| Author | Message | ||
     Austiego |
Hey fellow Thumpers! Ok guys so here is my problem. I just bought a bike this winter, and I replaced the stock dunflops with two Pirelli MT75’s. I did not have the tires balanced when I put them on I just put one once of dynabeads in the front tire and two ounces in the rear tire. The bike now rides much better, but at 60+ mph the bike is shaking in a weird way. The best way I can describe it is that it seems like the front of the bike shakes at regular intervals about every second. Like, it will be smooth for about a second then start to shake for about a second, then it will smooth out again. It does this over and over again at high speeds. I have looked down the front forks when the bike is doing this, and when the bike starts shaking I can see the front forks shaking, almost as if the front tire is hopping. I thought it was a problem with not having enough dynabeads to achieve balance so I installed another ounce in each tire and the problem did not go away. I can’t figure out for the life of me what is causing the bike to do this a high speeds!!! 1) Could it be the tire? 2) Could it be something not related to the tire, like a too tight or loose primary chain? 3) The front bearing sounds fine but could I have over tightened the front axle and messed up the front bearing? 4) Did I get a bad Tire? 5) Are the dynabeads causing the weird shaking? I have been trying to figure out what is causing the shaking for a about a month now and have racked by brain. I thought it was time to see what my friends at badweb thought! Thank you to everybody in advance!! | ||
| Gearheaderiko |
I'd ditch the dynabeads. I know guys that use them for offroad tires and they work, but thats an entirely different tire. Pirelli's have the reputation for needing very little weight to balance them and if the 'dot' is at the valve stem and your bearings arent too old and crusty or too new and tight, they can be balanced on the axle with a little patience. The Blast manual doesnt describe the procedure but older non-Buell manuals (and an internet search) detail the procedure. The hardest part will be purchasing the weights! Make sure the tire pressure is between 28-36 psi (depending on preference)36 per the manual, I run at 32. Bearings could be bad if you overtorqued and didnt use a torque wrench. The steering head or neck bearing could also be loose. You could also have a tire that isnt properly seated. Spin it on the axle and you'll notice if it isnt seated right. It'll have a major wobble. The forks could also be loose. Check for tightness with a torque wrench or at least look for loose bolts. But start with the balance. Bad tire is possible, but I havent heard of one yet. | ||
| Swampy |
There is a little rubber mark along the bead that you can follow as you spin the tire and follow it around. You can check your front engine mount, also you might check your steering head bearing adjustment. |
