Kawasaki Vulcan Forum banner

1 - 16 of 16 Posts

·
Registered
Joined
·
25 Posts
Discussion Starter #1
We bought this 2005 bike used in 2015. It only had 975 miles on it and was like new. Always kept in the garage, etc.

I rode the bike about 70 miles to home, but rarely needed to use the brakes much. I did not notice a braking problem.

My girlfriend rides this bike, not me. (I mean that I don't normally ride this bike. :wink2:) So on the rare occasion that I rode it, with maybe 4,000 miles on it, I noticed the front rotor was warped. We don't hose our bikes off when we clean them. We got caught in a slight drizzle on one ride, but a bike should be able to be ridden in the rain. I have no idea when the rotor became warped.

I had the rotor replaced and a quality EBC rotor.

With 7,000 miles on it now, on our last ride, we switched bikes for a few miles. The front rotor is warped again!! I don't see how this could be! She is not a fast rider, tending to ride slower and more cautious, I doubt she is over-using the brakes. We do not commute on our bikes, only nice mountain back roads. She does not enter hot and use the brakes hard, etc. She didn't mention the pulsing to me, so I have no idea how many miles this has been happening.

After doing a search on this forum, I did not find any other mention of warped rotors on our 500s.
 

·
Registered
Joined
·
2,075 Posts

·
Registered
Joined
·
11,753 Posts
I will say that the front brake hydraulics/calipers are binding causing the brakes to drag.
Time for servicing.
 

·
Registered
Joined
·
25 Posts
Discussion Starter #5
There are no signs of binding or dragging. The front wheel spins freely. Easy to push the bike around. No discoloration on the rotor, no burning smells. Even though we are taught to "cover the brake" we do not do that. This does not seem like a common problem either. Hence the mystery!
 

·
Registered
Joined
·
11,753 Posts
1. Have you changed the brake fluid?
2. Did you check that the calipers are free?
3. Did you check that the piston is free?
4. Did you check that the disk run-out on the new rotor is within Kawasaki specs?
 

·
Registered
Joined
·
25 Posts
Discussion Starter #7
1. Have you changed the brake fluid?
2. Did you check that the calipers are free?
3. Did you check that the piston is free?
4. Did you check that the disk run-out on the new rotor is within Kawasaki specs?
1. Yes. About 2 years ago. It still looks very good. I know it's time to do it again, but it is not causing the problem.
2. Yes. Front wheel spins freely. Brake application is strong.
3. Yes. Front wheel spins freely. Brake application is strong.
4. New rotor just over a year ago, about 3,000 miles ago. OEM rotor warped. This one cured the pulsing at that time, but now it is back.


She put over 3,000 miles on her V-Star 250 without any problems. Hmmm....
 

·
Registered
Joined
·
245 Posts
Check your brake fluid level that it's not too high. As you ride, the fluid will expand slightly due to the heat from the brakes especially if it has contaminants in it, so it needs expansion room. Does the caliper compress easily? Even if the caliper and piston are good, a restriction inside the brake hose can cause the brake to drag longer than it should.
 

·
Registered
Joined
·
25 Posts
Discussion Starter #11
In not trying to be a smart ass you said you dont use your brakes much maybe you should, I always drag my rear brake to give me better control specially at low speeds and stop lights
We are usually on canyon back-roads where all we need to do is roll off the gas before some turns, then roll back on. Occasionally downshifting as needed.
 

·
Registered
Joined
·
25 Posts
Discussion Starter #12
Check your brake fluid level that it's not too high. As you ride, the fluid will expand slightly due to the heat from the brakes especially if it has contaminants in it, so it needs expansion room. Does the caliper compress easily? Even if the caliper and piston are good, a restriction inside the brake hose can cause the brake to drag longer than it should.
Useful information. Thanks. But there is an airspace visible in the master cylinder window.

This reminds me of an incident on my used Honda Ascot. While riding home on the freeway at 65mph, the bike stared to slow down, even when giving more gas. I knew right away that the engine was ok, so it had to be the brakes (that I had not used since getting on the freeway.) I pulled over onto the shoulder and found the rear brake was very hot and was binding. I opened the caliper bleed screw and there was pressure there. A small amount of fluid came out, but the brake released. I got back on the road, but it happened again without ever using the rear brake. I had to pull over two more times. Did the same thing. I attributed the brakes self-energizing due to the increase in ambient temperature.

What I found was that there was a tiny port in the master cylinder that was plugged with a spec of corrosion. Best advice to flush your brake fluid every few years at the most. Cheap insurance.

The shop that originally changed the rotor over a year ago was able to get a replacement under warranty. He also noted no binding of the caliper or piston. He too was stumped for a cause of the rotor warping.
 

·
Registered
Joined
·
18 Posts
I don’t think brake rotors warp anymore. What happens usually is that there may be a build up or something ‘different’ an part of the surface which creates a different amount of grip on a portion of the rotor make the brakes pulse LIKE it is warped.

For instance sometimes if a vehicle sits for a period of time you can start to develop a thin layer of oxidization on the rotor surface everywhwerw BUT here the brake pad is sitting. Now you have a the part of the rotor that has oxidization (with less grip) and the one spot that is normal and has more grip.

You can take the rotor off and using some 000 steel wool, you can go over the surfaces of the rotor and see if that helps.
 

·
Registered
Joined
·
25 Posts
Discussion Starter #14
I don’t think brake rotors warp anymore. What happens usually is that there may be a build up or something ‘different’ an part of the surface which creates a different amount of grip on a portion of the rotor make the brakes pulse LIKE it is warped.

For instance sometimes if a vehicle sits for a period of time you can start to develop a thin layer of oxidization on the rotor surface everywhwerw BUT here the brake pad is sitting. Now you have a the part of the rotor that has oxidization (with less grip) and the one spot that is normal and has more grip.

You can take the rotor off and using some 000 steel wool, you can go over the surfaces of the rotor and see if that helps.
I have heard of this theory as well. On the OEM rotor, I did try to lightly sand the rotor surface with some emery paper while still on the bike...just to try to break whatever might be on the surface, but it didn't help. I agree that this should not be an actual warp problem, but surface contaminants of some sort could be, although not sure where or why this bike would have gotten them and none of the other bikes I have ever had have gotten it. I have 3 bikes in the garage right now.
 

·
Registered
Joined
·
11,753 Posts
I have heard of this theory as well. On the OEM rotor, I did try to lightly sand the rotor surface with some emery paper while still on the bike...just to try to break whatever might be on the surface, but it didn't help. I agree that this should not be an actual warp problem, but surface contaminants of some sort could be, although not sure where or why this bike would have gotten them and none of the other bikes I have ever had have gotten it. I have 3 bikes in the garage right now.
See post #6, point #4.
 

·
Registered
Joined
·
117 Posts
I'm not sure if this problem ever got repaired, but I've had similar issues in the past. I kept having my rotor warp after just a couple hundred miles.

Pads changed, rotor turned or replaced, same problem. I got sick of it and changed the caliper, and I've never had it happen again after a several thousand miles.

I don't know anything about rotors never warping, but I don't think that's right... Just the physics alone make it unlikely that rotors can't warp. Heat, metal, tension, and compression... I've never seen warp-proof metal... Just my experience.
 
1 - 16 of 16 Posts
Top