Author Topic: Excessive brake pad dust and pad rubbing? (Read 4527 times)

Pielz · « **on:** July 07, 2020, 05:01:15 PM »

I have what I believe to be either organic or semi-metallic pads on my front brake (750 k7 with an early DOHC wheel swap, single front disk) and there's a good bit of black brake dust on the front of my engine after a long ride. Is that normal? Like does anyone else experience this? I guess it could just be the pads I bought but who knows. I can't go back and check the listing to see the material used cause the eBay listing has expired.

Pielz · « **Reply #1 on:** July 07, 2020, 05:02:47 PM »

Oh also the front brake makes a slight rubbing/ticking noise that gets louder when I pull the brake and is directly related to my speed. Goes away after I get up to 20-30 mph. Not sure what's rubbing but it just started recently.

bryanj · « **Reply #2 on:** July 07, 2020, 10:48:07 PM »

Neither normal nor good would suspect misalignment caliper to disc and caliper sticking

Pielz · « **Reply #3 on:** July 07, 2020, 11:00:43 PM »

Quote from: bryanj on July 07, 2020, 10:48:07 PM

Neither normal nor good would suspect misalignment caliper to disc and caliper sticking

How would you go about attempting to resolve that? I rebuilt the caliper with new seals and whatnot not long ago..

I've put about 200 miles on the bike since then and it only started in the last 50 miles or so

grcamna2 · « **Reply #4 on:** July 07, 2020, 11:36:48 PM »

Have you checked the alignment and spacing of the caliper as it interfaces with your rotor from the non-stock wheel,possibly the spacers might need adjustment to center the caliper ?

ekpent · « **Reply #5 on:** July 08, 2020, 06:19:57 AM »

After a ride sometime when things are hot put it up on the center stand if you still have one and see how easy the front wheel turns. If it turns hard then your caliper is not retracting well. Could be the caliper, a collapsing or partially blocked brake line or the return hole on the master cylinder. You can check the disc also aftera good hard ride to see how hot it is.

grcamna2 · « **Reply #6 on:** July 08, 2020, 08:56:58 AM »

Quote from: ekpent on July 08, 2020, 06:19:57 AM

After a ride sometime when things are hot put it up on the center stand if you still have one and see how easy the front wheel turns. If it turns hard then your caliper is not retracting well. Could be the caliper, a collapsing or partially blocked brake line or the return hole on the master cylinder. You can check the disc also aftera good hard ride to see how hot it is.

This.

Pielz · « **Reply #7 on:** July 08, 2020, 09:04:38 AM »

Quote from: ekpent on July 08, 2020, 06:19:57 AM

After a ride sometime when things are hot put it up on the center stand if you still have one and see how easy the front wheel turns. If it turns hard then your caliper is not retracting well. Could be the caliper, a collapsing or partially blocked brake line or the return hole on the master cylinder. You can check the disc also aftera good hard ride to see how hot it is.

Okay, I'll do this! I do still have a center stand.

Some more info: my brake line is basically brand new. Bought a stainless steel brake line. Also, and this is probably the issue, I have a cheap master cylinder. One of those Chinese brake/clutch combos you can get for like 40 bucks on eBay. My stock one was toast. I still have it though so I could potentially rebuild.

Stev-o · « **Reply #8 on:** July 08, 2020, 10:07:16 AM »

Quote from: Pielz on July 08, 2020, 09:04:38 AM

Quote from: ekpent on July 08, 2020, 06:19:57 AM
After a ride sometime when things are hot put it up on the center stand if you still have one and see how easy the front wheel turns. If it turns hard then your caliper is not retracting well. Could be the caliper, a collapsing or partially blocked brake line or the return hole on the master cylinder. You can check the disc also aftera good hard ride to see how hot it is.

I have a cheap master cylinder. One of those Chinese brake/clutch combos...

Guess you got what you paid for! Dont buy cheapchinacrap for your Japanese bike!!
Now it will end up costing you more getting it to work properly.

DSS sells good aftermarket master cylinders if you decide to go that route.

Pielz · « **Reply #9 on:** July 08, 2020, 10:19:13 AM »

Quote from: Stev-o on July 08, 2020, 10:07:16 AM

Quote from: Pielz on July 08, 2020, 09:04:38 AM
Quote from: ekpent on July 08, 2020, 06:19:57 AM
After a ride sometime when things are hot put it up on the center stand if you still have one and see how easy the front wheel turns. If it turns hard then your caliper is not retracting well. Could be the caliper, a collapsing or partially blocked brake line or the return hole on the master cylinder. You can check the disc also aftera good hard ride to see how hot it is.

I have a cheap master cylinder. One of those Chinese brake/clutch combos...

Guess you got what you paid for! Dont buy cheapchinacrap for your Japanese bike!!
Now it will end up costing you more getting it to work properly.

DSS sells good aftermarket master cylinders if you decide to go that route.

Yeah honestly I usually don't buy Chinese when I can help it but when I do I usually stick to things that at least have decent ratings/reviews. It was meant to be a temporary solution but kinda forgot about it haha. I had to replace the left perch so I needed to get a clutch lever that didn't integrate controls. I'll check DSS and see what they have that can work for me.

grcamna2 · « **Reply #10 on:** July 08, 2020, 05:10:37 PM »

I like DSS,they're shipping is only $10 from England as they have a warehouse in PA.,you can order a few things and make it worthwhile.I've called them also to inquire about things they have but it's best to call them in the morning because of the time difference.

Pielz · « **Reply #11 on:** July 08, 2020, 05:16:55 PM »

Quote from: grcamna2 on July 08, 2020, 05:10:37 PM

I like DSS,they're shipping is only $10 from England as they have a warehouse in PA.,you can order a few things and make it worthwhile.I've called them also to inquire about things they have but it's best to call them in the morning because of the time difference.

Oh neat! Yeah I'm considering getting a nice quality brake master cylinder from DSS. Need to get a matching clutch lever though as the one I have is black and would look weird if the brake lever was silver

BenelliSEI · « **Reply #12 on:** July 08, 2020, 06:23:18 PM »

Beware of original rubber brake hoses. I’ve seen more than a couple that look good, but are so deteriorated inside they act as a check valve. The master cylinder forces fluid to the caliper, but the hoses close down and don’t allow the pressure to release when you let go of the lever......

Pielz · « **Reply #13 on:** July 08, 2020, 06:31:12 PM »

Quote from: BenelliSEI on July 08, 2020, 06:23:18 PM

Beware of original rubber brake hoses. I’ve seen more than a couple that look good, but are so deteriorated inside they act as a check valve. The master cylinder forces fluid to the caliper, but the hoses close down and don’t allow the pressure to release when you let go of the lever......

I actually ended up using stainless steel brake line that had good reviews online. I'll try replacing the master cylinder with the spare I have and see if that changes anything. If it fixes it I'll be sure to buy a better one so it doesn't happen again. If it doesn't I'll look in to the line and whatever else has been suggested

scottly · « **Reply #14 on:** July 08, 2020, 06:58:27 PM »

Quote from: Pielz on July 07, 2020, 05:01:15 PM

I have what I believe to be either organic or semi-metallic pads on my front brake (750 k7 with an early DOHC wheel swap, single front disk)

Don't be so quick to blame your cheap master cylinder.

Is the DOHC wheel a comstar with a five bolt mounting disc? Please show a picture of the brake and K7 caliper from the side, and from the top looking down.

Pielz · « **Reply #15 on:** July 08, 2020, 07:01:30 PM »

Quote from: scottly on July 08, 2020, 06:58:27 PM

Quote from: Pielz on July 07, 2020, 05:01:15 PM
I have what I believe to be either organic or semi-metallic pads on my front brake (750 k7 with an early DOHC wheel swap, single front disk)
Don't be so quick to blame your cheap master cylinder.
Is the DOHC wheel a comstar with a five bolt mounting disc? Please show a picture of the brake and K7 caliper from the side, and from the top looking down.

The forks and caliper were swapped too so it's a caliper from a year that was designed to work with those comstars. I'll see if I can dig up an example pic. More detailed pics will be tomorrow as it's dark here now!

Pielz · « **Reply #16 on:** July 08, 2020, 07:04:04 PM »

May have to zoom but you can see the setup in this pic. I'll take better photos tomorrow

grcamna2 · « **Reply #17 on:** July 08, 2020, 07:06:45 PM »

That front tire could be rubbing on your fender? it's huge for the application,it could be out-of-round.

scottly · « **Reply #18 on:** July 08, 2020, 07:08:51 PM »

OK, I thought you were using a K7 caliper with the comstar; didn't realize you swapped forks also. Still, not sure the MC is to blame..

Pielz · « **Reply #19 on:** July 08, 2020, 07:15:16 PM »

Quote from: grcamna2 on July 08, 2020, 07:06:45 PM

That front tire could be rubbing on your fender? it's huge for the application,it could be out-of-round.

It does totally look huge doesn't it? It's a 110/90 19" so it's not an uncommon size but it is very close to the fender. I can hear pebbles bouncing around in there sometimes

scottly · « **Reply #20 on:** July 08, 2020, 07:17:24 PM »

Tires "grow" with speed.

Pielz · « **Reply #21 on:** July 08, 2020, 08:12:57 PM »

Quote from: scottly on July 08, 2020, 07:17:24 PM

Tires "grow" with speed.

Is it significant? I've only had the thing up to like 75 or so and haven't seen the fender get hot. I'll keep an eye on it. I'd imagine it'd heat up like crazy if it's rubbing

scottly · « **Reply #22 on:** July 08, 2020, 08:16:18 PM »

It depends how close the fender is; it doesn't take too much rubbing to make black tire dust.

Pielz · « **Reply #23 on:** July 08, 2020, 08:33:56 PM »

How would I remedy that? Buying a smaller wheel?

grcamna2 · « **Reply #24 on:** July 08, 2020, 08:39:18 PM »

Quote from: Pielz on July 08, 2020, 08:33:56 PM

How would I remedy that? Buying a smaller wheel?

A lower profile tire;is that tire what they run on the DOHC donor bike front ?

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Author Topic: Excessive brake pad dust and pad rubbing? (Read 4527 times)