anyone have a runout gauge?

[scubasteveRR]

Didn't he say he couldn't feel the pulsating at the lever.


Me thinks you might have a different problem. Check the rotors make sure they are good-clean everything and then road test. If there is no pulsating at the lever you have a different problem.

Speed Demon, you are correct, i do not feel the pulsing at the brake level at all!

but I can feel it in the bike. what are you thinking?

[Speed Demon 828]

How do the pads look?

[scubasteveRR]

original pads, never took them off before but.... when I got my tires on at tricky mikes during the summer he said there was plenty of pad left at around 7k miles and the bike now has 11k. So I'd assume by now I am ready for new pads?

Also mentioned the pulsating to him and he said the tire spins like it should but never got into what the issue could be at that point because it was already late in the evening and the bike was ridable.

[Rambunctous]

Put the bike up in the air and spin the front wheel. Be observant. Any problems with a tire, bent rim, etc.

[Speed Demon 828]

Well it's hard to do this with out having the bike here. I would start by inspecting the pads- look for uneven wear, how much material is left, scoring, over heating, stuff like that. Check the calipers- make sure all the pistons are working-none frozen or sticking out more than the others. Check the rotors and carriers look for over heating (purple color), and scoring (check for deep lines in the rotors). Check fluid- it shouldn't need to be replaced at 10k but if you're hard on the brakes you never know.

If all that looks good I would do a quick neck bearing adjustment. A lot of the time if the neck bearings are loose the bike may have a pulsing type feeling when you are on the brakes.

Again this is where I would start. It's very hard to tell you what to do without riding the bike for myself.

[scubasteveRR]

def not tires, had the issue before I replaced those. I just got a front stand for x-mas and haven't been over were the bike is being stored to check that, i'll check this tonight and run a ruler over the rotors, maybe clean the calipers and check the pads.

[scubasteveRR]

If all that looks good I would do a quick neck bearing adjustment. A lot of the time if the neck bearings are loose the bike may have a pulsing type feeling when you are on the brakes.

Again this is where I would start. It's very hard to tell you what to do without riding the bike for myself.

Hmmmm, never thought of that. maybe thats why I can't feel anything in the lever?

[stoinkythepig]

Follow Paul's advice. He is very likely dead-on about the carrier. You can also use and EZ out to spin each button around 10 times or so to loosen them up, sometimes they bind and cause vibrations when braking.

I have a few dial indicators and a jig I made that gets bolted on with my caliper bolts. If you send me your caliper bolt spacing and bolt diameter, I can modify the jig to fit your bike and you are welcome to use the setup. I work in Westford, so I'm not far from Bolton during the day.

[Uncle Snake]

Most rotors are made from 420 series SS and are NOT that hard, they WILL warp.......

[Mad Max]

I think Mr. Duval has the right idea. The carriers (aka hat) are not as robust as the rotors and I would venture a guess that they be the point of plastic deformation as the result of a lateral load placed on the rotor surface.

[kawi997]

hey guys you cant check run-out on a motorcycle rotor because they flex.. what you need to do is measure thickness of the rotor in similar spots all around the rotor. when they pulsate it is caused by thickess variation. is is he variation is excessive hence look upa spec then replace dont repair. have fun.

[slideruleracer]

Hey guys, Paul is dead-on correct on this one. The carrier is most likely tweaked and the best way to fix it is to tweak it back. Cleaning all the stuff is really unlikely to do anything.

And you're unlikely to feel any pulsing in the lever - the bike itself will pulse because everytime the 'bent' area goes through the caliper, the bike tries to slow down more..

This was a huge problem on my VFR after I tried driving away with the wheel lock on..

I took the rotor off the wheel, made a carrier for my lathe so that I could indicate it easier, and just rotated it on the late with a little mallet in hand tapping appropriately until it ran true again.

Stock 'floating' rotors don't really 'float'. They have a wave spring washer that is supposed to give to help prevent this kind of thing but in my experience, the spring rate is simply too high. As Paul mentioned, the floating race style ones work much better, but they rattle like crazy.

If you don't want to use a hammer, then use a large screw driver as a pry bar, but either way, the easiest and cheapest fix is to just true it back up..

-Chris