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CBR650F Insane front brake drag

How many revolutions do you get on the front wheel when trying to spin it

  • Less than 1

    Votes: 0 0.0%
  • 1 revolution

    Votes: 0 0.0%
  • More than 1 revolution

    Votes: 0 0.0%

  • Total voters
    0

TondeuseMaxxxer

2015
CBR650F ABS
May 16, 2024
Riding Since
2024
Hi everyone, first time posting here, such a nice forum that has already helped me a lot with my CBR650F (2015) that I got 3 months ago.
It had 21k km when I bought it and now has over 25k ! I just did a big service on it with :

-engine oil + filter
-replaced air filter, put new spark plugs (iridium)
-coolant flush with a big big cleaning with vinegar and distilled water multiple times (there was quite a lot of rust)
-brake bleed

My chain is dead and I'll replace it soon, didn't do the valve clearance yet, the garage I bought it from told me it's unecessary until ~40k km but I'll probably still do it soon when changing my chain+ sprockets.

The bike works really fine, except for the front brake ! Ever since I had the bike, the front brake has been noisy, a squeal that only happens at very low speeds. The garage I bought it from told me to be gentle on the front brake because they had put new front pads were, so I just thought the noise was because the pads needed bedding. 4000km and the squeal is still there !
I've tried everything, cleaned everything, pistons, pads, caliper, retaining pins, anti rattle clips, I put copper grease, I tried with nothing, the noise kept coming back, the only time there was a slight relief was when I went to clean the bike and everything was wet, for 5-10km the noise was gone lmao.

Apart from the noise, I've also observed that there was a really big brake drag, I got a front wheel stand and the wheel doesn't even turn 1 revolution when trying to spin it, it moves like 10cm, literally like if I was applying brakes.

So I thought calipers were stuck, I've dissassembled the calipers completely, looked at the piston seals and they seemed in good condition (I might have been wrong). The pistons are also in good shape, only a very very slight pitting on one piston on the left caliper. When putting back the pistons, they slided in with no resistance, so I thought ok should be fine now !?
The only thing I haven't looked at is the front master cylinder, maybe it has debris in it.
The other thing I suspect are the brake hoses, the bike is almost 10 years old (2015) maybe the hoses have collapsed inside or are damaged ?

I guess my option now is to buy a seal kit for the front, test that, if it doesn't change anything look at the master cylinder, and I might also change the brake hoses and put braided steel ones, even after bleeding the brakes the lever feels a bit spongy not very firm (maybe some air bubbles are stuck in the master cylinder ?).

What do you guys thing, and for guys that have the CB/CBR650F with these shitty floating Nissin calipers, how many revolutions do you get on the front wheel and do you have issues with brake drag ?

Thanks 🙏
 

miweber929

2014
CBR650F
650 Alumnus
Staff
Feb 13, 2015
Woodbury, MN
Riding Since
1975
Absolutely nothing wrong with the Nissin calipers on the bike as it comes so no reason to call them shitty because they are not.

You‘ve done most of what I would have and i find about 1 revolution is not uncommon on done bikes. If the front wheel in correctly? Are the bearing in the wheel good? Are the rotors out of round? Are they at the end of their life?

Some brake pads do have a noise, EBC HH do have a strange noise a tick until you get used to it so it may just that. Is that’s what in it?

If the braking performance is fine, I would say leave it as long as the pistons retract correctly and release as they should. As far as replacing lines, remember you have ABS so that needs to be bled as well but those can help, I doubt they will make a difference, though. That’s more a power or feel.

I would say rebuilding with new seals may be needed if everything else checks out.
 

miweber929

2014
CBR650F
650 Alumnus
Staff
Feb 13, 2015
Woodbury, MN
Riding Since
1975
I don’t know of anyone in 45 years plus of riding and repairing motorcycles that have replaced a brake line unless it’s failed or upgrading to steel lines. The book also recommends replacing your coolant hoses as well but again I’ve never known anyone to do it until it breaks or hardens.

Just food for thought.
 

Redrocket

CBR650R
Mar 17, 2023
Riding Since
1968
I agree few bother; I don't either but I did once have a solid-looking front brake hose on a Triumph start to break up at around 10 years. It caused the symptoms here. I usually put braided on when the brakes start going mushy.
 

TondeuseMaxxxer

2015
CBR650F ABS
May 16, 2024
Riding Since
2024
Thanks for the response guys, I might have done a stupid thing and simply put too much brake fluid when bleeding the brakes. 🤣
I've removed a good amount of the brake fluid from the reservoir (although I might have removed too much since the pads aren't very worn) and now the noise is gone and the wheel seems to have less drag.

I'll put the wheel on the front stand and see tonight
I think the pads on there are the EBC HH model, I'll confirm that as well.
I guess Nissin didn't do anything wrong but why doesn't the bike have floating rotors and a fixed caliper instead of a floating one ? I see almost every bike even older than 2015 with floating rotors.
 

miweber929

2014
CBR650F
650 Alumnus
Staff
Feb 13, 2015
Woodbury, MN
Riding Since
1975
Thanks for the response guys, I might have done a stupid thing and simply put too much brake fluid when bleeding the brakes. 🤣
I've removed a good amount of the brake fluid from the reservoir (although I might have removed too much since the pads aren't very worn) and now the noise is gone and the wheel seems to have less drag.

The reservoir is marked with a minimum and maximum line, there should be no reason not to know if it’s the right amount in there or not. The service manual linked in the resources section will also be a big help to you.

I guess Nissin didn't do anything wrong but why doesn't the bike have floating rotors and a fixed caliper instead of a floating one ? I see almost every bike even older than 2015 with floating rotors.
Cost. The bike was built to a budget and the brakes are one of the areas to cut costs. Once they went to inverted forks on the R model they went to a more “modern” setup (though arguably still a budget brake) but with the conventional forks it was a standard setup to save money. There’s nothing inherently wrong with it, when properly maintained they stop the bike adequately, and bikes have used that system for many years without issue. Fresh fluid, good pads, and if you’re up to it, steel brake lines will give you more power than you know what to do with.
 

TondeuseMaxxxer

2015
CBR650F ABS
May 16, 2024
Riding Since
2024
The reservoir is marked with a minimum and maximum line, there should be no reason not to know if it’s the right amount in there or not. The service manual linked in the resources section will also be a big help to you.


Cost. The bike was built to a budget and the brakes are one of the areas to cut costs. Once they went to inverted forks on the R model they went to a more “modern” setup (though arguably still a budget brake) but with the conventional forks it was a standard setup to save money. There’s nothing inherently wrong with it, when properly maintained they stop the bike adequately, and bikes have used that system for many years without issue. Fresh fluid, good pads, and if you’re up to it, steel brake lines will give you more power than you know what to do with.
When I bled the brakes I topped brake fluid right at the upper limit which might have been too much since the pads weren't new. I've actually pirnted some of the service manual when servicing the bike, helped quite a bit for removing the air box with all the hoses and attached cables.

I confirm the wheel now does like 2 revolutions so its all good.
I guess the main thing with a floating caliper is that it must be maintained regularly, especially the sliding boots, I've also done that and put fresh silicone grease in there + new boots.
 

Brammers

2014
CBR650F ABS
Staff
May 30, 2014
Hampshire, England
Silicone grease should be fine there as it's usually plastic safe, however the best thing for the slide pins/boots is called "red rubber grease" and is specially designed to not cause the rubber to swell and bind the caliper.

J
 

TondeuseMaxxxer

2015
CBR650F ABS
May 16, 2024
Riding Since
2024
Silicone grease should be fine there as it's usually plastic safe, however the best thing for the slide pins/boots is called "red rubber grease" and is specially designed to not cause the rubber to swell and bind the caliper.

J
I actually put dielectric grease since I bought it to clean and regrease the left commands (high beam passing light button was sticky) and it was the only thing good for rubber I had. But silicone grease = dielectric grease right ?
 

TondeuseMaxxxer

2015
CBR650F ABS
May 16, 2024
Riding Since
2024
Talking about grease do you gyus put copper grease on the back of the pads, & the retaining pin and clips or do you put everything dry ?
 
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