vibration in front

[Deeder]

Okay, frustration is starting to get deeper! I have a intermittent vibration from the front. Had new tires put on in the beginning of the season and had them balanced again. No change. Any suggestions? How do I go about inspecting the front bearings?

[Dan Dubeau]

Re: vibration in front

Okay, frustration is starting to get deeper! I have a intermittent vibration from the front. Had new tires put on in the beginning of the season and had them balanced again. No change. Any suggestions? How do I go about inspecting the front bearings?

Wouldn't happen to be riding on 1-75 running through michigan would you?

I had the same problem on the way down to the gap rally. Just ask Jackal and woobie

[KatDan]

need a lot more info than that-bike, mileage, fork condition, only on certain roads?, type of vibration?

[The CyberPoet]

I need to know:

Year/model of the bike;
Last time the fork oil was replaced and whether there are any oil smears on the fork tubes;
if there is any notchiness in the steering if you rotate it all the way left-to-right and back at a standstill;
when the vibration occurs (specific RPM's or specific speeds, does it increase with speed, etc);
how often it oscillates (less or more than 4 times a second at speed & what speed);
Whether the behavior changes when you add some brake pressure (better, worse, front brake, rear brake);
brand of tires and mileage on them (close-up photo of front tire tread helpful); AND
whether you have dropped the bike at all (or whether the previous owner may have -- check the barend weights for scratches or scuffs).

Cheers,
=-= The CyberPoet

[Deeder]

Cornering is nice and smooth. Sorry it's an 02 Kat 600. Only on straight away around 90-120kmh on decel. Noticed huge wheel wobble when letting steer on it's own. Yes with hands of wheel. I have 23000kms on the bike and have never changed fork oil. Have a hard time believing fork oil would cause a vibration like this. I think the front tire is crrrrr...not so good. It actually feels like an out of balance feeling, even though tires were just rebalanced. But if it was wouldn't you think it would happen all the time? The brand of tires are Shinkos. I have 160 60s on the rear and stock size on the front. My forks are nice and dry, no signs of leakage. I guess I shouldn't of cheaped out on tires!!!!

[The CyberPoet]

Based on your statements, it should be narrowed down to the following:

Most Probable: uneven tire tread wear (where one block of tire starts higher than the trailing edge of the block before it or visa-versa), aka cupped or scalloped.

Other possibilities:
warped rotor or wheel
brake caliper piston not retracting as it should
bad head stock bearings
one handlebar bent more than the other (suspect if the bike was ever in a spill or fall, including a parking lot fall).

Cheers
=-= The CyberPoet

[xbubbax]

i love marshmallows

[Deeder]

I think it is tire fault. Bike has never been laid down in any way. rims never damaged. How do I inspect head stock bearings without complete disassemble.
Marshmellows seem sticky!

[Spedee]

I think it is tire fault. Bike has never been laid down in any way. rims never damaged. How do I inspect head stock bearings without complete disassemble.
Marshmellows seem sticky!

You must support the bike from underneath at the exposed frame areas so that the steering is free from weight.
Then you can slowly turn the steering from side to side to feel for rough spots. Then pull on the forks from the straight ahead position to feel for any movemement front to back. All is well if she is tight and smooth.

[kiba]

You must support the bike from underneath at the exposed frame areas so that the steering is free from weight.

Easy way: put it on the center stand and have someone hold the rear down.

/kiba

[Deeder]

Thanks. Will try in the morning, I think it will be okay though.

[md86]

I'm betting the tire's cupped .

[FatBlue]

I had a similar thing happen with a cupped Michelin Macadam. Changed for Metzler Z6s and couldn't be happier!

[The CyberPoet]

I had a similar thing happen with a cupped Michelin Macadam. Changed for Metzler Z6s and couldn't be happier!

Remember to keep the tire pressures higher on the Z6's than the Suzuki specs (Z6's should run around 35 - 36 psi front and 38 - 39 psi rear for a 200 lb rider). If you get any cupping on the Z6's, it means you ran them too low on pressure. Malloc was having issues, but when I checked his tires, he admitted that he checked his pressures infrequently and they were at 30 psi...

Cheers
=-= The CyberPoet