Suspension noise question

After rebuilding the front forks on my 07 St1300, sonic springs, 125mm spacers & oil depth level, 7.5 wt. oil, new bushings, sliders and seals, etc.
I am still getting a loud thunk when I push the forks down, and when I pull the forks back up.
The steering head bearings & races are new and adjusted to specs.
What else inside the fork would make this loud noise?
Would having my preload spacer too short, and not enough preload on it, cause this type of noise?
Seeking comments & suggestions.
Thanks
Igofar

Well, I'll bite.

Second part first...not enough preload shouldn't be a problem. Previously you posted the forks had about 36-38mm or 1.5" rider sag IIRC. If you didn't have sufficient preload this figure would be much higher. A stock 1300 will have at least 45 to 50+ mm of rider sag under 220 lbs of rider so your spring/spacer/washer stack must be longer or stiffer in spring rate in order to reduce sag to 36-38 mm or 1.5". Not enough preload just means the bike settles (sags) further down the suspension travel before the weight of bike is supported by the spring.

Thoughts in no particular order.... please don't blast me because they might be considered dumb questions on my part......Is the washer between the top of the spring and the spacer in place and the correct diameter of approximately 1.5 inches? If it is not the spring and spacer can get out of column and tap against the inside of the fork tube when compressed......... Is the spacer also about 1.5" in OD and extremely close fitting inside the ID of the fork leg? Are you holding the front brake whilst compressing the forks or is the front wheel held in a chock or against a wall? Play in the SMC pushrod or caliper pivot can make knocking or clunking sounds. Perhaps trying the fork compressions with no front brake applied can rule out a source in the linked brake hardware.

Loose caliper, rotor, fender, brake hose bracket . . . I've had a clunking wheel bearing . . . ???

dduelin said:

Well, I'll bite.

Second part first...not enough preload shouldn't be a problem. Previously you posted the forks had about 36-38mm or 1.5" rider sag IIRC. If you didn't have sufficient preload this figure would be much higher. A stock 1300 will have at least 45 to 50+ mm of rider sag under 220 lbs of rider so your spring/spacer/washer stack must be longer or stiffer in spring rate in order to reduce sag to 36-38 mm or 1.5". Not enough preload just means the bike settles (sags) further down the suspension travel before the weight of bike is supported by the spring.

Thoughts in no particular order.... please don't blast me because they might be considered dumb questions on my part......Is the washer between the top of the spring and the spacer in place and the correct diameter of approximately 1.5 inches? If it is not the spring and spacer can get out of column and tap against the inside of the fork tube when compressed......... Is the spacer also about 1.5" in OD and extremely close fitting inside the ID of the fork leg? Are you holding the front brake whilst compressing the forks or is the front wheel held in a chock or against a wall? Play in the SMC pushrod or caliper pivot can make knocking or clunking sounds. Perhaps trying the fork compressions with no front brake applied can rule out a source in the linked brake hardware.

Click to expand...

First...thanks for the comments and suggestions...
The spring plate (washer) is oem honda and is beteen the spring and spacer.
I kept the oem spacer and had it cut down to 125mm so the stack should not be binding.
I have ordered a new needle bearing because I can pull the smc bracket sideways just enough to make a loud clicking noise.
The idea about a chalk or using the wall is a good idea I will try that tonight.
I fear my races are not seated completely? The race tool I used (threaded rod) almost started to stick in the steering head. Will pull forks if I need to to tap it in some more with the old race and a socket to listen for sounds.
Could something in my dampening rod have failed?
The bike now tracks true and smooth, but feels like you hit a small rock with the front wheel everytime I turn left.
Thanks for the suggestions and help.
Larry

Igofar said:

First...thanks for the comments and suggestions...
The spring plate (washer) is oem honda and is beteen the spring and spacer.
I kept the oem spacer and had it cut down to 125mm so the stack should not be binding.
I have ordered a new needle bearing because I can pull the smc bracket sideways just enough to make a loud clicking noise.
The idea about a chalk or using the wall is a good idea I will try that tonight.
I fear my races are not seated completely? The race tool I used (threaded rod) almost started to stick in the steering head. Will pull forks if I need to to tap it in some more with the old race and a socket to listen for sounds.
Could something in my dampening rod have failed?
The bike now tracks true and smooth, but feels like you hit a small rock with the front wheel everytime I turn left.
Thanks for the suggestions and help.
Larry

Click to expand...

I would think that any play in the head stock/steering bearings would be readily felt in the old fashioned way of jacking the front wheel clear of the ground then grasping the lower fork legs and attempting to move fore and aft as well as side to side.

Damping cartridge....are you sure the locking thingy ( the hex head screw inserted into the bottom of the fork leg above the axle opening ) screwed into the cartridge and tightened up? I'm sure it must have otherwise fork oil would be leaking out. Can't be that.

I don't know Larry. Mine has made a clunk for a very long time and it's the SMC pushrod where it enters the bore. I tune it out as it apparently doesn't affect the brake operation.

Being Deaf, I'm not so much worried about the noise it makes, but rather the way the bike now handles.
It almost feels like you've hit a small rock in the road, whenever I turn left...hard to describe, but kind of a jerk in the front end.
Steering head bearings loose or not seated completely? I don't know.
I did try your idea of chalking the front wheel tonight, interesting results. When I didn't touch the brake, and was just pushing against the wedge, I couldn't feel or hear the familiar clicking, so it may be the needle bearing in the left caliper after all. Seems strange that it would have that much affect that I can feel it bumping in the grips, and jerking in the turns.
However, I noticed something else on the way home tonight...when I rolled up to a stop sign and applied either brake, and didn't let go of them after stopping, I could push down on the forks and not hear or feel anything...until I let go...then the clanking returned ? Could it be forcing pressure on the smc bracket and holding it in place with the linked system? then once released, feel all the slop and play again?
Or could it be the steering head races or bearings in the same situation?
I greatly appreciate all the comments and suggestions, as I have run out of ideas.
Igofar

Your description is exactly what it feels like when turning. It sounds like you ride my bike! Loved the million. Comment too.
I have replaced the front bearings three times already, as well as the flange bearings. The only ones I have not replaced are the rear wheel as they felt smooth and quiet with no play in them at all.
Think at this point I will start from scratch and pull the forks and stem again and make sure the races are seated BFH!
Do you think going back to 10st oil would help also? I am going to remove the springs and check for binding in the lower legs too.
May even try some longer spacers because when I sit on it the bike still sags a little bit. My math may not be as good as my suspension guy, but I am reading 42mm at both ends ?

Igofar said:

Snipped.....

Do you think going back to 10st oil would help also? I am going to remove the springs and check for binding in the lower legs too.
May even try some longer spacers because when I sit on it the bike still sags a little bit. My math may not be as good as my suspension guy, but I am reading 42mm at both ends ?

Click to expand...

Speaking for myself I would not go back to 10wt fork oil if Sonic recommends something else. I don't believe the fork oil has anything to do with the clunk, steering, or noise problem you describe and will further muddy the waters...so many variables.... I would try to work on one thing at a time. Also, fork oil "weights" are all over the map and can't be readily compared like engine oils so one brand of 10wt might actually act like another brands 5wt and further confuse the matter. If you stay within brand the odds are better that a 10wt will be "thicker" as expected compared to a 7.5 or 5wt in same brand. The first fork oil change I did I used Belray 10wt instead of Honda OEM SS-8 10wt and the results were disturbing. The front end chattered across bumps and ran wide on corner exits. I went back to OEM and handling returned to normal. Not bashing Belray at all just noting that the two brands of 10wt oil were very different in viscosity. There are charts that list fork oil by "lighter" to "heavier":

http://www.peterverdone.com/wiki/index.php?title=Suspension_Fluid

The rattle or clunk in my front end goes away under braking. I can make a similar noise by moving the left front caliper forward and back and engaging the SMC. I replaced the needle bearing at some point not long ago and it had no effect on the rattle. I'm 99% sure it's the SMC pushrod where it goes thru the steel washer under the boot as there is no lateral or torsional play in the caliper. The noise is there going over a bump or series of bumps but not there if the brake is applied.

This is an easy one person method for checking the sag number the suspension guy gave you - put a zip tie around one fork tube and slide it down against the dust seal. Dress up in normal riding gear and get on the bike, easy does it, left it up off the kick stand without pushing down on the forks. Try and balance the bike upright just barely tapping or touching tippie toe to do it. Easy does it, we don't want to depress the forks anymore than weight of bike and rider. Gently let the bike down on the kickstand and get off the bike. Jack up the bike so there is daylight under the front wheel. Now measure the distance the zip tie is from the dust seal. This is your rider sag. This figure can change from stiction but for a ball park figure it works well enough for comparison to what the guy told you.

Larry, I wish I knew more and could be of some help. Sounds like some of the other posters are hitting closer to the problem than I can... but watching this thread and learning.

dduelin said:

Jack up the bike so there is daylight under the front wheel. Now measure the distance the zip tie is from the dust seal.

Click to expand...

Okay... confused on this part.
When doing a two person measurement method you don't jack it up... do you?

T_C said:

Okay... confused on this part.
When doing a two person measurement method you don't jack it up... do you?

Click to expand...

At some point you have to fully extend the forks see how far the bike settles on the suspension under weight of bike and rider. You can do it at the beginning and place the zip tie against the dust seal with the forks fully unloaded but I've found it hard to get the bike off the centerstand gently enough not compress the forks past the at - rest position.

You can also tape a batten to a fork leg and get the second person to measure sag against the bottom edge of the lower fork clamp but you still have to jack up the bike to fully extend the forks to get the datum point.

Bummer...I used belray 7.5 and I am getting chatter, and wide steering in turns too.
I will measure my rider sag again tonight and report my results.
Thinking outside the box for a moment...I have replaced 3 sets of steering head bearings for other bikes in the last month or so, but all of them were after 07 models. I used the SM specs for "AFTER 07" And torqued them to iirc 23ft lbs and have not had a single complaint. What are your thoughts in ignoring the SM 07 specs and trying the earlier and later than 07 specs.
From what I can see all bearings, races, and parts are the same.
Wondering if mother honda figured out that 11ft lbs was not enough and raised the torque.
Your thoughts?

Whenever I pull a triple tree I use the torque on the nut as a starting point and fish scale as the final determining measurement.

As far as a clunk goes, I would check and grease the slide pins on the front brake calipers. My pins were very dry and clunked after rebuilding my front end. Greasing the pins fixed this.

Thanks for the comments...and sending them this time LOL
I think I may have made some progress today. I removed the bars and adjusted the steering bearings no less than 5 times today. I adjusted to the 07 spec, the after 07 spec, by feel, and even loosened the nut enough to feel the play in the forks, then adjusted it 1/8 turn at a time until the play was gone. Still loud cluck could be felt and heard in the bars. I rode the bike over to Justytroll's house and let him listen to it, and compared it to his 07 model. His didn't make as much noise. Back to the garage....I lifted the bike, and pulled the stem nut off, dropping the forks out a little, checked everything, bearings and races still packed with pretty blue polyuria high temp grease etc. Asked my neighbor to assist me in lifting the forks up into place while I started the nut. We bumped it a couple times, then he said it felt like it slipped up into the headstock "better"? I took a 16 inch snap on 1/2 drive ratchet and tightened the bearings to almost 40 pounds, when I did this, We heard what sounded like the race seat completely. I backed off the nut and when through the entire procedure again for the 07 spec instructions. 18 lbs then back off, then up to 11lbs, then when I did the 45 degree further turn...guess what, it ended right back at 18 lbs again?
Tried the trigger scale, and it starts moving around 3.5 pounds. There is a slight bit of drag, but the bike rolls and steer ok now, and MOST of the noise and cluck has been greatly reduced. I think the only think left I'm hearing how is the SMC which as everyone knows is somewhat normal.
I did find one other thing that I want to explore a little more with the front forks. While the bike was up in the air, I pulled the fork caps and removed the springs & spacers so I could slide each fork leg up one at a time to check for bent tubes, binding, or sticking etc. That all turned out normal, the damper rods work well and smoothly in each direction, it was then that I noticed that the spacer(s) OEM Honda metal ones, were too short! IIRC the stock spacer & spring set up would leave the spacer about 1/8 of an inch sticking out of the fork tube. The 125mm spacer that Rich at sonic told me to use, (1.2 spring/OEM washer/OEM spacer cut down to 125mm) was too short! It is almost 7mm down inside the tube! I think this may be what I am feeling and hearing. I'm going to cut some 130 & 140mm spacers tomorrow out of PVC and see if that makes my problem go away.
Wish me luck.
Igofar

When you install the caps do you have to push agaisnt this spacer to get the caps threaded into the tube? You should have to compress the springs slightly when installing the caps. Your sag numbers wont even be close if you're not, and this would cause some clunking. If your forks are fully extended and you are compressing the spring as you install the cap, then the height of the spacer will only affect your sag and not cause any clunking as there is no way for the spacer to move.

Finally almost finished on other folks bikes so I can continue trying to figure out what is wrong with mine!
The noise has to be IN or connected to the forks.
Removed the smc completely and the noise still there.
Removed both calipers and greased sliding pins, have 130mm spacers In Forks..... when I push down it almost feels like it bottoms out...then when I pull it back up it seems to jump up about two inches...again making the noise.
New smc, sonic springs, complete for rebuild with bushings and sliders etc.
It has to be either races not seated completely even though I do not have any play when pulling on forks...stanction tube bent....too thin oil....or damaged damping rods?
May rip everything apart and start over from scratch.

Back when I did AJAugust's '04 we had a similar noise, it was the spring sliding on the washer and contacting the tube where the washer holds the bottom of the spring. I machined a nylon bushing that fit the OD of the rod and the ID of the spring to hold it better on center, that just sat inside the spring at the bottom. That took care of the noise, but I don't recall having this issue on the other ST's where we outfitted Sonic 1.2 springs.
Check how the bottom of the spring seats and if it is able to shuffle around and touch the tube.

Curious. How many miles on this bike that you put new goose neck bearings in?
thanks

Only have 65k on the bearings. The top bearings and races were in good condition, the bottom race was starting to show signs of wear, probably from too many wheelies
Just replaced them because I was in there and wanted everything to be OCD.....I mean new

I may have discovered the problem today. I pulled the front end apart, checked the races to make sure they were seated completely, then pulled the fork and ran the tubes in V-blocks, they were straight, when checked all the internal bushings, they were all brand new, etc. I then pulled the damper rods out and as I was flushing one out in ATF fluid, I noticed it was nice and smooth in both directions with no issues. The left one however, was not moving fluid smoothly, but more of a jerky motion on the rebound direction when it did grab fluid, which was only sometime etc. . I checked the right damper again, smooth in both directions, left leg, binding, and spitting fluid out with a jerky motion! This may explain why I was feeling it in the left grip, and with U-turn's to the left, and why the front tire felt as if it had low tire pressure. I believe I blew out my damper valve on the left side.
I ordered new damper unit(s), oil locks, o-rings and some other misc. parts. We'll see what happens next week when I put it all back together again.
The last decision I need to make is, 7wt oil or back to the factory 10wt oil again?
Igofar