unsettling hi-speed wobble - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
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post #1 of 18 (permalink) Old 08-21-2011, 07:03 PM Thread Starter
If only it had 6th gear..
 
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unsettling hi-speed wobble

Hey guys. Got a new front tire put on a couple of weeks ago and just this weekend got to play a little on the highway. Somewhere between 95 and 100 I get an interment wobble, particularly after a strong cross wind or road surface change/blemish. I don't ride at those speeds all the time but I'm pretty sure I'd have remembered it doing this before with the old tire. The newbie balanced out fine and the rim is true, and other than this there isn't anything else going on other than the regular vibrations. I put the tire back on myself so I'm going to check the axle bolt, bearings, trees, side play, all the regulars but I'm putting it out here to see if anyone else has had this happen to them. Again, it isn't constant but comes unexpectedly, which is worse. Doesn't last long but just feels like the front end is sloppy. If I find anything that rears it's ugly head I'll update just so other's can have the info. Wasn't too happy when it first happened .

I know some of you run the Super Brace. Are you happy with it? I went to the site but couldn't find our model on there. Was probably me though

Also,what about air pressure in the forks? I've never messed with'em and I haven't seen evidence of leaking but uneven pressure? (Just thinking out loud....uh....well, on screen.)

Thanks to all,
dave

Last edited by DavesVulster; 08-21-2011 at 07:14 PM.
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post #2 of 18 (permalink) Old 08-21-2011, 07:49 PM
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I would re check the balance, and check the steering head bearings for play. Vulcans rake is generous enough that getting high speed wobbles is usually do to something worn, or loose. Occasionally you can lose a wheel weight, but checking the forks is a good idea too.

I had a Superbrace, and liked it.... But you need to find out what is wrong with the bike before installing one. They may have removed the VN750 off their list, but a call to them will find if they still make them.

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post #3 of 18 (permalink) Old 08-21-2011, 08:28 PM Thread Starter
If only it had 6th gear..
 
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Thanks Knifemaker. Good advise, and I will look into the balancing as well as the other items, I was kidding myself that it was the wind but normally this bike is fairly stable, for what it is, at high speed. Then I was thinking maybe there's a problem with one of the fork springs but I would think that would show itself at lower speeds and cornering which still feel the same as always.
Dave
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post #4 of 18 (permalink) Old 08-21-2011, 09:57 PM
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Here is the link to the Superbrace for the vn750:
http://www.superbrace.com/proddetail.asp?prod=4434

Gordon

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post #5 of 18 (permalink) Old 08-21-2011, 10:20 PM Thread Starter
If only it had 6th gear..
 
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Quote:
Originally Posted by OlHossCanada View Post
Here is the link to the Superbrace for the vn750:
http://www.superbrace.com/proddetail.asp?prod=4434
Thank you Gordon, that's great. Do you have one on yours?
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post #6 of 18 (permalink) Old 08-21-2011, 10:56 PM
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Quote:
Originally Posted by DavesVulster View Post
I put the tire back on myself ...
I guess you made sure the bead of the tire seated evenly around the rim on both sides?
You lined up the balance mark of the tire with the valve stem, right?
Checked directional mounting with rotation?

Might be worth a double check ...

~~C8> Ratt
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post #7 of 18 (permalink) Old 08-21-2011, 11:47 PM
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Quote:
Originally Posted by DavesVulster View Post
Thank you Gordon, that's great. Do you have one on yours?
No, I don`t have one yet. Southern Alberta praries have roads so straight and flat that I have to ride at least a hundred miles to find any decent twisties. I will decide if I need a superbrace after I rack up a few thousand miles on the bike. It needs lots of other stuff first.

Gordon

1991 VN 750 -"Cosmic Lady" or "Bad Girl"?
Purchased May 16, 2008
Approx.19,300km (12,000 miles)

H-D windshield
Relocated R/R
MF-AGM battery
Fiamm Freeway Blaster horns
F&S luggage rack and engine guard
Kury Offset Hiway pegs
July 13, 2016, Riding on the DARKSIDE now, Classic Radial 165/80-15


TOP TEN THINGS A NEW RIDER/OWNER SHOULD DO. Click on link.
https://www.vn750.com/forum/showthread.php?t=9127

Last edited by OlHossCanada; 09-23-2011 at 07:16 PM. Reason: spelling correction
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post #8 of 18 (permalink) Old 08-22-2011, 01:26 PM Thread Starter
If only it had 6th gear..
 
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Quote:
Originally Posted by ZCraggRatt View Post
I guess you made sure the bead of the tire seated evenly around the rim on both sides?
You lined up the balance mark of the tire with the valve stem, right?
Checked directional mounting with rotation?

Might be worth a double check ...
sorry, I should have said put the wheel back on. I had a shop mount and balance the tire. The arrow is correct but I'll look at the bead to see if its even and the balance mark too. Thanks for the suggestions.

I know what you mean Gordon. There are other things that are more important on mine also. Probably look at one for next season since it's really not a necessity.
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post #9 of 18 (permalink) Old 08-22-2011, 02:20 PM
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I mounted and balanced (using Marc Parnes balancer) both tires and have had it up to 100 MPH w/no issues. I also have a Superbrace...no difference running straight, but decidedly firmer in the twists.
I agree w/others...prolly needs to be re-balanced. Suggest removing both front brakes...set up on center stand...have someone sit in seat..raising front wheel off ground. Front wheel should rotate freely and stay put (not rotate AT ALL) when you let go. Turn wheel 1/4 turn, try again and so on. Not the best test, but a good (cheap) starting point.
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post #10 of 18 (permalink) Old 08-22-2011, 02:27 PM
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Ride On or Dynabeads will fine tune the balance. I like Ride On as it helps prevent flats.

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