Rear brake

[jacob11379]

Anybody modify rear brake for stability control?

And does it pass AFM and Track day tech inspections?

The brake would technically work but very poorly and have lots of play in foot pedal....

 

[afm199]

Anybody modify rear brake for stability control?

And does it pass AFM and Track day tech inspections?

The brake would technically work but very poorly and have lots of play in foot pedal....

Lots of racers cut part of the brake pads down, add air to the system, etc. The AFM requires a rear brake, IIRC. That's about it. As to trackdays, most providers require a rear brake, that's about it.

 

[motomania2007]

Back when I raced in late 80s early 90s, it was common to cut down the pads, reduce diameter of the rear rotor, add air in the system, adjust the pedal to have reduced leverage... all sorts of things.

 

[jacob11379]

Lots of racers cut part of the brake pads down, add air to the system, etc. The AFM requires a rear brake, IIRC. That's about it. As to trackdays, most providers require a rear brake, that's about it.

Back when I raced in late 80s early 90s, it was common to cut down the pads, reduce diameter of the rear rotor, add air in the system, adjust the pedal to have reduced leverage... all sorts of things.

I was gonna drill out an aluminum Banjo bolt and fit a mikuni carb jet. Grind down the pads.

School I was at talked about it....Considering I dont currently use the rear brake I see no reason not to give it a try...

Putting air in the system might be easier than doing what i was planning on but how consistent is it using air?

 

[Junkie]

as they said at Supercamp, air is harder to tune. Jets are easy to tune.

 

[jaybocc2]

I was gonna drill out an aluminum Banjo bolt and fit a mikuni carb jet. Grind down the pads.

School I was at talked about it....Considering I dont currently use the rear brake I see no reason not to give it a try...

Putting air in the system might be easier than doing what i was planning on but how consistent is it using air?

if you don't need the rear don't use it. Making it less useful seems really silly.

You can buy a drilled rotor for like $80 or less and just swap that out which has lot less brake bite

 

[Junkie]

if you don't need the rear don't use it. Making it less useful seems really silly.

You can buy a drilled rotor for like $80 or less and just swap that out which has lot less brake bite

Making it less sensitive in a way makes it more useful. If your options are nothing or locked, reducing sensitivity will make it more useful.

Restricting fluid flow isn't uncommon.



I know that they said to do it at the master end, but I question that: the hose expands some under pressure, so when you let off the rear brake it'll take time for it to depressurize and release. If you do it at the caliper end, it won't take as long.

I'd still start off by beveling the pads instead of going straight to the banjo.

 

[jacob11379]

Making it less sensitive in a way makes it more useful. If your options are nothing or locked, reducing sensitivity will make it more useful.

Restricting fluid flow isn't uncommon.



I know that they said to do it at the master end, but I question that: the hose expands some under pressure, so when you let off the rear brake it'll take time for it to depressurize and release. If you do it at the caliper end, it won't take as long.

I'd still start off by beveling the pads instead of going straight to the banjo.

If only the brakes where ground down would that increase foot pedal travel? I dont like that theres like 1" of play. would be nice to have more play so it could be used more easily with some sort increasing and decreasing pressure ...

 

[Junkie]

I don't think beveling would increase play, it would just increase how hard you have to push (which does mean you'd be pushing it farther)

 

[Holeshot]

You've got to be kidding me...the riding school suggested modifying your rear brake with Cooter's garage?

If you don't want to use your rear brake, don't modify it and use your front brakes only...it's easier to learn anyway with only one brake to modulate. The rear brake is well used when you depart the track...I don't want mine to work LESS...

 

[Junkie]

I've never found myself off pavement on street tires or slicks and wishing I had *more* rear brake. is your rear brake that weak stock?

beveling pads is very common in flat track. it makes it easier to install and easier to modulate. that's the background Supercamp is from.

 

[stangmx13]

Put a stiff spring on the master

 

[Enchanter]

Anybody modify rear brake for stability control?

And does it pass AFM and Track day tech inspections?

The brake would technically work but very poorly and have lots of play in foot pedal....

As has been addressed in the previous replies, yes, modification of the rear brake is allowed.

Help us help you:
What is your intent with the proposed modifications? What are you experiencing now that you want to fix? What do you mean when you state “for stability control”?

I’ve previously done everything listed above with the exception of placing a ‘jet’ in the brake line. That one appears less than ideal because it not only restricts fluid flow in application of the brake, but also when releasing the brake. It is not something I would do.

If you look at many high level race bikes you’ll likely see the stiffer spring on the master cylinder. I’ve seen many with what are obviously an old or spare valve spring installed.

To ask again, what is your intent when it comes to using the rear brake? Do you have a problem you need to address, or is this just a theoretical thing right now? The above listed modifications will all have some sort of effect. I’m unclear on how this will address stability control. What is your goal?

 

[Med23]

You've got to be kidding me...the riding school suggested modifying your rear brake with Cooter's garage?

If you don't want to use your rear brake, don't modify it and use your front brakes only...it's easier to learn anyway with only one brake to modulate. The rear brake is well used when you depart the track...I don't want mine to work LESS...

What are you saying about Cooter's Garage!?!?

Anyways, yes. You need something back there at least for an off-track excursion, if not more. I am one of those outliers though. I believe in rear brake usage and put it to practice on the track. Also have a stiff Graves spring on it to return that lever quickly and help me with more controlled modulation since my foot lacks finesse.

 

[jaybocc2]

If only the brakes where ground down would that increase foot pedal travel? I dont like that theres like 1" of play. would be nice to have more play so it could be used more easily with some sort increasing and decreasing pressure ...

Grinding them down would reduce bite until you wear into the ground down part.

It would be easier and more effective to buy a drilled/light weight rear rotor.

Considering I dont currently use the rear brake [...]

Considering you don't use the rear brake at all, i would personally try using it first before deciding I need to improve/change it.

My limited experience is the rider that focuses on rider before bike will always be faster than the rider that is constantly changing the bike to try and be faster.

The scientific method applies to everything.

Just because it was done does not mean that the person was faster because of it, some were fast in spite of. awwww

 

[Enchanter]

^^^^^ solid post!

 

[Tumbleweed]

The rear brake is well used when you depart the track...I don't want mine to work LESS...

^^^^^Yep. First time I used my rear brake, I was sailing through T10, T11, T12, and T13 at T-hill on the grass/gopher hills. I departed the asphalt at speed, and had that thing MASHED to get the bike slowed. Was an excellent save and quite the show for those following me. Other than off-track excursions, I don't use it on the track. I use it on my dirt bike a ton, and very seldom on the street bike. On the flip side, my bf uses his rear brake on all his bikes, regardless - but he was a dirt-racer before a road racer. To each their own

 

[Honey Badger]

Agree 100% with Jay's post - if you're not using, why change it now? If you're not using it, then what are you trying to fix?

I haven't done any mods to my rear brake, and instead practice rear brake drills to improve my own ability to modulate rather than smash the darn thing. I'm now able to start adding these things at speed a little bit and finding the usefulness of some rear brake.

If you don't have something that is "broken" maybe work on the skills first THEN, when you've got that part down, fix things to make it easier/more useful to you?

 

[Biga]

I've done a private day with Ty Howard, here in Texas, and one of the drills for the day, was to ride the entire session only using the rear break.
I've learned a lot from that... now I use the rear break more often than before...

 

[Biga]

The rear brake is well used when you depart the track...I don't want mine to work LESS...

That's the correct way to go out picking flowers