Disc tips for avoiding their early demise

[Andre]

A few tips to get most out of your brake discs.

When installing discs clean the mounting surfaces (on hub and disc) meticulously. They have to be perfectly plane which includes being free of any matter.

The bolts have to be fastened to the proper torque using the over-cross technique with gradually higher torque applied (for the front that would be first all with 5 Nm, then 10, 15, 20, at last with 23 Nm)

The pistons need to be moving freely. Dirt, worn seals, and worn pistons need to be addressed.

Caliper pins must be clean, smooth and definitely without pitting so the pad can glide unimpeded. Do not apply things to them like oil, grease, etc. as this will attract dirt in a hurry. (EDIT: copper paste to the thread is good though)

Good for the fork and the discs. After remounting your front wheel, release right front fork tension by pushing straight down on the yoke without applying the bake BEFORE you tighten the two axle pinch bolts on the right fork leg.

Using a run-out Gauge to confirm that the disc runs true. The service limit is 0.30 mm according to the service manual. How much is acceptable for a new disc? On most European cars 0.025 to 0.05 mm run-out is recommended. (EDIT: Manufacturer of your discs is best source for that info. Don't bother if they are Chinese  )

[Eric GSX1400K3]

Noted and thanks - just fitted new METAL GEAR front rotors yesterday.  Runout I will have to check, but I agree that 0.05mm should be OK.  Thanks for the tip on the right fork tension, I expect that is due to the 100Nm required to tighten the axle bolt?

BTW: what tool do you use for the axle bolt?  Its a 1" (25.4mm) internal hex, requiring an external hex head driver - I made one out of a HD 1" bolt and nut, surely there must be a proper tool to use?  Im thinking a 3/4" drive 1" external Hex driver would do the job....

Minimum thickness is 4.5mm as specified on the rotor, the "old" discs were at this limit, but worse they were warped - created an 'undulating surge" feeling when braking to a stop in traffic.  Heavy braking was OK, but I decided to replace anyway.  Ive also re-set the suspension compression, rebound and preload settings, ensuring both L and R forks are the same.    calipers and brake pads are good, copper coat or "Nevaseize" (nickel based lithium grease on the caliper pins is also good).

[Andre]

BTW: what tool do you use for the axle bolt?  Its a 1" (25.4mm) internal hex, requiring an external hex head driver - I made one out of a HD 1" bolt and nut, surely there must be a proper tool to use?  Im thinking a 3/4" drive 1" external Hex driver would do the job....

No, it is not a 1" internal hex! The 14 is a proper metric bike. Proper is to always use METRIC tools 24 mm hex (Allen, Imbus) key is what you want.

[KiwiCol]

I've got a nut & bolt welded together & use 1 end in the axle & a socket on the other. Cheap as chips & does the job perfect.

[Andre]

Top  if you got a welder.

[KiwiCol]

Nah, I just brought the nut n bolt & took it to the local fabricators.  Welded it for nothing for me.  Nice guys.

[mlivkovich]

24mm...

[grog]

nut n bolt welded together, works fine for me.

[black14]

All Thread rod coupler from the hardware store and a socket or spanner on that...

[froudy]

I use an adaptor similar to this one...

[Mick_J]

I use an adaptor similar to this one...

Now that is posh 

[Eric GSX1400K3]

I use an adaptor similar to this one...

That's what I'm using as well. Especially since we're putting 100Nm on it to do up the axle bolt

[turner]

Im with Black 14, what we call a m16 treble nut makes it 24mm . easy 

[Kiwifruit]

Perfect fit.........came with my chainsaw !!

[mlivkovich]

Perfect fit.........came with my chainsaw !!

I hope it will handle 100 Nm or it will not damage the axle.