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post #11 of 41 Old 11-22-2015, 09:57 AM
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Quote:
Originally Posted by MotoMike View Post
I'll say it again... it's a tire/wheel balance issue.
Can be.
Can be a damaged rim or tire, or the balance weight is gone.
You are right.

But:
"Front tire is pretty new at less than 3k miles on it. "
"I just noticed it today when riding"

The question is, what has changed, since the tire got on the rim, < 3k miles ago
Is the balance weight gone?
Is it more with cold or hot tires, or always?
Is a fork spring involved?
Some bearing?

But what has changed, for sure, is the thickness of the rubber on the carcass.
Even the IRC's are losing some mm on 3k miles.
That's why I pointed on the shimmy.
Less rubber on the carcass, less damping. In case, it comes from there.
It's still not a radial. Can happen.
Also how old is the tire? How much UV did it get
As older, as harder. Less damping

There are several options to the tire wheel balance thing.
And I assume, usually, that a rider will look for tire (pressure, damage), rim-damage or
a gone balance weight, before he starts to ask others.

Maybe I expect to much?

Last edited by CBR-250-R; 11-22-2015 at 10:04 AM.
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post #12 of 41 Old 11-22-2015, 10:29 AM Thread Starter
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Quote:
Originally Posted by CBR-250-R View Post
Can be.
Can be a damaged rim or tire, or the balance weight is gone.
You are right.

But:
"Front tire is pretty new at less than 3k miles on it. "
"I just noticed it today when riding"

The question is, what has changed, since the tire got on the rim, < 3k miles ago
Is the balance weight gone?
Is it more with cold or hot tires, or always?
Is a fork spring involved?
Some bearing?

But what has changed, for sure, is the thickness of the rubber on the carcass.
Even the IRC's are losing some mm on 3k miles.
That's why I pointed on the shimmy.
Less rubber on the carcass, less damping. In case, it comes from there.
It's still not a radial. Can happen.
Also how old is the tire? How much UV did it get
As older, as harder. Less damping

There are several options to the tire wheel balance thing.
And I assume, usually, that a rider will look for tire (pressure, damage), rim-damage or
a gone balance weight, before he starts to ask others.

Maybe I expect to much?
No damage to the rim. No dry rot of what I can see, no abnormal wear on tire.
I see no tire weights, however no markings of where they should have been. So I'm siding with Mike on the tire being out of balance and I just noticed now. I'll check the steering head bearings next time a friend comes over and pull the wheel or take it to a shop next time I have the day off and the weather is nice.

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post #13 of 41 Old 11-22-2015, 02:57 PM
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I'm still fighting slightly with this issue. Happened after swapping my front tire at 21k miles.

Two matching Kenda's, both are balanced (beads and weights multiple times), alignment checked, bearings good, forks good, steering bearings good. Chased my tail for several thousand miles. Still haven't found the culprit, but it's isolated to the front tire itself. I've eventually learned to live with it as it is more of an annoyance if anything, and only noticeable if I'm looking for it. My guess is I probably got a defective front, and I just haven't bothered to have it removed and shipped back. The downtime in gas and parking woes would cost me more than just breaking down and buying another new tire.

Tis better to be thought a fool and remain silent, than to open one's mouth and remove all doubt.
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post #14 of 41 Old 11-22-2015, 05:28 PM
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I put up with the same problem on my MZ for years. However, when I replaced the front tyre, I made a point of getting the balance right. The problem completely disappeared and the wet weather road-holding was improved too.


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post #15 of 41 Old 11-22-2015, 08:08 PM
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easy check for basic balance is spin and mark
method.. on the motorcycle [front wheel free
to spin, on blocks etc] or on a wheel stand
or purpose made balance holder..

spin or turn wheel to observe its stopping point
and mark the opposite side of the tyre [ chalk, tape
or spit on finger], spin again etc, or move mark to
horizontal then observe it stays there or moves..
if it stays, its basically balanced,, if it moves
again [gravity has access to uneven weight]
repeat first step with another small weight..
back to horizontal, release, observe etc..

there are plenty of youtube demos of wheel changing
and balancing or just balancing, on or off the bike..

if tires were changed by strangers you dont know
how thorough they were..
my 250 tyre change at dealer had its rear axle bolt
way,, over tightened, needing to get a breaker bar
to move it..
if you didnt do it yourself
check your front axle, which might
not have been tightened correctly..
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post #16 of 41 Old 11-23-2015, 12:59 AM
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A perfect balanced wheel can still get you a shimmy!

Wheels get balanced without load!
That's why it's good to know, is it happening on acceleration (little load), constant speed (normal load) and slowing down (full load).
Or only on one or two of these conditions.

But in case there is no balance weight on the rim, also no mark of one, ...
With a mark, I would say :lost
Without : Why OP start feeling it after so many miles, but not before?

Edit:

Oh, I know a reason:

Tire moved on the rim?

Don't know, if IRC delivers prebalanced tires, but check opposite of the valve.
(btw, is it a H-spec IRC?)
In case, the IRC was prebalanced, around there should be a colour mark on the flank.
Heaviest point of the tire opposit heaviest point of the rim

Last edited by CBR-250-R; 11-23-2015 at 01:05 AM.
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post #17 of 41 Old 12-06-2015, 03:07 PM Thread Starter
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Got to ride it again only noticeable on decel at ~50 mph. As for pre-balanced tires I doubt it because the rear has some of the tire weights plus I remember seeing the less ugly ones on original set of tires.
It's also S-spec.

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post #18 of 41 Old 12-06-2015, 06:22 PM
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Do the string thing your rear wheel is pointing the wrong way.

Learn Simple Motorcycle Wheel Alignment | Motorcyclist Online
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post #19 of 41 Old 12-06-2015, 06:42 PM
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if 'only noticeable at decel over 50mph' it would seem
to be or include natural dynamic force changes
amplified by any 'weak point' [out of balance etc]..

one minor thing tho worth trying is riding [very slowly]
at reduced tyre pressure, which could, work away at
any uneven stiffness in the tyre carcass..
while checking pressure etc, wouldnt hurt to deflate
completely then reflate a few times, observing..

my father taught me to belt the tyre with a rubber mallet..
ie, during installation, including while inflating it..
dont know if that did much actual good,
but my self changed tyres all worked well..

heres a link to a happy motorcyclist balancing
[with banjo solo]
https://www.youtube.com/watch?v=T2AuivYzaBs
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post #20 of 41 Old 12-06-2015, 07:11 PM
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Quote:
Originally Posted by isaacm12 View Post
....
It's also S-spec.
So you got them @ Honda, right?

You probably right, not pre-balanced.
I haven't seen some color dots on IRC flanks, yet.
But still worth a look.

You could try shisoshin's last hint.
Not sure, it will work, in case the carcass has some unusual overlapings.
Which you feel more with less rubber tread on them, and 'aging' (harder) tires.
But playing around with the tire pressure may let find you some pressure area, it is still safe, but not that much shaling. Still ~15k km of life in the front tire.

Question: How old are the tires?
Made this year, or ....?

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