FRONT END VIBRATION...part III
- Thread starter BUSA_CHeMiST
- Start date
<div class="iF-Passage"><div class="QUOTEHEAD">Quote:[/Quote]<div class="QUOTE clearfix"><span class="quoteBegin"> </span>
Just a shot in the dark here - I noticed in your previous post that you put 75W oil in the damper. That seems pretty thick. Could this be too high of a viscosity and over restricting the handle bars?[/quote]
Most people here run a heavier weight oil in the damper, just gives more steering stability. I've seen guys here running as high as 90w and having no problems.
<div class="iF-Passage"><div class="QUOTEHEAD">Quote:[/Quote]<div class="QUOTE clearfix"><span class="quoteBegin"> </span>
BUSA-CHeMIST I just checked runout on my wheel and rotors left rotor was.007" right was .009" runout /wheel has about .008" runout.Then Itook notice of my front tire which is a Dunlop Qualifyer it has a serrated type pattern on it if I run my hand with tread I feel it is kinda bumpy.Put my stock tire and rim and stock rotors back on this evening,but it started to storm out so I'll test ride tommorrow.Pics of tire with only about 2k on it,RED arrow shows low area Blue shows raised area kinda serrated.VERY obvious when you run your hand across it. [/quote]
In the beginning we thought it was gonna be a tire, since the vibration started with the Qualifier. So we swapped over to a race slick, still did it. Swapped that over to my current set, Bridgestone 002's racing tires and it still does it. I have not had it on a true digital balancer yet, just the stand balancer (the one that you level, spin the wheel, wait for it to stop, add weight accordingly. Thats how my buddies shop balances all their wheels and they don't seem to have a problem, but i will found out this morning just how bad out of balance it is.
Plus, im pulling the rear off and gonna check...
-Rear wheel balance
-Cush rubbers
-Sprocket (loose?)
-HUB
-Rear bearings (even though we checked the play in the wheel at the track and the bearings seemed fine)
Just a shot in the dark here - I noticed in your previous post that you put 75W oil in the damper. That seems pretty thick. Could this be too high of a viscosity and over restricting the handle bars?[/quote]
Most people here run a heavier weight oil in the damper, just gives more steering stability. I've seen guys here running as high as 90w and having no problems.
<div class="iF-Passage"><div class="QUOTEHEAD">Quote:[/Quote]<div class="QUOTE clearfix"><span class="quoteBegin"> </span>
BUSA-CHeMIST I just checked runout on my wheel and rotors left rotor was.007" right was .009" runout /wheel has about .008" runout.Then Itook notice of my front tire which is a Dunlop Qualifyer it has a serrated type pattern on it if I run my hand with tread I feel it is kinda bumpy.Put my stock tire and rim and stock rotors back on this evening,but it started to storm out so I'll test ride tommorrow.Pics of tire with only about 2k on it,RED arrow shows low area Blue shows raised area kinda serrated.VERY obvious when you run your hand across it. [/quote]
In the beginning we thought it was gonna be a tire, since the vibration started with the Qualifier. So we swapped over to a race slick, still did it. Swapped that over to my current set, Bridgestone 002's racing tires and it still does it. I have not had it on a true digital balancer yet, just the stand balancer (the one that you level, spin the wheel, wait for it to stop, add weight accordingly. Thats how my buddies shop balances all their wheels and they don't seem to have a problem, but i will found out this morning just how bad out of balance it is.
Plus, im pulling the rear off and gonna check...
-Rear wheel balance
-Cush rubbers
-Sprocket (loose?)
-HUB
-Rear bearings (even though we checked the play in the wheel at the track and the bearings seemed fine)
TXBusa05LE
Registered
I had the same shake ~40mph. I would take my hands off the bars and watch them go nuts.
Busa has ~18k miles on it w/ original pads and rotors.
Added new tires, front & rear, properly balanced and added 30w to the damper.
Rides smooth as silk"¦
Busa has ~18k miles on it w/ original pads and rotors.
Added new tires, front & rear, properly balanced and added 30w to the damper.
Rides smooth as silk"¦
Yeah, im thinkin bout going back down to a 40w or so oil in the damper, see what that'll do.
Leavin in a little bit to take wheels up to be properly balanced and we can go from there...
SO, checkin this stuff out today
-Rear wheel balance -- <span style='color:RED'>Will be checking today...</span>
-Cush rubbers -- <span style='color:Green'>Look fine, HUB kinda wants to fall out on its own, but not
terribly bad</span>
-Sprocket (loose?) -- <span style='color:GREEN'>Rear Sprocket is fine</span>
-HUB -- <span style='color:GREEN'>HUB looks and feels fine, no problems</span>
-Rear bearings -- <span style='color:GREEN'>Pulling on the wheel and upon visual inspection, the bearings all look good, greased up and evereything.</span>
Will keep everyone posted on my findings with wheel balance issues as soon as I get back from dealer today and ride it around.
-Rear wheel balance -- <span style='color:RED'>Will be checking today...</span>
-Cush rubbers -- <span style='color:Green'>Look fine, HUB kinda wants to fall out on its own, but not
terribly bad</span>
-Sprocket (loose?) -- <span style='color:GREEN'>Rear Sprocket is fine</span>
-HUB -- <span style='color:GREEN'>HUB looks and feels fine, no problems</span>
-Rear bearings -- <span style='color:GREEN'>Pulling on the wheel and upon visual inspection, the bearings all look good, greased up and evereything.</span>
Will keep everyone posted on my findings with wheel balance issues as soon as I get back from dealer today and ride it around.
Just got back from Honda shop...had wheels balanced on Digital Balancer
Front wheel was 15g off balance... got it to 0
Rear wheel was 23g off balance... got it to 2
Got it home, installed wheels, everything buttoned back up...
VIBRATON IS STILL THERE!!!! Im serious, this is taking everything out of me guys. I can't handle this much anymore. Am I gonna just have to take it to Suzuki and let them look at it?? God I HATE THIS!
Front wheel was 15g off balance... got it to 0
Rear wheel was 23g off balance... got it to 2
Got it home, installed wheels, everything buttoned back up...
VIBRATON IS STILL THERE!!!! Im serious, this is taking everything out of me guys. I can't handle this much anymore. Am I gonna just have to take it to Suzuki and let them look at it?? God I HATE THIS!
Jerry keep good documention with all the stuff you have done and I would agree with you see what Suzuki has to say and see if they give you any guidance
UPDATE:
I noticed the other day, when i added oil to the steering damper, that when working the rod back and forth after reinstalling the screw, when the rod would bottom out on one side, it would act "jumpy" when working it back the other way, almost like an air bubble was staying in there.
So, i pulled the steering damper (AGAIN) and changed out the oil (AGAIN), this time going with an 80W (from a 75W) and made as damn sure as possible to get all the air out of the damper.
The vibration is still there, BUT HAS BEEN REDUCED BY SAY, 50% OR SO. It is definately a noticeable decrease.
Wonder if I should try going with an 85w? Am i just masking the problem or could this be it?
Inputs needed
I noticed the other day, when i added oil to the steering damper, that when working the rod back and forth after reinstalling the screw, when the rod would bottom out on one side, it would act "jumpy" when working it back the other way, almost like an air bubble was staying in there.
So, i pulled the steering damper (AGAIN) and changed out the oil (AGAIN), this time going with an 80W (from a 75W) and made as damn sure as possible to get all the air out of the damper.
The vibration is still there, BUT HAS BEEN REDUCED BY SAY, 50% OR SO. It is definately a noticeable decrease.
Wonder if I should try going with an 85w? Am i just masking the problem or could this be it?
Inputs needed
TO BE CONTINUED....
Headin out to the rig tomorrow, so I will be away from the bike for a week. I will continue to brainstorm as to what the cause might be, and formulate more plans for when I get back.
Thanks for all the help everyone, we will pick this up again in a WEEK!
Headin out to the rig tomorrow, so I will be away from the bike for a week. I will continue to brainstorm as to what the cause might be, and formulate more plans for when I get back.
Thanks for all the help everyone, we will pick this up again in a WEEK!
Thanks Powers,
Rubber2Burn and I are gonna meet up the day after I get off the rig and were gonna start swappin stuff out, gonna do a little process of elimination and see what it is. Gonna start with the wheels and go from there!
Thanks for the offer though man!
Here's a quick way I check for bent forks. With the front wheel hanging loosen the tree clamps (one side at a time) & spread them with screw drivers or small chisels. Rotate the top of the fork in the trees & watch where the lower leg exits the top leg. If any wobble is present the forks need to be repaired. Its best to have a helper when checking in this manner.
Some bikes only allow .004 runout for the rotors. If you can score a dial indicator you can index the rotors to the hub. record the runout then move the rotor one set of bolt holes & check again, record the runout etc. Reinstall the rotor in the position that has the least amount of runout. Do both rotors. Regardless of what Suzuki says most cars only allow .007 / .008 runout
While you have the dial indicator:
You can also check the wheel for lateral & radial runout. I like to do it with the wheel on the bike. Check both sides on the lip then check both sides on the surface 90 degrees from the lip for radial run out. I will not use a wheel with more than .20 in any direction. If the wheel has lateral runout (side to side) mark the wheel at the point that the runout is the most severe. Check the other side of the wheel. If the runout on the other side is more than 90* from the first side add the runout from both sides together. IE: if one side is .020 & the other side is .015 you have .035 runout in the wheel.
Some bikes only allow .004 runout for the rotors. If you can score a dial indicator you can index the rotors to the hub. record the runout then move the rotor one set of bolt holes & check again, record the runout etc. Reinstall the rotor in the position that has the least amount of runout. Do both rotors. Regardless of what Suzuki says most cars only allow .007 / .008 runout
While you have the dial indicator:
You can also check the wheel for lateral & radial runout. I like to do it with the wheel on the bike. Check both sides on the lip then check both sides on the surface 90 degrees from the lip for radial run out. I will not use a wheel with more than .20 in any direction. If the wheel has lateral runout (side to side) mark the wheel at the point that the runout is the most severe. Check the other side of the wheel. If the runout on the other side is more than 90* from the first side add the runout from both sides together. IE: if one side is .020 & the other side is .015 you have .035 runout in the wheel.
Another shot in the dark
How is the weight bias? Have you raised the rear with a higher profile tire, more preload, adjusted the shock length or lowered the front in some way, putting more weight on the front which in essence, changes the castor angle? This may cause a shimmy much like a shopping cart wheel. Good luck!
How is the weight bias? Have you raised the rear with a higher profile tire, more preload, adjusted the shock length or lowered the front in some way, putting more weight on the front which in essence, changes the castor angle? This may cause a shimmy much like a shopping cart wheel. Good luck!
hey Jerry, another shot in the dark, and I don't know if it's possible, but could it be something in the final drive? like a bad link, tweaked output shaft or sprocket? just curious ' cause it seems to be speed related and if the suspension checked out- well maybe it's something with the final drive and the vibration is passed through to the bars where you can feel it. anyone that's ridden / driven a car that had a slightly bent or out of balance driveshaft can relate. it happened to me, took a while to narrow it down, but with the advice from an old farmer (my grandad) took the driveshaft in to get it checked and yep... it had slung the factory tacked on weight. problem cured. on the bright side, by the time I decided to listen to him, I had a new set of tires, new struts, and 2 alignments
+1 Yup- plus I would be all over those fork bearings as much work you put into everything else...hey Jerry, another shot in the dark, and I don't know if it's possible, but could it be something in the final drive? like a bad link, tweaked output shaft or sprocket? just curious ' cause it seems to be speed related and if the suspension checked out- well maybe it's something with the final drive and the vibration is passed through to the bars where you can feel it. anyone that's ridden / driven a car that had a slightly bent or out of balance driveshaft can relate. it happened to me, took a while to narrow it down, but with the advice from an old farmer (my grandad) took the driveshaft in to get it checked and yep... it had slung the factory tacked on weight. problem cured. on the bright side, by the time I decided to listen to him, I had a new set of tires, new struts, and 2 alignments
He sold the bike but he did find out what the problem was his Steering head had not been torqued to the proper spec's so that was what was causeing the head shake.
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