| Author | Message | ||
     Stuckinoregon |
I have had tremendous problems with the front brakes and after 2 different pad brands (EBC and Lyndall Gold)and new rotor hardware - I am fed up with pulsing front brakes. Has anybody taken their rotor to a machinist for a surface grind? I searched and found nothing other than buy a new rotor or buy new pads etc. to fix the problem | ||
| Id073897 |
Did you clean them before replacing pads? Did you check/replace floaters? | ||
| Stuckinoregon |
Oh yeah, scrubbed both sides with 220 multiple times, then cleaned with brake cleaner etc. I replaced all bolts, washers, springs etc too. | ||
| Jblausey |
If you have new pads and rotor and still have the pulse I would be looking at the front engine mount for worn or cracked rubber webs. | ||
| Tootal |
If your rotor is different thicknesses, which can happen, then using a blanchard grinder works real well. If it's warped then grinding will not help since the magnetic table will pull it flat unless the machinist knows to take the time to shim under the high spots and this takes a lot of time and might cost as much as a new one. If you have changed all this and still have a problem then as mentioned check the front motor mount and maybe your steering head bearings. | ||
| Stuckinoregon |
Thanks for the responses. Tootal, why would the thickness vary? | ||
| Natexlh1000 |
Something I was toying with: You know the breather holes in the disk? I noticed that they are very sharp-edged. What would the effect be if one were to chamfer each hole a bit? | ||
| Tootal |
The steel in different places can wear more or less depending on hardness. Heat treating doesn't always cause a perfectly even condition. Sometimes material differences will cause this. It comes down to the quality of metal and of the heat treatment. What I'm talking about is found on a used rotor where the rotor has worn unevenly due to the above circumstances. Does that make any sense? I understand it but sometimes it's hard to explain it. If this occurs then the pad will push into a thin spot and then hit a wider spot causing more pressure which will give you the surging effect. My father had a Yamaha Venture Royal that had this very problem. If you hit the brakes with any force it would shake the bike so violently that it was hard to control. I checked the rotors with a micrometer and found the different dimensions. I had them blanchard ground and it completely cured the problem. As far as chamfering the holes, in automotive racing we call these disk cheese graters. If your running a softer pad and drilled or slotted rotors they won'd last very long. If your running racing pads, that are much harder, it has less effect. Motorcycle pads are designed for the cheese graters but chamfering the edges could not hurt IMO. (Message edited by tootal on May 27, 2009) | ||
| Stuckinoregon |
well I am going to try it - It cant be too expensive to have it done... cheaper than $145 for a new rotor. | ||
| Wolfridgerider |
How many miles are on it? | ||
| Hughlysses |
I think American Sport Bike used to sell a specific drill-mounted pad for this, but I checked their site last night and couldn't find it. | ||
| Stuckinoregon |
32K but new to me wolfridgerider | ||
| Stuckinoregon |
The front mount is new - I just replaced it after reading through some of the posts on solving these kind of issues | ||
| Wolfridgerider |
http://www.badweatherbikers.com/buell/messages/142 838/461865.html?1243509215 I would just replace it. When I put the wheel from my race bike on the front of my Uly it made a world of difference. 32K is a bunch of miles for a rotor... | ||
| Tootal |
Stuckinoregon, If you have a micrometer or some dial/digital calipers you can check the thickness in several spots and see if that's your problem. If so then have it ground. I think it cost me $25.00 to have it done. If it's all the same thickness but warped then just buy a new one. If they need to take more than .030" off the thickness then buy a new one. If you get it too thin it will warp easier. | ||
| Florida_lime |
I have measured my front rotor runout. It was only 0.006 the last time I checked. The service manual allows way more than that (don't have it here for the exact #), but I have read that anything more than 0.004 can be felt as pulsation. I've sanded countless times, changed pads twice (Lyndalls and EBC) - all with very temporary results. | ||
| Stuckinoregon |
So what did you do Florida? Replace the rotor or get used to the pulsation? | ||
| Jim_rowley |
I have the exact same issue. New to me 06 Uly with 8880 miles on it and a warped rotor. I have a new one coming. I have a little experience with brake rotors. When a rotor gets hot, it wants to expand. If the mounting hardware is too tight, meaning if there's not enough clearance between the hardware and the rotor for expansion, that rotor is going to warp. So, when I get the replacement rotor and hardware, I'll make sure there's no binding and the rotor is able to "float". | ||
| Wolfridgerider |
Just a FYI, when you mount your new rotor it will have little round dot drilled on one of the mounting tabs. That goes next to the valve stem facing out. | ||
| Jim_rowley |
Thanks for the tip. |
