Oversized Brake Rotor Dragging - With Pictures

[Mighty_Whitey]

Hello fellow TTrs. I'm all out of ideas and hope to tap into some experience from the TT community. This is a real brain melter to me...

 

Bike: 2011 YZ450f

 

Issue: Front brake dragging, slightly (the wheel will complete 3 or 4 revolutions with a firm spin) but enough to overheat the rotor after about 2 minutes of ride time

 

Details: I recently purchased a Galfer 270mm oversize rotor kit, (seen here: http://www.motosport.com/dirtbike/Galfer-Oversized-Front-Brake-Rotor-Kit) with pads and relocation bracket. It's very important to know the brakes in stock form had absolutely no issue with dragging or heat. I have installed this same kit on my 04 and 06' YZ450f race bikes and am familiar with the process. After I installed the kit I could tell the brakes were dragging very aggressively, right away so I completely and thoroughly bled the brake system, with only a slight improvement. At this time, the wheel would spin maybe 1 1/2 to 2 revolutions with a firm spin. I then took out the new pads and re-installed the new stock pads that have 10+ hours and 80-90% padding. The problem improved, slightly. 

 

Galfer: After a few calls to Galfer, they had me bevel the leading edge of the pads, re-bleed the system...none of this worked. So the kit was sent back to Galfer, everything was measure with micrometers and supposedly "in spec" and sent back to me. I would be suspicious of this claim, but Galfer (through MotoSport) had already refunded my money and were still willing to send the kit back to me, partially because it had signs of use and no longer could be sold as-new. 

 

More interesting details: When I bolt the stock rotor back up with the pads, no issues...the wheel spins freely.

Also, if I don't torque down my axle, and leave the front wheel finger tight, lose, the wheel spins rather freely...it's only when I torque everything down that i get the dragging. 

 

Thoughts/Observations: I have removed the pads and the rotor does appear to be near perfectly centered in the caliper pad holder (which is part of the Galfer kit), seems to me I can adjust this by letting my axle ride deeper into the fork by just a mm or two..which I tried and the problem didn't really improve.
I know it's not the caliper/master cylinder because the stock kit works great, i've literally re-installed the stock kit 3 times and test rode the bike and it's fine. 

I have checked the new Galfer oversized rotor for warping by spinning the wheel on the axle without pads and it's 100% true, no vertical or horizontal wobble.

 

So, i'm completely out of options. I have never had to take my bike into a shop for repairs, i can do just about everything myself, but this is frankly embarrassing!

At this point i'm about to buy another Galfer oversized kit and if it bolts up without issue then i'll know it's them...

 

Frustrated, appreciate any helpful responses...

 

Happy Holidays!

Doug 

#484 

 

 

[RockerYZWR]

What else could it be besides the caliper relocation bracket? If the holes in it are not machined correctly and don't move the caliper to the exact right place and angle, I would think it could cause this. Since these are made by the hundreds by machines, it would seem unlikely, but entirely possible no doubt. I would ask Galfer to send you a new bracket to try. Or a different kit...which is what Galfer or Motosport should have done in the first place. In all cases, the one you got isn't working for you, and it's on them to remedy the situation.

Edited December 31, 2013 by RockerWR450

[Mighty_Whitey]

I have to agree with you RockerWR450. All though Galfer did "confirm" the entire kit is in spec, i'm not so sure. I have one final test before I contact Galfer again. A friend of mine has the exact same model/make/year bike as me, I'm going to install the kit on his bike and if there's issue, then i know for certain. If theres no issue, then I will rebuild my caliper seals and swap axles with him to see if that fixes it...perhaps my axle is just slightly out of true or my caliper is working at 96%, just enough to be a problem with a larger rotor disc 

[72degrees]

What is the oversize rotor thickness? Same as standard or thicker? I had fun putting a 320 Braking disk in my KTM (involving modifying a KTM Power Parts relocator). Part of that was because the Braking is 4mm thickness (which I like because it resists warping). The new pads only just go in to the standard  Brembo caliper even with the pistons pushed back in as far as they will go. The drag is acceptable but I can imagine with a caliper with slightly 'sticky' pistons it would be much worse.

 

The Braking disk on my  04 YZ450F is fine because it also has a huge matching Braking caliper.

[Reekers58]

Get new brakes, and while you have it off open the break oil reservoir and push the pistons all the way back in and then you should be good to go

[KJ790]

Are you sure it is brake drag causing the problem and not a wheel bearing issue? Bad bearings or an over-tightened axle can do the same thing. Remove the caliper and spin the wheel to be sure that the drag is coming from the brakes and not something else.

[RockerYZWR]

KJ, you're right, but he says it's fine when he puts the stock setup back on.

What is the oversize rotor thickness? Same as standard or thicker? I had fun putting a 320 Braking disk in my KTM (involving modifying a KTM Power Parts relocator). Part of that was because the Braking is 4mm thickness (which I like because it resists warping). The new pads only just go in to the standard Brembo caliper even with the pistons pushed back in as far as they will go. The drag is acceptable but I can imagine with a caliper with slightly 'sticky' pistons it would be much worse.

The Braking disk on my 04 YZ450F is fine because it also has a huge matching Braking caliper.

You're definitely onto something here. Doug, have you measured the thickness of both rotors? Especially since you say it's a little better with the slightly used pads - that might point to a difference in rotor thickness.

[zeuszuki]

KJ, you're right, but he says it's fine when he puts the stock setup back on.

You're definitely onto something here. Doug, have you measured the thickness of both rotors? Especially since you say it's a little better with the slightly used pads - that might point to a difference in rotor thickness.

Try fitting some used brake pads and see if everything works then. Could be a pad / disc interference issue. I had a similar problem after fitting custom discs to my Ducati, thinner pads solved the issue ( and they were not much thinner so go figure! ).

[RockerYZWR]

Absolutely. If the wheel hand spins a couple of times, even a couple of millimeters will help. Might even take the 90% pads to a sanding block with some 220 or 320 paper and lightly surface them equally. Then if they don't drag, a couple of hard brake applications should break them back in.

[essex426]

Have you tried taking some fluid out,or take master cylinder cap off then push the pads back, before you try it again.

If the new disc is thicker might make a difference.

[Mighty_Whitey]

? thanks for all the thoughts guys.

 

To answer some questions.

-wheel bearings are new, less than 4 hours on them

  - even the hubs and wheels are new from Dubya...
-forks are aligned straight

-i've micrometered the thickness of the oversized Galfer rotor, it's the same as stock

-i've used the stock pads, issue persists

 

This all lead me to not believe Galfer's claim of the clamp being in SPEC so I drove over to Ride Engineering today in HB and Adrian and his sales/tech Curt Allen helped me out with one of their Ride Eng. brackets made specifically for the Galfer/Ride Eng. 270mm rotor.

After i bolted up the Ride Eng. bracket the problem was 100% completely solved. The tire spins freely as well as the stock rotor. Curt was very friendly and helpful, great guy over there at Ride...

 

I just wanted to follow-up with everyone here so they knew what the outcome/fix was.  

Lesson learned...don't take the manufacturer's word as bond, they have every reason to claim it's not there issue when clearly, at the cost of a track day lost and 20+ hours of my time, the issue was their bracket.

 

Doug

Edited January 4, 2014 by Mighty_Whitey

[RockerYZWR]

Glad you found the problem. You should tell Galfer it might have been "in spec," but not for the bike it was made for.