01smokes
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posted July 17, 2008 09:54 PM
does your bike hook in the street?
Hey guys i was wondering what i can do to make my bike hook on the street.
Its sitting at 62'' now and i have a shinko 003 ultra on it set at 25psi and all it does is spin.
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BlackMagic14
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posted July 17, 2008 11:06 PM
12psi should do the trick! oh and a longer burnout... but get ready the lat person I gave that advice to looped his bike on the first race
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fifth
Expert Class
The Magnificent Bastard
Posts: 303
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posted July 17, 2008 11:09 PM
looping would suck...... especially on a lengthen bike.....
I'll take the zero, thank you.....
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bawls
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re-learning to ride
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posted July 18, 2008 05:14 AM
Fifth, i'm pretty sure that you don't have to worry about looping.... EVER
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Best 60ft: 1.42
Best 1/8th: 5.97
Best 1/8th MPH: 119
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Sticks_n_Stones
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posted July 18, 2008 03:44 PM
 Edited By: Sticks_n_Stones on 18 Jul 2008 16:45
Two words for you: Track Bite. Put that stuff down, quick spin in it and you're golden. Only need a few ounces to do the trick, I used to redirect the windshield squirters on cars to spray it directly on the tires of my friends cars when they they ran into that problem.
A street racing secret: soak a rag with it, leave it in a ziplock bag until you need it, then pretend that you are wiping the rocks off your tire just before the race. Works best at night so no one can see that its soaking wet. .... it aint cheating if you dont get caught...
One more thing: with cars, you never want your rear end/ drive shaft to ever be higher than the transmission, it was a guarantee that you would spin instead of hook. The equivelant force/leverage should apply to the swing arm to frame attach point. One of the drag racers on here might be able to clarify that (if they are willing to divulge a secret). If your swing arm pivot point dips at or below your wheel centerline during launching you will spin, thats just simple physics. It causes your tire to "climb" up and bounce, breaking it lose. Not sure how far lowered you are, but its a recurring theme on this board with guys that extend there swing arms and have lowered bikes. We get a post every month from guys that seem to be losing traction when they go longer. Film you bike launching, with a close up on that area and it should make itself clear whats going on.
Another thing: drive line shock. the longer chains of extended bikes will always have more slack to take up than shorter bikes chains, which you should be taking up by slightly loading the bike before launching. Something that wouldnt be an issue on a shorter bike becomes troublesome on longer setups...
It's the little things like that that will win you close races. I was a horsepower nut, always loving a come from behind win (hp versus 60' times) but there is nothing like the smile inducing ephoria of smoking someone on the launch and leaving him in your mirrors from the git-go.
Bawls: "Fifth, i'm pretty sure that you don't have to worry about looping.... EVER" That a big guy (aka fat guy) comment? Better be careful, us big (fat) guys might just decide to eat you. 
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'06 zx14
Muzzy M10/M14
PCIII w/ Muzzy map
Flies out K&N in!
bits n pieces...
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bawls
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re-learning to ride
Posts: 2701
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posted July 18, 2008 03:58 PM
I wasn't calling him fat... But he is a giant in comparrison to me. In order to eat me, you've got to catch me. Next friday ring a bell? 
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Best 60ft: 1.42
Best 1/8th: 5.97
Best 1/8th MPH: 119
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Sticks_n_Stones
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posted July 18, 2008 04:45 PM
As I've told all the fast little rodents that used that line "you've got to catch me",
"You have to come back eventually, and I've got the memory of an elephant and a size 16 boot" 
And really, do you want the vision of me sliding my 14 around the corners and methodically catching up to you in your mirrors? lol
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'06 zx14
Muzzy M10/M14
PCIII w/ Muzzy map
Flies out K&N in!
bits n pieces...
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wrongway
Pro
Posts: 1078
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posted July 18, 2008 04:46 PM
i use a bigger tire .... a BFGoodrich 205/45/17
Roy
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Sticks_n_Stones
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posted July 18, 2008 04:57 PM
Edited By: Sticks_n_Stones on 18 Jul 2008 18:00
edited off so I aint post whoring
Crap, how does that tire work for you? Surprised you arent at least running a Drag Radial! Bet you get plenty of life outta that monster, ehh? Does it mount up to your rim, or did you modify the rim seat to accept it?
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'06 zx14
Muzzy M10/M14
PCIII w/ Muzzy map
Flies out K&N in!
bits n pieces...
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dubious
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Needs more time to ride!
Posts: 8442
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posted July 18, 2008 05:09 PM
hmmm, a zx12 wheel on a zx14...
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natural selection.....
destiny will overcome intervention.
Some are not worthy of the effort.
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dubious
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posted July 18, 2008 05:12 PM
oh, and I did find it difficult to launch the bike above 4500 rpm on the street witha 5 inch stretch...
liked to spin., but I could wring her right to redline in every gear!
the shift to second gear would light it up sometimes too.
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natural selection.....
destiny will overcome intervention.
Some are not worthy of the effort.
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wrongway
Pro
Posts: 1078
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posted July 18, 2008 05:27 PM
quote:
edited off so I aint post whoring
Crap, how does that tire work for you? Surprised you arent at least running a Drag Radial! Bet you get plenty of life outta that monster, ehh? Does it mount up to your rim, or did you modify the rim seat to accept it?
It mounted on the rim with no issues. I went with a road race tire so it would last longer and still have traction. I have done alot of burnouts with it and there seems to be no sign of wear :-) I statrted at +8" and had traction issues , so I kept shortening it till I had a good bite without wheelies. I think it is at +4 now and hooks on anything.
Roy
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wrongway
Pro
Posts: 1078
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posted July 18, 2008 05:30 PM
quote:
hmmm, a zx12 wheel on a zx14...
It was an experiment , and that was the cheapest wheel I could find. I had to make an adapter for the rotor, but it wasn't too much work. Axle was the same size, and the sprockets i had for the zzr1200 and the zx6 fit the zx12 hub also , so I had sprockets to test with.
Roy
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Sticks_n_Stones
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posted July 18, 2008 05:38 PM
Edited By: Sticks_n_Stones on 18 Jul 2008 18:41
I friggin knew it! Just looked over all the pics of the different 14s I could find and they all share the same dynamics as ninjaboys bike above (hope you dont mind me using yours as an example ninjaboy).
Look at that relationship of swingarm angle and pivot point. Imagine it squatting hard on launch, rear axle matching or most likely exceeding the level of the swingarm pivot point. Any car drag racer worth his salt will be able to tell you thats a traction killer, wheel hop initiating drive line and tranny trashing combo. On a bike, it simply means you are gonna spin.
Doubt me? Then why do the Moto GP guys always try to get that pivot point just right? Because putting down the traction is just as important there as in drag racing. Show me a single GP bike currently running that has a low pivot point relative to the axle. Check this out as an example:
I've heard it mentioned over and over when they are talking to the new liter bikes heads of design and /or engineering, about how they moved this or that bikes pivot up or down to get just the right angle for that chassis to plant the tire properly. Same exact thing that car drag racers do, its a HUGE chassis issue that is considered a "black art" by most.
Call this post a free hint to one of Bikelands members or sponsors to look into. Because if my well based and founded instincts are correct, you could be lookin at the next big thing in street legal drag racing (pro stock and top fuel use a rigid frame that eliminates that problem). Think along the lines of a rigid structure that moves the pivot point 4 inches back and 1 1/2 - 2 inches up, which would also elimate needing a swing arm extension. Come on fellas, all I'm asking that you make it available to the 14 guys first.
____________
'06 zx14
Muzzy M10/M14
PCIII w/ Muzzy map
Flies out K&N in!
bits n pieces...
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Sticks_n_Stones
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posted July 19, 2008 08:40 AM
bump till I get a response. All that thinkin gave me a headache, so someone better respond!
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'06 zx14
Muzzy M10/M14
PCIII w/ Muzzy map
Flies out K&N in!
bits n pieces...
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bawls
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re-learning to ride
Posts: 2701
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posted July 19, 2008 03:46 PM
rabbble rabbble rabbble happy?
____________
Best 60ft: 1.42
Best 1/8th: 5.97
Best 1/8th MPH: 119
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wrongway
Pro
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posted July 19, 2008 04:48 PM
I dont think you can generalize traction as simply as looking at the relative position of the axle and pivot heigth.
with an extended swingarm , you need to compensate for the reduced weight on the rear tire with a stickier tire or better track surface.
And a public street is usually not a good surface.
Roy
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bigdtd
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Interceptors
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posted July 19, 2008 04:55 PM
you stretched it and now you are bitchin, stock wheelbase will dead hook with a michelin pilot power on the street, learn ro ride a stocker
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Sticks_n_Stones
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posted July 19, 2008 05:03 PM
yeah you really can. Its a formula all serious car drag racers use for there Instant Center of Gravity calculations. I just found this, it covers what I'm talking about. And when it comes to cars and bikes, the only difference really is the drive chain versus drive shaft. Thats it.
From Wikipedia:
"Instant center
A tire's force vector points from the contact patch of the tire through a point referred to as the "instant center". This imaginary point is the effective geometric point at which the suspension force vectors are transmitted to the chassis. Another way of looking at this is to imagine each suspension control arm mounted only at the frame. The axis that the arm rotates around creates an imaginary line running through the vehicle. Forces, as far as suspension geomentry are concerned, are transmitted either along this axis (usually front to rear) or through this axis at a right angle (usually right to left and intersects the ball joint). When you intersect the force lines of the upper and lower control arms, where they cross is the Instant Center. The Instant Centers when viewed from the front or side may not seem to have much of a relation to each other until you imagine the points in three dimensions. Sometimes the Instant Center is at ground level or at a distant point due to parallel control arms.
The instant center can also be thought of as having the effect of converting multilink suspension into a single control arm which pivots at the Instant Center. This is only true at a given suspension deflection, because an unequal length, multi-link system has an instant center that moves as the suspension is deflected."
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'06 zx14
Muzzy M10/M14
PCIII w/ Muzzy map
Flies out K&N in!
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wrongway
Pro
Posts: 1078
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posted July 19, 2008 05:15 PM
the instant center on a bike is always the swingarm pivot. that is the same as a ladder bar on a car. I think the only bike with a multilink suspension is a concours 1400.
the real issue is getting enough traction to have weight transfered to the rear tire by getting the front wheel off the ground without going too high.
Roy
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smokinzx14
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Posts: 10197
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posted July 19, 2008 06:10 PM
Edited By: smokinzx14 on 19 Jul 2008 19:20
Sticks_n_Stones is on the right track but thet is alot more to it ....Ladder Bar cars like mine like the ladder bars aimed down or lower than the axle ..... The lower the bars and it trys to pick up more weight and plant the tires harder .. This only works if you know where the CG is on the car...Lets say the CG on my 63 super stock car is in the middle of the door i would want the bars pointing down just below the spot on the door ... Now if my cars wheel stands at that setting i can raise the bar to a point just about above the CG and that will cause the car to drive forward harder and not lift the front wheels ...Wheelies in a car are like a motorcycle , they look cool but slow you down ..
Now we need to know the CG of a motorcycle , most times it's just like a car ( the crank shaft ) One way to find it is find the ballance point of the car or bike ... Lets say you jack up a zx14 at the drain plug and the bike is ballanced at that point ... You want to aim the ladder bars ( swing arm ) just below that point or at that point .. Now if you look at fast drag bikes you will see the rear axle is bit lower than where the swing arm bolts ups , so the swing arm is aiming just above the CG ...But when the bike leaves the line hard the angle changes, the bike squats in the rear and the swing arm points just below the CG ...This loads the tire with all the weight of the bike and rider by trying to lift the front wheel ... All this is good but you need a GOOD shock to controll all the power and movement ....Brock has a good write up on the shocks and what is needed to hook a bike, anybody that drag races should read it .. .. I'll see if i can copy and paste it here ... If you look at Ninjaboys bike (above picture ) his bike is set up as it sould be for a bike that long , proof is the bike has 1.33 60 foot times at 68 inches... Mine set up very close to his at 64 inches had gone 1.35 60 foot times .... Will mine or His hook on the street ??? Hell NO it will not hook .... It will need a much softer set up to hook on the street ... The shock will need to be set up much softer to soak up the hit off the line to keep the tire from spinning ....I have see guys with long bikes hook good on the street but they leave much softer ...The only way around this is a bigger tire and a different set up than used on the track ... Here is what it comes down to , you can't have your cake and eat it too ....One set up for the street and one for the track ..
From Brocks >>
First and foremost, you must have properly-functioning front and rear suspension. When you witness a hard launching Unlimited bike "squat", the energy release that occurs, which would normally lift the front wheel, is partially dissipated through the rear shock and converted to traction. Secondly, when you apply this much horsepower to a D.O.T. tire that was originally developed for a stock machine and it starts to spin (over bumps in the track, etc.), the tire does not want to stop.
The most critical aspect of the rear suspension appears to be the balance of spring pre-load/compression dampening and rebound dampening. Spring pre-load and compression dampening determine the rate of time relevant to the amount of force applied that it takes for the bike to squat. If a bike doesn't squat properly, it has a tendency to wheelie or spin the tire.
The wheelies are partially due to the fact that the center of gravity (CG) is higher for a bike that does not squat. As a general rule: for each inch that the chassis is lowered, approximately one tenth of a second improvement in a quarter mile elapsed time can result. This applies to the static or stationary position. General safety regulations require a 2" minimum ground clearance. I generally set up Unlimited machines at 4" to compensate for squat. Dynamically, when the machine squats on take off, you get the improved traction, but also a lower CG to offset wheelies. Additionally, you receive the added benefit of the bike raising while moving down the track, which results in more traction on the top end. Typically, machines with a taller chassis set-up leave poorly, but hook better up top. Of course, we are trying to achieve the best of both worlds!
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Gen 2 ZX14R Best ET 8.43 , Best MPH 164.95
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smokinzx14
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posted July 19, 2008 06:17 PM
Take a look at the swing arm angle on the fastest super street bike in AMA prostar ...
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Smokin Performance Cycles..
Tampa Bay , FL .. Brocks Performance Dealer ..
Gen 2 ZX14R Best ET 8.43 , Best MPH 164.95
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smokinzx14
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posted July 19, 2008 06:23 PM
Edited By: smokinzx14 on 19 Jul 2008 19:35
This is my NSS/AA superstocker... The bars are aimed just below the crank shaft line .... Just the right amount of wheel lift to load the tires with 3680 pounds of 63 plymouth ..
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Smokin Performance Cycles..
Tampa Bay , FL .. Brocks Performance Dealer ..
Gen 2 ZX14R Best ET 8.43 , Best MPH 164.95
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smokinzx14
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posted July 19, 2008 06:26 PM
This is my old 68 Hemi super stocker ... The bars are to low and to much wheel stand ...
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Smokin Performance Cycles..
Tampa Bay , FL .. Brocks Performance Dealer ..
Gen 2 ZX14R Best ET 8.43 , Best MPH 164.95
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Sticks_n_Stones
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posted July 19, 2008 08:27 PM
Thanks Smokin, you know what you're talking about. All I ever did was street race, and as you know its all about the soft launch/soft rear suspension to keep the shocks on the tire to a minimum. We always set up the CG to the front tires centerline, which is basically the crankshaft centerline. The main thing I was thinking was you dont ever want the rear axle centerline to get above the pivot point, which would waste power as the pull of the chain and drive of the tire tries to 'pull' the swingarm up, or overcenter. That kinda movement I would imagine will lift the tire just enough to cause problems. A bit higher pivot point would allow a bike to be lowered further and keep that CG in the sweet spot. Then, of course, you are running into oil pan clearance issues... "chasing the dog"
There has to be something different out there that becomes a game changer. Bikes launch hard, no doubt, but when that 1/8th mile is where your sport lives or dies you gotta try every avenue to maximize it. And a lower bike creates less drag on the top end.
Thanks for the time guys, just figured new ideas and fresh looks at a stale concept might help...
____________
'06 zx14
Muzzy M10/M14
PCIII w/ Muzzy map
Flies out K&N in!
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