79-80 Conversion For Front Brake Disc Rotors From 276 to 320mm

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Duffey Lake rd.
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79-80 Conversion For Front Brake Disc Rotors From 276 to 320mm

Post by Duffey Lake rd. »

I just noticed Webike Japan now sells a Big Rotor kit.
The details are still a bit sketchy.
It uses stock calipers, but the pads require cutting though, still, it looks cool, and will be more effective.

Stock Rotor 79-80
Measurements
Outside Diameter: 276mm
Thickness: 5mm

Sunstar Rotor
Outside Diameter: 320mm
Thickness: 5mm

320mmDisc Caliper Support
Product # 04-02-00S Read 0 reviews
https://japan.webike.net/products/25617840.html
-Scott
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Re: 79-80 Conversion For Front Brake Disc Rotors From 276 to 320mm

Post by steve murdoch icoa #5322 »

I don't get it?
How would this improve braking for street riding? MAYBE slightly better heat dispersion?

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Re: 79-80 Conversion For Front Brake Disc Rotors From 276 to 320mm

Post by Duffey Lake rd. »

I think the new dual rotors being 22mm further away from the axle would have more leverage, increasing the stopping power.
The only thing is, it's not very cost-effective.
It's probably better to go some other route like adding Honda 2-piston calipers.
-Scott

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Re: 79-80 Conversion For Front Brake Disc Rotors From 276 to 320mm

Post by AshishNJ »

Use same old single round caliper ??
What’s the upgrade ?
1979 CBX (faster Red)
1981 CBX Streetfighter
2017 Aprilia Tuono.
Past rides : FZ1, BMWS100rr,S1000r,k1300S,YAMA RD350,Enfield 350

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Re: 79-80 Conversion For Front Brake Disc Rotors From 276 to 320mm

Post by 512tr »

The 320mm rotor will increase the brake torque.

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Re: 79-80 Conversion For Front Brake Disc Rotors From 276 to 320mm

Post by CBX-tras »

I've done this conversion several times.
The larger diameter rotor increases the leverage to stop the rotation, even with the stock caliper.
What more? Then install calipers with more clamping pressure. The ones I've used are the Brembo 4 piston with 2 different sizes of pistons which provide a smoother, progressive clamping action.
What more? Install a radial design master cylinder.
You should be upgrading to stainless braided lines too (pick a supplier) I'm a dealer for Spiegler DOT approved lines and highly recommend them.

Here's photos of the setup on my 1100F and blown GL. Webike sells the Sunstar rotors and Metalgearworks brackets and Brembo calipers.

The final result is "2 finger" power brakes
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Re: 79-80 Conversion For Front Brake Disc Rotors From 276 to 320mm

Post by CBX-tras »

BTW, there's nothing "sketchy" about these brakes.

Serious stuff, you can probably do "stoppies".

Also, the semi-floating buttons are quieter than the full floating rotor.

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Re: 79-80 Conversion For Front Brake Disc Rotors From 276 to 320mm

Post by Jeff Bennetts »

Beautiful setup JR, looks like it all belongs there!

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Re: 79-80 Conversion For Front Brake Disc Rotors From 276 to 320mm

Post by Duffey Lake rd. »

Yes, well done! They look more like 2020 brakes instead of 1980.
I found myself stopping about 10ft behind the white line at intersections after upgrading to stainless braided lines. lol
-Scott

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Re: 79-80 Conversion For Front Brake Disc Rotors From 276 to 320mm

Post by Duffey Lake rd. »

Somebody went all in on what looks like an 80 Red CBX but only drilled the rotors.
People need to pay more attention to their brakes if they're going to drive a customized classic.
-Scott
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Re: 79-80 Conversion For Front Brake Disc Rotors From 276 to 320mm

Post by CBX-tras »

Go fast, stop fast. My motto.

All that going on and stock, old brake lines too.

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Re: 79-80 Conversion For Front Brake Disc Rotors From 276 to 320mm

Post by Jeff Bennetts »

Duffey Lake rd. wrote:
Fri Mar 31, 2023 11:31 pm
Somebody went all in on what looks like an 80 Red CBX but only drilled the rotors.
People need to pay more attention to their brakes if they're going to drive a customized classic.
-Scott
What do you know about the induction system?

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Re: 79-80 Conversion For Front Brake Disc Rotors From 276 to 320mm

Post by Duffey Lake rd. »

What do you know about the induction system?

It looks like he's using these carbs, guess the guy doesn't care about sucking in dust and dirt particles.
FITMENT
HONDA
CBX1000 $2650 USD

JB Power's FCR carburetor has been selling KEIHIN products for many years and has the best sales record in the world.
The FCR carburetor is highly pre-set based on the data accumulated from many driving tests from the circuit to the open road.

● The throttle actuator uses a bearing to provide a significantly lighter feel.
● Inherits the traditional high-efficiency venturi to reduce overflow loss.
This allows for more power in the high RPM range.
● The diaphragm-type acceleration pump enables powerful acceleration.

https://japan.webike.net/products/20342330.html
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Last edited by Duffey Lake rd. on Sun Apr 02, 2023 1:00 pm, edited 2 times in total.

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Re: 79-80 Conversion For Front Brake Disc Rotors From 276 to 320mm

Post by Duffey Lake rd. »

This has been covered before, but what do I need to put these 81-82 rotors on a 79-80?
On eBay, I've been searching for:
HONDA 81 82 1981 1982 CB 900F CB900F SUPER SPORT FRONT RIGHT LEFT BRAKE CALIPER MOUNTING BRACKET BRACKETS

BRACKET, L. FR.
part # 45110-445-632
BRACKET, R. FR.
part # 45210-445-632

Is this correct?
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Last edited by Duffey Lake rd. on Fri Apr 07, 2023 1:07 pm, edited 1 time in total.

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Re: 79-80 Conversion For Front Brake Disc Rotors From 276 to 320mm

Post by NobleHops »

Are those the wide-jaw Prolink calipers there? Yes, to your question, those are the bracket you need,
Nils Menten
Tucson, Arizona, USA '80 CBX, sort-of restored :-)

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