« previous next »
Pages: 1 [2] 3   Go Down

Author Topic: Motorcycle question from a newbie...  (Read 15257 times)

0 Members and 1 Guest are viewing this topic.

stayt`ie

  • Guest
Motorcycle question from a newbie...
« Reply #15 on: August 30, 2006, 05:17:25 AM »
how much pressure :?:  you ask,  on my zx12 with all fairings fitted (frontal area `bout 4s'),,,,   i have calculated that at 180mph it is pushing approx 275flbs :)     naked up around 315flbs :?
ya know how to position that screwdriver and sit, may help :lol:
Logged

Offline JackD

  • NOBODY'S FOOL
  • Hero Member
  • *****
  • Posts: 4684
CLOSE
« Reply #16 on: August 30, 2006, 06:14:23 AM »
Quote from: stayt`ie
how much pressure :?:  you ask,  on my zx12 with all fairings fitted (frontal area `bout 4s'),,,,   i have calculated that at 180mph it is pushing approx 275flbs :)     naked up around 315flbs :?
ya know how to position that screwdriver and sit, may help :lol:


Ya know, he is probably pretty close, with a large % on the white knuckles and newly stretched arms. :wink:
Logged
"I would rather lose going fast enough to win than win going slow enough to lose."
"That horrible smell is dirty feet being held to the fire"

Offline Seldom Seen Slim

  • Nancy and me and the pit bike
  • Administrator
  • Hero Member
  • ***
  • Posts: 13166
  • Nancy -- 201.913 mph record on a production ZX15!
    • Nancy and Jon's personal website.
naked riding
« Reply #17 on: August 30, 2006, 08:59:27 AM »
I've ridden naked bike a couple of times -- a couple of records, too.  First comment:

As I completed my first run down the long course, with best speed around 185, I endured some amazingly serious psychological concerns about holding my head where I wanted it to be so I could see and control.  I worried that if I let my head turn to the side -- that I wouldn't have the strength to turn it back to straight ahead again, and then I'd either get my head ripped off -- or I'd have to lift.  Dang, it's windy out there at a buck--eighty-five.  So I finished the run, and when Cris and Ed Shearer met me they helped me take off the helmet -- and didn't say hello, didn't say "Good Run", they jumped to the back of their pickup to get cold cloths to put on my head and neck.  That's how stressful that ride was on me.

So the next year, when I bumped the record in M/F 1350 to 191+, I learned -- and rode the short course!  Still lots of wind, but at least not for so long.

At the end of a run I'll roll out of the throttle and begin to slow down, then start lifting my head slowly at (maybe) 160-170.  At about 140 I can start to sit up, and form then on it's all easy.

At Maxton we don't have the luxury of a long deceleration run, so as I approach the first light I start to grip the bars REAL TIGHTLY, and when I'm in the second light it's out of the throttle and sit up straight, holding on for dear life!  You don't get blown out of the saddle -- but it could happen if extreme care isn't taken to be comfortable in the manuever.

Would I want to sit upright and make a naked bike run at speeds over 180?  Well, it'd be nice to have enough horsepower and traction to be able to get to those speeds while sitting up, that's for sure.

As an aside, I've occasionally thought of asking for a rules modification that would allow a vertical stabilizer on the back of the helmet -- to help keep it straight during high-speed runs.  The wind forces are so high up at high speed that it'd be nice to use the wind to help, not to scare the rider.

Best wishes to those guys.  At least it'll give their deodorant a chance to be refreshed...
Logged
Jon E. Wennerberg
 a/k/a Seldom Seen Slim
 Skandia, Michigan
 (that's way up north)
2 Club member x2
Owner of landracing.com

aswracing

  • Guest
Motorcycle question from a newbie...
« Reply #18 on: August 30, 2006, 09:45:13 AM »
I was watching one of those chopper shows once and the famous builder was bragging on the motor in his bike, how it made 160hp, and how he was considering taking it to Bonneville and running 200mph with it. I about fell out of my chair. It's amazing the assumptions people make about horsepower and speed, most folks have no clue what it takes to go 200.
Logged

Screwdriver

  • Guest
Motorcycle question from a newbie...
« Reply #19 on: August 30, 2006, 05:26:32 PM »
OK guys thanks for the comments and the experiences. It does get pretty damned windy at high speed (!) and I have a better perspective on the forces involved. I'd forgotten (or never knew) the cube law and had been assuming a square. I guess that's a killer for those last few mph hey.

People do throw numbers around especially when it comes to motorcycle performance; casually, in exaggeration and often without any personal experience. It's nice to hear from those who know wherof they speak. I'll be popping in and out of here I reckon, thanks again. :D

Screwdriver.
Logged

Offline Dean Los Angeles

  • Hero Member
  • *****
  • Posts: 2370
Motorcycle question from a newbie...
« Reply #20 on: August 30, 2006, 08:44:15 PM »
Watch the MotoGP guys and they sit up to help breaking at 200 mph.

On the other hand, Ron Cook sat up at 200 mph at El Mirage and was blown off the bike.

Accelerating up to speed while sitting up, and sitting up at speed are two different things.

Going 180+ while sitting up is gonna take some real horsepower!
Logged
Well, it used to be Los Angeles . . . 50 miles north of Fresno now.
Just remember . . . It isn't life or death.
It's bigger than life or death! It's RACING.

Offline JackD

  • NOBODY'S FOOL
  • Hero Member
  • *****
  • Posts: 4684
FALLLING DOWN
« Reply #21 on: August 30, 2006, 09:09:18 PM »
Quote from: Dean Los Angeles
Watch the MotoGP guys and they sit up to help breaking at 200 mph.

On the other hand, Ron Cook sat up at 200 mph at El Mirage and was blown off the bike.

Accelerating up to speed while sitting up, and sitting up at speed are two different things.

Going 180+ while sitting up is gonna take some real horsepower!


Ron Cook was thrown off the bike after control was lost and bailed.
He had the same problem at Muroc the month before and worked on the wrong end of the bike.
Rear steer as it hooked up at speed was the problem.
If you want to test it at a much slower speed , drive out of a water burn out and see it pull sidways when it hits the dry stuff.
Logged
"I would rather lose going fast enough to win than win going slow enough to lose."
"That horrible smell is dirty feet being held to the fire"

Offline John Noonan

  • Hero Member
  • *****
  • Posts: 3606
  • 306 200+ mph time slips. 252 mph on a dirtbike
Motorcycle question from a newbie...
« Reply #22 on: August 30, 2006, 11:19:07 PM »
Quote from: Dean Los Angeles
Watch the MotoGP guys and they sit up to help breaking at 200 mph.

On the other hand, Ron Cook sat up at 200 mph at El Mirage and was blown off the bike.

Accelerating up to speed while sitting up, and sitting up at speed are two different things.

Going 180+ while sitting up is gonna take some real horsepower!


Uh, Ron Cook never went 200mph nor did he "sit up" while running his KZ1000, however he was and is sill an inspiration of mine that I think of everytime I make a top speed run....

Rons website is  www.pureguts.com

J

PS, sat up well over 200 with no problem, place feet firmly on the pegs, open up knee area to aissist in air braking, sit up with a firm hold on the bars and I have stopped at the 6.5mile with no brakes after running over 250+

Jason has run over 240 on gps on an open bike with no front bodywork at last years Bub's meet so hanging on is possible..

J
Logged

Offline JackD

  • NOBODY'S FOOL
  • Hero Member
  • *****
  • Posts: 4684
Yup
« Reply #23 on: August 30, 2006, 11:25:02 PM »
One thing for sure, it is a lot easier to pick up stuff from the ground. :wink:
Logged
"I would rather lose going fast enough to win than win going slow enough to lose."
"That horrible smell is dirty feet being held to the fire"

Offline MadDuck

  • Full Member
  • ***
  • Posts: 52
Motorcycle question from a newbie...
« Reply #24 on: August 31, 2006, 10:35:38 PM »
We ran a standard dirt track handlebar in 2003 on our XR-750s on the short course.  The best pass was at 138, Don Camlin did all the riding.  He was up to about 135 at the start of the measured mile in a dirt track tuck and was really beaten up badly at the three mile.  That helmet attached to his flexible neck was the biggest aggravation, even at 135 the slightest movement went to twist it off.  You're not just going at speed, your maintaining that speed for thirty seconds.  We could have found a little more speed but we clearly had the wrong set up.

In 04 we added a fairing to one of the bikes and set a few more records.  We had another XR in the trailer and Don never got it out.
Logged
Fly on RI Rocket #27

Offline tomsmith

  • Full Member
  • ***
  • Posts: 168
blow-offs
« Reply #25 on: September 01, 2006, 07:42:36 PM »
Here is a 208mph blow-off video from the RB Racing site:
http://www.rbracing-rsr.com/cinema/topfuel5.mov
Note that the rider was not tucked in (just crouched over), but was still apparently blown off due to losing his grip on the left hand handlebar.

I was almost blown off at a much lower speed.  I wasn't thinking (as usual) after making a fully tucked-in dry lakes run and abruptly sat up at something over 120mph.  If I hadn't been holding on, I would have gone off the back end.   I went from NO wind to the full blast in just a couple of seconds.  If I had raised up slowly there would have been no problem, but the unexpectd surprise was what did it.  That's the problem with brain lock.
Logged
139mph with no bike, but with speedo and helmet.

Offline panic

  • Sr. Member
  • ****
  • Posts: 845
    • My tech papers
Motorcycle question from a newbie...
« Reply #26 on: September 05, 2006, 02:20:31 PM »
Logged

Offline 1212FBGS

  • Hero Member
  • *****
  • Posts: 2532
    • http://www.motobody.com
Motorcycle question from a newbie...
« Reply #27 on: September 05, 2006, 02:33:05 PM »
I have molds for several different helmet tails. We made them for the hang gliding people years ago. They are the only people that are brave enough to use them. The tails are outlawed by most motor sports organizations because of neck accelerations in an accident. The hang glider/parachute people stopped using them cuz they couldn?t turn their heads.
The head is only a small aero problem with an open bike
Logged

Offline JackD

  • NOBODY'S FOOL
  • Hero Member
  • *****
  • Posts: 4684
ESTATE SALE
« Reply #28 on: September 05, 2006, 04:11:54 PM »
Their estate will put yourself and everything you own up for sale. :wink:
Logged
"I would rather lose going fast enough to win than win going slow enough to lose."
"That horrible smell is dirty feet being held to the fire"

dirtydave

  • Guest
Motorcycle question from a newbie...
« Reply #29 on: September 12, 2006, 08:19:20 AM »
A few years back i ran a 1327 prostocker ( oz rules back then ) we ran around the 170 mph range, and my home track had a real short braking area, we got real used to jumping up and jamming your body into the air to help slow down. but that was still a full fairing bike,
I got boarded with prostock and put the same donk in a stock efe 1100 lowered street bike, no fairing, man i forgot how powerful the full force of air was like, One run i got a powerstand up in top gear at close to 160mph I got of the gas close to the traps and it just floated there for a while and came down "O" so softly, the air was holding her up there .Lost a small end next pass, So i started building my 1642 landspeed open project,,  DLRA 07 ,,,, :roll:  :roll:  :shock:  :shock:  :lol:
Logged
Pages: 1 [2] 3   Go Up
« previous next »