Topic: Dual Brake conversion info CB550

[AirCanuck]

hey folks,

I'm looking for the definitive how-to on this. 

I've used the google search function and found practically unlimited topics on this but most refer to dead links for guidelines. 

Help please?

Thanks, hope all in North America are enjoying their off-season... I am REALLY hoping to have all my stuff sorted by the spring!

Question for you all:

Should there be some kind of 'splitter' valve or regulator valve that ensures pressure is applied evenly and at the same time to both discs?

cheers

[calj737]

If you use a rear disc brake, then you use a separate rear brake Master Cylinder. The front disc is controlled by its own single or dual caliper, MC.

The 750F had a rear disc and an MC mounted to its rear brake mounting peg. This is a common approach even on modern bikes.

What disc and rotor are you planning for your swap?

[Clinto]

If you're trying to add a second disc to the front end, I cant find any definitive guides either but really it's pretty straightforward.

I think these are the only parts that you absolutely need to add the second disc:
500/550 caliper and all internals, pads, etc
500/550 caliper mount including the spring adjuster
500/550 rotor
6 longer hex bolts to accommodate added rotor (8mm x 1.25mm x 110mm)
6 nyloc nuts
Second lower brake line (most upgrade to stainless steel)
"Double banjo bolt" to accommodate the second lower brake line (this would be your "splitter" running from the brake light switch mounted on your lower triple)

The trickiest thing is adapting your speedometer drive to accept the added caliper. Info on that can be found here:
http://forums.sohc4.net/index.php?topic=53532.0
a place called Godffery's Garage sold an adapter that made it easy if you didn't want to mess with adapting your stock speedo drive. His website seems to be down now but he can still be contacted through facebook it seems if you search for him.

Also, random washers to use as shims are needed when mounting the second caliper to the fork. This varies case to case I believe depending if you're running a front fender, what fender, etc.

Also, some people upgrade their master cylinder to one made for dual discs (16mm piston size) -- a lot of us (including myself) just run the stock 14mm MC

[calj737]

Crap, sorry, I misread your post. I interpreted it (for some odd reason) as a rear disc conversion. Dual discs are much easier. Mostly a 14mm or 15mm MC for dual fronts will serve you well. Clinto has the other bits documented for you.

[AirCanuck]

Hi all,

PO has already performed the front dual conversion, but I am trying to sort out how it was done.  He says he did it by piecing together various articles on here.

[AirCanuck]

If you're trying to add a second disc to the front end, I cant find any definitive guides either but really it's pretty straightforward.

I think these are the only parts that you absolutely need to add the second disc:
500/550 caliper and all internals, pads, etc
500/550 caliper mount including the spring adjuster
500/550 rotor
6 longer hex bolts to accommodate added rotor (8mm x 1.25mm x 110mm)
6 nyloc nuts
Second lower brake line (most upgrade to stainless steel)
"Double banjo bolt" to accommodate the second lower brake line (this would be your "splitter" running from the brake light switch mounted on your lower triple)

The trickiest thing is adapting your speedometer drive to accept the added caliper. Info on that can be found here:
http://forums.sohc4.net/index.php?topic=53532.0
a place called Godffery's Garage sold an adapter that made it easy if you didn't want to mess with adapting your stock speedo drive. His website seems to be down now but he can still be contacted through facebook it seems if you search for him.

Also, random washers to use as shims are needed when mounting the second caliper to the fork. This varies case to case I believe depending if you're running a front fender, what fender, etc.

Also, some people upgrade their master cylinder to one made for dual discs (16mm piston size) -- a lot of us (including myself) just run the stock 14mm MC

Ok, sounds good.  He put in I believe a CBR MC.  It does need to be shimmed I believe, it hasn't been yet I don't think.  I'll have to look into that double banjo bolt.  What does it accomplish exactly, how does it work?

[calj737]

The double banjo bolt connects to the MC and circulates brake fluid through two separate lines, each to a single caliper. You either use this method or a splitter downstream to plumb both calipers.

[sixthwisconsin]

Here is the double banjo bolt on my 550

[AirCanuck]

The double banjo bolt connects to the MC and circulates brake fluid through two separate lines, each to a single caliper. You either use this method or a splitter downstream to plumb both calipers.

OK, makes sense.  PO mentioned (I'm emailing back and forth with him) that he followed this list almost exactly and installed a double banjo at the hydronic brake switch

http://manuals.sohc4.net/cb500/technical_reference/TR500550_DUAL_DISK.pdf

[jakec]

I might be picking up a 550 this weekend. Hoping to do this conversion in the future sometime. When people say that you need a "550 caliper," is it that you just need a regular left side caliper? and that can bolt up on the right side?

[AirCanuck]

I might be picking up a 550 this weekend. Hoping to do this conversion in the future sometime. When people say that you need a "550 caliper," is it that you just need a regular left side caliper? and that can bolt up on the right side?

As far as I know, yes, there is no right side caliper for the 550. You will need a master cylinder from a different bike to, I believe mine is from CBR, some have talked about using one from a GL. It’s all over this site.

[MikeSimon]

Does the bike have a fork lower that will take a caliper/mount? We had that discussion elsewhere about a custom I saw last year at Mid_Ohio where the "owner" said they used a fork lower with the mounts and "flipped it around". Answer was still open.

[robvangulik]

I might be picking up a 550 this weekend. Hoping to do this conversion in the future sometime. When people say that you need a "550 caliper," is it that you just need a regular left side caliper? and that can bolt up on the right side?

As far as I know, yes, there is no right side caliper for the 550. You will need a master cylinder from a different bike to, I believe mine is from CBR, some have talked about using one from a GL. It’s all over this site.

Most important when choosind a master cylinder is piston size.
On all MC's Honda put that size on the outside, usually on the side facing the handlebars. The standard 14mm MC works fine with a dual setup, I prefer the 1/2inch from a CBR1000f.(12,7mm)

[calj737]

I might be picking up a 550 this weekend. Hoping to do this conversion in the future sometime. When people say that you need a "550 caliper," is it that you just need a regular left side caliper? and that can bolt up on the right side?

Any caliper from a 500 or 550 will work. You also need the same adjuster arm. You simple install it on the right side.

On the right side, you will need to do a little modification for the second rotor as the speedo will now not fit without a bit of trimming. There’s plenty of docs on that mod within the site too.

[AirCanuck]

I might be picking up a 550 this weekend. Hoping to do this conversion in the future sometime. When people say that you need a "550 caliper," is it that you just need a regular left side caliper? and that can bolt up on the right side?

Any caliper from a 500 or 550 will work. You also need the same adjuster arm. You simple install it on the right side.

On the right side, you will need to do a little modification for the second rotor as the speedo will now not fit without a bit of trimming. There’s plenty of docs on that mod within the site too.

Cal, I know mine still needed shimming.  When I bought it the caliper was dragging slightly on the rotor.  Where exactly are the shims supposed to go?

[Don R]

Does the bike have a fork lower that will take a caliper/mount? We had that discussion elsewhere about a custom I saw last year at Mid_Ohio where the "owner" said they used a fork lower with the mounts and "flipped it around". Answer was still open.

 If you use two rights and flip one around one caliper will be in front and one in back. Right?

[kaptainkid1]

Here is a link to my Dual Disc Conversion and a few photos with the double Banjo and shims set up.
Also, I ran across a few problems and it had to do with used parts that were dirty and needed to be rebuilt.

http://forums.sohc4.net/index.php/topic,170298.0.html

Good luck on the dual disc conversion.

[calj737]

Does the bike have a fork lower that will take a caliper/mount? We had that discussion elsewhere about a custom I saw last year at Mid_Ohio where the "owner" said they used a fork lower with the mounts and "flipped it around". Answer was still open.

 If you use two rights and flip one around one caliper will be in front and one in back. Right?

Only if you flip the lower. I experimented with this on my son's cafe bike. Would have been fine, except the fender I had made and the fender brackets, would not align from the rear.

[MikeSimon]

So, again, what lower do you use? Does the 550 have a lower with the bracket mounts or not?

[DaveBarbier]

Does the bike have a fork lower that will take a caliper/mount? We had that discussion elsewhere about a custom I saw last year at Mid_Ohio where the "owner" said they used a fork lower with the mounts and "flipped it around". Answer was still open.

 If you use two rights and flip one around one caliper will be in front and one in back. Right?

Only if you install the caliper assembly the wrong way. It’s a simple bolt on deal, not a brain twister. Both forks on the 550 have caliper mounts. Just bolt up the caliper assembly and it’ll be in the proper orientation. Shimming the caliper arm to get the caliper pads aligned to the disc is the tedious part.

Also, if you want the calipers aimed backwards just swap the left fork to the right side and vice versa. This might be what Mike Simon is talking about. But not sure why it went unanswered on the other forum he is talking about. This info has been known since the 70’s.



Or

[DaveBarbier]

So, again, what lower do you use? Does the 550 have a lower with the bracket mounts or not?

Both fork lowers have mounts for calipers from the factory.

[DaveBarbier]

I might be picking up a 550 this weekend. Hoping to do this conversion in the future sometime. When people say that you need a "550 caliper," is it that you just need a regular left side caliper? and that can bolt up on the right side?

As far as I know, yes, there is no right side caliper for the 550. You will need a master cylinder from a different bike to, I believe mine is from CBR, some have talked about using one from a GL. It’s all over this site.

Your existing 14mm master will be fine.

If anyone is interested, I have a complete front end off my 550. Calipers, lines, forks, triples, wheel (no tire), clipons but no master cylinder. I was thinking of selling it eventually but haven’t gotten around to packing it up.

Maybe I’ll post in the for sale section too, but if interested, PM me.

[AirCanuck]

I might be picking up a 550 this weekend. Hoping to do this conversion in the future sometime. When people say that you need a "550 caliper," is it that you just need a regular left side caliper? and that can bolt up on the right side?

As far as I know, yes, there is no right side caliper for the 550. You will need a master cylinder from a different bike to, I believe mine is from CBR, some have talked about using one from a GL. It’s all over this site.

Your existing 14mm master will be fine.

If anyone is interested, I have a complete front end off my 550. Calipers, lines, forks, triples, wheel (no tire), clipons but no master cylinder. I was thinking of selling it eventually but haven’t gotten around to packing it up.

Maybe I’ll post in the for sale section too, but if interested, PM me.

I hear so many opinions on this. It’s funny how varied so many theories still are on these bikes

[jakec]

When I was working on my 81 750 (dual discs) I swapped my master for another, newer, nicer one and never thought twice about what it was, how big it was, etc. The reservoir was a bit smaller, and it worked out ok.

[DaveBarbier]

I might be picking up a 550 this weekend. Hoping to do this conversion in the future sometime. When people say that you need a "550 caliper," is it that you just need a regular left side caliper? and that can bolt up on the right side?

As far as I know, yes, there is no right side caliper for the 550. You will need a master cylinder from a different bike to, I believe mine is from CBR, some have talked about using one from a GL. It’s all over this site.

Your existing 14mm master will be fine.

If anyone is interested, I have a complete front end off my 550. Calipers, lines, forks, triples, wheel (no tire), clipons but no master cylinder. I was thinking of selling it eventually but haven’t gotten around to packing it up.

Maybe I’ll post in the for sale section too, but if interested, PM me.

I hear so many opinions on this. It’s funny how varied so many theories still are on these bikes

The key word is opinions. You don’t have to change out the MC. It will feel and function fine but if one is looking or used to a different feel then they can change it out.