FlatoutBu
Pro
Posts: 1054
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posted June 18, 2009 06:45 AM
 Edited By: FlatoutBu on 18 Jun 2009 14:49
Little help from the dragracers....
I'm having a little issue with my 60ft lately. I'm going to try and explain the best I can and i'll give my set-up and what I changed between now and then. Ok last year I started training MMA and fighting. I dropped serious weight since then(60lbs before fights). This was a plus for 2 reasons...I feel a hell of alot better and I dropped 2 tenths off my ET. But I'm having a little problem. Ever since then, I can't 60 foot my bike. Before I would do 1.40-1.43 on the average (at 240+ pounds!), now I'm lucky too see a 1.50-1.53. I'm not saying the weight is the problem but that's when it all started. The bike wants to hop out of the hole, which in turn kinda pogo sticks the motor. It comes out good, does this little "buck" thing, then shoots away. It still pulls 1.50 60's at 65 inchs and ran 9.20@149mph (-1+3 gear) lastnight with 80% humidity and 80+ temps. I'm wondering if I'm having shock issues from being lighter. I'm guessing it's loading then unloading coming out of the hole? I put in a new dragpak the other day and it helped a little but the bike is still doing the bucking thing. I shim my springs .140thou and the springs are new. I'll give you guys a short list of the bike and maybe you can throw some ideals my way.
65"WB
new clutch
new springs (shimmed .140)
straight link
shock set on stiff both rebound and compression
spring turned half way down
-1+3 gear
good chain and sprockets
I even thought about going back too the worn out springs too see what happens. I'm not sure if i'm getting the clutch out too fast or it's in the suspension somewhere...
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06 Blue 14
9.008 at 153mph @ 195 suited
  
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Shane661
Needs a life
Posts: 11494
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posted June 18, 2009 06:48 AM
Edited By: Shane661 on 18 Jun 2009 14:49
Sounds like some issues with the shock damping to me. Did you reduce your preload after you lost the weight? The spring sounds like it is overpowering whatever damping you have.
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FlatoutBu
Pro
Posts: 1054
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posted June 18, 2009 06:51 AM
No I haven't touched the spring yet. I was more centered around the clutch, but after replaceing it and it still happens i'm starting too wonder. I had a long ride home lastnight from the track too think about it. I havent touched the shock settings in over 2 years...
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06 Blue 14
9.008 at 153mph @ 195 suited
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Shane661
Needs a life
Posts: 11494
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posted June 18, 2009 07:17 AM
Edited By: Shane661 on 18 Jun 2009 15:18
The extra weight you used to carry would certainly help to slow down the return of the shock. Sounds like the rear wheel is out of control. If the clutch is hitting harder, that is only going to make it worse.
Obviously I'm not an expert, but that is my .01. 
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iflyems
Expert Class
Posts: 233
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posted June 18, 2009 07:18 AM
I think you took one to many too the head.
Seriously though, try loosening the preload on your rear shock a couple of turns. Your not getting the weight transfer to the rear wheel like before, and that is critical for 60 foot times.
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FlatoutBu
Pro
Posts: 1054
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posted June 18, 2009 07:25 AM
quote:
I think you took one to many too the head.
Seriously though, try loosening the preload on your rear shock a couple of turns. Your not getting the weight transfer to the rear wheel like before, and that is critical for 60 foot times.
Ha, your prob right...but I try too give them as good as I get.
Should I loosen the preload up or the compression screw or both? Compression screw top or bottom screw?
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06 Blue 14
9.008 at 153mph @ 195 suited
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dubious
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Needs more time to ride!
Posts: 8442
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posted June 18, 2009 08:10 AM
Edited By: dubious on 18 Jun 2009 16:13
screw the rebound in!
The shock is rebounding, which will cause hop, and the stock spring is really soft for a 180 lb guy on a 6 inch stretch.
You used to weigh enough the spring wouldn't bounce or rebound as fast is my guess....
Might want to reduce tire pressure a little too.. depending on where your at with that
The lost weight might be allowing it to hop too.
____________
natural selection.....
destiny will overcome intervention.
Some are not worthy of the effort.
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iflyems
Expert Class
Posts: 233
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posted June 18, 2009 08:25 AM
Yea, screw the spring tighter. There are those two collars on the top of the spring, get a big screwdriver and whack the hell out of them. Forget about that compression screw, that's a waste of time. Just screw the spring down.
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Shane661
Needs a life
Posts: 11494
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posted June 18, 2009 08:35 AM
Hey, I'm not trying to cause trouble...but I think he needs to loosen the spring...for less preload. Your rebound and compression will probably need to be right at the max...minus a half turn.
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kawasakijockey
Pro
Posts: 1876
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posted June 18, 2009 08:40 AM
quote:
screw the rebound in!
The shock is rebounding, which will cause hop, and the stock spring is really soft for a 180 lb guy on a 6 inch stretch.
You used to weigh enough the spring wouldn't bounce or rebound as fast is my guess....
Might want to reduce tire pressure a little too.. depending on where your at with that
The lost weight might be allowing it to hop too.
I second ya Dub. Rebound is too fast and quite possibly the compression too.
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Get on the shortbus boys 'cause its time to get schooled.
2007 ZX-14
1.38 60ft
9.03 @ 149mph
8.95 @153 small shot n2o
8.68 @160mph 5lbs boost
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Wheelie
Needs a life
Old Man
Posts: 6902
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posted June 18, 2009 08:45 AM
Edited By: Wheelie on 18 Jun 2009 16:57
what rpm you leaving? I think its the clutch.
wee
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smokinZX14
Needs a life
Posts: 10197
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posted June 18, 2009 09:18 AM
quote:
Hey, I'm not trying to cause trouble...but I think he needs to loosen the spring...for less preload. Your rebound and compression will probably need to be right at the max...minus a half turn.
I'm with Shane ... Put the spring back to factory setting and run the adjustment screws all the way in and back off a 1/4 turn ..
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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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FlatoutBu
Pro
Posts: 1054
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posted June 18, 2009 09:22 AM
Ha, what good are you guys?!!! lol Here is my train of thought...with the extra butter in my butt it was holding the bike down harder on launch and the shock wasn't shooting back up when I started getting the clutch out. With less weight the bike compress's the spring/shock but it shoots right back up and unloads the chassis, that's when I get the pogo action. I understand the spring is mostly just a ride hight adjustment tool and not too be used a stiffness fix. That's what revalveing is for. I also have a straight link which stiffens up the suspension alot too. I'm thinking I need too loosen up the spring and turn the compression and rebound screws out a few clicks. I'm thinking the bike needs to squat in the ass a little more. I could be totally wrong but I'm just throwing out ideals here..
Dubious....I run 22 psi in a 180/55 Mich Power One. I'm not having alot of traction problems but when I do this leads me too believe it only spins when the chassis wants too unload itself on launch.
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06 Blue 14
9.008 at 153mph @ 195 suited
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FlatoutBu
Pro
Posts: 1054
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posted June 18, 2009 09:25 AM
okay I see..turning screws in equals slower compression/rebound (brain fart)
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06 Blue 14
9.008 at 153mph @ 195 suited
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dubious
Needs a life
Needs more time to ride!
Posts: 8442
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posted June 18, 2009 10:35 AM
LOL
I too think Shane hit the nail on the head.
I wasn't disaagreeing with anyone, simply to prevent the shock from extending too fast, rebound needs to be increased. That was the only part I felt confident contributing...
I don't know much else about the current set up, track conditions etc.
I am sure these guys are right about the compression, and tightening the spring would be the wrong direction as it exerts more force for the damping to control, so it all makes sense.
they all have more track time than I do too!
____________
natural selection.....
destiny will overcome intervention.
Some are not worthy of the effort.
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FlatoutBu
Pro
Posts: 1054
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posted June 19, 2009 05:06 AM
You would think with 500-750 pass's on this bike I would have a handle on it too...
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06 Blue 14
9.008 at 153mph @ 195 suited
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iflyems
Expert Class
Posts: 233
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posted June 19, 2009 06:58 AM
quote:
You would think with 500-750 pass's on this bike I would have a handle on it too...
Really?? Good luck with that. I have probably over 10,000 passes on various bikes since the mid 80's, and the ZX14 is one of the tougher ones out there to launch. Combination of the hydraulic clutch, length, and especially the horsepower.
I did OK with it stock, but as soon as I started adding "power adders", it got real interesting, and no two runs were the same.
Plus, you lost weight, took a few blows to the head, etc. etc.
Every time you go out, things will be different. Air density will change, track conditions change, latent brain damage......
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FlatoutBu
Pro
Posts: 1054
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posted June 19, 2009 07:13 AM
LMFAO...I have been racing bikes since I was 13 and always had fun doing it. I never took it real serious till I got my 14 now I can't stop thinking about it. People called me crazy for dropping that much weight just too go racing. Everybody keeps telling me I look like a crackhead but I have been overweight all my life...people are just used too seeing me fat.
I'm sure I could line up a little latent brain damage for ya at the gym, you'll even take some weight off...might help ya go faster...lol j/k
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06 Blue 14
9.008 at 153mph @ 195 suited
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iflyems
Expert Class
Posts: 233
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posted June 19, 2009 08:16 AM
ROFL.....it's gotta be the pipe that causing you all these problems.
Your just going "mental". Happens to the best of racers. Your over analyzing things now, and wussing out with your clutch hand. Wing that biotch to 9000 to dump the clutch like a man.....LOL
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FlatoutBu
Pro
Posts: 1054
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posted June 19, 2009 08:51 AM
I wish I could get more practice in. After sitting for a 6 month winter and having so many rain out's, you can't get much practice in.
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06 Blue 14
9.008 at 153mph @ 195 suited
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iflyems
Expert Class
Posts: 233
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posted June 19, 2009 11:52 AM
Get a SeaDoo....much more practical, and fun. Mine has 255hp, goes zero to 50 in about 3 seconds, and tops out at 70mph, and can seat myself, and TWO girls. I'm having way more fun with it, than I did with my ZX14. Not to mention I can be on the lake in 5 minutes.
When I was in Louisiana, it was the same. So many rain outs, then the heat and humidity would just eat up horsepower.
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carlsbadbusa
Parking Attendant
Posts: 20
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posted June 30, 2009 08:17 PM
+1 on preload, lt will transfer the weight and power to the rear tire and you will hookup better, granted its not something else. i was having the same issue, my rear suspension was to stiff and i would not hookup (spinoff) i went down 4 psi, switched to a fullbore and went back 3 turns on the preload and magic,
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Quarter Pounder
Pro
with Cheese
Posts: 1069
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posted July 01, 2009 04:44 AM
Shock Tech 101
The spring rate on your spring is what it is...the "preload" only dictates how much more pressure is needed to start to compress it. It just delays the compression with more preload making it feel stiffer. If you are extended, you are in a sense, making that spring softer due to the extra leverage being put on the suspension.
Compression damping adjustment screw adjusts the rate the shock compresses. More compression damping dialed in, the slower the shock will compress.
Rebound damping adjustment screw adjusts the rate the shock extends after being compressed. More rebound damping dialed in, the slower the shock extends.
Now, with that info, you want your bike to squat when you launch and to stay there as you come out of the hole. If you are rubbing, you need to try and dial in more preload. If you are a big guy, a heavier rate spring will be in order (especially if you are extended causing MORE leverage to be acted upon the shock).
You want very little compression damping to allow your bike to squat (weight transfer), so UNSCREW the compression adjustment to full soft.
You want a lot of rebound damping to keep it from popping back up, so screw IN your rebound adjustment screw to full hard.
From here, it'll just be minor adjustments to get it dialed in. Maybe a 1/2 turn or full turn on either once you get your preload set properly.
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SWB 2008 ZX-14
9.19 @ 151
5.98 @ 123
1.53 60'
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FlatoutBu
Pro
Posts: 1054
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posted July 01, 2009 05:56 AM
Thanks for all the help guys. I havent had a chance to get back too the track yet. I'm supposed to go today but it looks like rain. Traction is not so much the issue it was the pogo stick launch I was having coming out of the hole. The bike was squating,rebounding,squating,rebounding....and my 60's were horrible (for me). I also have a straight link which does stiffen it up alot too. I did unscrew the spring alot and turned both rebound and compression screws in and backed them out a 1/4 turn.
I'm also going to look over my clutch real good and see if there is any problems there. The fluid is black and needs too be changed. I also was used to running a little taller stack hight, then went back too stock. I'm wondering if i'm not getting the clutch released all the way then dropping it at the last second...which is causing the sudden hop. I'm guessing the suspension is not helping and only exaggerateing the problem.
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06 Blue 14
9.008 at 153mph @ 195 suited
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Wheelie
Needs a life
Old Man
Posts: 6902
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posted July 01, 2009 06:28 AM
I still think its a clutch, ive never been wrong, only mistaken. lol
wee
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