Topic: Goon's dual disc brakes...

[goon 1492]

I am in the process of doing the dual disc setup on my 76 750k, I have a few questions for the folks that have already done this.
I do have the second disc, drilled it and this last weekend I was able to break away from the kids long enough to get the front wheel off and stripped the original rotor off. Its at work with me now and hopefully this weekend I can get another template cutout to use and get the original rotor drilled.

I am also rebuilding my master cyclinder and original caliper, but I think I will have to sell the rebuilt MC and buy a MC for a 1500 goldwing to supplement the dual disc's.

One question I have is concerning using the cb500/550 speedo drive plate that is explained in the conversion article on the main webpage. does this have to be the 500/550 drive plate?
 Also is there a good source for the double banjo bolt and possibly a source for GL1500 MC?
One more(pesky southpaws.... ) Would I just be able to buy a replacement flexible and hard brake line for the original "left caliper" and use it for the right side?

Any help would be the shizzle and I plan on taking plenty of pics to show and document for all to see, even thought its probably not new news.

[goon 1492]

Yeah and the pics above were the pour boys way of drilling (by hand  ) and I don't reccomend anyone do this, The only reason I did is because of all the thousands of holes I drilled by hand when I was a concrete flatworker... So I can drill a few holes manually....
I also have to fill some small holes on the piston for my caliper and I was going to use some jbweld, I have heard others doing this and it working well for them. I gotta try and find some siliconized grease for the calipers too.

[MCRider]

As far as the Speedo drive: this has been addressed in previous threads. I'll get you a link when I have time. Essentially the reference to the 500/550 speedo drive is an error. You use the original drive and you have to modify it. Essentially cut it down and fold over some new tabs. I did mine with a bench grinder and vice grips.

You have to reduce the outside radius of the drive to fit inside the 2nd disc, and you have to leave enough material that you can then fold over making a couple of little tabs that engage in the flats of the hub. Mine was real sloppy but worked fine and no one knew but me.

i have seen on this sight pictures of others done much more nicely with patience skill and a Dremel tool.

I finally broke down and had a machinist make me one. He cut done the radius on a mill and welded 2 little drive tabs on for $20. Very pretty.

For the double banjo bolt, I took the stock ones and thinned them with a flat file being careful to keep them parallel until two would fit on the stock bolt. One could use the side of a bench grinder wheel too i suppose. Clean it well afterwards.

[ev0lve]

I am also rebuilding my master cyclinder and original caliper, but I think I will have to sell the rebuilt MC and buy a MC for a 1500 goldwing to supplement the dual disc's.

I'm in the process of doing this as well. My understanding is that any MC from a dual up bike will work with the finery of why having to do with the piston size. I'm going to use one off a early 90's Katana for example. The Goldwing MC looks pretty much just like the original though.

One question I have is concerning using the cb500/550 speedo drive plate that is explained in the conversion article on the main webpage. does this have to be the 500/550 drive plate?

No. Turns out that's a bit of misinformation in the FAQ. The drive plate seems to be the same 500/550/750 so you'll have to cut the bell off of it and bend the tangs or weld them to get a tight fit.

Also is there a good source for the double banjo bolt and possibly a source for GL1500 MC?

Got mine from Dennis Kirk. Seems to be pretty standard stuff. eBay's probably a good bet for a used MC.

http://www.denniskirk.com/jsp/search/search.jsp?resultType=subCategories&searchString=double+banjo+bolt&store=Main&x=0&y=0

I collected a bunch of threads on the subject. Might be useful?
http://forums.sohc4.net/index.php?topic=38242.msg426222#msg426222

Wow. I think I just answered a question. It's like I've learned stuff since joining this board  

[WHALEMAN]

I have dual discs and they work perfect with the stock master cylinder with braided stainless lines from the master cylinder to each disk but most important are speedbleeders to get ALL the air out. Dan

[goon 1492]

Wow! thanks for the info guys, MCRider I forgot to mention that I had seen something like what you had stated in another thread too but was unclear exactly what to do. I will have to search and see...

Whaleman I had thought about going ahead and using the original MC but I figured since I was in there... I told my wife I needed a goldwing mastercylinder because it was bigger and would work better for both brakes, and that I was thinkin' of rebuilding the original MC and putting it away for a future project. But she didn't seem very enthusiastic about it, I generally lose her in conversation about motoscooters cars and most guys stuff.

Thank you for the links Iggy, as soon as I get some tax money I can resume on spending all my play money on my sled.

Now say it with me as you lookat the pic's.....
EEeeeeew!!!!!

[MCRider]

Wow! thanks for the info guys, MCRider I forgot to mention that I had seen something like what you had stated in another thread too but was unclear exactly what to do. I will have to search and see...
SNIP
Thank you for the links Iggy, as soon as I get some tax money I can resume on spending all my play money on my sled.

Now say it with me as you lookat the pic's.....

Once you hold the stock speedo drive plate up against the hub and second disc you'll see what has to be done. Its all in those threads Iggy supplied.
I noticed in those threads someone had a plate machined from stainless steel. He was going to look into having a few more made, but no further contact...

[goon 1492]

It wasn't really that bad for being as old as it is, along with sitting in a storage unit for 15 yrs.
What sucked was how me speedo cable broke off right at the gearbox mount when I tried to get it apart, at least its only a 15 dollar part from hondaparts-direct, I'm gonna get new longer disc bolts from home depot today
I am going to paint both my calipers with red caliper paint and also paint the center of the disc hub too, and I am thinkin about tryin' the bead blast trick to the surface of the rotor as well that was explained in another thread to help improve the braking alittle. Or atleast until they re-glaze over. Here is the back brake to match.
the fins on the front calipers are going to get the same detail 

[tygrant]

That looks pretty cool man, nice work. theres a guy on ebay that sells the MC I bought really cheap, if you shoot him a message he will sell it for 45 shipped. I just got mine in the mail few days ago and it looks pretty dam nice for the price. im sure you have seen it but this is his store

http://myworld.ebay.com/ebaymotors/usa-motorcycles-inc/

[mystic_1]

Yeah and the pics above were the pour boys way of drilling (by hand  ) and I don't reccomend anyone do this...

Mad props to your drill-fu.

mystic_1

[Alan F.]

Years back I ordered up a double banjo bolt from a Honda dealership, I just wandered through the used bikes until I found the bolt I needed, then had the parts guy search that model for the bolt, I think specifically the bike was a 94 CB1000, and the bolt was located on a splitter on the lower triple tree, early CB750 style, with a single line leading up to the master cyl.  This is also a handy way of running a single line from your master to keep a clean look at the bars.

[bryanj]

Why bother with a double banjo bolt just remove the brake light pressue switch and screw a standard one in there then remember to use the back brake to put the stop light on for numpties behind you

[754]

Amazed no one thought of this, clamp disc together, and drill thru the first into the 2nd, a drill guide of sorts, and get them exactly the same..

at least I think it will work!

 I think the SS dual disc 750 hasd the long banjo bolt you speak of..

[mystic_1]

You can get double banjo bolts out of just about any aftermarket parts catalog.  For example, Dennis Kirk carries these:



http://www.denniskirk.com/jsp/product_catalog/Product.jsp?skuId=&store=Main&catId=&productId=p193611&leafCatId=&mmyId=

"Goodridge Stainless Steel Double Bolt for Honda, Kawasaki, Suzuki and Yamaha"


mystic_1

[MCRider]

You can get double banjo bolts out of just about any aftermarket parts catalog.  For example, Dennis Kirk carries these:



http://www.denniskirk.com/jsp/product_catalog/Product.jsp?skuId=&store=Main&catId=&productId=p193611&leafCatId=&mmyId=

"Goodridge Stainless Steel Double Bolt for Honda, Kawasaki, Suzuki and Yamaha"


mystic_1

I saw this done somewhere, come off the lower tree with one line to one caliper, then unscrew the bleeder valve and come out of that hole with a line over top of the fender down to the other caliper, which carries the sole bleeder valve. Think I'll try it. Doesn't accomplish much but looked cool. Especially with a smaller front wheel and a fork brace to attach it to.

[Spikeybike]

I saw this done somewhere, come off the lower tree with one line to one caliper, then unscrew the bleeder valve and come out of that hole with a line over top of the fender down to the other caliper, which carries the sole bleeder valve. Think I'll try it. Doesn't accomplish much but looked cool. Especially with a smaller front wheel and a fork brace to attach it to.

sounds kinda sloppy to me , it would make bleeding easier i suppose , ...i guess if you run the line cleanly

[MCRider]

I saw this done somewhere, come off the lower tree with one line to one caliper, then unscrew the bleeder valve and come out of that hole with a line over top of the fender down to the other caliper, which carries the sole bleeder valve. Think I'll try it. Doesn't accomplish much but looked cool. Especially with a smaller front wheel and a fork brace to attach it to.

sounds kinda sloppy to me , it would make bleeding easier i suppose , ...i guess if you run the line cleanly

It was very clean. Only one line down from the triple. THe over the top line barely visible, clipped to the fender, all stainless braid. I think I saw it on a modern sport bike like a GSXR or such.

YOu'll see it on Phaedrus II when  I get that far. With the calipers in back, the over the top line is like not there.

[Spikeybike]

well with the calipers in back , that would be a whole other story     




 can't wait to see that BOTM   

[goon 1492]

Ok back in the saddle again, got the stomach flu last sat and was down and out until today. Now I just have puke-lash from the violent vomiting 

I got a Pm from mmtsquid stating that I would have to source special bolts for the dual discs with high tensil strength; he said that he was looking for some too and to let him know when I found them. I was going to just take the old ones to the hardware store and match them up to new longer ones hopefully with a long enough shoulder to cover both disc's and get them out of grade 8 at least. Has anyone heard of this problem? Is there like a part number for a dual disc bolt off of a goldwing or close to cross reference too? I can go to fastenal (hardware suplier) and probably get somewhere with them if the hardware store fails to avail.
Mcrider that is a great tip too on drilling the rotors at the same time, or atleast a few of the holes on both rotors to line up templates with after separating them. I wish I would have done this but one rotor was on the bike and the other was in my hands... I couldn't wait to get the other one off.
That does bring up an important part of the conversion too that is explained in the conversion for these in the main sohc website and that is making sure that the bolt hole pattern and the spokes for the rotors line up, that way when the holes are drilled and the rotors are installed it all is more cosmetically appealing than anything. I lined mine up after doing one rotor and marked lines on both rotors and then lined up both rotors on the wheel just for good measure, like I learned in school measure twice cut once.

[MCRider]

I had the stomach bug last week too, mine was out the other end.  

Twasn't my idea about how to drill the rotors, don't want to take any undue credit.

As far as the bolts, we had a big discussion about this last summer. Started with the idea of using stainless bolts. While its true the stainless don't have the strength an engineer might say is appropriate, fact is many have used them with no failures, The design is overengineered. I have testimony from a stainless supplier that SS are perfectly up to the job and they wouldn't hesitate to sell them for that application. I was coming down on the side of getting stronger bolts during that discussion but have since decided stainless is fine.

I used standard grade on the bike in my avatar and on Phaedrus I which had many years on the racetrack and 50k on the street. If memory serves, I had to grind down the heads of the bolts, or the nuts, to clear the speedo drive. PS: Its your neck, I don't recommend anything. 

So standard bolts from the hardware or Fastenal are likely fine as well.  I think MRieck said he taps out the hubs with helicoils and threads in bolts (screws?) from each side. Didn't mention if they were higher grade or not, that i remember.

I've heard the Goldwing bolts are drop in replacements. You can get the part number form any online OEM retailer like Honda-Parts Direct  http://www.hondaparts-direct.com/fiche_select.asp

[MCRider]

I thought it was measure once, cut short, then back fill it... 

"I cut it twice and it's still too short" 

[MCRider]

well with the calipers in back , that would be a whole other story     




 can't wait to see that BOTM   

You and me both. One step at a time, I'll get there.

[goon 1492]

I had the stomach bug last week too, mine was out the other end.  

Twasn't my idea about how to drill the rotors, don't want to take any undue credit.

As far as the bolts, we had a big discussion about this last summer. Started with the idea of using stainless bolts. While its true the stainless don't have the strength an engineer might say is appropriate, fact is many have used them with no failures, The design is overengineered. I have testimony from a stainless supplier that SS are perfectly up to the job and they wouldn't hesitate to sell them for that application. I was coming down on the side of getting stronger bolts during that discussion but have since decided stainless is fine.

I used standard grade on the bike in my avatar and on Phaedrus I which had many years on the racetrack and 50k on the street. If memory serves, I had to grind down the heads of the bolts, or the nuts, to clear the speedo drive. PS: Its your neck, I don't recommend anything. 

So standard bolts from the hardware or Fastenal are likely fine as well.  I think MRieck said he taps out the hubs with helicoils and threads in bolts (screws?) from each side. Didn't mention if they were higher grade or not, that i remember.

I've heard the Goldwing bolts are drop in replacements. You can get the part number form any online OEM retailer like Honda-Parts Direct  http://www.hondaparts-direct.com/fiche_select.asp

This is what I wanted to hear, a direct replacement. Because I want others to be able to do a search and find this thread and get what they need to do the task with little guess work. You are correct about stainless tensile strength.

[MCRider]

So I looked them up at Honda Parts Direct. The Goldwing bolts are 8x112. Whats called for in the CB750 conversion minutes are 8x110. So they would need to be trimmed I'm pretty sure as there are clearance issues. But a Dremel with a cutoff blade should make quick work of it.

There would be no issue with strength being OEM bolts. The part number is 90122-371-000 and they list for $4.01 each (probably hardened).

The nuts are 90309-357-000 at $1.43 each. And they may be too thick. But a grinder could fix that. There is no washer listed, so I would guess they are shouldered nuts and the cylinder head nuts are likely the same. I've got bunches of them laying around.

You're welcome. 

[goon 1492]

Kewl...
Thank you MCRider. I think I might just go with Honda parts like you said and document it all and take pics too along with any cutting involved..
Now I have one thing that might put this thread into hibernation for a bit, Apologies in adavance for jumping the gun and starting a thread on this without sourcing all the main parts.... I have to source a right side caliper and mounting bracket/hardware. Tax time is around the corner so come on refund!!
Unless someone on here has a setup they want to get rid of that matches what I got(k6 hint hint  ), I have things to trade with or custom badges to make or money. If not ebay here I come.
This is what I got: