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Discussion Starter #1
Stock thruxton wheels and tires with 4K miles. Front tire pressure at 33psi. No steering dampener or fork brace, just Hagon progressive springs in the forks. If I take my hands off the bars over 40mpg, the front wheel wobbles like mad and I have to grab the bars again before the bike loses control. Road pavement type really doesn't matter (some of course are smoother than others)

I am just curious if this is normal or if I should be able to take my hands off the bars upwards of 50mph without this much wobble.

Thanks.
 

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Well, tain't normal. My '07 is rock solid over the Ton, I can take my hands off it, and it was the same with the Metzelers as it is with the Pirellis. I say again, this is not normal behavior for the Thruxton!
It sounds like the bike wants to do a "tank slapper", which you DON'T want to experience;
http://www.youtube.com/watch?v=LZ1srcQMa_0
You could cover this up with a steering damper, which, IMHO, is like putting a Band-Aid on an arterial bleed. Better to fix the cause.
I run 36 psi, but I doubt that pressure, or the progressive spring is the cause. Has the bike ever hit anything?
I would;
- Check and re-torque the steering stem tension. With the front wheel off the ground, the wheel should stay centered, and you should be able to turn the steering about an inch either way (measured at a centerline at the front of the mudguard) before the steering "falls away" to either side. If the wheel refuses to stay centered, it's way loose.
- Put a wire pointer up beside the side of the rim, then rotate the wheel. You shouldn't have much more than 1-2mm of side to side "wobble." Then bend a small "L" on the end of the wire, and do the same against the inside radius of the rim, checking for an "egg shaped" wheel. This will catch gross errors, but to do it properly, you need a Dial Indicator, dirt cheap from Grizzley;
http://www.grizzly.com/catalog/2009/Main/649
Get the combo with the magnetic base.
- Go around the wheel with a light hammer, tapping on the spokes, listen for any that give a dull thud instead of a ringing sound.
- Finally, I'd remove the wheel, put the axle in a padded vise, slide the wheel on, and see if there's a heavy spot. Look for evidence of missing "glue-on" wheel weights.
-As an ultimate resort, I'd replace the front tire, mis-molded tires are not unknown.
I do most work myself, but I take wheels to someone who has the skills to work on them, which I manifestly do NOT. I've found a good off-road shop, those guys true wheels on a weekly basis.
I would most certainly not ignore this. The wobble is survivable if convergent (damps itself out) or static (stays the same.) But, if it goes divergent, (gets worse with each occillation) it will crash you.
Let us know what you find
Redhawk
 

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Stock thruxton wheels and tires with 4K miles. Front tire pressure at 33psi. No steering dampener or fork brace, just Hagon progressive springs in the forks. If I take my hands off the bars over 40mpg, the front wheel wobbles like mad and I have to grab the bars again before the bike loses control. Road pavement type really doesn't matter (some of course are smoother than others)

I am just curious if this is normal or if I should be able to take my hands off the bars upwards of 50mph without this much wobble.

Thanks.
I had the same problem.

After over a month of investigation it was determined to be a warped wheel spindle. They gave me a new wheel from a showroom bike and I was fine. The wobble eventually returned, though. I changed my stock Metzlers to some Avon Road Riders and now it tracks like it's on rails.

I personally think the stock tires exacerbate what is a somewhat wobble-prone bike.

Other potential sources are an out of true wheel or a bad head bearing.
 

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Discussion Starter #4
Damn, sounds like I've got a problem.. I should get it into dealer and see if they can handle it under warranty. I have never hit anything, but I have layed it down at low speed, however, seems like this was always an issue from the beginning.

Thanks guys! I will let you know how it turns out.
 

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The stock Metzeler tires are junk. The combination of a radial in the rear and a bias ply in the front make the bike handle weird when they're new and it gets worse as they wear. I replaced mine at 6000 miles with Dunlop GT-501's; they are both bias ply, front and rear. I'm on my second set; I got approx. 8000 miles out of my last set.

When the front tire wears unevenly (cups) the front end starts to feel unstable, usually at the end of their useful service life. You can't usually see it, unless it's extreme; but you can feel it with your hands. This is less pronounced with the Dunlops as opposed to the Metzelers. This is not to say that Dunlops are the only brand worth considering; others have had good results with Avon Roadriders, Pirelli SportDemons, etc.

This of course doesn't rule out a bent axle or loose steering head bearings. If your bike is under warranty, have the dealer check these two out first. FWIW, I can take my hands off the bars at 70 mph+ with no wobble while my tires still have useful service life. ...........James.
 

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wobble

Hey nekkid,
I ran into same wobble @ 7k & ran them till about 9k.When I switched them out for some pirelli sport demons, I noticed the casing was compromised.(the surface had a soft spot/hit expansion joint @60 mph) So maybe your memory might be triggered by my experience.I had no problems until that with the metzlers, but opinions differ.
Good luck,
sob
 

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Stock thruxton wheels and tires with 4K miles. Front tire pressure at 33psi. No steering dampener or fork brace, just Hagon progressive springs in the forks. If I take my hands off the bars over 40mpg, the front wheel wobbles like mad and I have to grab the bars again before the bike loses control. Road pavement type really doesn't matter (some of course are smoother than others)

I am just curious if this is normal or if I should be able to take my hands off the bars upwards of 50mph without this much wobble.

Thanks.
Could be a crappy tire . Could be loose spokes . I'd put my money on the bad Metzler . I knew mine were crappy . It could even be as easy as a rebalance . Ya never know .
 

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It could be numerous things, but the tire is usually not the problem to the point yoiu can really feel it outside of it just not being smooth.

The problem is balance and the lack of balance can be caused by a few thigs. My problem was a loose spoke, others have mentioned other things as well.Take the bike in and get it fixed before something goes wrong.
 

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Discussion Starter #10
Hey guys, I did some more investigation, this is what I found.

Front wheel has no wobble up to about 48mph, at which point between 48 and around 56mph it wobbles like crazy.. if I take it up to 60 or 70mph, and release my hands, it is straight and true. As the bike decelerates down below 60mph, it begins to wobble again. Any thoughts on that?

Anyway, I have an appt at the dealership to bring it in and have them look at it.

Thanks.
 

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Hey guys, I did some more investigation, this is what I found.

Front wheel has no wobble up to about 48mph, at which point between 48 and around 56mph it wobbles like crazy.. if I take it up to 60 or 70mph, and release my hands, it is straight and true. As the bike decelerates down below 60mph, it begins to wobble again. Any thoughts on that?

Anyway, I have an appt at the dealership to bring it in and have them look at it.

Thanks.
Sounds like mine before I had it fixed.

Good luck with the dealer. It took them over a month to get mine diagnosed and fixed.
 

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Damn, now you got me worried about my bike. I just bought my 2007 from a private seller. I am getting pretty much exactly the same thing you are getting. THe bike only had 700 miles when i bought it. I put almost 200 miles on it over the weekend and the front feels like there is a lump on the tire around 40-50 mph. It bounces up and down, not wobble side by side. WHen i pull pass 60 its feels smoother, but not as smooth as my yamaha. I first thought it was the road or maybe even the preload needs adjusting. I already have a pair of sport demons on order. Stock front and 140 rear. Plus im in the process of changing the suspension to racetech springs and emulators. Keep us posted on your resolution. If its a spindle, I'll have the dealer check it out since I need to bring it in for a cam cover gasket oil leak. THanks!
 

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Discussion Starter #14
Damn, now you got me worried about my bike. I just bought my 2007 from a private seller. I am getting pretty much exactly the same thing you are getting. THe bike only had 700 miles when i bought it. I put almost 200 miles on it over the weekend and the front feels like there is a lump on the tire around 40-50 mph. It bounces up and down, not wobble side by side. WHen i pull pass 60 its feels smoother, but not as smooth as my yamaha. I first thought it was the road or maybe even the preload needs adjusting. I already have a pair of sport demons on order. Stock front and 140 rear. Plus im in the process of changing the suspension to racetech springs and emulators. Keep us posted on your resolution. If its a spindle, I'll have the dealer check it out since I need to bring it in for a cam cover gasket oil leak. THanks!
Likewise, let me know how your situation turns out.
 

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Don't underestimate how truly horrible a match the stock tires are for these bikes.

My wobble, although previously fixed, came back later as the tires wore. Changing to Avon Road Riders cured it.
 

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Hey guys, I did some more investigation, this is what I found.

Front wheel has no wobble up to about 48mph, at which point between 48 and around 56mph it wobbles like crazy.. if I take it up to 60 or 70mph, and release my hands, it is straight and true. As the bike decelerates down below 60mph, it begins to wobble again. Any thoughts on that?

Anyway, I have an appt at the dealership to bring it in and have them look at it.

Thanks.
Hi
Mine did exactly what your describing at that speed.
I changed the metzler to the bridgestone battlax. Its a different bike now. I can't begin to tell you the improvement.
Also i have noticed the front wheel is a little out of true and needs attention, but even with that, the wobble has gone completly. Also i do not have a steering damper or brace.
My advive change the tire.
Cheers John.
 

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My 05 has the exact same wobble between 50 and 55. Anywhere else she is fine. I have 10k plus on her with the stock tires. I am assumming that is where the problem lies and can't wait to get new tires on it. It seems like most of the comments are very good once you put different tires on the bike.
 

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Dangermouse, out of curiousity, what size Roadriders did you put on your Thrux?
Stock size.

The bike tracks so much better now -- it feels like a different bike. Before the new tires, it would grab at any little line in the pavement. No wobbles now, either.

I don't think Metzlers are bad tires per se -- I just think that those specific tires are a bad match for the bike. It seems like everyone who has changed to something different feels that their new tires vastly improve the characteristics of the bike. My gut tells me that this isn't because all the different brands are just so awesome -- it's just that the stock tires are a bad fit. And what's the deal with mixing a bias ply and a radial, anyway?
 

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Discussion Starter #20
Well just got back from the dealership. The wheel was not out of true, but they said the front tire was worn down and in need of replacing.. Funny, it didn't look worn down much, but I guess enough to get close to the warning track on the center treadline. These pieces of junk didn't even last 4500 miles. I really don't think I ride it THAT hard.

Anyway, I ordered a set of Avon Roadrider AM26 and hopefully will have them in a couple of days to see how they do.... couldn't be any worse than the Metzelers.

I did get to test ride the new Ducati Streetfighter.. damn, that thing is light and powerful... took it up to 111 on the freeway before I even realized it. Oh, what 155 horses can do.
 
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