Front Wheel Oscillation-Part 3: The Resolution (merged)

[nicocorea]

Originally Posted by MotoJPizzle

Dude, I totally have the same thing - it only happens sometimes but its like a bouncy feeling and at speeds lower than 40 in 4th or 5th. it only happens when Im in a higher gear than needed for the speed Im at.

Is that what you are seeing?

No, not at all. My front end oscillation was completely independent of the drivetrain. It didn't matter which gear I was in, I could even be coasting with the clutch pulled (i.e., disengaged). It was entirely related to speed: If my speed was in that dreaded 40-55 mph range, the front end would be undulating.

Based on your description, it sounds like one of two things:

1) the perfectly normal response of an engine that's being forced to run too slowly for the load being placed on it (commonly referred to as "lugging" the engine). But that would feel to the rider more like a repeated jerking or lurching than it would a "bouncing".

2) Something's wrong with your drivetrain. To troubleshoot, I'd try the simple stuff first, like changing the shaft oil.

[MotoJPizzle]

nico, good tips - will check that out

[Core]

As a person who spent 6 years installing and ballancing tires and who has performance tire expert certs from Michelin and BFGooodrich. There are some key points to rember when it comes to tire/wheel combinations and balancing.
1. The low spot (referred to in this thread as the "dot") on a quality tire will always be marked.
2. Wheels should also have the low spot marked with a sticker, but this is typically removed, especially on Factory wheels. It is a common misconception that the valve stem is always the low spot on the wheel. The low spot could be anywhere, more so if the wheel is cast.
3. Anyone properly trained on mounting and balancing wheels will know that if a tire/wheel combination is calling for a lot of weight, than the tire should be rotated at 90 degree intervals until the two actual low spots line up. If that doesn't work it can then be rotated at 45 degree intervals, but that is rare.

In my experience I have had to rotate the tire on the wheel 3-4 times to get an exceptable weight requirement.

Hope this info helps. Don't let the dealers you work with feed you crap. If their installers are properly trained, they should know.

[donny662]

Originally Posted by MotoJPizzle

Dude, I totally have the same thing - it only happens sometimes but its like a bouncy feeling and at speeds lower than 40 in 4th or 5th. it only happens when Im in a higher gear than needed for the speed Im at.

Is that what you are seeing?

You are probably just running the engine at very low RPMs. On my Marauder, when I get below 35-40mph in fifth gear, the vibrations are terrible. At that point, I think the engine is running at RPMs significantly lower than idle. If the bounciness reduces significantly when you down shift, I think you just had a case of poor gear selection and hypochondria. If you keep doing that, you will have an engine/drivetrain problem.

[nicocorea]

Originally Posted by Core

As a person who spent 6 years installing and ballancing tires and who has performance tire expert certs from Michelin and BFGooodrich. There are some key points to rember when it comes to tire/wheel combinations and balancing.
1. The low spot (referred to in this thread as the "dot") on a quality tire will always be marked.
2. Wheels should also have the low spot marked with a sticker, but this is typically removed, especially on Factory wheels. It is a common misconception that the valve stem is always the low spot on the wheel. The low spot could be anywhere, more so if the wheel is cast.
3. Anyone properly trained on mounting and balancing wheels will know that if a tire/wheel combination is calling for a lot of weight, than the tire should be rotated at 90 degree intervals until the two actual low spots line up. If that doesn't work it can then be rotated at 45 degree intervals, but that is rare.

In my experience I have had to rotate the tire on the wheel 3-4 times to get an exceptable weight requirement.

Hope this info helps. Don't let the dealers you work with feed you crap. If their installers are properly trained, they should know.

Now this is an excellent post! Thank you, Core. If you read my thread, you'll see that my dealer originally delivered the bike to me with a lot of weight oppoiste the stem/dot. But the tire tech at the shop that finally solved my problem did precicely what you described: He first mounted the new rear tire with the dot at the stem and saw that it was far out-of-balance. So he re-mounted the new tire with the dot opposite the stem, along with 2.5 ounces of weight--still a lot of weight, but less than half what it was originally. That was enough to fix my oscillation problem. But from now on, I'm going to have to find an (apparently rare) tire tech that actually knows what he's doing.

BTW: Is there anyway to tell where the "low spot" on the wheel is once the sticker is removed?

[Core]

BTW: Is there anyway to tell where the "low spot" on the wheel is once the sticker is removed?

Some wheel manufactures may stamp their wheels, but this is rare. Once the sticker is gone, it is purely trial and error unfortunately.

There is a way for you to find out for yourself approx. where the low spot is. You have to be able to spin the wheel without the tire on it and it must be able to spin freely preferably off the bike/car. When you spin the wheel on the shaft, the low spot of the wheel will almost always stop at the bottom when allowed to spin freely. Do this exercise three or four times and mark the point of the wheel that stops at the bottom and you should find your low spot.

Have fun,

[MotoJPizzle]

Originally Posted by donny662

You are probably just running the engine at very low RPMs. On my Marauder, when I get below 35-40mph in fifth gear, the vibrations are terrible. At that point, I think the engine is running at RPMs significantly lower than idle. If the bounciness reduces significantly when you down shift, I think you just had a case of poor gear selection and hypochondria. If you keep doing that, you will have an engine/drivetrain problem.

I think i got the flu from riding my bike too - I was just trying to save some gas.

[donny662]

Originally Posted by MotoJPizzle

I think i got the flu from riding my bike too - I was just trying to save some gas.

Did any birds fly in front of you? It might be bird flu. Make sure you quarantine yourself, or you are going to have a pandemic on your hands.

[omegajim]

Some wheel manufactures may stamp their wheels, but this is rare. Once the sticker is gone, it is purely trial and error unfortunately.

they quit doing this? dang, now I need to check the tires on my bike.

normally, they stamp the light spot on the tire with a stamp, an ink stamp that will wear off with much rain or water sprayed on it. Usually stamped in yellow.

[tolsten82]

Hey guys,

So I have the same problem. I just got a new set of tires and now when I let go of my steering wheel it starts to wobble badly. I used to be able to just drive down a straight rode and the bike was steady all the way.

Is this a bad balance job? It is the strongest between 40-55 MPH, so it seems like the same problem as "nicocorea". I am going back to the dealer tomorrow morning. They better fix this for free or I am going to be seriously pissed.

Thanks for such a comprehensive story, hopefully I won't have to go through the same process.

[nicocorea]

Your problem doesn't sound exactly like mine--my front end would bouce up and down at certain speeds as if the front wheel were slightly egg-shaped. It sounds like yours problem is a left-right sort of thing. I believe that's a classic symptom of an out-of-balance front wheel. Plus, the fact that it started happening right after getting new tires makes it almost certain that one or both of your wheels is out-of-balance.

Still, I'll bet the dealer says "one of our techs rode it and couldn't find anything wrong."

[womper]

mine wobbles back and forth at certain speeds...
it does it more when i'm loaded up...

it did it with the original tires and doing it with the set on it now, just more pronounced..

go about 65 and then put the bike in neutral and see if it still wobbles when you are coasting at that speed...
do the same when the bike is in gear.
if it does it both times, prolly the front wheel. if it only does it when engaged to the back wheel... i dunno, that's where i'm at.

[tolsten82]

Stopped by the Dealer this morning. They said there is nothing wrong with it. The bike does not wobble when running in neutral, only when in gear.

I was told the wobble is caused by the engine deceleration. I have a throttle boss and if I am slightly holding it down with my hands off the wheel there is no wobble. So I think they might be right. So the solution is to just keep my hands on the bars

[nicocorea]

Originally Posted by tolsten82

Stopped by the Dealer this morning. They said there is nothing wrong with it.

What a surprise.

Originally Posted by tolsten82

The bike does not wobble when running in neutral, only when in gear.

How did you manage to get the tranny in neutral at 55 mph???

[nicocorea]

Originally Posted by womper

go about 65 and then put the bike in neutral and see if it still wobbles when you are coasting at that speed...

Put the bike in neutral at 65 mph? Are you serious???

[tolsten82]

I just rolled down a hill in neutral. Definitely not at 55, but close to 30 with no wobble.

[womper]

Originally Posted by nicocorea

Put the bike in neutral at 65 mph? Are you serious???

umm... ya...
i did it... not gonna hurt the bike
you just have to be going like 80 when you start doing that

[07M50zAllDaWay]

Originally Posted by Windwalker7

Hmmm! I'd think that if the tire were out of round, it would be hopping at all speeds.



Are you sure that when the dealer replaced the tire that they really did replace it. I'm kinda wondering if they just didn't just clean up your original tire.


Seems odd that they just happened to have a tire to replace it that first time, but when you wanted to buy another tire, they were out of stock.

Maybe try another Suzuki dealer.

They went from an IRC to a Dunlop, thats some cleaning job.

[nicocorea]

Originally Posted by womper

umm... ya...
i did it... not gonna hurt the bike

I'm not so sure about that. To get to neutral you have to pass through 2nd gear--at 65 mph. I would never do such a thing to my tranny. Just imagine if you tapped the shifter just a bit too hard and acidentally dropped it into 1st at 65 mph! Mechanically, the result could be catastrophic. Saftey-wise, also.

[donny662]

Originally Posted by nicocorea

I'm not so sure about that. To get to neutral you have to pass through 2nd gear--at 65 mph. I would never do such a thing to my tranny. Just imagine if you tapped the shifter just a bit too hard and acidentally dropped it into 1st at 65 mph! Mechanically, the result could be catastrophic. Saftey-wise, also.

What damage does it do when you have the clutch pulled in? If there wasn't a neutral light, it would be pretty risky because you couldn't be sure it was in neutral before you let the clutch out, but that's a moot point with a working light.