The best Brake fluid for trackday use?

[doogalman]

I have started putting my foot back in the water if doing trackdays.
I run a Ducati 996 with a 1098 motor and there’s a few things I want to do before my next outing. One of them is to change out the brake fluid.
So what is the current go to for track use.
I’m guessing dot 5.1 as it has the highest boiling point.
I sort of come from a car background and motul rbf660 seems popular there but it’s only dot 4. Am I missing something in why would a lot of car guys use a dot 4 when a dot 5 could be better.

Please enlighten me as to what would be the best make/type to use and why?

[trickywoo]

You are overthinking it. Bike brakes are nowhere near as close to the limit on track compared to even high end sporty cars.

Just make sure the fluid is newish and the pads are good and any quality dot 4 will be fine.

[doogalman]

trickywoo said:

You are overthinking it. Bike brakes are nowhere near as close to the limit on track compared to even high end sporty cars.

Just make sure the fluid is newish and the pads are good and any quality dot 4 will be fine.

Maybe, maybe not! Just asking the collective for guidance. But I take your point on the chin!

[Krikkit]

Motul is the expensive stuff which serves very little benefit unless you're racing on the bleeding edge (cars included)

ATE Typ200 is a great option for value vs performance

[doogalman]

Krikkit said:

Motul is the expensive stuff which serves very little benefit unless you're racing on the bleeding edge (cars included)

ATE Typ200 is a great option for value vs performance

Will have a look. Thanks

[richhead]

trickywoo said:

You are overthinking it. Bike brakes are nowhere near as close to the limit on track compared to even high end sporty cars.

Just make sure the fluid is newish and the pads are good and any quality dot 4 will be fine.

very much this, bike brakes are no where near the limits on the track, have always just used normal dot 4 in race bikes, just change it often, it will be fine.

[doogalman]

richhead said:

trickywoo said:

You are overthinking it. Bike brakes are nowhere near as close to the limit on track compared to even high end sporty cars.

Just make sure the fluid is newish and the pads are good and any quality dot 4 will be fine.

Thanks.

[Sidecar Man]

Wow Had plenty of issues with boiling fluid on trackdays/racing when pushing really hard.
Always use either Motul 660 or Castrol SRF react.

[richhead]

But sidecars don't have open brakes like a bike, more like a car, if you are who I think you are., so cooling is more of an issue, I run race cars, and have huge problems with brake temps, but also run a few race bikes, and never had any issues.

[IanUAE]

DOT 5.1 is more hygroscopic than DOT which means it is more likely to absorb more moisture, so you would have to change the fluid more often. We used to use Motul 660 in our race bike.

[Krikkit]

Sidecar Man said:

Wow Had plenty of issues with boiling fluid on trackdays/racing when pushing really hard.
Always use either Motul 660 or Castrol SRF react.

What caliper temps do you see? Any cooling?

[Sidecar Man]

richhead said:

But sidecars don't have open brakes like a bike, more like a car, if you are who I think you are., so cooling is more of an issue, I run race cars, and have huge problems with brake temps, but also run a few race bikes, and never had any issues.

No I'm talking about Solos Here not outfit.
Have had brake fade a few times as race wore on. I even had lever adjuster on left handle bar.

[anonymous-user]

Possibly depends on the bike/brakes. I'm 18 stone and heavy on the brakes and I've not cooked my brakes even on hot euro trackdays on my RC8 - Brembo M50s. RBF600 was fine, and last I just used normal Castrol brake fluid.

I'd say fresh fluid is more important that the rating.

[doogalman]

Killboy said:

Possibly depends on the bike/brakes. I'm 18 stone and heavy on the brakes and I've not cooked my brakes even on hot euro trackdays on my RC8 - Brembo M50s. RBF600 was fine, and last I just used normal Castrol brake fluid.

I'd say fresh fluid is more important that the rating.

Back brakes on Ducati’s are notorious for being shonky nonexistent. But in the past and on track Saturday the back brake faded very quickly. I know some would say don’t use the rear but I’m in my 60’s and do still use the rear. But as the master cylinder is a matter of mm from the exhaust headers I’m figuring heat is a major contributor. On road it’s normally fine unless I’m going stupid. I know I have an issue with my rear line route as the line is too long and it was what I had available in my spares when building the bike. but I’ve ordered another line so and some rbf660 so that will all get changed end of the week and bled out fully.
The front though I do think I need to go through my system and give it a full fill with new fluid as the old fluid is/was just some generic dot4 from when I’d done stuff on my car. So that’s going to get changed more purely for the sake of just doing it with a known datum of decent fluid.

[SteveKTMer]

I'd just make sure the pistons in the callipers move freely, the pads are fresh with plenty of material left and the fluid is flushed through frequently with fresh, new fluid. I use Motul mainly because it comes in little bottles, you hardly ever need very much and it 's not a good idea to use old fluid.

Discs need to be within tolerance and if they're floating on bobbins, make sure they do move, clean out the bobbins, they collect dirt, brake dust etc.

[Timbo_S2]

I use RBF 660; standard brake fluid boils far too quickly. But it needs to be changed regularly, i tend to do it every other oil change (so about 8-10 days). Stahlbus values help massively, makes it a ten minute job...

[doogalman]

Timbo_S2 said:

I use RBF 660; standard brake fluid boils far too quickly. But it needs to be changed regularly, i tend to do it every other oil change (so about 8-10 days). Stahlbus values help massively, makes it a ten minute job...

Thanks.