Only Single disc on front wheel

[rod185651]

Besides halving the braking power on the front, what are the disadvantages of only having single disc on front brakes. I only want to put the left disc back on the front wheel of my ZX9R. I only intend using my fighter for street use, and obeying all road rules so I won't be riding it hard.

[sharky]

Why ?????????????

[rod185651]

I want to expose the front wheel more, purely aesthetic.

[nick76]

Id rather look at the brake,than the wheel.
Go buy some flash looking looking discs instead.

Maybe just take one off,and go for a quick squirt.You may hate the way one disc feels??

[TurboKat]

In 99% of braking situations on the road, a single disc will do the job fine Rod.
Remember, it's a 320mm rotor & a 6 piston caliper with a pretty big pad area, there is more brake torque available from that setup than say, a big, heavy 80s model GSX 1100, CB 900, XS 1100, Z 1000, etc, that had twin 260 - 280mm discs with single piston calipers - the old aircooled dinosaurs stopped OK unless you were on a big downhill twisty road, then you'd boil the fluid & the brakes would fade away pretty quick.
I'm planning on using a single front disc on my GSX project so if you die horribly under a truck or something from running out of brakes, let me know & I'll re assess it ;)

[rod185651]

What I'm more concerned about is whether going to single disc on the front will effect things such as heat displacement and warping as a single disc will be used a lot harder than two. Also how much effect would it have on ware of pads etc as well as the stopping power.

[rod185651]

LOL will do TK.

[RevHead]

hey rod look at the discs i just fitted to my gsxr1100 in my ride section

[robmac]

quote:Originally posted by rod185651

I want to expose the front wheel more, purely aesthetic.

What about getting some rim discs off a Buell? I reckon one downhill mountain run at a reasonably legal speeds (and don't kid urself that you will keep it legal all the time) will cook a single disc on something that is 200kgs plus.

[Gitzy]

Agree ZTL rotor would look the bomb, and do the work easily..

[oldskool]

quote:Originally posted by TurboKat

In 99% of braking situations on the road, a single disc will do the job fine Rod.
Remember, it's a 320mm rotor & a 6 piston caliper with a pretty big pad area, there is more brake torque available from that setup than say, a big, heavy 80s model GSX 1100, CB 900, XS 1100, Z 1000, etc, that had twin 260 - 280mm discs with single piston calipers - the old aircooled dinosaurs stopped OK unless you were on a big downhill twisty road, then you'd boil the fluid & the brakes would fade away pretty quick.
I'm planning on using a single front disc on my GSX project so if you die horribly under a truck or something from running out of brakes, let me know & I'll re assess it ;)
Alot of people died on those 80's bikies because they had crap brakes Z900 1000 CB's etc this was one of the bad points to 80's bikes don't die like TK for looks , he has an excuse (UGLY KUNT)

[TurboKat]

quote:Originally posted by oldskool

Alot of people died on those 80's bikies because they had crap brakes Z900 1000 CB's etc this was one of the bad points to 80's bikes don't die like TK for looks , he has an excuse (UGLY KUNT)

A lot of people raced those same 80s bikes at Bathurst before the 'chase' was put in & they seemed to pull up from 260 km/h at the end of Conrod Straight lap after lap OK.
More people would've died from the hinged frames, spaghetti forks & rubber swingarms on those bikes than the brakes, believe me, they stopped a lot better than they handled.

[80s freak]

^^^^^^^^^^^ Ill vouch for that TK.

[Jinx]

If you think the bikes from the 80s had shit brakes you should have rode some of the 70s stuff. Dont know how we stayed alive with crap tyres, brakes, frames and suspension but they were great in a straght line.

[rod185651]

Looks like I'll have to test it out down Mt Ousley

[TurboKat]

Not recommended !!! [:0]
I reckon you could cook a pair of ZTLs with 8 piston Speiglers down there, I love that road but it's real hard on brakes if you're trying to set the lap record, like the Reefton Spur in Victoria.

[Tony OW31]

Although a modern single disc setup will probably have much the same power as an 80's twin disc job, it does not have the same area for heat dissipation. Braking is essentially heat energy, so for equal braking power you will get the same heat output, and that heat has to go somewhere, and a large percentage of that heat is radiated from the disk surface, less surface area means it will overheat the disc, and boil your fluid.
125 and 250 gp bikes do not need the power of twin discs, and would prefer the reduction in unsprung weight from removing one, but they have them to reduce brake fade over race distance.
Another thing to consider is that your master cylinder ratio will be wrong for a single disc.

[Tony OW31]

Incidentally, does anyone remember those terrible inboard ventilated discs honda brought out in the 80's? I was given a vf400 to race with them on, and it lasted 2 laps of practice before it cooked the brakes.

[nick76]

You may have to try a brake fluid with the highest boiling point you can find.
I had to do this to a motard years ago,back then,the highest i could find was the Motul RBF600, or 660.
Boiling point was over 300c.
When/if your lever ever comes back to the bars,its not fun,and there is only so much you can do with a rear brake.

[rod185651]

quote:Originally posted by nick76


When/if your lever ever comes back to the bars,its not fun,and there is only so much you can do with a rear brake.


A thought that gives me a sick feeling just imagining it happening.

[Shadowzone]

Compression Braking will always help slow you down, but I'd be inclined to go the buell brake discs myself even a single sided one will help you disperse heat much better due to the larger disc size.

[RevHead]

problem is that if its adr to run twin discs i think you,ll need to get it engineered to go backwards,n i know that no engineer is going to pass a single 330mil, unless its a buell unit

[sharky]

And if you have an accident..even not your fault, the police and most likely your ins. company will want a word with you for due to your modified brakes....which would most likely mean void insurance...and lots of $$$$.
I really don't see the point...Why risk it ?
You might find out the hard way that your stopping distance has increased in an emergency....

[Redmohawk]

Measure your disk area swept by the pad of the old setup and the area that will allow heat to disipate (will be larger than the swept area but prob not by much) then look at a larger disk of twice the area to allow for more heat dissapation (wont need to be huge as area increases very fast with disk diam) and finding a better caliper might be a big ask though as your bike already has 6 pistons at a guess? More than double the area may improve it enough to make the difference on the street a moot point. Your disk is 320mm diam if it has a swept depth of say 3cm gives you an area of around 270 cm2 so if you had a disk made up around 380mm diam but with a depth of heat dispersion area of 6cm it will give you an area of 600cm2 if you mount a longer 8 piston caliper in it you could increase your pad area.

[puppet]

Sounds like a great idea. You've inspired me, I'm going to convert my car from 4 wheel discs to 3 wheel drum brakes and disconnect the ABS while I'm at it.

[Redmohawk]

I did say it was a good idea , just that it can be done. Personally I would stick with twin disks and make them more interesting going up in dia and custom ground wave etc perhaps flames lazer cut into them , or make your own rim disks etc to open up the wheel. The point is Rod asked for input and ideas as he wants to do something different, but wants to remain safe. Definitly not my preferd choice a single disk on a bike with real grunt but in the end its his bike and he knows what he wants to do, cant be much worse than trying to ride a larger harley with stock brakes lol

[rod185651]

Thanks for the input guys, was just an idea I thought I would throw out there, but will stick with the twin disc set up for now. Glad it promoted some positive discussion.

[el sammo]

works fine, will feel harder at the lever and not have as much bite but still pull up pretty good

[hooligan]

quote:Originally posted by rod185651

I want to expose the front wheel more, purely aesthetic.


you could make some disc centres made to match the spoke pattern to open up the front wheel.
I had ben make some centres to matche the carrozzerria's pattern, so from the side all you saw was the wheel and the buzz saw rotors.

[mattymagoo22]

quote:Originally posted by Tony OW31

Although a modern single disc setup will probably have much the same power as an 80's twin disc job, it does not have the same area for heat dissipation. Braking is essentially heat energy, so for equal braking power you will get the same heat output, and that heat has to go somewhere, and a large percentage of that heat is radiated from the disk surface, less surface area means it will overheat the disc, and boil your fluid.
125 and 250 gp bikes do not need the power of twin discs, and would prefer the reduction in unsprung weight from removing one, but they have them to reduce brake fade over race distance.
Another thing to consider is that your master cylinder ratio will be wrong for a single disc.



The master cyl to piston ratio wouldn't change as nothing has been swapped, only the amount of fluid that needs to be displaced.

[fimpBIKES]

i'd just do it rod
if you find its fading after a few hard downhill runs then bung the other one back on