Worn discs

[GSTourer]

This thread isn't about warping its about disk thickness. But if your disks are warping there's something wrong with your bike - they don't do it of their own free will.

I am well aware of what the thread is about and making slightly, or even horrendously 'off topic' comments in threads is hardly something new on here is it?

As far as I am aware and the dealership were aware there was nothing wrong with the bike just the discs..........I think if you do a search on here you will find others who have had or are at least aware of the problem.

ALTHOUGH I DO REALISE THIS THREAD ISN'T ABOUT WARPED DISCS.

 

[Schtum]

So if your disks were not warped when originally fitted, what made them warp if it wasn't a problem with the bike?

I'm not sure what you're suggesting by "problem with the bike". A replacement set of discs and pads and all was well for the next 9K miles until I sold the bike.

 

[GSTourer]

I'm not sure what you're suggesting by "problem with the bike". A replacement set of discs and pads and all was well for the next 9K miles until I sold the bike.

I think he knows our bikes better than we do........maybe he has ridden them when we weren't looking

Strangely enough mine was exactly like yours.........new discs...fixed the problem up until recently (I still have the bike).

 

[Beemerman59]

I think he knows our bikes better than we do........maybe he has ridden them when we weren't looking

Strangely enough mine was exactly like yours.........new discs...fixed the problem up until recently (I still have the bike).

You're both missing the point. So what made the disks warp? Was it the pads binding, were they incorrectly fitted, were the disks out of true or what? Something makes them warp - they don't do it on their own

 

[Schtum]

You're both missing the point. So what made the disks warp? Was it the pads binding, were they incorrectly fitted or what? Something makes them warp - they don't do it on their own

Oh yes they do. If the design isn't particularly good and as I've already implied, I don't think that four pot calipers without fully floating discs are a terribly good idea. As I said, the early Multistradas which had exactly the same brakes also suffered from warped discs.

 

[Beemerman59]

Oh yes they do. If the design isn't particularly good and as I've already implied, I don't think that four pot calipers without fully floating discs are a terribly good idea. As I said, the early Multistradas which had exactly the same brakes also suffered from warped discs.

OK, so it could be that the design means the disks get hotter on one side more than the other....and due to variations in heat dissipation in the disk they warp. Maybe. Thats a potential cause.

 

[Schtum]

OK, so it could be that the design means the disks get hotter on one side more than the other....and due to variations in heat dissipation in the disk they warp. Maybe. Thats a potential cause.

I suspect that it's more to do with there not being enough float to allow radial expansion of the dics when they were hot and it was, therefore, converted into axial distortion. I think that later designs use different washers to allow a bit more float.

The above was probably exacerbated by demon late braking.

 

[Beemerman59]

I suspect that it's more to do with there not being enough float to allow radial expansion of the dics when they were hot and it was, therefore, converted into axial distortion. I think that later designs use different washers to allow a bit more float.

The above was probably exacerbated by demon late braking.

There we go then....a reason. Thanks

 

[jacro]

Warping is caused by overheating. Unless its my brain, which is just warped.
Rear disk starts its life at 4.5mm and is apparently worn by 4mm. I will take mine to 3.5 and then replace.
In an ideal world, my world, discs would be 8mm( feck the extra weight, minimal imho) and we wouldnt be worried for atleast 40,000 miles.
Cheers

 

[skywalker]

Disc wear is also accelerated by some brands of aftermarket pads and before you all say they're not I see evidence of it everyday. The other old chesnut on this subject is "I never use the back brake" - well it don't wear out on its own!!
There is no minimum thickness limit for the MOT. The tester has to assess in his opinion wether the disc is of an acceptable limit and not dangerous.
You cannot fail a bike because it says 4.5mm on the disc and the disc actually measures 4.0mm
What a lot of people do not seem to get with the MOT is that its the minimum standard for a vehicle to be deemed fit for road use.
When a vehicle is presented for test and issued with a pass certificate it signifies that on that day the vehicle in question past the standard reqd for it to be roadworthy, the following day it could illegal such as a lamp failure etc.

 

[GSTourer]

So if your disks were not warped when originally fitted, what made them warp if it wasn't a problem with the bike?

Perhaps it's a problem with the design of the discs?