Front wheel noise

[Jfundo]

I'm wrong about the caliper sliding.  Apparently our calipers have opposing pistons.  So you have 8 pistons and it only takes one of them to have some crud under the seal to cause this problem. The pads themselves slide on pins, so that could be the source of the problem too.  

Edited February 5, 2021 by Jfundo

[peteinpa]

For the record I went to the basement and squeezed my lever, let it go, spun the wheel and got just short of 2 turns.  I'm good with that, but could be better.

The piston seals actually flex out with the piston then pull the piston in.

One thing I don't agree with is spraying the caliper with brake cleaner. My cans say right on the label "keep away from rubber brake components."

I've never used it that way.  I have polished pistons with chrome polish before shoving them home on a brake pad job.

I don't agree with everything on Delboy, but he is one of the best out there. Two Wheel Obsession is another.

[petshark]

3 hours ago, Lone Wolf said:

The fact that you could FEEL the issue while riding = something very wrong. Your video confirms not OK.

Just for info, here is what a normal pad dragging on the rotor sounds like:

 

Thank you, I also remember the normal dragging being like this but thought perhaps the EBC HH pads had more drag.

 

3 hours ago, Jfundo said:

I think the noise your wheel is making is a stone or something caught either in the wheel spokes or in your tire.  The noise isn't rhythmic enough to be a part attached to the wheel going back.  The spin rate and the frequency of the noise don't match up.

That is true. As a musician I had the same thought. There is no relation between the noise and the rotation of the wheel. It sounds like a metal particle bouncing around in a larger metal container.

3 hours ago, Jfundo said:

Mind you, this is a very small issue.  I'm sure you are aware that it doesn't take a lot of pressure on the brake lever to make it so you can't possibly turn the front wheel by hand.

I can really feel the bike braking all the time and am unable to ride because of it so to me it is a huge issue but I know what you mean. 😉

3 hours ago, Jfundo said:

As everyone suggested, I think you need to start eliminating sources of the extra pressure.  It is likely either in the master cylinder or the caliper (unless you have a very serious kink in the hose which I'm sure you would've found by now).  Disconnect the hose to see if it fixes the problem.  If it does, then the master cylinder is the issue, if it doesn't, then it is in one of your calipers.  I would then remove one caliper and then the other and see which one makes the difference.  Whichever it is needs to be taken apart and cleaned or re-built.  

I haven't needed to do this on a motorcycle before, but I've run into it with cars that when the brakes are dragging like this it is because the slide (or slide pin) is corroded and the caliper can't retract smoothly.  A quick sand, polish and grease of the sliding surfaces and it is good to go.

Half the piston has calipers that need to go in and out, but the other half of the caliper slides on the first half, and this sliding needs to be smooth too.  

Unfortunately I have already tried all these suggestions. I've opened the bleed valves and the dragging remains which indicates the the fluid pressure is not causing this.
I've removed the calipers one by one and they each are responsible for half the dragging. That they are identical and all pistons move and are clean indicates that it is not the pistons. I have yet to try some tests with the master cylinder but would still expect some fluid to come out when opening the bleed valves if fluid pressure is the issue. I've lubed the slide pin (again) and no improvement.

Thank you for your help though, I will keep looking and trying variations of the these tests.

[petshark]

2 hours ago, peteinpa said:

One thing I don't agree with is spraying the caliper with brake cleaner. My cans say right on the label "keep away from rubber brake components."

  I actually did this only once to be sure that even a spatter of WD40 would be dissolved.  I saw it in a video and I even think it was one of Del's. It would be really weird if I got this result from that one time but who knows which combination of variables got me in this mess. Could be part of it.

2 hours ago, peteinpa said:

The piston seals actually flex out with the piston then pull the piston in.

Now that is really interesting! Will test this out tomorrow. Great video, just plain proof how it works. And thank you for testing the rotation on your bike!

My hopes are up that I might be able to fix it tomorrow 😁 Should go to bed now as it's 2 AM

[peteinpa]

Since the EBC HH pads are more grippy, with everything else being equal the wheel should spin less. Right?

When I switched to EBC HH on my ST1300 they also didn't spin too freely. I removed them, sanded the new pads slightly on sand paper on the basement floor, then they broke in correctly and the wheel spun well when released.         Worth a try.

On the ST1300 forum almost all went with OEM pads, they had less problems with them.  Had to do with the Linked Braking System it had. One of many things I don't miss on this bike.

[whisperquiet]

I've read this thread and have a few thoughts.  

I would definitely remove the aftermarket brake lever to see if anything changes....I had an aftermarket clutch lever on my Super Tenere hydraulic clutch, it had terrible feel, and I could not bleed it properly.  I installed the OEM lever and all was good.  

Can you remove a caliper and take some detailed pictures of the pistons....they should look like new when cleaned.  I always clean mine with pipe cleaners when installing new pads before they are pushed back in the caliper.

Remove enough brake fluid from the reservoir so the brake fluid is at the low level...not at the top line.

Have you polished (not just lubed) the brake pad pins/sliders as many will wear a slight ridge or groove over time.

Can you see the return brake squirt in the open master cylinder when lightly squeezing the brake lever?

That's all I got.

 

 

 

 

 

[BBB]

7 hours ago, peteinpa said:

Since the EBC HH pads are more grippy, with everything else being equal the wheel should spin less. Right?

My understanding is that HH pads are more grippy as they generate more friction when hot. They should not affect wheel rotation when cold, in fact a common complaint is that they are less effective on a cold rotor.

[petshark]

13 hours ago, whisperquiet said:

I would definitely remove the aftermarket brake lever to see if anything changes....

I did this today and it made no difference.

13 hours ago, whisperquiet said:

Can you remove a caliper and take some detailed pictures of the pistons....they should look like new when cleaned.  I always clean mine with pipe cleaners when installing new pads before they are pushed back in the caliper.

I did another deep clean of the calipers and pistons today. I did not polish them because I have never done that before and don't have anything to polish with. I cleaned them one by one with soapy water and a toothbrush.

19 hours ago, peteinpa said:

The piston seals actually flex out with the piston then pull the piston in.

I've made some video's to demonstrate the retraction:

It looks normal to me.

13 hours ago, whisperquiet said:

Remove enough brake fluid from the reservoir so the brake fluid is at the low level...not at the top line.

I tried this and it did not make a difference

13 hours ago, whisperquiet said:

Have you polished (not just lubed) the brake pad pins/sliders as many will wear a slight ridge or groove over time.

I did a search on how to polish and found that I could use toothpaste. This is the result:

It feels smooth to the touch and I have special brake lube that I reapplied after.

13 hours ago, whisperquiet said:

Can you see the return brake squirt in the open master cylinder when lightly squeezing the brake lever?

I checked and it does.

23 hours ago, betoney said:

briefly loosen it just to see if it relieves any pressure at the caliper pistons.

I tried this and let some fluid out of the MC banjo bolt and it did not relieve pressure

More details and result

I think I tried every suggestion here. Once the pistons were clean I spent a lot of time moving them back and forth until I was satisfied that they all moved out at the same time so none were restricted in any way.

The spin test showed a small improvement so I went for a 10 minute ride.

I still feel dragging but what's more upsetting is that I now also feel something weird through the footpegs. Like small shocks or hickups. At first I thought it was the engine misfiring but at standstill the engine sounds normal for a 3 cylinder I think, also when revving up. It's my first triple so I'm not sure.

I kept riding because I was doubting if what I was feeling is because I was so focused on any sensation.  So I tried a little more speed and pulled the clutch and just let it roll a couple of times. The bike rolled quite far but I still felt like the brakes were dragging a little. But definitely better, before the brakes really slowed the bike down quickly. Again not sure if it is back to normal or not.

Something is still off, and I did not dare ride further.

Back home I checked the heat on the rotors. One side was hot and the other was almost cooled down, that was at least a clue. I did this before the cleaning and the heat was exactly the same then. I did do a more thorough job on the one that was cooler (with the moving of the pistons etc) so I went to work on the other one again and made it perfect.

I have not gone for another test ride but the wheel spin test yields the same result as before so I don't think it helped.

[peteinpa]

I like your last brake retraction videos...But, wood has flex to it, and all the pistons didn't pull back. You need to use steel, and watch all the pistons. One piston sticking is all it takes.

Concentrate on the hot caliper from the ride.

Edited February 6, 2021 by peteinpa

[peteinpa]

Watch this video and follow it verbatim. 

I have to admit I didn't do the caliper alignment, to me there just isn't much play in the caliper mounts.    But try it anyway.

[petshark]

The previous post was long enough and covers everything I tried. I have another idea though; could be nothing but I would like to check with you all what you think.

Some of you may have read my suspension/geometry post. It struck me that the tuner did not use any measuring device when he raised the forks in the triple clamp. At the handlebar clamps they look equal but below I measured a difference.

visible fork above upper bracket

L= 14.95 mm / R = 15.12 / Diff = 0.17 mm or 0.0067 inch (very small difference)

between upper and lower bracket (measured with distometer)

L = 209.9 / R = 209.5 mm / Diff = 0.4 mm or 0.016 inch

lower bracket to line on fork (analog measured = less precise)

L = 13.5 mm / R= 12.5 mm / Diff = 1.0 mm or 0.039 inch

lower bracket to bottom of fork (measured with distometer)

L = 530.50 mm / R = 531,10 mm / Diff = 0.60 mm or 0.024 inch

 

Does anyone think that having this 1 mm difference could be at play here? Could this offset the axle enough to cause problems in the bearings and dragging of the brakepads as the rotors are also slightly offset?

I honestly can't imagine that this could be the case as that would mean that the tuner messed up big time. Surely he knows what he is doing? He works on race bikes all the time on the track...

 

[petshark]

57 minutes ago, peteinpa said:

Watch this video and follow it verbatim. 

I have to admit I didn't do the caliper alignment, to me there just isn't much play in the caliper mounts.    But try it anyway.

This is exactly how I did it. Except the Tracer does not have 4 pinch bolts but just one. But it could be an extra argument for the measurement above to have to be exact perhaps? But I did ride around for a while without problems after that. That's the confusing part, this problem seems to have come out of nowhere.

1 hour ago, peteinpa said:

and all the pistons didn't pull back. You need to use steel, and watch all the pistons. One piston sticking is all it takes.

Which one? I can see all of them moving back and forth when I enlarge the video.

Edited February 6, 2021 by petshark

[Lone Wolf]

17 minutes ago, petshark said:

Does anyone think that having this 1 mm difference could be at play here? Could this offset the axle enough to cause problems in the bearings and dragging of the brakepads as the rotors are also slightly offset?

No I don't think it would cause what you are experiencing.

Think about front forks with compression damping in one leg. The difference in force acting on left and right fork leg would be much more than this height adjustment - but it works out OK because the axel secured to forks creates a single unit.

I know you didn't pull the front wheel just before all this trouble, but that is where the binding would occur is improper spacer or axle placement pushing the disk rotor out of place in relation to the calipers. But you didn't touch that stuff so it is a mystery.

Edited February 6, 2021 by Lone Wolf

[Lone Wolf]

5 minutes ago, petshark said:

Which one? I can see all of them moving back and forth when I enlarge the video.

Right, I could see all of them moving. Looked normal.

[peteinpa]

Remember in the 80's when all bikes came with fork braces? Now we have forks that don't even do the same thing on both sides.

I just had my whole front off. I set one fork at 10mm above the triple then set the other by how smooth the bare axle goes through and alligns with the threads. The end result is 2-3 mm difference at the top.

The important part is alignment at the bottom with both forks unloaded.