lookatmy6

i have an 01 cbr f4i with about 12k miles on it. just recently i've noticed that the front end shakes slighty at around 50 mph. the higher i go above 50 mph the worse it shakes. it only shakes if i let go of the handlebars. the easy answer is just dont let go of the handle bars, but now i'm scared to ride the bike at all. somethings obviously wrong. i've checked all the bolts on the front end and everything is tight.

any opinions / other possible solutions? thanks in advance

Real Random

sound like a busted rim
Fullmetal any theories?

skr00zloose

either a rim out of balance, or a rim with a bend. it may not be the front though, you'd be surprised how many rear end problems can be noticed in the front end.

zx636skiv

Easiest thing to check is to make sure the rear rim is straight in the swingarm...if you've ever adjusted your chain, you will notice the marks on the side to line up when you adjust it. Make sure you are on the same marks on both sides.

Any wrecks on this bike that you are aware of?

djgrom

Come on guys, we all know the real problem is that he is actually using the front end. Look man, you ride a motorcycle, that means All wheelies all the time everywhere. Your front end should never actually touch the ground unless your bike is at rest. It is cool to ride around on one wheel anyways.

tundrafiend01

What is the status of your tires? If your front tire is in sad shape, whether its cupped or just plain worn down, this could be another cause of your front end shaking. Before I replaced the front tire on my EX500, it would always shake if I let go of the bars and this was due to a cupped, worn out, front tire.

I would also suggest checking your fork alignment to make sure they are square. The following is a how-to borrowed from EX-500.com that covers checking the rear wheel alignment and how to check fork alignment:

The String Thing
Motorcycle rear wheel alignment

This applies to chain driven bikes the have two sided swing arms
The most common cause of a lot of the shakes and wobbles that afflict single track vehicles is, they are not on a single track. This set of instruction will fix it.

Mount the bike upright on the center stand or a race stand or lacking those, a pair of cinder blocks and 2X4s.

Wrap a long string around the back tire as high up as it will go without fouling some other part of the bike. A piece of tape will hold it.

Run the string forward on both sides and tie them to a set of moveable objects.

Check to be sure the string is just touching the same part of the tire on all four points and not touching any other part of the motorcycle. Move the front stands so that the string just lightly touches the front edge of the rear tire and is not bent over it.

Now the strings show the path the rear tire is taking on its way to the point where the front tire was. I said that strange sentence to illustrate the point of what were doing here.

Now turn the handle bars to make the front tire parallel to the strings.

Now measure the space from the string to the front wheel rim on both sides. Both measurements should be the same w/in 1/16”

If they are you’re done.

If they are not: adjust the rear wheel chain adjusters to correct the error.

Re- set the strings and measure again. Repeat till OK.

Rocking the Forks

While the bike is still rigged for the horizontal work, do this.
Before we go into the vertical plane it’s important to be sure your front forks are parallel to each other. Forks are often not. This can be easily corrected.
Obtain a flat piece of metal or glass about 3” wide and long enough to span the forks.
Rock this piece across the bare part of the fork tubes just below the bottom triple clamp.
By rock I mean the plate should touch both tubes evenly from top to bottom. If it rocks like a chair with a short leg, that means your tubes are twisted.

To fix this loosen all the pinch bolts on the triple clamps the top center triple clamp nut and the front axel.

Now with you a knee holding the front wheel twist the bars till the plate doesn’t rock.

Then gradually tighten all the bolts while constantly checking the “rocker” till all is tight and the plate doesn’t rock.

Re check the center alignment of the front tire.

Real Random

damn u and your long post fiend!
lol

Chino

tire pressure check

djgrom

it is cause his front wheel is on the ground..

skr00zloose

might want to check the neck bearings too. had a gsxr600 come thru the shop today with that same problem, and his were loose.