Brake rotor replacement

[PaulBK7]

Just had a 24k service and have been advised that both front rotors are on the limit 4.1 and 4.o5 and the rear is 0.5 under the minimum limit (checked myself with a mic and they are).
Now i know the safest thing to do would be to change them but has anyone got any ideas on how far past the minimum limit you can go before you're into danger territory.
Have to say i can't believe that the rotors are worn after only 24k they must be made from cheese, very poor.

 

[(RIP) DitchWater]

Don't worry about it until your MOT or the braking becomes a problem; have a look at a couriers' front brake discs...

 

[Boxerboy55]

Do you like stopping on a sixpence when the need arises? Yes?
Then maybe new discs are in order. You may find non-BumWee discs that are better and cheaper than the originals. Dig around with some of the peeps who advertise around here. Changing discs is pretty straightforward.
Would be interested to know what new discs measure in at to understand the wear rate. Indeed the originals may be of the cheese variety

Perhaps a different brand of pads will help in future too.

 

[Fluffy Bridges]

Just had a 24k service and have been advised that both front rotors are on the limit 4.1 and 4.o5 and the rear is 0.5 under the minimum limit (checked myself with a mic and they are).
Now i know the safest thing to do would be to change them but has anyone got any ideas on how far past the minimum limit you can go before you're into danger territory.
Have to say i can't believe that the rotors are worn after only 24k they must be made from cheese, very poor.

As and when you need to change then have a talk to James Sherlock. He's got some reasonable replacements. Advertises on here.....

Fluff

 

[(RIP) DitchWater]

As and when you need to change then have a talk to James Sherlock. He's got some reasonable replacements. Advertises on here.....

Fluff

Make sure he sends what you ask for and make sure you know what you need beforehand...

 

[alex_rsa]

Ran mine to about 0.5mm thinner than that, only changed them when the MOT man said they were a bit thin.

They only start at 5mm so you have probably got another 10k miles if you ignore BMW.

If you have a pre-2008 bike (I think) without the floating disks you can get non-oem replacements. I think mine are Hakane(?), took about a week to bed in as the machined holes seem to have lips on them.

 

[Spike]

I got mine from sherlock who advertise on here.
make sure you get new bolts ,old ones might look nasty, and also be sure to get all new washers too, both sets, the flat ones and the crinkle ones. This is recomanded on the bmw repair disc.

When changing them make sure you note which way they come off the bike (the washers that is) as they need to go back exactly the same way.

spike

 

[(RIP) DitchWater]

They only start at 5mm so you have probably got another 10k miles if you ignore BMW.

Or 4.5mm which is why I said make sure you get the ones you want because you will need additional parts as described below.

I got mine from sherlock who advertise on here.
make sure you get new bolts ,old ones might look nasty, and also be sure to get all new washers too, both sets, the flat ones and the crinkle ones. This is recomanded on the bmw repair disc.

When changing them make sure you note which way they come off the bike (the washers that is) as they need to go back exactly the same way.

spike

Change them if they are broken but otherwise you could save the money for a couple of pints and a pie.

 

[davegs]

Discs

When the are tansparent start worrying! then see Steptoe his discs are No1.
dave GS. ( In an nartical in the Daily Telegaphs "Honest John" car help colume.
He reckoned the since asbestos was banned for brake pads a softer grade of disc material has been used to give a better friction coefficiant.

 

[Spike]

Change them if they are broken but otherwise you could save the money for a couple of pints and a pie.

It says on the reprom disc from BMW that the washers must be changed, these are pennies anyways, ok the bolts are more a cosmetic thing so you could save a little there. But nothing worse than getting the bike stripped the 9 bolts out and the last one rounds off because it is stuck in so tight so a new one is needed anyways, its may be just me but I changed mine, just for this reason.

spike

 

[Sgt Bilco]

Be very careful changing the rear disc as it's very easy to strip the torx holding the disc to the rear drive. DAMHIK

 

[The Grey One]

He's right you know

When the are tansparent start worrying! then see Steptoe his discs are No1.
dave GS. ( In an nartical in the Daily Telegaphs "Honest John" car help colume.
He reckoned the since asbestos was banned for brake pads a softer grade of disc material has been used to give a better friction coefficiant.

Same with cars, we had an increase in sales of discs when asbestos in pads went. Many cars need new discs each time the pads wear out!

Problem with manufacturers quoted minimum thickness is they are bound to err on the side of safety. Think back (a long way in my case) to schoolroom physics. Energy of vehicle is converted to heat heat when braking and if the discs are too thin they can't cope. Manufacturers have to specify for worst case-fully loaded, high speeds, continuous braking etc. In the real world you can probably get away with thinner discs but my experience of insurance company engineers is that they would recommend refusing a claim should the discs be below spec. I worked for 30 years in the motor trade and saw this happen many times-the engineer checks the obvious, tyres etc and on a bike the discs are in plain view. So yes you could get away with it but it could cost you lots if the worse happened.

John

 

[Pukmeister]

The rear disk bolts are fitted into the alloy disk carrier hub with Loctite. Be sure to use a hot air gun to soften the Loctite prior to undoing, otherwise you risk cracking the hub. Check the hub fingers for cracking anyway, do a search on here and you should find the posting regarding this.

 

[PaulBK7]

The rear disk bolts are fitted into the alloy disk carrier hub with Loctite. Be sure to use a hot air gun to soften the Loctite prior to undoing, otherwise you risk cracking the hub. Check the hub fingers for cracking anyway, do a search on here and you should find the posting regarding this.

FFS! Not only do you have to change them as frequently as an old tart changes her drawers but they make it so you f**k up another component when removing then........incredible!!!!.
Thanks for the heads up.

 

[Mark Hooton]

mmmm

Just had a 24k service and have been advised that both front rotors are on the limit 4.1 and 4.o5 and the rear is 0.5 under the minimum limit (checked myself with a mic and they are).
Now i know the safest thing to do would be to change them but has anyone got any ideas on how far past the minimum limit you can go before you're into danger territory.
Have to say i can't believe that the rotors are worn after only 24k they must be made from cheese, very poor.

do whatever you want pal but try not to put your life in any danger eh? there`s enough fools out there trying to kill us, you don`t wanna add to that risk through trying to extend any safe service life.

Ride safe.