Go Back   Two Wheel Fix > Riding > Beginner's End

Reply
 
Thread Tools Display Modes
Old 03-24-2008, 11:17 AM   #1
OTB
The Man
 
OTB's Avatar
 
Join Date: Feb 2008
Location: CrabTown USA
Moto: 00 Bimota DB4
Posts: 823
Default Practical Application of Theory

Much space in many motorcycle journals and books on the effects of accleration and deceleration; many magazines tout the wonderful benefits slipper clutches.....but why are they desireable?

When you accelerate a motorcyle, a couple of things happen: the weight transfer of acceleration slightly compresses the rear suspension, simultaniously unloading and extending the front forks. At the same time, the front sprocket is tightening the top run on the chain pulling the suspension upward and accentuating the squat of the rear end. This squat loads the rear tire, enhancing rear wheel traction, but also the extending forks, extends both rake and trail, widening the turning radius and slowing steering inputs.

Conversly, slamming the throttle shut mid-turn in response to coming in too hot or making panicky mid-course corrections has just the opposite effects...... sudden unloading of the rear (and the decrease of traction that goes with lack of load), shortening of rake and trail (and the sudden quickening of steering that accompanies it) adding load to the front tire.

That's why the old racers saying of "go in slow, come out fast" applies to the streetrider, too. Negative or neutral throttle in turns leaves the rider in a decreased traction mode, encouraging both rear wheel slides and front wheel washouts.

Get your braking done early, and use a little positive throttle ALONG WITH A LITTLE BIT OF REAR BRAKE to encourage squat and the additional rear traction that goes with it.

Happy Riding
OTB is offline   Reply With Quote
Old 03-24-2008, 11:23 AM   #2
t-homo
WSB Champion
 
Join Date: Feb 2008
Location: Springfield, MO
Posts: 7,146
Default

Have you ever considered writing for a Motorcycle Magazine? Everything you post has tons of depth, you have ridden a ton of different motorcycles, you are an all around knowledgable person.
t-homo is offline   Reply With Quote
Old 03-24-2008, 11:25 AM   #3
Rider
Moto GP Star
 
Join Date: Feb 2008
Posts: 12,156
Default

Excellent tip. I always enter my corners this way since I read the book, Sportriding Techniques.
Rider is offline   Reply With Quote
Old 03-24-2008, 05:21 PM   #4
dReWpY
RIP REX
 
dReWpY's Avatar
 
Join Date: Feb 2008
Location: Murfreesboro, TN
Moto: 2008 1125R
Posts: 7,467
Default

i had a perfect example of this, went into a on ramp too hot and had to remember what i have been taught and not my natural instinct to cut the throttle, poured a lil throttle leaned it over, put trust in my tires and made it though, def didnt have chicken strips after that ride, but the last time i enter a ramp at >80 with out leathers on
__________________

Venom R1-016 Squadron
Quote:
Originally Posted by Trip View Post
Moral of this story is everyone is fucked up no matter atheist or religious.
dReWpY is offline   Reply With Quote
Old 03-24-2008, 05:42 PM   #5
Captain Morgan
Let's do another U-turn
 
Captain Morgan's Avatar
 
Join Date: Feb 2008
Location: Indiana
Moto: 2009 V-Strom
Posts: 3,816
Default

Quote:
Originally Posted by drewpy View Post
i had a perfect example of this, went into a on ramp too hot and had to remember what i have been taught and not my natural instinct to cut the throttle, poured a lil throttle leaned it over, put trust in my tires and made it though, def didnt have chicken strips after that ride, but the last time i enter a ramp at >80 with out leathers on
Yep, had a similar situation in a corner. Car was coming opposite direction and I was starting to run wide. If it hadn't been for track time, I would have let off the throttle in fear and subsequently taken out the car and myself. Instead, I gave it a bit more gas and looked deeper through the turn. Could feel the rear wheel slipping just a bit, but I didn't panic, just kept moving through the turn. Yes, I was shitting bricks (I bet the cage driver was too), but made it through due to a little bit of training and forum reading. Thank god for track time...
Captain Morgan is offline   Reply With Quote
Old 03-25-2008, 01:36 PM   #6
No Worries
Keyboard Racer
 
No Worries's Avatar
 
Join Date: Feb 2008
Location: Mile High City
Moto: Old Superbikes
Posts: 1,016
Default

Quote:
Originally Posted by OTB View Post
...Conversly, slamming the throttle shut mid-turn in response to coming in too hot or making panicky mid-course corrections has just the opposite effects...... sudden unloading of the rear (and the decrease of traction that goes with lack of load), shortening of rake and trail (and the sudden quickening of steering that accompanies it) adding load to the front tire.

...Get your braking done early, and use a little positive throttle ALONG WITH A LITTLE BIT OF REAR BRAKE to encourage squat and the additional rear traction that goes with it.

Happy Riding
Going up Lookout Mountain, it's pretty much all throttle control. Coming downhill is a different story. There is this one section where you can come down a straight section around 60. This leads into a 15 MPH hairpin turn. The road is steep, crowned, and no shoulder.

I start braking, front and rear before the turn. I forgot, the road jogs to the right before it hairpins to the left. I also start leaning off the bike while I'm in the jog. I keep the brakes on in the turn. This probably goes against what every racer has said or written. But like OTB says above, if you go off the front brakes, the front rises and loses traction. You can't give it gas in this situation to load the rear, but with the rear brake on, the rear is loaded.

About seven-eights through the turn I let off the brakes and start giving it gas. It looks and feels so smooth. Like I've been doing it a thousand times. Actually, I have done it a thousand times. But I've seen bicyclists crash there, and I've stopped to move motorcycle fairing parts off the road.
No Worries is offline   Reply With Quote
Old 03-25-2008, 10:23 PM   #7
OTB
The Man
 
OTB's Avatar
 
Join Date: Feb 2008
Location: CrabTown USA
Moto: 00 Bimota DB4
Posts: 823
Default

Quote:
Originally Posted by No Worries View Post
Going up Lookout Mountain, it's pretty much all throttle control. Coming downhill is a different story. There is this one section where you can come down a straight section around 60. This leads into a 15 MPH hairpin turn. The road is steep, crowned, and no shoulder.

I start braking, front and rear before the turn. I forgot, the road jogs to the right before it hairpins to the left. I also start leaning off the bike while I'm in the jog. I keep the brakes on in the turn. This probably goes against what every racer has said or written. But like OTB says above, if you go off the front brakes, the front rises and loses traction. You can't give it gas in this situation to load the rear, but with the rear brake on, the rear is loaded.

About seven-eights through the turn I let off the brakes and start giving it gas. It looks and feels so smooth. Like I've been doing it a thousand times. Actually, I have done it a thousand times. But I've seen bicyclists crash there, and I've stopped to move motorcycle fairing parts off the road.
That is why there is no substitute for experience. The book might say not to use the front brake in turns, but practical experience says that at times, not only might you do so, some times it is required. I, too have been on some truly gnarley, downhill, off camber nastiness that, if I followed convention and "common knowledge", I would have been off in the tooly bushes somewhere. That doesn't mean I grabbed a handful of front brake.......it does mean that I squeezed that lever with care and trepidation....
OTB is offline   Reply With Quote
Old 03-28-2008, 12:01 PM   #8
ceo012384
Pompous Prick
 
ceo012384's Avatar
 
Join Date: Mar 2008
Location: MA
Moto: 06 R6 (race), 04 CRF Tard (race)
Posts: 3,040
Default

Good info as always, my good man.
Quote:
Originally Posted by OTB View Post
The book might say not to use the front brake in turns
A lot of motoGP riders don't even start braking until they are IN the turn
ceo012384 is offline   Reply With Quote
Old 03-28-2008, 12:10 PM   #9
Trip
Hold mah beer!
 
Trip's Avatar
 
Join Date: Feb 2008
Location: 80 Miles South of Moto Heaven
Moto: 08 R1200GS
Posts: 23,268
Default

Seriously, we should have the OTB/No Worries reeducation thread. Always good reads from ya'll.
__________________
Quote:
Originally Posted by ebbs15 View Post
according to the article tell him to drink ginger tea...
Quote:
Originally Posted by Tigger
Whatever,Stoner is a bitch! O.J. Simpson has TWO fucked knees and a severe hang nail on his left index finger but he still managed to kill two younger adults,sprint 200 feet to his car (wearing very expensive,yet uncomfortable Italian shoes) and make his get a way!!!
Trip is offline   Reply With Quote
Old 03-29-2008, 04:38 AM   #10
Mr Lefty
TWFix Legend
 
Mr Lefty's Avatar
 
Join Date: Feb 2008
Location: Denver CO
Moto: 01 BMW F650GS Dakar
Posts: 15,677
Default

Quote:
Originally Posted by Trip View Post
Seriously, we should have the OTB/No Worries reeducation thread. Always good reads from ya'll.

not thread... Subforum... call it Knowledge... or School!

only they can start threads there...


awesome info
Mr Lefty is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 06:15 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.