Dsankey1 Posted August 3, 2015 Share Posted August 3, 2015 Hi - I have recently picked up a second hand 09 vfr800 and love it. While working through a few gremlins I discovered a substantial vibration through the handlebars at anything over 80mph. Had the wheel balanced and changed the wheel bearings but the vibration was still there. Myself and the local bike shop were stumped - everything else at the front looked fine. I decided to put the top box back on the bike and oddly, the vibration stopped. The bike feels so much better with the weight of the top box on the back so I assume my suspension settings need adjustment. Everything is standard at the moment at factory settings. Question is - what would I need to do to the fork settings to stop the front vibrating without the weight of the top box? I can't help thinking there are probably more factors at play here as I can't believe the factory standard settings would cause this problem..? Any ideas greatly received. Thanks in advance. Sent from my iPad using Tapatalk HD Link to comment Share on other sites More sharing options...
Member Contributer oyama Posted August 3, 2015 Member Contributer Share Posted August 3, 2015 How old or used is your front tire? Link to comment Share on other sites More sharing options...
Dsankey1 Posted August 3, 2015 Author Share Posted August 3, 2015 Hi, front tyre was on the bike when I got it but looks almost new. Sent from my iPad using Tapatalk HD Link to comment Share on other sites More sharing options...
Member Contributer oyama Posted August 3, 2015 Member Contributer Share Posted August 3, 2015 I only had vibrations at deceleration on the original Dunlop tire. Replacing that solved the issue. Funny thing is, none of the other tires (I am mostly a Pirelli kind of guy) produced vibrations at their end of life. What brand and model tire do you have on the front? Link to comment Share on other sites More sharing options...
Dsankey1 Posted August 3, 2015 Author Share Posted August 3, 2015 Tyre is a Michelin - it's in great condition so I don't think that's the problem. Sent from my iPad using Tapatalk HD Link to comment Share on other sites More sharing options...
smoothsailin Posted August 3, 2015 Share Posted August 3, 2015 I purchased a Triumph Speed Triple several years ago and have experienced similar out-of-balance (vibration) issues involving the front wheel as long as I've owned it. I replaced the tire right after purchasing it and have tried re-balancing the wheel, using "dyna beads" and have inspected the wheel bearings for problems-all without finding a solution. I've also tried to determine if the front wheel might have been slightly bent or dented while the S3 was in the care of a prior owner, but so far have been unsuccessful in making this determination. I do know that at least one of my S3's front rotors is slightly warped, for I can sense a pulsation under deceleration with light pressure applied to the front brakes. Do you feel a similar sensation when braking your VFR? If so, it's possible warped rotors could be causing at least some of the symptoms. Yesterday I replaced the front rotors and brake pads on my wife's Kia. Afterward, the pulsation we'd felt under light braking was eliminated, however most of the shimmy we've been feeling through the steering wheel at speeds of 55-60 mph was still noticeable. While working on the brakes I discovered that an out-of-alignment issue had caused the car's front Michelins to wear severely on the inside corners. In fact, one of the tires was showing cords, so I decided to rotate the wheels (front to back) until I can get the worn tires replaced. Voila...when I drove the car after rotating the Michelins, I discovered the shimmy was eliminated after the less-worn Michelins previously mounted on the rear were moved to the front! So wheel imbalance (vibration) issues can have more than one cause. I'm also not sure I understand why adding weight to the rear of your VFR would reduce the amount of vibration felt in the front. Link to comment Share on other sites More sharing options...
Member Contributer Rectaltronics Posted August 3, 2015 Member Contributer Share Posted August 3, 2015 Have you checked to make sure the sub-frame bolts are all tight? Have you tried re-setting the triple tree? Have you checked the swingarm bearing or bushing? (yes, really!) My only other thought is that the top-case is making the front end lighter so maybe too much rebound damping? Any difference with full tank vs nearly empty tank? Any difference with seating position, posture? Feet on rear pegs vs proper front pegs? Does weighting the pegs (pushing with your feet and moving the weight off your butt) help? Link to comment Share on other sites More sharing options...
Dsankey1 Posted August 3, 2015 Author Share Posted August 3, 2015 Thanks for the input. The brakes on the VFR are smooth and even. The whole issue felt to me like wheel balance and I even went to the length of taking all the weights off the wheel and going for a ride - the vibration was exactly the same - still started at 80mph and the balance has been checked and rechecked by my local garage. The head is tight - I can't help thinking it's something to do with the forks or the suspension setup. It's definitely only wheel speed related and happens in any gear, clutch in or out.. Sent from my iPad using Tapatalk HD No difference with fuel load, haven't checked the other things yet. What is the triple tree..? Sent from my iPad using Tapatalk HD Link to comment Share on other sites More sharing options...
Member Contributer Mohawk Posted August 3, 2015 Member Contributer Share Posted August 3, 2015 How old is the tyre ? Never mind it's condition, check the age date. Does bike still have centre stand, if yes, how long & where was bike stood before you bought it ? It's not unusual for old tyres to get hard & develop a flat spot where the bike weight has been parked on it the whole time. Happens on front on centre stand & both wheels if stored on side stand. Balancing will NOT help this. Link to comment Share on other sites More sharing options...
Dsankey1 Posted August 4, 2015 Author Share Posted August 4, 2015 The bike was well used before I got it - looking through the receipts the front tire was only on the bike for a couple of months. Rear tire was put on when I got the bike just 6 months ago. Biggest thing I find odd is that the vibration doesn't happen with the top box on. Any idea what I could do with suspension settings to compensate for these symptoms or am I barking up the wrong tree. Sent from my iPad using Tapatalk HD Link to comment Share on other sites More sharing options...
Member Contributer gswanson Posted August 4, 2015 Member Contributer Share Posted August 4, 2015 Are you sure the vibes are coming from the front wheel? Any rear wheel imbalance if you run through the gears with the bike on the center stand (safely anchored, of course)? Link to comment Share on other sites More sharing options...
Dsankey1 Posted August 4, 2015 Author Share Posted August 4, 2015 Are you sure the vibes are coming from the front wheel? Any rear wheel imbalance if you run through the gears with the bike on the center stand (safely anchored, of course)? Just tried this - spun the rear up to 80mph and there is some vibration.. With the wheel spinning slowly it looks like the wheel is true but the tire is slightly mis-shaped. The tire is a Michelin pilot road and has only been on the bike for 6 months and done around 1000 miles. Looks virtually new. Haven't hit any big pot holes and it's always been at the correct pressure. Is there any way to sort this? Sent from my iPad using Tapatalk HD Link to comment Share on other sites More sharing options...
Member Contributer JBAXX Posted August 4, 2015 Member Contributer Share Posted August 4, 2015 I'll chime in here - I had a very similar problem with my '04. I balanced the front tire and I still had the speed-related vibration. Turns out my bike is very finicky about tire balance. I very carefully rebalanced the tire again and the problem was fixed. I would also be sure that the rear tire is balanced as well. Link to comment Share on other sites More sharing options...
Dsankey1 Posted August 5, 2015 Author Share Posted August 5, 2015 Thanks - hopefully get the back wheel down to the shop tomorrow for balancing and a check. Sent from my iPad using Tapatalk HD Link to comment Share on other sites More sharing options...
Member Contributer Mohawk Posted August 5, 2015 Member Contributer Share Posted August 5, 2015 Check the rear rim, I dented one once without noticing, only came to light when cleaning the rim, if rim is good, then try deflating the tyre fully then spin it up on centre stand as before, then inflate in place & see if the odd shape goes. Link to comment Share on other sites More sharing options...
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