Brake Rotors

Hi,

I have been feeling the front brakes pulsing when braking to a stop, not noticeable at speed or hard braking.

So the bike shop tells me the disc is warped. Now i don't know if it is one or both, or if it is the carrier that is bent.

So, how to tell if it is the carrier or the Rotor?
If it is a rotor then should i purchase just that one or replace as a set?
Can you buy just a rotor or just a carrier and are they able to be reinstalled on the non-bent bit?
I have seen various ones advertised, there is even NZ made ones and Chinese ones, does anyone have any experience with non-MG rotors?

BTW, i have checked all the bobbins and the rotors are all loose on the carriers.

Some, years back, because they were "warped" had pad buildup on them. Turns out the bobbins were the culprits. Might be worth a clean with disc cleaner - then go our and do a few hard stoppies to ensure the buildup (if any) is gone. Bit of fun anyway...

Best replacements.
Grimeca rotors off an early RSV4 (don't know if current model is the same)
Can only purchase from Aprilia dealer .............. in Europe they were only Euro130 each.

Why? Cheap compared to most alternatives. AND THE LIGHTEST DISCS AVAILABLE.
Local product (Metal Gear) are AUD$200 each.
I imported BrakeTech Axis-Iron rotors from America, cost me nearly AUD$1000 a pair and they are still heavier than the Grimeca's.

For once I agree with Wayne. Get the Grimeca's. You'll see rainbows, frolicking ponies, and unicorns. I did.




I know where there's a new pair for sale. Cheap.

[You must be registered and logged in to see this image.]

beetle wrote:

For once I agree with Wayne. Get the Grimeca's. You'll see rainbows, frolicking ponies, and unicorns. I did.




I know where there's a new pair for sale. Cheap.

[You must be registered and logged in to see this image.]

Are they wave discs?

No.

Good, I'll pm you

You feel the pulsing on the lever or on the handlebar? The steering bearings may need tightening/replacement

Interesting. I have the same issue with my GRiSO. A slight pulsing through the lever when coming to a stop. Can only feel it on light front brake applications at low speeds. Not bad enough to be annoying, but it’s there nonetheless.

Check the bobbins first [You must be registered and logged in to see this link.]

#3 for the bobbins and an easy fix!

After checking the bobbins measure the thickness of the brake disc over a number of points. Anything more than a 0.02mm variation will cause pulsing.

What I did to find out, take a piece of metal as thick as the disk, take one caliper off, and bind it to the forkleg. Put the metal in where normal the disk is. Fix that secure.

Drive and brake. Best on quest road. If no vibration it must be the other side. You can swap the test to be shure.

This is a dangerous test be careful!

Also clean pads, see if all pistons operate freely. Clean disks.

Replacement disks are the stelvio >2011 grimeca stock. The RSV4 are even better, look the same, but have a alu carrier, where the Stevio ones have steel carrier. I think now since Grimeca went out of business, Piaggio lets make in china, look the same, but no grimeca print on them.

Righto,
Step 1
Order Gremeca off ebay, beetle put me on to them
Step 2
Spray Brakleen over everything including the bobbins, and made sure the disc has freeplay.
find that the pulsing has gone away, at least for 20-30 kms.
Step 3
check out video above, realise that I need to make sure the bobbins rotate - Tomorrows job
step 4
check disc thickness as suggested - Tomorrows job
Step 5
Replace with Grimeca anyway, when they turn up. Can always do with more unsprung weight, or is that less unsprung weight

OK,

So with the new tyres, I thought I would get the Grimeca rotors put on as well.

The bike shop had a look and said i has two discs for the RIGHT side. So, there is an arrow on the rotor showing the direction of travel, and Lo and Behold, they both point the same way.

So the part no is 896011
Desription DISCO FRENO ANT DX D 320

Apparently there is a SX for left and the DX for right.

Anyone want to swap a new Grimeca right for a new Left?

I'm not too keen on putting one on backwards, any thoughts..


[You must be registered and logged in to see this image.]

MrGPz wrote:

I'm not too keen on putting one on backwards, any thoughts..

You would have good braking both forward and reverse!

Seriously, how do they differ?

I have pair of replacement brembos on my and they can go either way - Could understand if they were vented discs & sort of if they had ABS integrated on back but agree with Dave on 'why'?

paulbrice wrote:

I have pair of replacement brembos on my and they can go either way - Could understand if they were vented discs & sort of if they had ABS integrated on back but agree with Dave on 'why'?

I was researching further (i.e. Google) and they did mention something about ABS

You could be right about that.
I need to see what OEM bike they are for and see if it has ABS, if so then they could be good to use the GRiSO.

Cheers

MrGPz wrote:

I need to see what OEM bike they are for and see if it has ABS, if so then they could be good to use the GRiSO.

Check this, Piaggio dealers site, Greek language but you'll recognize the bikes. (3 pages list)
[You must be registered and logged in to see this link.]

Seems that 896011 (RH) and 896012 (LH) have alternative (new) codes, B044279 (RH) and B044280 (LH), much lower price, cant tell if its the same thing or some low cost crap - could be "Brambo"? (I don't trust Piaggio much)