Yamaha R6 Rear Brake Problem

[CB ARGH]

Hey guys,

I know this is in the wrong section however I need a fast response (mini biker emergency). I'm half way through my trip (entire coastline of the north island), in Tolaga Bay at the moment (50km North of Gisborne).

Bike: 2001 Yamaha YZFR6

Now this sounds very "noobish"... before my trip I adjusted my chain for the first time since I purchased it, it has about 1000 k's on it. I've noticed that the rear brake is super hot after riding, so hot that it has heated up the rim.

Both alignment markers are in the same place, I have tried loosening the bolt that allows you to adjust the brake position and riding ten or so km's for it to seat in and that didn't work.

Any help is much appreciated.

[FJRider]

When the bike is on the main stand with the rear wheel off the deck, will the wheel spin freely ???

[CB ARGH]

The brake rubs when up on the stand. Cheers

[CB ARGH]

What's weird is it isn't enough of a "rub" to slow the bike down, I'm actually getting better fuel mileage than usual (4.53L/100km over three fills instead of 5.10L/100km) thanks to an carb cleaner).

[jasonu]

Are you inadvertently resting your foot on the rear brake pedal?

[FJRider]

The brake rubs when up on the stand. Cheers

If it rubs intermittently ... it it likely the disc is slightly warped. If it rubs through the whole revolution ... it could be a few things.

1. Pads worn to limit and pistons at the end of their travel and not returning after brakes applied ([and or] out of brake fluid).

2. Stone between pad and disc.

3. Disc VERY badly warped

Excessive (rear) brake use and puddle splash on the hot disc can warp a disc.

You weren't riding with your foot covering/resting on the rear brake were you ...???

[FJRider]

What's weird is it isn't enough of a "rub" to slow the bike down, I'm actually getting better fuel mileage than usual (4.53L/100km over three fills instead of 5.10L/100km) thanks to an carb cleaner).

Quite common actually ...

[Trade_nancy]

Did u overfill the rear brake fluid reservoir by chance?

[CB ARGH]

Thanks for the replies.

I did not touch the brake fluid at all. I do not ride with my foot on the brake. Disc is in good condition, only a slight groove on the outer of the disc. It has got to be something to do with the alignment of the wheel, as it was perfectly fine pre chain adj.

[Trade_nancy]

RU certain the brake rotor is excessively hot? After a good thrash - using trail on the rear brake - it would be HOT to touch. The rim in my experience doesn't heat up though. Have u perhaps overdone rear wheel axle nut tightening....?

[FJRider]

Thanks for the replies.

Disc is in good condition, only a slight groove on the outer of the disc.

If you checked by eyesight alone ... you'd need a bloody good pair of eyes to confirm there is no disc warp ...

Usually the amount of warp (even bad ones) is measured in thousands of an inch ...

It has got to be something to do with the alignment of the wheel, as it was perfectly fine pre chain adj.

If you say so ... But how many km's since the adjustment .. ???

[FJRider]

RU certain the brake rotor is excessively hot? After a good thrash - using trail on the rear brake - it would be HOT to touch. The rim in my experience doesn't heat up though. Have u perhaps overdone rear wheel axle nut tightening....?

A partially collapsed wheel bearing may not help ...

[CB ARGH]

RU certain the brake rotor is excessively hot? After a good thrash - using trail on the rear brake - it would be HOT to touch. The rim in my experience doesn't heat up though. Have u perhaps overdone rear wheel axle nut tightening....?

I made sure that the rear axle was in my opinion super tight. I did not use a torque wrench. This could be it.....?

[CB ARGH]

If you checked by eyesight alone ... you'd need a bloody good pair of eyes to confirm there is no disc warp ...

Usually the amount of warp (even bad ones) is measured in thousands of an inch ...

If you say so ... But how many km's since the adjustment .. ???

There is no warp. Never had a problem before the chain adjustment. I have travelled around 1600 km since the adjhstment.

[FJRider]

I made sure that the rear axle was in my opinion super tight. I did not use a torque wrench. This could be it.....?

The rear axle tightens directly onto the bearing center through the spacers. No direct contact onto the rim itself from the axle. Otherwise the wheel would not spin.

If the wheel bearing is ok ... the axle should not heat up.