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996 super head shake...

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Old 10-22-2008 | 08:33 AM
  #31  
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If you have to ask why make modifications, you wouldn't understand.

I'm basing my educated guess on the fact that the bike hit a car when it crashed and the known fact that the stanchion tubes are soft.

If your riding style generates head shake after fixing tire issues and eliminating bent forks and brinelled head bearings, it's time to improve the front end.

Start with springs and valving. Next would be a fork brace. Finally a steering damper. For a track bike - do all of the above.

If you like to spend money on your bike, upside-down forks are very cool and are a noticable improverment over the above modifications.

Then you can start the tuning process all over again.

Modifications are fun. On a VTR, they have significant and noticable benefits when done correctly.
Old 10-22-2008 | 08:58 PM
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Originally Posted by RCVTR
If you have to ask why make modifications, you wouldn't understand.

I'm basing my educated guess on the fact that the bike hit a car when it crashed and the known fact that the stanchion tubes are soft.

If your riding style generates head shake after fixing tire issues and eliminating bent forks and brinelled head bearings, it's time to improve the front end.

Start with springs and valving. Next would be a fork brace. Finally a steering damper. For a track bike - do all of the above.

If you like to spend money on your bike, upside-down forks are very cool and are a noticable improverment over the above modifications.

Then you can start the tuning process all over again.

Modifications are fun. On a VTR, they have significant and noticable benefits when done correctly.
Huge!

Knowledge that is - but my first learning with the Superhawk was how small the adjustments were for the maximum gains. After I did all the big **** (forks, brakes, Penske, calipers) it was amazing to me how much little adjustments made to the ride of the bike.

Example, after my last build I had not torqued the stem bearings tight enough. The bike handled like a bag of dead cats. Weird, wiggly, fucked up balance with the rear end.

So I jack it up, jerk off the top triple - retighten everything - maybe got 4 thousandths out of it. Suddenly it's a dream machine.
Old 10-23-2008 | 11:52 AM
  #33  
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This is a great discussion. My 98 Superhawk ALSO has a little wobble. But never when I'm applying throttle. Accelerating it's as straight as an arrow. While cruising on freeway, if i cross uneven pavement, it's like the rear tire stops following the front for a second, and I feel the shimmy go through it. I don't like it at all, but i keep my speed below 100mph and exercise as much caution as possible. I figure i shouldn't be going faster than that anyway, as LAPD and CHP are cracking down on speeders. Two speeding tickets in 18 months and you can have your licence suspended.
Now the other weird thing is that at low speed, like riding up to a traffic light in 1st gear, if I cross a rounded ridge of asphalt built up between lanes, the thing is squirrely as hell. It's like I could lose control at 3mph. If I go left off the ridge, or right, it's like the bike wants to fall over or drive into the side of a car.
I tried to rebuild the forkls and steering bearing two years ago, but the fork oil all ended up leaking at the seals. I just cleaned the brakes and rode it anyway. It would really bottom out then. I had a shop redo them this summer, but the guy seems to have lost his grip on it. He got stuck when the rear cylinder kept dropping out when the bike warmed up, and he kept my hawk for six weeks, no time to work on it. Real bummer. Honda of Hollywood and Honda Van Nuys both said they had no time to look at it. The other shops around here are full of tweakers. I don't intend to give it over to anyone alse again. I'm going to check tire pressure today.
Old 10-23-2008 | 01:57 PM
  #34  
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Jeez, I just realized how old this thread is!

HollywoodAngel, your situation is not normal and you need to get to the bottom of it soon, and should stay off the bike untill you do, IMO.

Do you know the history of the bike? There is s severe problem somewhere in the chassis. Could be grossly loose suspension parts, bound up or overtightened pivot points (head bearings?), bent and sticking forks, cracked or bent frame. Find a good mechanic, or start methodically taking parts off and checking everything until you get to the bottom of it.

Not good!
Old 10-23-2008 | 03:02 PM
  #35  
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This is really long...

Yeah, i agree something ain't right. But i'm so used to it that I just compensate in my riding style. I do know some history of the bike. It was a salvage title when i bought it in 04. Had been wrecked/built back up. I've put about 38,000 miles on it since (odo was at 7,200) when I scored it.

Suspension was never that right-on. I could put it in neutral at 40mph and coast for a block with my hands off the bars. But in turns it always seemed a little weird. I bought from a 220 lb. guy and he had the forks tightened all the way down. I weigh 155, and still the forks would bottom out on me when i crossed a drainage way in the street or a steep driveway.

I set out to redo the forks and steering bearings myself a couple of years ago. I've done a bit of work on CBRs and i had the book, the OEM fork rebuild stuff, new fork fluid... After i pulled the triple clamp i brought it to a local shop to extract the lower bearing, and the guy made a horrible meal of it. He had ripped the outermost three threads clean off the thing. He was like; Hey sorry bro, we had some trouble with the machine, but i won't charge you. It still worked in that the threads were still there where they were needed. But a couple weeks after I put it back together, both forks began to lose fluid at the seals. Brakes were covered with the ****. I cleaned it up and kept riding. Just more carefully.

Finally this summer i brought it into a pertty reputable shop, guy i've known for three years, does all my tires and chains. He charged me $1000 to get the suspension straight, plus he would adjust the valves, replace the coils, wires and plugs. The day I tried to ride the bike home, it was Fu-cocked. I couldn't get it over 30mph, and the back cylinder would die out, stink of gas... I had no idea if the suspension was improved or not. i brought it back, and the mechanic looked all surprised. he said leave it here, i'll have to ride it, and then he kept it for six weeks. he kept saying he was trying to get a test computer as he thought the problem was that. I really felt like he was past caring. (I know this is long)

He finally finished it at the end of the summer, i believe the problem was the vaccuum petcock, which is what all three mechanics at Honda hollywood suggested. they were cool but had no time to look at it. I went to several shops, no one had time to look at a 10 year old Superhawk with mysterious ignition and handling problems , and I was already in for $1000 from the 1st mechanic.

Okay, so I'm riding the bike again with the supposedly tuned forks and suspension... only there is a lot of play in the main steering bearing. It seemed to be getting worse. So i got the bike up on an apple box, and pulled the upper yoke and drifted the steering adjustment nut about a quarter turn. Since then it's been good. It was steering smooth with the front wheel off the ground. Now the forks are just weird. It's like I can hear a clatter down there when the weight comes off the front end.

BTW. I checked my tire pressure when i was out this morning. I was 30 front and 25 rear, on Michelins with a suggested 42psi. That actually made a huge difference. Next i think I will check the straightness of the rear tire.

I appreciate your advice, and accept it solemnly. But i still gotta get around. I've got a lot of faith in the hawk. She's kind of a beater, but she's stayed up and avoided some bad things over the years here.

I'm not really a cornering guy. I have not time or desire to ride the canyons like guys do out here. Too dangerous IMO. Every Sunday there seems to be a bad wreck on Mullholland or Angeles Crest. I ride the superhawk in straight lines between the lanes. And it does that perfectly. But i agree that it's not a *safe* bike.
Old 10-23-2008 | 03:22 PM
  #36  
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$1000 to not fix your bike!!
Tape a message to a brick and throw it through his window!

The thing that concerns me is the low speed jumpiness. It seems like something is moving around a lot, with very little force input, to upset the chassis that much.

It's either binding and releasing or just plain rattly. There's a dead gorilla in the room somewhere.
Old 10-23-2008 | 03:25 PM
  #37  
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Originally Posted by HollywoodAngel
So i got the bike up on an apple box
Welcome to the forum.
I'm guessing you're in the film industry. 'Cause only film people and farmers have apple boxes.
Old 10-23-2008 | 03:59 PM
  #38  
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Yeah, I'm in the biz. Apple boxes are great for working on the bike, cause it has three different heights, based on the side on which it's resting. I have a second one for tools, and to hold my brew.

The thing with the mechanic was really a drag. I thought of all the stuff one thinks about doing to someone who ***** us over, but at the end of the day I can only get experience. If i tried to fight every ******* in LA... Well, i wouldn't have much time left over to ride.

I had the engine rebuilt on my 71 Olds cutlass supreme by local guy who everyone goes to... And they fucked that up so bad... A decent shop gave the car over to a really green mechanic. But the auto mechanic I have now is amazing. He works on the olds and my 73 chevy custom deluxe, and those two are super road warriors. I just need a guy like that for the Superhawk.

BTW, just bought a new in box ($200) Corbin Saddle for the *reggae machine* (that's my superhawk). I am so stoked on that bitch. I'm waiting for the mailman everyday.

I'm really happy to have found this site. I'll try to edit myself a little better.
Old 10-23-2008 | 10:15 PM
  #39  
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Wish I could recommend a mechanic for you, but I don't know any. The most a shop has done for my Hawk is mount a tire. I do like the parts guys at the dealership in Marina Del Rey.
Old 10-24-2008 | 03:48 AM
  #40  
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Funny I rebuilt a olds 455 engine to throw in my chevelle, worked flawlessly, I destroyed two trannies and sold the car, I still onw the engine (I think, but I have lost the adress, phone and even his name...

Even without freeplay in the steering head bearings, just not enough preload the front end will shift and will feel like crap, tankslap, do all sort of weird things. If you have freeplay, you definitely need to fix this, they should be torqued down to 16 lb/pi if my memory is still functional.
Old 10-24-2008 | 10:02 AM
  #41  
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Good call.

*thread jack*
I wanted to mention something about material science. A bit of technical info.

I mention that the stanchion tubes are relatively soft. This does not mean that they are necessarily soft compared to other conventional forks. Probably not.

But as fork tube diameter has increased, the wall thickness decreases, so it then needs a higher yield strength, especially for dent resistance. Plus with a higher yield strength, you can design a thinner wall and hence lighter weight. The yield point is the point where, if the tube is bent, it does not return to it's original position.

But it is important to note that the yield strength has nothing to do with the stiffness of the tube. This is a function of the modulus of elasticity of the material and all steels have the same modulus. Aluminum has a much lower modulus of elasticity, but in many cases has the yield strength as some steels.

Tube stiffness is a function of the tube diameter, the wall thickness and the modulus of elasticity. A given steel tube will have the same stiffness, regardless of yield strength. Yield strength relates to the amount of deflection before yield only. An aluminum tube requires will require a larger diameter, for a given wall thickness, to provide the same stiffness as a steel tube.

Just some technical stuff to throw in, for people who like this stuff.
Old 10-24-2008 | 04:25 PM
  #42  
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Originally Posted by 996er
Yeah I drive my bike like ghost rider on the highway on occasion. It just feels wobbly over bumps and at higher speeds tank slappin if I dont hold on tight. Even in a straight line around 100 starts to bobble back and forth for a second. Could the compression get messed up and the forks not be leaking? Can I get the forks checked to see if theyre outta spec?
Originally Posted by 996er
Youre right. My back tire just started showing threads today. I ordered the new one. The front I just put on a Dunlop Qualifier. Rotors are good, new front wheel is balanced, forks are torqued to the manual specs and procedures. Im gonna see what happens with a new rear tire & front wheel bearings and go from there.
- J
your second quote shows me you don't do much in the way of maintainence on your bike, threads showing? come on bro... this by itself should make you think twice about "riding like ghostrider"

if you don't think twice about endangering your life by taking stupid risks on a bike that you do not maintain, i'd just like to say that i'm glad you're in jersey and not around here. i'd hate for my wife to be the one to scrape you and your pieces off the road.

ride safe man. don't be a moron.
Old 10-24-2008 | 05:04 PM
  #43  
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Ordering a tire when it's worn out is maintenance to me. Your life is not in danger when you see the first set of wires. I pushed a tire until it blew, it took forever and I came back on the rim. If you go at highway speeds when one or more set of wires are cut, then I call it dangerous.
17 years of carelessness and not a single scratch (except trackdays )
Old 10-24-2008 | 05:44 PM
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i change mine at the wear bars; when my tread is significantly less than I need to do the type of riding that I do, which sounds like he should be doing as well by the type of riding that he does at times. it's not safe to do stupid **** like that period, and even less safe on tires that bald.
Old 10-24-2008 | 06:10 PM
  #45  
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I'd urge 996er to get his bike fixed. These things shouldn't wobble. There's something wrong and it's dangerous just to accept it.
I had an SR500E Yamaha in the early 80's. It would hop sideways over bumps on highway and shake like crazy on a really bumpy road. By some miracle the wheels would align perfectly so I didn't let it bother me much.
I got into two nasty wobbles. I rode one out successfully but the other I didn't.
I found out later from a good shop that the forks were bent. I should have taken it in sooner but I couldn't identify what was wrong and I didn't think anyone else could either.
A shop that caters to racers would be your best bet.
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