Off Center Front Tire

[Solaran]

Hi everyone,

So every once in a while when riding, I've been hearing this odd 'whum-whum-whum' noise at various speeds when going along. I thought it might just be the road, but it'll start and stop on the same fresh paved road. Yesterday after riding and hearing it again, I stopped and took a close look at my front tire, as that's where the sound seemed to be coming from. When looking from the front of the bike towards the rear, the front tire seems to be offset towards the right (left when sitting on bike). It's about a finger's breadth away from the fender on that side, while about a thumb and a half away on the left (right if sitting).

On the side with the larger gap, there's a ring of what looks like lube close to the fork, but well away from the wheel proper. It's about as far away from the fork as the wheel seems to be off center and the distance separating the two is darker like it's also been lubed. I did take a spill about 2.5 weeks ago, going down on that side, and did scrape up the front fender (and bent the foot peg, dinged the gas tank, and bent the turn signal, good thing this is my (brand new :cuss:) learning bike), but I think I remember hearing that noise before the spill. The forks look straight, heck everything looks right except for that gap and the random ring of lube.

My questions are:
A) Is that normal, that much difference between the 2 sides? (I'm guessing not...)
B) Could that possibly be making the noise? (I'm guessing so...)
C) Is re-centering a wheel difficult? Or should I get a shop to do it?
D) Would a drop cause something like this?

I'll see if I can get some photos ith my digital camera and figure out how to post them.

Thanks for any help, thoughts, or comments.

[patrick_777]

Sounds odd, but look at this part of the Tire Thread (http://www.gz250bike.com/viewtopic.php?p=8583#8583)and see if this is what you're talking about. Samato noticed his wheel looking off-center, but it seems to be an optical illusion due to the brake rotor being on only one side.

Yours could be truly messed up though.

[Easy Rider]

So every once in a while when riding, I've been hearing this odd 'whum-whum-whum' noise at various speeds when going along.

but I think I remember hearing that noise before the spill. The forks look straight, heck everything looks right except for that gap and the random ring of lube.



I think the noise is "normal". Noticed it on mine on the highway after changing windshields. Don't know if it is wind noise, spoke noise or a vibration with the engine......or a combination of all three. It IS a rather interesting noise and was quite disconcerting the first time I noticed it...........until I realized that either speeding up or slowing down eliminated it.

I suspect the "gap" that makes the wheel look like it is off center is just a bent fender and the ring of grease is just normal leakage from the front wheel bearing.
Since it has been down, however, I think it would be a good idea to have someone with experience look at it.

[Solaran]

Thanks Patrick, that photo is exactly how it looks.

I think the fender is slightly bent, as it does seem to be much closer on the front than on the back. I'll swing it by the shop next weekend since they're closed now. I'm glad to hear that noise isn't necessarily just me. Easy Rider you're spot on the sound comes and goes as I speed up and slow down. I've been riding it most days and not had any problems, but I'd rather set my mind at ease about that fender.

[Easy Rider]

Easy Rider you're spot on the sound comes and goes as I speed up and slow down. I've been riding it most days and not had any problems, but I'd rather set my mind at ease about that fender.

Someone has since mentioned a similar noise due to a (badly) worn chain so......before you relax completely....might should check the chain, sprockets and spokes. Come to think of it, I probably need to check my OWN spokes too. Maybe that curious noise isn't "normal". ;)

Just kidding.....mostly! :cool:

[Badbob]

This isn't a normal sound. I had a similar problem that tuned out to be the chain/sprockets were misaligned.

A worn chain or sprockets can also cause this.

These nosies are sometimes difficult to trouble shoot because the shound can come deom just about anything that spins.

[Sarris]

:plus1: to Badbob's comments. My whump whump noise disappeared after chain replacement. I bought an o-ring chain for $41 + ship from e-bay. The OEM chain is $100. Also, worn tires can be noisey as well.

:biggrin:

[Easy Rider]

:plus1: to Badbob's comments. My whump whump noise disappeared after chain replacement.

This is really good, guys. You and Bob both seem really sure you can diagnose this noise without ever really hearing it. That's some nice trick. :roll: :biggrin:

Note that the OP said "whum" not "whump" and that it only did it at certain specific rpm/speeds.
I am NOT sure what his noise is but I AM sure that MY bike has a harmonic vibration hum at certain speeds and it does not indicate a problem. I think the sound from mine comes mostly from the tank and is more prominent when the tank is getting empty.

While I agree that it MAY be a problem, I don't think you can really say "That is not normal." without really hearing it. :tup:

[Sarris]

I'm not diagnosing anything. I'm just relaying my personal experiences. They can take 'em or leave 'em.

:cry:

[patrick_777]

Easy may be really onto something with the tank theory. It could be acting as an echo chamber (like whales have) that changes the pitch depending on fullness.

[Easy Rider]

Easy may be really onto something with the tank theory. It could be acting as an echo chamber (like whales have) that changes the pitch depending on fullness.

I don't normally have any body parts in contact with the tank but after hours of riding and an ever increasing butt cramp, one comes up with some.....unusual....riding positions. The tank does have some interesting vibrations at certain speeds. :biggrin:

[patrick_777]

:puke:

I have that same harmonic vibration at speed. Like I've said before, it changed/disappeared when I put on the 16T sprocket, and came back when I switched back to the 15T. It also diminished a little right after I lube the chain, but comes back very quickly.

There are many variables that seem to affect it though, including temperatures/road conditions/fuel amount/etc etc etc...

[Easy Rider]

There are many variables that seem to affect it though, including temperatures/road conditions/fuel amount/etc etc etc...

Yep. I do find it kind of interesting. I can be on the road for an hour and then suddenly I hit just the right speed....or the wind direction changes....or I go down a slight hill, and there it IS. Might last a few seconds or a few minutes and then it is GONE again for another hour or so.
I think it is a GZ ghost !!! :skull:

Even more "interesting" is the harmonic bounce; when your speed is just right and the spacing of the pavement sections is just SO and it feels like a rocking horse. Only had that happen twice in the last year but it is VERY unsettling the first time.

[Badbob]

This is really good, guys. You and Bob both seem really sure you can diagnose this noise without ever really hearing it. That's some nice trick. :roll: :biggrin:

Basically, any thing on the bike that spins could cause these symptoms. However, I have up close and personal experience with chain misalignment and wear causing the sort noise that pulsates and varies with speed.

Engine vibration is normal. Pulsating sounds are not and should be investigated. They may be benign but they could be dangerous.

[Easy Rider]

They may be benign but they could be dangerous.

Thank you! Much better than: "This isn't a normal sound." :biggrin: