Front brake pulsating

[SoBurn]

Hi all
Just joined this group. I ride a trimph bonneville america, in california, oregon and nevada mostly. was researching a front brake pusating problem with my bike and found that others have had the same issue with the bonny front brake disc uneven cooling causing parts of the disc to be harder (denser) than other parts, thus causing the severe pulsating and diving at low speeds. does anyone think that, if i cleaned the disc well and put it in a hot oven (450) for a cirtain time, that this would help the pulsating problem?
look forward to hearing from you

 

[Dilligaf]

Re: new to triumph talk-front brake pulsating

Welcome to TT, I am unable to answer but I am sure someone will soon.

 

[The Seeker]

Re: new to triumph talk-front brake pulsating

I know people here have talked about this problem, but I can't recall what was said (I don't own a new Bonneville).

But I doubt that heating it in an oven will correct the problem....I think once it's messed-up, it going to stay that way.

Hopefully one of the folks that knows more about this Bonneville rotor problem will see this and chime in.

 

[devo]

Re: new to triumph talk-front brake pulsating

Hi SoBurn
warped discs was a common issue with the earlier americas and speedmasters.
I bought my first speedy as a three year old bike in 2007 and it had a warped disc which was replaced by the dealer as a warranty issue even tho the bike was out of warranty.
You dont mention the age of your bike, but it would still be well worth talking to your dealer and see if you can get it replaced under warranty.
Oh, and welcome to TT

 

[Silli]

If you put it in the oven (to stress relieve it) it may warp some more, and it also may affect the structure of the material adversely. Either way it would require machining afterwards.

Suggest you get a new rotor. :y8:

 

[Rocky]

I'm having the same problem with my Bonneville.
According to what I have been able to find out it's caused by light braking resulting in the condition described by SoBurn.
Once it has happened replacing the disc seems to be the only solution and then don't be easy with the front brake.
Over the winter I think I'll install a floating rotor and pads kit.

 

[DaveM]

This worries me as I don't really hit my breaks that hard most of the time use the gears to slow down

 

[avion]

Silli +1

 

[Rocky]

This worries me as I don't really hit my breaks that hard most of the time use the gears to slow down

Many riders "gear down", but I prefer to use the brakes.
According to the sources I've found going easy on brakes is not the thing to do as it causes hard spots in the rotor which eventually causes the pulsing action.
And once it has happened there isn't much you can do about it except replace the rotor.
My Buddy Carl has a BMWGS and he's having the same sensation with his front brake. He's not an aggressive rider and is easy on brakes.
Many refer to this as a warped rotor, but it's actually soft and hard spots caused by light braking and not imposing a hot heat cycle on the rotor.
A couple of months ago I posted a question and answer thread about this problem, but I don't know how to find it or bring it forward here.

 

[Rocky]

https://www.triumphtalk.com/showthread.php/11112-Bonneville-brake-disc-warping?

I'm a computer genius! I found the thread.
I had nothing the fear but fear itself

I can't believe it was 10 months ago that I brought this up. It seems like just a couple of months ago.

 

[DaveM]

Wow I also thought it was just the other day when you mentioned it

 

[avion]

Yeah, these days you mustn't be kind to discs. Give 'em hell. The hotter they get the better for them.
I know of a few riders who don't really used the brakes much, they suffer from warped discs.

0.02

 

[Rocky]

Wow I also thought it was just the other day when you mentioned it

It was last February that I started a thread about pulsing brakes, but it was also a month or so ago that I again brought up the subject in a new thread so you're not imagining things

 

[Gromit]

Please can I answer this one??

I don't know about 'pulsating' brakes but when my brakes were squeeking, I grabbed the WD40! Luckily Farside was there to stop me. Whatever you do, DON'T use the WD40 on any brake problem.

Sincerely
The Technical Guru

 

[Rocky]

Please can I answer this one??

I don't know about 'pulsating' brakes but when my brakes were squeeking, I grabbed the WD40! Luckily Farside was there to stop me. Whatever you do, DON'T use the WD40 on any brake problem.

Sincerely
The Technical Guru

Thanks for the warning! I was just reaching for the WD40 when I saw your message
Phew, that was a close one

 

[DaveM]

 

[CarlS]

Good find, Rocky. Keep this up and you will be rivaling Dame for Geek of the Month!

 

[Silvergator]

SoBurn,
I replaced my front disk with a floating disk I got from Fast Eddy Sports. My brake started pulsing at about 16K miles and the dealer replaced it. Recurred around 30K. When I replaced the brake, I noticed that the caliper was not floating properly and that one side of the pad was not retracting so there could have been other problems. I could not detect a warpage problem with the disk by placing it on a glass plate. What I do know is that after replacing the disk with the floating disk, the brake has been perfect and I'm happy I made the switch however I wish I had checked the other problem before making the upgrade. I might have saved some money. Hope this helps.

Bill