Author Topic: Twin Piston Brake Upgrade Using OEM parts For CB750F  (Read 52688 times)

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Offline jaguar

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Twin Piston Brake Upgrade Using OEM parts For CB750F
« on: May 25, 2011, 10:45:42 am »
OK so I have gotten a lot of questions about the brakes that I'm running on my F, so i figured I would do a write up here.
I cant take the credit for figuring this upgrade out.  A friend of mine told me about it (geeto67 here and on other sites).

The basic idea is to take the Honda OEM twin piston calipers off of a 1982 CB900F and mount them on a 1977 or 1978 CB750F.
These DOHC calipers have twin 30mm pistons and also let you run better pads.
The pistons and seals are available from honda to rebuild them and are not expensive to rebuild.
Another great part is they bolt on!
And look great

Here is what you need to do the FRONT
137905-001 left bracket
137515-001 right bracket
139361-001 left caliper
137472-001 right caliper

You can cross reference these part numbers to a few other bikes if you really want to dig through eBay.
Of coarse you will need the sliders and bolts for those calipers and brackets.

The install is very simple, the brackets from the DOHC bike bolt on to the SOHC bike using the stock SOHC mounting bolts.

SOHC left                      DOHC right



Mounted to the legs.  There are no shims needed as the spacing is perfect



Then you just install the calipers.

Im running braided lines for a stock SOHC CB750F and a CBR600F2/3 front brake master cylinder.
I feel that in order to get the most out of the upgrade you need to change the master.
You can look at the chart in the link to help figure out the master that you need for your bike and riding habits.
http://www.vintagebrake.com/mastercylinder.htm


Here is what you need for the REAR
143578-001 Bracket
143471-001 Caliper
Again you will need the sliders and bolts to attach the caliper to the bracket.

This again is a relatively simple bolt on upgrade
The bracket takes the place of the stock SOHC bracket


Stock but im sure you know what that looks like


DOHC bracket bolted on
Some of the DOHC brackets seem to have a casting "bump" that interfere with the rotor.  Simple fix is to grind this bump flat and then there is no interference with the disc.  The spacing is perfect so there are no need for spacers or shims
The bracket arm bolts up to the stock arm using stock hardware.


I decided that a taller reservoir would help with, but I honestly do not know if its needed.
Another reason that i changed the reservoir was because mine was old, faded, and ugly.  The original one is not available.


As for pads I went with EBC HH rated FA69 pads
There are a few different options with FA69 pads, some are just a tiny bit thinner or thicker then others.

The OEM parts that were used on this upgrade can be found on eBay for very reasonable prices.
I will add that through a mistake on my end I found out that a different Honda caliper works.
My calipers are off of a V65.  The V65 calipers are 32mm twin piston.  They will bolt on to the 1982 brackets.
If you want to run a 32mm rear then you need to get a second right hand V65 caliper to use on the rear.
I have found that the tabs that hold the brake lines center are missing on the V65 calipers but that does not effect how the lines bolt on, it just makes you have to hold the line while tightening the banjo.

Well that does it for the upgrade.
If anyone has any questions feel free to ask


« Last Edit: November 03, 2011, 04:58:21 pm by jaguar »

Offline Trav-i

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F
« Reply #1 on: May 31, 2011, 11:52:18 am »
Awesome upgrade!  Now you have me thinking about what I can do to my F.  Just wish I could see the pics though. :'(
Forum member #9962

I don't know a lot about anything, but I know a little about practically everthing. 

If your not first, your last - Ricky Bobby

1992 GL1500 Interstate

73 CB750 Bobber Project (Always an on going project) Sold
71 CL350 Scrambler Project (Done and riding it) Sold
78 CB750 F3 Super Sport with F 0 engine (Current project)

Offline jaguar

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F
« Reply #2 on: May 31, 2011, 11:59:30 am »
Sorry about that.  Guess i wasnt paying attention to my photobucket account and went over my free limit....

should be back up next week

The pics show the install well.
It really is easy and is a huge improvement in looks and performance

Offline jaguar

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F
« Reply #3 on: June 08, 2011, 10:08:05 pm »
pics are up again.

Offline sonomadrifter

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F
« Reply #4 on: June 28, 2011, 10:03:47 am »
Is the spacing different on a 77k model (single disc, spoked)? I've been searching but can't find specifics.

This seams to be an easier and cheaper option than swapping the forks completly out but I want to make sure it will all line up if I did do a dual disc set up with these dual piston calipers.

Offline jaguar

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F
« Reply #5 on: June 28, 2011, 10:26:45 pm »
K bikes use different mounts for the calipers then the F bikes
This write up used an F fork.

Offline diekstra

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F
« Reply #6 on: September 19, 2011, 12:06:32 pm »
This is almost to good to be true :)
Does it mather from which type of CB900 the calipers are? I've found a local guy with an nice offer, but I don't know if these are the right calipers.
It seems there are several types... (CB900Fb-2b) But I can't imagine Honda made different calipers for them... ;)

This is the fiche he mailed me, looks good to me, but the productnumbers don't match with the ones mentioned in the first post...
...Hmmm...can't post external links... The type is: CB900F2B BOL D'OR, you can find it on CMS... :S

Anyone with an idea?

btw, is the mastercilinder of the CB900 usable for this caliper swap?

Offline jaguar

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F
« Reply #7 on: September 19, 2011, 05:21:49 pm »
This is almost to good to be true :)
Does it mather from which type of CB900 the calipers are? I've found a local guy with an nice offer, but I don't know if these are the right calipers.
It seems there are several types... (CB900Fb-2b) But I can't imagine Honda made different calipers for them... ;)

This is the fiche he mailed me, looks good to me, but the productnumbers don't match with the ones mentioned in the first post...
...Hmmm...can't post external links... The type is: CB900F2B BOL D'OR, you can find it on CMS... :S

Anyone with an idea?

btw, is the mastercilinder of the CB900 usable for this caliper swap?

You should be able to copy and paste a link.
What year are they off of?

The master should work just fine.  if not check the vintage brake link i posted

Offline diekstra

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F
« Reply #8 on: September 20, 2011, 05:20:54 am »
I'm a new member (well I'm a member for quite some time now, but haven't posted much...) so I can't post links yet...
When I check the partsfiche of the calipers of the CB900F mentioned in the first post (CB900F 900 SUPER SPORT 1982 USA) they seem to have the same partsnumber as the ones listed in the fiche the seller mailed me, which is from a 900F2B BOL D'OR.
The left caliper listed in the first have code: 45100445633 (45100445634).
The price is right, so maybe I'll just buy them to try it...  :-\

Offline jaguar

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F
« Reply #9 on: September 20, 2011, 06:12:02 am »
I'm a new member (well I'm a member for quite some time now, but haven't posted much...) so I can't post links yet...
When I check the partsfiche of the calipers of the CB900F mentioned in the first post (CB900F 900 SUPER SPORT 1982 USA) they seem to have the same partsnumber as the ones listed in the fiche the seller mailed me, which is from a 900F2B BOL D'OR.
The left caliper listed in the first have code: 45100445633 (45100445634).
The price is right, so maybe I'll just buy them to try it...  :-\

Honda had a ton of bikes that used the same calipers.  The same is true for the bracket.  often the small difference is just in color.

Please let us know how it works when you get them

Offline diekstra

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F
« Reply #10 on: September 20, 2011, 06:34:16 am »
I think I'll try it, the price is right and I've got a second front-end to try it all out...
I'll keep you guys posted...:)

Now discussing about buying a rear-caliper from the same guy... ;)

Offline diekstra

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F
« Reply #11 on: September 20, 2011, 07:23:54 am »
Received a mail from SpeedDragon a minute ago, my velocity stacks are send this morning... With all the extra HP they will add, I need the upgraded brakes!   ;)

Offline austinbikerftw

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F
« Reply #12 on: October 15, 2011, 07:20:32 pm »
Do you know if the rear bracket and caliper from a cb900 custom will also work, or is there any difference at all?

Thanks

Offline jaguar

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F
« Reply #13 on: October 15, 2011, 07:42:49 pm »
Do you know if the rear bracket and caliper from a cb900 custom will also work, or is there any difference at all?

Thanks

Not 100% sure about the 900C but i know that some of the other bikes that use a rear twin piston caliper mount it on the other side of the bike so it will not work

Offline austinbikerftw

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F
« Reply #14 on: October 16, 2011, 07:20:08 pm »
Jaguar,

Do you know if the 82 cb900f rear brake caliper will hook up with the stock 78 cb750f rear master cylinder brake line?

Thanks,
Hank

Offline jaguar

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F
« Reply #15 on: October 17, 2011, 04:30:19 am »
Yes

Offline austinbikerftw

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F
« Reply #16 on: October 17, 2011, 08:30:10 am »
Awesome!
I just ordered a 78 cb750f rear master cylinder so that I knew it would bolt right on. Now that I know it will work with the 82 cb900f double piston caliper im gonna look for one of those and go for the upgrade.

Thanks for the help

Offline diekstra

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F
« Reply #17 on: October 17, 2011, 08:37:06 am »
I've found out that the dual piston rear calipers are more difficult to find than the front ones. Due to corrosion, most of the rear calipers aren't in a very good shape.... I've managed to find one, including the bracket, but the seller really knew how rare they are, so I payed quite a lot for it.... And still it was dodgy, so I needed a full rebuild kit including the pistons, which aren't cheap either...

But hey, it's for safety and looks!  :)

Offline burnoutking1971

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F
« Reply #18 on: October 17, 2011, 08:37:17 am »
That's a sweet upgrade, seems very straight forward as well. Thanks for sharing.
:)

Offline jaguar

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F
« Reply #19 on: October 17, 2011, 09:05:59 am »
Bikebandit.com used to let you cross the part numbers, it was a great tool to find out what other bikes shared the same parts....
Its amazing how long and how many bikes honda used the same parts for...
But they took that down.  so anyone know another site that will let you cross part numbers?

Offline Scott S

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F
« Reply #20 on: October 17, 2011, 01:34:24 pm »
 Can anyone measure the distance between the mounting holes on the CB750 forks? I'm wondering (and hoping) if they're the same as the later '77-78 CB550?
'71 CB500 K0
'17 Triumph Street Scrambler
'81 Yamaha XS650

Offline gsb

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F
« Reply #21 on: October 20, 2011, 09:53:30 pm »
Hi !
I,m new on forum and build my first bike together.My frame is cb750 K3 from 1973 .I know  mod is
for F model and my question is - can I mount F MODEL fork on my K3 ? Will caliper hit spokes on whell.?
thanks  gsb

Offline jaguar

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F
« Reply #22 on: October 21, 2011, 06:19:43 am »
This thread is more about "bolt" on OEM mods so here's the answer

You can not put a spoked wheel where a comstar was meant or the other way around.  The 77-78 F forks are meant for comstar wheels.
That said guys have machined parts to make it work

Offline bruzer59

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F UDDATE.....
« Reply #23 on: June 24, 2012, 12:00:36 pm »
 
       *********1982 CB900F  FRONT BRAKE CALIPER NUMBERS **********

  This Honda # 45201-MA3-006   FRONT RIGHT CALIPER

  This Honda # 45101-MA3-006   FRONT LEFT  CALIPER

     is also used on these models and components:
 

1981 CB400T A FRONT BRAKE CALIPER 81

1981 CB750F A FRONT BRAKE CALIPER 81-82

1981 CB900F A FRONT BRAKE CALIPER

1981 CM400C A CM400C FRONT BRAKE CALIPER 81

1982 CB750F A FRONT BRAKE CALIPER 81-82

1982 CB900F A FRONT BRAKE CALIPER

1982 CM450A A CM450C-AFRONT BRAKE CALIPER

1982 CM450A A CM450C/AFRONT BRAKE CALIPER

1982 CM450C A CM450C-AFRONT BRAKE CALIPER

1982 CM450C A CM450C/AFRONT BRAKE CALIPER

1982 GL1100 A FRONT BRAKE CALIPER 82

1982 GL1100I A FRONT BRAKE CALIPER 82
 
« Last Edit: June 24, 2012, 12:20:24 pm by bruzer59 »

Offline jaguar

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Re: Twin Piston Brake Upgrade Using OEM parts For CB750F
« Reply #24 on: June 24, 2012, 06:19:51 pm »
Yeah there are a number of bikes that the calipers were used on.  Have to watch because some are only single front disc, so this means buying calipers from different bikes.
The brackets are the key really to this swap, and are used on more then just the 82 DOHC bikes

I have not test fit one yet, but wonder if the latter VFR calipers would also work, the ones that are not  cast with "Honda" but are cast with a simple "cross" across the pistons.