have on the motorcycle your brain registers whats going on more as if it were happening to you personally instead of it being the vehicles fault. So you end up with termanology like "backing it in" or "loosing the front" because it feels more like that is whats happening to US instead of it simply being mechanical feed back that a car is giving you.

 

As far as a mechanic not using a torque wrech goes. That is completely rediculous. I don't know how anyone could work on the top end of one of these engines without a torque wrech and not strip the threads out of everything. Spark plugs and cam journals are torqued to 8 ft/lbs on my bike and it seems like a rediculously small amount to keep the bolts in place. A little tighter and the threads will strip.

[tmckeen]

On the subject of torque wrenches,

 

using one is good, but just like tire pressure gages unless you have it calibrated at regular intervals and store them properly they only give you a rough estimate, not a precise measurement. Asking your mechanic if he uses one is good, asking him when he last had it calibrated is better. I'm constantly amazed at how many people are unaware of the most important rule of torque wrench care, ALWAYS back the wrench off to its lowest setting when not in use, that and don't use it as a hammer

 

Tyler

[Pepsi Drinker]

Torque wrench as a hammer; A very expensive hammer and quite ineffective too, IMO.

 

I question all my torque wrenches when I send them out yearly/bi-yearly for the lessor used and get them back. What did they really do for my $120.00?

 

Just once I would like to see where they really are at and how they actually adjust them if they did need recalibrating. Then atleast I could feel good about the expense instead of wondering if I am just throwing away money.

 

Occassionally I have gone out on the snap on truck with one or more of them and "compared" it to one of the brand new still on the truck ones, but how well have those been calibrated? Well they do have the certificate saying they are calibrated ~shrug~

 

Yes i am a little skeptical in life.

[tmckeen]

While I can't tell you what they are "actually" doing with you torque wrenches, I can tell you what they are supposed to be doing, They should be testing them with either a torque transducer or a mechanical loading system with a accuracy of at least 1%, but preferably one of 0.25%. They start by setting your wrench to its maximum setting and "exercising" the wrench several times, and then test it at 20, 60 and 100% of its full range, if its a snap action wrench they should take at least 4 readings at each point and average them. The standard accuracy for a torque wrench in a clockwise direction is 4% of its Indicated value, should any of the readings fall outside of that it would require adjustment or repair. Adjusting snap action wrenches differs a bit between brands and wrench designs but for the most part its a matter of removing the end cap on the handle, loosening the lock nut and adjusting a hex screw. Adjusting a Deflecting Beam style torque wrench is virtually impossible, but can be done by heating the bar with a torch to weaken it or tempering it, its much more economical to replace them however. For Dial Indicating wrenches, which also operate on a deflecting beam principle, you have to adjust the dial mechanism inside the wrench.

 

If one of your wrenches is adjusted they should give you "as found/as left" data, if you are truly suspect of the Lab testing your wrenches you can ask them for the data from the test points, though they will most likely charge you more for this. If the lab you take them to is local you can simply ask see them test the wrench as its a fairly simple process, any Calibration Lab that refuses to let you observe them testing your wrench is HIGHLY suspect.

 

Tyler

[Jasonzilla]

We call understeering a "lowside." Hahaha!

[EricG]

I tend to agree with the OP. being somewhat new to performance riding, but being an old road racer myself, I can completely understand where he's coming from. There is a lot of terminology in motorcycling I don't yet understand, his list being a very good start. Coming from a street racing background we had our own nomenclature that has since become much more scientific. I'm sure the motorcycle vernacular is of much the same ilk.

 

So, perhaps someone can develop a "bike jargon for dummies" book to help us make the transition?

[Hansi]

"Threshold braking". I have come across this term in plenty of riding instruction books. It is not a foreign term to motorcyclists. I use it regularly.

 

Noamkrief - on threshold braking - I didn't really mean that people might interpret that as holding the lever as hard as possible (although they could, I suppose) - more what I meant was that some riders might misunderstand 100% braking to mean - braking exactly the same amount from start to finish, versus modulating your braking to ease it off as the bike slows and you approach your turn point.

 

Maximum or threshold braking seems a little tougher to define on a bike compared to a car. For example, even on identical bikes with identical setups, one rider might slide or stoppie much more easily than another, due to stiff arms or uneven bar pressure.

 

 

How about "1G" braking. I always try to be as close to 1G for as long as I can during braking. Using a G-force logging device greatly helped me improve braking. How's that for using data acquisition :-) Now I know how my bike feels at 0,7 - 0,8 - 0,9 - 1.0G after analyzing my log files and overlaying G-force bars on my onboard video.

 

 

I always use my torque wrench and have most of the specs of my bike memorized....rear axle 150NM, Front Axle 72NM, Brake caliper bolts 40NM, Pinch Bolt....damn what was that again, 9NM or so. Actually I usually cheat and fit the pinch bolt by feel as I have to go and get a smaller torque wrench for that one...

[EricG]

Hansi, that's awesome, man! How much does one of those things cost? I've seen them used on motoGP videos & a lot of the Ilse of Man TT stuff, bu I had no idea mere mortals can ge them too! Any chance these apps are available for cell phones? They've got all the hardware: gyroscopes, accelerometers, GPS tracking...

 

[YellowDuck]

Wow. 59-degree lean angle? Really?

[Lnewqban]

Wow. 59-degree lean angle? Really?

 

Check these schematics out:

http://forums.superb...t=40#entry26802

[Hansi]

Hansi, that's awesome, man! How much does one of those things cost? I've seen them used on motoGP videos & a lot of the Ilse of Man TT stuff, bu I had no idea mere mortals can ge them too! Any chance these apps are available for cell phones? They've got all the hardware: gyroscopes, accelerometers, GPS tracking...

 

The thing that does the lean angle and g-force is dirt cheap

http://www.leanometer.com/ £79 or so

 

I use a starlane gps laptimer, there is a g-force module available for that too.

 

Alternatively, look at http://www.speedangle.com/ $489 laptimer with lean angle and g-force

[Hansi]

Wow. 59-degree lean angle? Really?

 

In my video? The right hand part of the S curve is heavily banked, I have logged up to 60 degree lean angle there. Related to horizon, not tarmac :-)

 

looked again, yes there was briefly 59 degrees in a small left. One of the fun parts of the track where you can bottom out your suspension :-)

[ktk_ace]

Hansi, that's awesome, man! How much does one of those things cost? I've seen them used on motoGP videos & a lot of the Ilse of Man TT stuff, bu I had no idea mere mortals can ge them too! Any chance these apps are available for cell phones? They've got all the hardware: gyroscopes, accelerometers, GPS tracking...

 

The thing that does the lean angle and g-force is dirt cheap

http://www.leanometer.com/ £79 or so

 

I use a starlane gps laptimer, there is a g-force module available for that too.

 

Alternatively, look at http://www.speedangl... $489 laptimer with lean angle and g-force

 

Looks like im lagging behind the times... gotta get one asap