Author Topic: dual discs  (Read 676 times)

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Offline sensei1231

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dual discs
« on: June 17, 2014, 04:06:38 PM »
so call me new to this whole thing but I am currently building an 1970 cb750 as a race replica. I have bought just about everything I need. The only thing I am wanting to get, but don't know where to start, is I want to put dual discs on the front.
what do I need to get? What are my options?

Offline 70CB750

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Re: dual discs
« Reply #1 on: June 17, 2014, 06:05:53 PM »
Google search here is your best option. It was discussed many times.

If you want to be period correct, you will need C brake brackets, the early style, while T brake brackets from newer models are generally easier to use since they just flip over. Fork bottoms must match brake brackets, if you go with T style, you will need to upgrade your fork to newer style, not just bottoms, tubes too.

here are some notes from my dual setup:

http://forums.sohc4.net/index.php?topic=110116.0

The original master cylinder can handle dual setup with ease, no need to upgrade master cylinder. It is reommended to go with SS brake lines - slingshot cycles has discount for forum members and his product is A1.

You can run brake hose to one caliper and from there to the second or you can use double banjo bolt - slingshot has them too - and split the line in brake switch.

Also possible to skip the steel line from caliper and run hoses all the way.

« Last Edit: June 17, 2014, 06:10:24 PM by 70CB750 »
Prokop
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I love it when parts come together.

Dorothy - my CB750
CB750K3F - The Red
Sidecar


CB900C

2006 KLR650

Offline flybox1

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Re: dual discs
« Reply #2 on: June 18, 2014, 09:49:39 AM »
There are many threads on the subject.
start here.......http://forums.sohc4.net/index.php?topic=53532.0
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

Past Bikes
1974 550K0 (stock), 1973 CB350F (stock), 1983 Yamaha XS400K (POS)
77/78 cool 2 member #3
"Knowledge without mileage equals bullsh!t" - Henry Rollins

"This is my CB. There are many like it, but this one is mine…"

Offline SKTP

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Re: dual discs
« Reply #3 on: June 18, 2014, 11:17:51 AM »
I added a brake...it was much easier than I thought (other than the frickin' piston seal leaking that I am still fighting)...but's that's more caliper re-building issues than the disk adding...

Got my lines from Slingshot: http://slingshot-cycles.com/ and they are sweet...there's a forum promo code somewhere to save you money
1978k rebuild thread http://forums.sohc4.net/index.php?topic=68423.0
BIKE OF THE MONTH - OCTOBER 2017
2003 Ducati M800ie
1997 Honda CR-V
2004 Honda CR-V
1966 Honda S90

Offline Whaleman

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Re: dual discs
« Reply #4 on: June 18, 2014, 12:22:51 PM »
A little harder to set up and line up than meets the eye. Spent a lot of time building the right side carrier and haveing it welded up. The Lester wheels made it harder also. As stated all info is on the site. Dan

Offline Jim F

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Re: dual discs
« Reply #5 on: June 18, 2014, 03:02:11 PM »
I tool mine to the next step
Gl1000 front end
Rc51 rotors and 6 pot calipers
I thought I had pictures of just the disk set up
Sorry
2002 RC51 1000 (SP2)
1983 GS1100EC Suzuki
2002 998 Dukati (Customers Bike)
1992 KTM500 2 stroke
1975 CB750/836 Honda
1978 GS750/840 Suzuki

Offline flybox1

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Re: dual discs
« Reply #6 on: June 18, 2014, 03:09:32 PM »
nice work there, Jim!  8)
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

Past Bikes
1974 550K0 (stock), 1973 CB350F (stock), 1983 Yamaha XS400K (POS)
77/78 cool 2 member #3
"Knowledge without mileage equals bullsh!t" - Henry Rollins

"This is my CB. There are many like it, but this one is mine…"

Offline 70CB750

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Re: dual discs
« Reply #7 on: June 18, 2014, 03:16:05 PM »
Prokop
_______________
Pure Gas - find ethanol free gas station near you

I love it when parts come together.

Dorothy - my CB750
CB750K3F - The Red
Sidecar


CB900C

2006 KLR650

Offline 750K

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Re: dual discs
« Reply #8 on: June 18, 2014, 03:24:19 PM »
nice work there, Jim!  8)

I bet those dual RC brakes come in handy with a turbocharged cb750, looks great.

I say!
77 Cb750, 78 Kz1000

Offline Jim F

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Re: dual discs
« Reply #9 on: June 19, 2014, 03:18:46 PM »
Well that's just my take on a way to do a break
System that's more up to date
I still have the rotors and calipers from the gl1000 front
End that would do the job nice
2002 RC51 1000 (SP2)
1983 GS1100EC Suzuki
2002 998 Dukati (Customers Bike)
1992 KTM500 2 stroke
1975 CB750/836 Honda
1978 GS750/840 Suzuki