Topic: Question about dual disc brake conversion, CB750k7/k8's

[Eydugstr]

Forgive me for asking another DDC question...But I'm working with a front end off of K7, and it looks like I'll need to grind some notches in the backside of the rotor to accomodate the speedo drive.  Is it okay to use a dremel tool with a grinding wheel for this?  Know that some guys have said they "milled" theirs and it looks fantastic, but the machine shops around here won't take on small jobs or require that customers know a secret handshake or something...

[bollingball]

That secret handshake is a Benjamin folded small in the cup of your palm.
Ken

[Eydugstr]

That secret handshake is a Benjamin folded small in the cup of your palm.
Ken

They could've bypassed all that BS when I asked "How much would it cost?" !!!   

[BobbyR]

Actually you can get a speedo drive from the F model and just install it. There are threads that show how to do the mods properly using the standard drive. You need to do a search.

[flybox1]

Yes, you can have the rotor carrier routed to accept the winges on the speedo drive plate
Godffery provides the rotor carrier service.
OR
You can also modify the speedo drive plate to work, do this with a dremel or cutoff wheel, and save the rotor carrier from destruction.  I did this and its a clean and easy solution.  dont worry that this is for a 550.  the concept is the same.
http://forums.sohc4.net/index.php?topic=70195.0
In this thread, member Nippon also provides a bolt-on solution thats pretty slick.

many good threads on this lately. Just search speedo drive plate modification  here's the one i followed when doing my conversion.
http://forums.sohc4.net/index.php?topic=53532.0

[Eydugstr]

Guess my question still remains...Can you rout out the backs of the rotors to accomodate the drive plates with a dremel tool?  Or do you have to have a milling machine?

[flybox1]

sure it can.  give it a go and let us know how yours turns out 

[Rookster]

I don't know how you would do it with a dremel.  It is more than just cutting the wings.  You also have to remove some material around the big hole in the disk.  A dremel would make a mess out of it.  Here's mine:



I had to take it to a retired tool maker as the machine shops wouldn't touch it due to set-up costs.  See if any of them will recomend someone when they tell you they can't do it.  There has to be someone in your area that still does hand work for a little side money.

Scott

[scottly]

Doug, do you have one of the Dremel attachments that holds the Dremel perpendicular to the work for routing? That would help. If you modify the drive plate by removing the black areas in the attached pic, then you will only need to remove metal from the black areas of the rotor hub. The drive plate should be more or less free to "float" in the pocket, so it will center itself in the drive housing.

[Eydugstr]

Doug, do you have one of the Dremel attachments that holds the Dremel perpendicular to the work for routing? That would help. If you modify the drive plate by removing the black areas in the attached pic, then you will only need to remove metal from the black areas of the rotor hub. The drive plate should be more or less free to "float" in the pocket, so it will center itself in the drive housing.

TY for the pic, Scottly.  Yes I do have one of those attachments, also have a spare junk rotor to practice on.

[Eydugstr]

Well, for future reference...Here's what I learned.  Yes, you can mod the rotor with a dremel tool, looks like crud but it'll work.  After trying to find a shop that would mill it with no luck whatsoever, decided to go the dremel route, and trim down the speedo drive plate.  Using the drive plate as a template, then used a sharpie marker to draw around the "wings".  After that, cut down the plate first, like Scottly's pic, then started the long process of shaving the cutouts in the rotor.  Used three or four dremel cutoff wheels.









Went ahead and fit the rotors on the wheel, used some GL1000 bolts and so far everything looks like a "go.", good clearance inbetween the speedo drive and bolt heads.  Thanks for the responses everyone.  Will get a pic posted once everything's done.