front tire wobble

[AtlantaKat]

I have noticed that at random speeds, but mostly higher speeds that my front tired wobbles. I don't think it is a weighting problem, i think that one of my front brakes is constantly grabbing the rotor, could this cause my problem?

Its not like its constantly applied, its just like its a small grinding..just enough to cause a sound....

any suggestions on what else it could be?

[Matt]

Is your front tire cupped? That will do it bigtime, on a Kat.

There is an issue with the steering head bearings, but more than likely, it's a cupped front tire.

[Anonymous]

Is your front tire cupped? That will do it bigtime, on a Kat.

There is an issue with the steering head bearings, but more than likely, it's a cupped front tire.

I'll second this....is it a wobble or a hum?

[The CyberPoet]

What to know:

If the vibration occurs less than 4 times a second, it's almost always from the rear end (either misaligned rear tire, warped rear rotor, bent rear wheel rim or off-balance rear tire).

If the vibration occurs more than 4 times a second, it's almost always from the front end. The list of possibilities is long, and can include such issues as:
uneven tread wear (particularly on Macadams and Dunlops in my experience);
warped or dragging rotor;
sticking brake caliper piston;
uneven fork settings or uneven fork oil levels;
warped or bent rim;
badly worn steering head bearings;
bent fork tube;
etc.

The first step is to check your rotors for a high spot and your wheel for damages, then inspect your tires and decide whether they need to be replaced or rebalanced. Proceed from there.

Cheers
=-= The CyberPoet

[AtlantaKat]

ok well my tires were just replaced about 100 miles ago, so i imagine that those aren't it. I noticed there is a slighty hum, also at walking speeds i hear a griding. I do not notice any diviance from normal wear and tear on my rotors, but i could be wrong. I don't think my rear is misaligned. Come to think of it it happened after i put on my last pair of tires, so maybe it could be something to do with the brake calipers or shocks...i hate to take it in for a diagnosis because around here they charge an arm and a leg.

Its not that bad but when i drider at high speeds its when it starts to wobble. At low speeds it doesn't. When i say high speed im talking about 35mph+..maybe even slightly higher than that.

[Anonymous]

I'm assuming this is NOT the famous Kat wobble???
Mine would wobble slightly at decell......and around 35mph.
Steve(MD), thought he had fingered this one...he repleced the head bearings and claimed success....but, we're not talking about that, right??

[AtlantaKat]

Well I can't forsure tell you if it IS the kat wobble, because i didn't know that there was such a thing. I doubt it is though, because i used to be able to no hand from about 65 to 10 slowing at redlights and such, and there would be no wobble what so ever. It just recently happened....maybe a year ago..after i changedthe tires and brakes at a local used dealership. Then i had some engine work done at another dealership, but for the past couple months it had a flat and i never fixed it. Now its coming up to the cold months and i still want to ride, but i want to make sure this isn't going to affect me in anyway over time....

So basically im asking one of you to fly to Atlanta and take a look at it..k?...J/K...Guess ill take it to one of the local dealerships and see what they can make of it....just hate to spend that type of money on it...oh well gotta do what you gotta do heh?

[The CyberPoet]

Well I can't forsure tell you if it IS the kat wobble, because i didn't know that there was such a thing.

I've only heard tales of it, but never have found it to be inherent to Katana's in specific unless they were abused or not maintained sufficiently.

I doubt it is though, because i used to be able to no hand from about 65 to 10 slowing at redlights and such, and there would be no wobble what so ever. It just recently happened....maybe a year ago..after i changedthe tires and brakes at a local used dealership. Then i had some engine work done at another dealership, but for the past couple months it had a flat and i never fixed it. Now its coming up to the cold months and i still want to ride, but i want to make sure this isn't going to affect me in anyway over time...

Q: Was the flat in the rear? While it was seated those months, did you ever rotate the front tire to keep it from developing a flat-spot?

Meanwhile, to test some of the other possibilities, here's what you're going to do:

Get a card board box, and a pencil. Place the wheel all the way over to the steering lock on the left, with the bike on the center stand. Weigh down the back end, so the front is lifted off the ground, or support the triple trees from above using a harness (unless you have a front race stand -- either way: off the ground). Place the box next to the wheel, put the pencil on the box and against the rim. Rotate the wheel. The pencil will be pushed backwards if you find a spot that rises out from the rest of the rim (letting you see total run-out). Repeat with the rotor, then repeat again on the other side of the wheel & other rotor. This will let you know if either rotor or the rim has a bad warp. Let us know the results...

Cheers
=-= The CyberPoet

[Anonymous]

Abused or not maintained properly, hmmm
Well, I bought my Kat new, and actually after the year I had it, it only had 7k miles on....all the services performed, and I'm not into wheelies so.....Just threw it out there...BTW, it didn't happen all the time...

Anyway, I would back off this, as you said you didn't notice it until you serviced your wheels...Makes me want to point the fingers at what was done. Alignment, balance, faulty tire? Wheel bearings???

[DINGBAT]

I had the "wobble" but it was all tire. I put on a Metzler Z6 (thanks to reading posts on KP) and the problem vanished. My tire did not looked that cupped out but the wobble was so bad on decel, if you took your hands off of the bars it was scary.