My solution to left brake cluncking on bumps...

Won't that decease you rear brake pressure????

ToddC

No. the spring isn't stiff enough to prevent the rear brake action, just stiff enough to hold in place...

Does mine clunk? If the SMC is full of fluid won't it cushion any possible movement?

Sometimes if a little play develops in the SMC, it reverberated through the forks and sounds like some loose plastic rattling in the fairing. Combining with bleeding the system helps.

It's not my place to tell another person what to do, however, I should point out that the ONLY time the SMC develops movement that causes noise is when there is either air in the system from an improper bleed, or worn needle bearings at the pivot point.
I would be very concerned with ANY type of modification to a brake system.

How many miles on the bike????

I agree with loose pivot or other linkages. Non of my three clunk that I'm aware of. Will be listening more closely now.

ToddC

Mine has a rattle in it and has for about 160,000 miles or so. In my case it has been nothing to worry about. The brakes work great.

I think it comes from the SMC clevis pushrod where it presses against the piston or passes thru the washer under the boot. When the brake is not in use there is a small amount of clearance, enough for a metallic knocking sort of rattle. I replaced the pivot needle bearing about 50,000 miles ago because I wanted to not because it needed it and it made no difference. The noise can go away for a while after a flush and bleed but it's always returned.

Shoot, thought I could slip this under the internet police.. So for the record, Please do not try this at home, without adult supervision. My mom was watching and I slept in a Holiday Inn last night, so those factors made for a safe modification... So without further a due, the rattling or clunking is somewhat typical of this design, it may be very slight or very noticeable but this noise will not affect the operation of the brakes or cause any safety issues.. I posted this as I researched fixes for this I saw some others do things maybe not so good... I posted this as an alternative for others...

dduelin said:

Mine has a rattle in it and has for about 160,000 miles or so. In my case it has been nothing to worry about. The brakes work great.
...
The noise can go away for a while after a flush and bleed but it's always returned.

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Same here, and it has been that way since new (some noise is not a sure indication of a problem).

Ltimb said:

Shoot, thought I could slip this under the internet police.. So for the record, Please do not try this at home, without adult supervision. My mom was watching and I slept in a Holiday Inn last night, so those factors made for a safe modification... So without further a due, the rattling or clunking is somewhat typical of this design, it may be very slight or very noticeable but this noise will not affect the operation of the brakes or cause any safety issues.. I posted this as I researched fixes for this I saw some others do things maybe not so good... I posted this as an alternative for others...

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Ltimb, no worries. You won't meet everyone's approval. I'll assume you've checked that the smc still functions correctly (bike on centerstand, someone turns rear wheel and you rotate the smc forward to verify that it brakes the rear wheel).

1. Torch
2. Welder
3. JB Weld
4. Pry bar
5. Hammer

Just some of the things I would not use to repair, service, or alter a brake system on any vehicle.
I wonder what your insurance company will do if your ever in an accident and they
discover your ingenious little modification?
As far as design....they all rattle to some degree....etc.
I will have to respectfully disagree with those comments.
While I have only bled a couple ST1300's, from New off the showroom floor, to high mileage ones with 200k plus on them, none of them ever made noise after they were serviced, and remained quiet until their next service was due....
Just saying....

The healthy SMC compresses very little during operation, maybe 2 or 3 mm. On the bike in this video the brakes work well, as designed by Honda, and are in good operating condition.

Note there is a slight amount of play the opposite direction that is when the caliper moves backwards in tension which pulls the end of the clevis pushrod against the metal washer that the pushrod goes through. I am pulling the caliper bracket backwards. This makes the knocking noise or a rattle we sometimes hear. It's nothing to worry about. The original post's idea of slightly preloading the caliper bracket to take up this play would seem to have merit as long as it doesn't prevent the caliper from moving forward and working normally to apply rear brake. I'm used to it after 163,000 miles and don't worry about it.

Great new, My patent paid off, on my modification, and Honda just offered me $1-million dollars for the design as they admitted their design is faulty and because of static drag on the front caliper it produces slight pressure through the SMC causing the rear brake to drag and could cause a lock-up. Effective immediately they will order a recall on every ST1300 ever made to update to this design and highly recommend all park their bikes till they get it fixed. Estimated time to repair 18 month...

Seriously, all this does is hold the caliper in place so when you hit a bump is doesn't "clank" down, I can still take my pinky finger and move the caliper applying the rear brake..... For those that have never J-Walked in their entire life, you may respond with a stern scolding for killing off humanity..

Ltimb said:

For those that have never J-Walked in their entire life, you may respond with a stern scolding for killing off humanity..

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I would, but the nuke has already dropped from being double darkside.

Ltimb said:

Great new, My patent paid off, on my modification, and Honda just offered me $1-million dollars for the design as they admitted their design is faulty and because of static drag on the front caliper it produces slight pressure through the SMC causing the rear brake to drag and could cause a lock-up. Effective immediately they will order a recall on every ST1300 ever made to update to this design and highly recommend all park their bikes till they get it fixed. Estimated time to repair 18 month...

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Too late. I scanned the pic to a business associate in China last night. Production of the ST1300 Clank-No-More goes into production 7/1/16 with first shipments in the US 9/1/16. They are shipping them in bulk to a repair shop in San Jose, CA.

Ltimb said:

Great new, My patent paid off, on my modification, and Honda just offered me $1-million dollars for the design as they admitted their design is faulty and because of static drag on the front caliper it produces slight pressure through the SMC causing the rear brake to drag and could cause a lock-up. Effective immediately they will order a recall on every ST1300 ever made to update to this design and highly recommend all park their bikes till they get it fixed. Estimated time to repair 18 month...

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When can we expect the retrofit kit to be available and any ideas on the cost already? Hoping the 1 mil from Honda will help subsidize the effort!

Igofar said:

That's funny....my TROLL alert just went off on my computer......

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What kind of sound does that make?!

You may have to re-route them Dave....both my daughters are moving to Florida as you read this, and the wife wants me to retire and move there also to be close to our grandson...
Looks like we may have a brake bleeding showdown coming soon

Wonder what the insurance company would say if you were involved in an accident? A home made modification to the brake system might be a basis for denying a claim. If it were me, I would have spend the $125 for a new SMC assembly. The other thing that comes to mind, what damage did the heat transfer from the welding do to the seals in the SMC? Maybe there is a contributing factor to the rattle in your SMC... like maybe a heat spotted or slightly warped rotor, dry needle bearings, warn pivot pin, or air in the system that has already been mentioned.

vinny said:

Wonder what the insurance company would say if you were involved in an accident? A home made modification to the brake system might be a basis for denying a claim. If it were me, I would have spend the $125 for a new SMC assembly. The other thing that comes to mind, what damage did the heat transfer from the welding do to the seals in the SMC? Maybe there is a contributing factor to the rattle in your SMC... like maybe a heat spotted or slightly warped rotor, dry needle bearings, warn pivot pin, or air in the system that has already been mentioned.

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You've seen my bike Vinny. You know how it's maintained. It has none of the things you mention as possible factors. The brakes are in excellent condition and kept that way. Those defects of worn or defective parts are not present in the video and wouldn't contribute anyway, the rattle is apparent when going over a bump or a rough spot of pavement when no brake force is applied. Braking applies force that takes up any play in the SMC assembly and there is no noise braking over bumps and rough spots.

The insurance argument is specious. No accident investigator checks for car tires on wrecked bikes do they? Darksiders run this risk routinely.