| Author | Message | ||
     Greenman44 |
I've looked through several post about head shake and brake issues, and I wasn't really sure if this fell into any of those categories. I hope somebody can offer some assistance. Here is what is happening, when I apply the front brake with a low or medium amount of forced I get a significant amount of high speed vibration through my handle bars. It seems like it is more through the right grip than the left if that makes any difference. This first started on Sunday at the end of about a 140 mile ride, on the way back into town slowing for a a stop light. I about soiled my self because it was something new, and extreme. I have had minor pulsing of the front brake which I have read is pretty common, but it is nothing that has been out of control. Brake pads still have a fair amount of pad left. Before this ride I had gotten a new set of front Dunlops which ride much better than the wore out ones, I had rode about 30 miles before sunday, now they have roughly 200 miles on them. I am planning on checking the steering nut bolt, but I have no torque wrench due to the fact I'm at school with the military and all my tools are at home. So I have to go to the shop on base and use their tools. I would like to know several things I could check at once to try and remedy this problem. Its kinda urgent because I am due to ride back to Utah the end of next week..2700+ miles. PLEASE answer up with any possible solutions. If you would rather talk in person PM me with your number or to get mine. Thanks a ton, Shawn  | ||
| Jlnance |
If it's the brake pads, you will feel it when the bike is going very slow (like 5 mph.) If you don't feel the pulsing then, it's likely something else. Check your suspension settings. If they are off, it can cause head shake. Since you just changed the tires, that's a likely suspect. Before you retorque the steering head bearing, do the spring scale test in the service manual, assuming you have the necessary equipment. | ||
| Greenman44 |
Jlance, I do feel the break pads slow and evenly spaced, I have had cars that have warped rotors and I recognize how people describe that. What I am feeling is usually over 35 MPH and is fast! Probably a 10 times a second. I will go over the suspension settings to make sure everything is ok, I did change the rear preload, but I'm unsure exactly how long ago it was. I was out in the field for a week so I'm not exactly sure of when it was. I was looking at the tire and they put like 3/4 oz of weights on one side, and 1/2 oz on the other side and around a couple inches. I thought it looks like a large amount of weight but I'm fairly new to street bikes so that may not be the case. Unfortunately I don't have the service manual, but if you don't mind telling me what I need to do for the spring test I would be extremely grateful. Thanks again. Shawn | ||
| Tank_bueller |
If it doesn't shake with no brake.. (poet and don't know it) It aint the steering. I'm betting on something with the rotor. Most cases are due to uneven pad debris on the rotor. If you can "scrub" the rotor with 220 grit, try that. If the brake lever is "smacking" your fingers when you brake, that's either junk stuck in between the rotor and the wheel, or a bent wheel. The rotor is supposed to "float" between the bolt head and the wheel. You should be able to push on the rotor at the bolts and move it about 1/16 of an inch.(spring loaded) (Message edited by tank_bueller on November 11, 2008) | ||
| Greenman44 |
Tank, Thanks for the info, I will get some sand paper tomorrow and scrub up the rotor. I have noticed that the rotor can move on the mounting bolts. The brake lever doesn't really smacking its the whole handlebars. I'm willing to try about anything to get this sorted out. I'll let ya know if that fixes things. I reset up the suspension today, I don't think that it was off any. It seemed to lower the speed at which the problem happens. Maybe its because they scraped up the paint on my wheel... Thanks for the help Shawn | ||
| Jason13 |
also check if you have black spots on the rotor if so those r hot spots and the could do the same if you have a lot of black spots and nothing you can do about that but get a new rotor | ||
| Greenman44 |
Jason, Thanks for that thought, there is a small amount of black on the rotors but I think it is buildup from the pads. Tank, I believe that may have been the issue, I got a sanding block and went at the rotor. They didn't have 220 so I decided to get less coarse and reduce the chance of damaging the rotor. I went for a short ride up the freeway and back and it seems to have a way better feel. I think I may need to upgrade to the lyndal brakes from american sportbike. But that may need to wait. Is there any negative affect if I were to check the torque of the steering nut? Let me know what your thoughts are on this. Thanks guys Shawn | ||
| Blake |
"also check if you have black spots on the rotor if so those r hot spots and the could do the same if you have a lot of black spots and nothing you can do about that but get a new rotor" I don't buy that. Such spotting is from deposits left by the brake pads. You can heat metal to white hot. It won't leave black spots. Clean the rotor to get rid of the spotting or install a set of Lyndal Gold pads, which don't leave so much residue and will clean up the rotor nicely. Other brands of brake pad may do the same. If you take to the track and get the rotor and pads really good and hot, that will tend to clean the excessive residue as well, but you really need to give the brake an aggressive work-over. Most folks aren't used to such aggressive braking. | ||
| Tank_bueller |
Yup, EBC's work as well. As for the steering head, it couldn't hurt. Preventative maintenance is never a bad thing. Just remember, when you check the steering, the front must be off the ground. | ||
| Greenman44 |
Mr Tank, When I lift the bike off the ground, do I just check the torque or should I just loosen it and re-torque it? Thanks Shawn | ||
| Tank_bueller |
I usually like to loosen, wiggle everything for comparison, re-torque, and wiggle again. After the re-torque, there should be no noticeable movement if you grab the bottom of the forks and push/pull front to back, but the bars must move freely from lock to lock. There will be a small amount of resistance from cables and wires, but not very much. | ||
| Greenman44 |
Tank, Question for when I do this tomorrow, if the bars don't move freely what fixes that? Also loctite on the head bolt? I know there is some on the pinch bolts for the bars but unsure of the stem cap bolt. Just to check the torques I have; Stem nut 38-42 lbs Resistance 1-7 lbs Upper pinch bolts 23-25 ft lbs Thanks for the help Shawn | ||
| Bud |
be sure to loosen the lower triple T fork bolts before TQ the head bolt ( front wheel off the ground ) | ||
| Tank_bueller |
Bud might be correct, but I didn't do it. The lower triple tree might need to move up the fork a few thousands of an inch. The "resistance 1-7" would be allowance for the cable resistance. 1-7 lbs is a broad range. No locktite on the head. The pinch bolt holds it. Torque looks good. Feel it out brutha! If it don't feel right, do it again. | ||
| Greenman44 |
Bud and Tank thank you guys very much for your help. I'll let ya all know how it went after I get done tomorrow. Thanks Shawn | ||
| Blake |
Before you loosen anything, check the bearing preload per the manual. It may well be just fine. |
