Author Topic: 550K Dual disc setup using 550 calipers, rotors etc....questions (Read 6213 times)

traveler · « **on:** December 15, 2009, 09:09:56 AM »

Ok,

I have sourced another 550 disc and caliper(currently frozen up, anyone have one??), and the caliper bracket. Aside from having to do some modifying of the bracket, i cannot see why i can't jsut bolt on another rotor, throw the caliper and bracket on, and splice in a "T" fitting into the brake line, and run an additional line to the 2nd caliper.

Seems to me that I would be keeping my stock brake switch, and the speedo drive would be untouched.....just bolt the rotor on the other side of the hub, remount wheel, and shim if necessary to get the caliper aligned.

What am I missing here?

I'm going for the "dual rotor look". This bike is just a cruiser...a little around town fun bike.

thanks in advance,

~Joe

Bill/BentON Racing · « **Reply #1 on:** December 15, 2009, 04:27:47 PM »

It's as easy as it sounds

,but really what you said is about it.Let us know how it works out.Good Luck,Bill
Theres lots of info on here on how to do it.

bmarshall · « **Reply #2 on:** December 15, 2009, 06:38:14 PM »

It is possible the master cylinder won't push enough fluid for a 2 disc set up since it was only designed for a single caliper.

traveler · « **Reply #3 on:** December 15, 2009, 07:03:17 PM »

If it turns out to not be sufficient, I can always upgrade to a GL1000 master cylinder.

Just wan't sure.....I'm reading about folks running hardlines to the T, etc., etc.

~Joe

cdoggy81 · « **Reply #4 on:** December 15, 2009, 08:05:12 PM »

curious about this swap as well. looking forward to seeing some pics...

Zaipai · « **Reply #5 on:** December 15, 2009, 08:06:22 PM »

Lots of posts on this I am sure you will find what you need to do it.

754 · « **Reply #6 on:** December 15, 2009, 08:48:19 PM »

Speedo wont fit without mods. look for longer bolts, to hold discs on.

Are you running calipers ahead of forks or behind?

traveler · « **Reply #7 on:** December 16, 2009, 04:21:33 AM »

Quote from: 754 on December 15, 2009, 08:48:19 PM

Speedo wont fit without mods. look for longer bolts, to hold discs on.

Are you running calipers ahead of forks or behind?

Right now...all is stock.

I would preferrably like to run both behind the sliders. I'm not going to do any half and half business. Either they are both forward, or both behind.

The other option I am looking at is using a CB750F front end with my 550 triple trees.

I really don't need to do any of this...jsut like the look of dual discs, especially drilled rotors on a cafe.

What is gonna make or break this is the bracket for the left side caliper.

That, and I'm not sure what "modify the speedo pickup" means/entails.

I can say that this is the only item I will add that will add weight. My ticket to performance will be through weight reduction....power to weight ratio.

~Joe

von_Wanderlust · « **Reply #8 on:** December 16, 2009, 05:09:06 PM »

Bryanj has a good rundown here: http://www.sohc4.net/index.php?q=node/53

You might not be to find the speedo drive he mentions, so you'll need mod the one you have. Have a search, there are a few good threads with some nice pics on what you have to do to mod it.

Ricky_Racer · « **Reply #9 on:** December 16, 2009, 05:50:12 PM »

Okay. Since I'm about to start on my first CB550K (1977) let me get this straight...

Setup One
1) Stock 550K '77 forks and triples
2) Two CB750K2-6 brake brackets
3) Two CB750K2-6 brake calipers
4) Two CB750K2-6 brake rotors

Setup Two
1) Stock 550K '77 forks and triples
2) Two CB550K brake brackets
3) Two CB550K brake calipers
4) Two CB550K brake rotors

Either combo will work as specified? Any clear advantage to either setup?

BTW, I have plenty of 112mm rotor bolts and a number of the early '69 speedo drive flanges, so no need to address the speedo issue. It's covered. Thanks! RR

754 · « **Reply #10 on:** December 16, 2009, 07:23:16 PM »

76 or earlier 750 discs, are bigger dia than 550.

I dont know what the other fellow does not understand about his speedo drive plate not bolting on with the 2nd disc added!!

T add second disc, you remove the speedo DRIVE PLATE.. now the speedo drive must be modded to fit inside the disc hole... its bigger right now..

traveler · « **Reply #11 on:** December 17, 2009, 12:29:03 AM »

Looks like I'll go with the 750F2 setup or stay single disc, and drill the other disc to make it look good.

Thanks,

-Joe

Yoshi823 · « **Reply #12 on:** December 17, 2009, 05:02:34 AM »

The extra disc was really easy.

The 2nd brake line was added to the original with a double banjo bolt.

The wife goes out for a ride...

traveler · « **Reply #13 on:** December 27, 2009, 08:27:22 AM »

Quote from: Yoshi823 on December 17, 2009, 05:02:34 AM

The extra disc was really easy.

The 2nd brake line was added to the original with a double banjo bolt.

The wife goes out for a ride...

I cannot tell you how sharp taht looks to my eye.

I am surprised at the amount of drilling you were able to accomplish....I would have thought that much drilling would be weakened the disc...apparently not.

Congrats on finding a wife that knows when to stop eating!

~Joe

Flying J · « **Reply #14 on:** December 27, 2009, 10:57:22 AM »

there is all kinds of stuff on the SOHC4 website too. Its a pretty good resource.
http://www.sohc4.net/index.php?q=content/dual-disk-conversion-cb500550
also
http://www.sohc4.net/index.php?q=content/dual-disk-conversion-cb750
im going to do this to my 76. I have the parts just not the time. The only issue i see is that the fork leg that you are putting the new caliper on was not set up and machied for a caliper like the other side so it may not be flush, and then you would have to shim or shave. But still seems pretty easy.

Yoshi823 · « **Reply #15 on:** December 27, 2009, 02:42:37 PM »

Quote from: traveler on December 27, 2009, 08:27:22 AM

Quote from: Yoshi823 on December 17, 2009, 05:02:34 AM
The extra disc was really easy.

The 2nd brake line was added to the original with a double banjo bolt.

The wife goes out for a ride...

I cannot tell you how sharp taht looks to my eye.

I am surprised at the amount of drilling you were able to accomplish....I would have thought that much drilling would be weakened the disc...apparently not.

Congrats on finding a wife that knows when to stop eating!

~Joe

Wife loved that bike...but she found it a bit heavy for her size 10 frame.
She still enjoys going out on the back of the Exup (after we sold the 550F2) & still gets into her old leathers.

traveler · « **Reply #16 on:** December 27, 2009, 06:38:34 PM »

Quote from: ffjmoore on December 27, 2009, 10:57:22 AM

there is all kinds of stuff on the SOHC4 website too. Its a pretty good resource.
http://www.sohc4.net/index.php?q=content/dual-disk-conversion-cb500550
also
http://www.sohc4.net/index.php?q=content/dual-disk-conversion-cb750
im going to do this to my 76. I have the parts just not the time. The only issue i see is that the fork leg that you are putting the new caliper on was not set up and machied for a caliper like the other side so it may not be flush, and then you would have to shim or shave. But still seems pretty easy.

Yeah....right now I have 90% of the parts....might become a summer project.

~Joe

bwaller · « **Reply #17 on:** December 28, 2009, 06:03:24 AM »

traveler, I read where you were looking to shed weight to gain performance. It is a tough task if you want to retain all stock parts, but alot of weight can be removed with subtle changes.

Just focusing on unsprung in the front, I added a second disc & caliper, gained a fork brace and it only cost .65 lbs more than stock. The benefit in improved braking is obvious.

You can shave over a pound off each stock disc taking them to 5mm. Then the end of the caliper bracket (sandwiched between cailper halves) can be thinned so the pistons aren't pushed out any further than stock.

Yoshi823 · « **Reply #18 on:** December 28, 2009, 06:21:32 AM »

I made the pistons from dural on mine...then anodised them.

The alloy rim makes a differance as well.

bwaller · « **Reply #19 on:** December 28, 2009, 07:31:38 AM »

I used phenolic pistons, offered by a member here.

traveler · « **Reply #20 on:** December 28, 2009, 10:41:23 AM »

what's wrong with stock pistons?

~Joe

Spikeybike · « **Reply #21 on:** December 28, 2009, 10:53:32 AM »

they're expensive ,hard to find and heavy as hell

edit: and if you go with the bigger 750 brakes the above mentioned member doesn't make phenolic pistons for them (550 and 400 only)

bwaller · « **Reply #22 on:** December 28, 2009, 11:30:08 AM »

Actually he offers phenolic for 750 calipers, at least early models. I replaced both mine last spring.

Spikeybike · « **Reply #23 on:** December 28, 2009, 11:38:12 AM »

really? we're talkin bout this caliper right?

i'll have to PM him

Flying J · « **Reply #24 on:** December 28, 2009, 11:56:19 AM »

Ok Out with this "member", Who is he? I would like a piston or 2 as well.

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Author Topic: 550K Dual disc setup using 550 calipers, rotors etc....questions (Read 6213 times)

traveler

bmarshall

traveler

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