Most probable cause of a....

[Shimster]

Pulsing front brake?

My '08 650GS (4000miles) has started to pulse when using the front brake at slow speeds and I've been told that it could be a warped front disc by my local dealer, and a cost of £180 for a new one. The bike hasn't done that high-a-mileage and I'm not a viscious braker by any standards, but does it sound right that the disc could be warped? Someone else suggested that it could be the pads, but I can't see why. As I've never had to replace a disc before, this is a new one to me

Have any other 650 owners (or any model to be honest) had similar problems?

 

[Micky]

Pulsing front brake?

My '08 650GS (4000miles) has started to pulse when using the front brake at slow speeds and I've been told that it could be a warped front disc by my local dealer, and a cost of £180 for a new one. The bike hasn't done that high-a-mileage and I'm not a viscious braker by any standards, but does it sound right that the disc could be warped? Someone else suggested that it could be the pads, but I can't see why. As I've never had to replace a disc before, this is a new one to me

Have any other 650 owners (or any model to be honest) had similar problems?

Yup ... your front disc appears to be warped

 

[Dave Ett]

That's about the only cause for a pulsing, unless the ABS system is playing up, and that'd feel pretty harsh.

Easy enough to check anyway - spin the wheel and use a marker pen against the fork leg to see where it's bent.

Skimming is possible providing the run out is tiny, the disks only have a wear limit od 0.5mm (down to 4.5mm).

 

[Tim Cullis]

The brake discs used on F-GS models have a lower chrome content than those used on the R-GS models which is why they rust so badly. The lower chrome content improves the braking ability, but also increases the wear rate. The more effective the brakes, the more likely the disc is to warp with heat. So goes the theory side.

I had to have new a new disc on my previous 2008 F650GS at about 18,000 miles. Do as Dave Ett suggests and if it is the disc (and your dealer could confirm this), buy a third party replacement and fit it yourself.

 

[Harleyquin]

Avmac7 had the front disk (on a 650GS) replaced twice because of a problem exactly like your's - the disk was badly warped. Finally, they replaced the front wheel because they decided that it wasn't true and was pulling the disk out of shape. Luckily this was all done under warranty.

P

 

[Shimster]

Thanks for the feedback I'll give my local dealer a call and get a new disc fitted. I'll mention about the front wheel maybe not running true at the same time, maybe they can check it while it's having the disc fitted. I recently extended the warranty on the bike, so hopefully it it does turn out to be the wheel, the warranty will cover it.

I'll let you know what the outcome is.

 

[Shimster]

Well, booked the 650 in to my loacl dealers today to have the new disc fited, and he told me that while it was in, that they would replace my chain and sprocket under warranty! One less thing for me to worry about eh