Hey guys, Need your help w/ Front End "Clunk"
 

My Super Hawk has developed a distinct & audible "clunk" sound & feel when coming to a moderately hard stop. Started since I put tires on a couple weeks ago.
It occurs right before I stop. I can feel & hear it as the fork reaches the end of its compression stroke & then again immediately as it rebounds back. I can also reproduce it by sitting on the bike, applying the front brake & pushing down on the bars really hard.
Rotors & pads look fine. I cleaned the pistons in the calipers, but not sure if I pushed them out far enough to do any good (I'm no expert mechanic, y'know!)
Any help sorting this appreciated.
Thx,
Steve

Re: Hey guys, Need your help w/ Front End "Clunk"
 

Sounds like loose head bearings.

Or (following the rule of "check the last thing you fixed, first" a loose caliper.

Sometimes you notice something that was there after you do a fix, so the headbearings are a good call too.

Re: Hey guys, Need your help w/ Front End "Clunk"
 

check your recent instalation job then, the head bearings.

Also it could be that the axle was not tightened properly, or a collar may be missing on either side of the axle.

I'm inclined to agree with the headbearings theory. The easy way to check them is to lift the bike up on the sidestand so that you have just the rear wheel on the ground. Then, using just a single finger, rotate the bars back and forth. If you feel a notch or stickiness in the middle postion, that's almost definitely headbearings. Easy enough to replace by yourself. Order a set of bearings, and in the meantime just tighten up the existing set a fraction to remove the clunk a bit (without overtightening, of course).

Ok guys, eliminated all of the above. I'm thinking now maybe it's the fork internals. Anybody ever had a problem here?

Re: Hey guys, Need your help w/ Front End "Clunk"
 

Have you tried supporting your bike somehow so the front end is in the air, grabbing hold of it and trying to repeat the problem?

Re: Hey guys, Need your help w/ Front End "Clunk"
 

There is a washer stack in the compression damping circuit of the VTR front end you might be hearing them clunking. Mine makes the same sound be fore and after I changed over to Race Tech internals. Hope this helps. I hope that's all that I'm hearing. Keep us posted.

Re: Hey guys, Need your help w/ Front End "Clunk"
 

Maybe this is worth a try...
Try loosening one fork tube in the triple clamp so it is free to slide up and down. (Static in the garage of course!)
Then the other will be the one going through the compression / rebound cycle.
Try both sides this way and see if you can isolate it to one fork tube.

Has anyone found the solution??

oh...and i had frontend springs done by hyperpro,..afterwards no change. Checked the headbearings while they where doing the springs. Could not feel any free play.

Could it be the brakepads?

ps: New here, no time to make ha hi-topic...so hi! Firestorm kicks ass!!

Kick!

Next measure your static preload. If its greater than about 30 mm and can't be adjusted, you need different springs. The problem makes the symptom you describe. Did it happen when you were testing the stopping traction on your new tires?

Here's the problem. None of the shit people are suggesting (me included I suppose) was changed by your tire install. It's either axle or calipers or perhaps a stripped lower fork cap nut. Then look to headbearings and fork seals. Then suspension related stuff like springing and fork oil.

I like to check the bearings with the wheel off. The test given above will tell if they are worn out, but it won't tell if they are simply too loose. They should be tight enough not to wobble but loose enough to turn easily.

But the problem didn't really start by a change in fork internals. I don't see any reason to be disassembling your forks just yet.

Static preload is perfect now,. thats the reason i fitted the springs.

Strange thing is, i can generate the clunking noise even by just braking moderately.

Oh and i'm not the topic starter ;-)
Did have new tires installed. But the problem was there before and its still there now.

Did you guys use the self-centering washers? I'm referring to the ones with the slots in them - they look like "C"s. That helps center the spring in the fork tube. This could be a source of noise .

Cant say what washer they used.

For now i want to rule that out because hyperpro is pretty experienced with springs/shocks.

Tonight im going to detach one of the calipers, place some wood between the pistons and brake with one caliper. Hope to find out something usefull.

Pushing the frontwheel against the wall does not generate (at least not convinceing) the same click so 'm really thinking brakes. although off course there is a difference between braking and pushing the front against the wall.

Shitty problem this is.

my money says steering head bearings...

sit on the bike, and place your left thumb on the joint between the upper fork clamps and the frame (where the upper steering head bearing is), now roll the bike forward and grab/release/grab/release the brake quickly... if you can make it do the audible clunk, you'll feel it in the steering head as it moves in relation to the frame... adjust or replace as you see fit... over 15k miles i'd advise a replacement (tapered roller if possible)

I think they are just loose.

haha..! ;-)

Ok, wel ive heard about tightening them up in a quick in easy way with a screwdriver and a hammer.

Under the uper yoke i can see 2 (gold?) rings above each other. Should i just losen the upper one then tighten the lower one , an then tighten the upper again.

(cant seem to find the page i read this....)

@johnny Rocket: Cant say that i feel any play, i can feel the klak in trough the whole fork. Doenst matter where i put my hand (while someone else is rocking the bike).

If you don't have a c-spanner then the screwdriver method will probably do it, if a bit crudely. you don't really need to loosen the upper ring first, it will loosen up when you tighten the lower nut. You probably won't have to tighten it too much, fractions of a turn make a big difference with head bearings. By doing it without removing the top triple you'll probably wreck the lock washer between the rings, but it's not a big deal if you get the top ring nice and snug. I hope that made sense.You could do the job in the time it takes you to read this.

Make sure you don't overtighten them Griffin. Get the front end off the ground while you re doing this, in order to get the adjustment just right.