Author Topic: Dual discs speedo drive is hitting rotor (Read 6006 times)

brandEn · « **on:** May 10, 2013, 02:19:50 PM »

My speedo drive hits the rotor. What did I forget to do here? I can't seem to figure it out on my own. I modified the speedo drive adapter but after looking at the parts fiche it seems what came with my K4 wheel is different than what came OEM...

CB750

flybox1 · « **Reply #1 on:** May 10, 2013, 02:28:28 PM »

does it hit the rotor carrier, or the heads of the bolts?
most conversions you must mill the bolts down 1-2mm for the drive to clear.
had to on mine

flybox1 · « **Reply #2 on:** May 10, 2013, 02:30:16 PM »

i see where it hits now.
is your rotor all the way down flush against the hub?
my speedo drive plate didnt sit that deep within the rotor carrier...

brandEn · « **Reply #3 on:** May 10, 2013, 02:33:39 PM »

Yes it's mounted all the way down. Kinda lost

flybox1 · « **Reply #4 on:** May 10, 2013, 02:37:06 PM »

interesting. i'll look at mine after the ride home.
whats with the milling along the rotor carrier?

brandEn · « **Reply #5 on:** May 10, 2013, 02:40:17 PM »

Godfreys mod.

I wonder if the powdercoat could be raising it that much?

flybox1 · « **Reply #6 on:** May 10, 2013, 02:43:54 PM »

doubt it. thats a good 4-5mm.
just emailed you a pic.
is there a difference in rotor carrier thickness? swap sides and see...

flybox1 · « **Reply #7 on:** May 10, 2013, 02:45:32 PM »

in looking at my rotor carriers, there's no way that much material could be removed for the bolt heads to sit down in for it to be safe.
you got fat carrier syndrome?

brandEn · « **Reply #8 on:** May 10, 2013, 03:18:26 PM »

I think the pictures make the machining look deeper than it is. Still plenty of meat left on em.

flybox1 · « **Reply #9 on:** May 10, 2013, 04:18:10 PM »

Yeah...plenty of meat. That's what's strange.
Gut tells me the carriers are thicker than OEM CB750 rotor carriers (read: not the right ones)
I hope im wrong and it's something easy, bro $:-\$

KRONUS0100 · « **Reply #10 on:** May 10, 2013, 04:31:51 PM »

rotor looks like it is installed backwards, the "dish' looks to be pointing outwards

flybox1 · « **Reply #11 on:** May 10, 2013, 04:32:21 PM »

B, measure the width at the little black mark shown in my picture. It should be roughly the width of your Speedo drive plate

brandEn · « **Reply #12 on:** May 10, 2013, 04:47:38 PM »

OK

approx .24"

Thanks for all your help Rob.

flybox1 · « **Reply #13 on:** May 10, 2013, 04:57:47 PM »

Rotor carrier too thick $:-\$
You measure .24 installed, and mine measures roughly 0.1 at the mark pictured above
My rotor carrier itself is only .24..

Godffery · « **Reply #14 on:** May 10, 2013, 05:21:52 PM »

brandEn,
For some reason your hub has a much lower step.!
Looks like it's been modified at some point in the past or is from year or model I'm not familiar with.

Here is a link to a twin disc Mod :
http://www.vinmoto.org/gallery/v/VinMoto-Garage/album03/Godfferys-Garage-123/Brad+B-s+Twin+Disc+conversion/

brandEn · « **Reply #15 on:** May 10, 2013, 05:27:28 PM »

Oh man I see what you mean. My hub sits way lower. Now how in the heck is that even possible? Geez, that REALLY sucks.

brandEn · « **Reply #16 on:** May 10, 2013, 05:30:37 PM »

off to eBay, All Balls and the powdercoater once again. Ugh, I feel sick.

Godffery · « **Reply #17 on:** May 10, 2013, 05:40:42 PM »

Where did that hub came from?

brandEn · « **Reply #18 on:** May 10, 2013, 05:46:43 PM »

Came from the basket case K4 that I am "trying" to rebuild.

Godffery · « **Reply #19 on:** May 10, 2013, 06:07:37 PM »

Lucky you, It came with some oddball hub.

Dream750 · « **Reply #20 on:** May 10, 2013, 07:04:02 PM »

Branden, looks to me that you have a early 750 K0 “wide hub" thin lip style as there is a 4.0 mm difference compared to the later 750 K1 to K6 “narrow hub" wide lip style as shown below:

scottly · « **Reply #21 on:** May 10, 2013, 07:07:11 PM »

Dream, do you mean it is from a SANDCAST???

Dream750 · « **Reply #22 on:** May 10, 2013, 07:15:46 PM »

Scottly, you could say that!

The early wide style K0 hub was used from frame: 1000001-1044649 making it desirable to a die hard restorer.

scottly · « **Reply #23 on:** May 10, 2013, 07:41:12 PM »

Branden, put that hub on Feebay and ask a zillion bucks for it! Kidding, but you might be able to come out OK in the long run...

brandEn · « **Reply #24 on:** May 10, 2013, 07:57:51 PM »

Dream to the rescue.

That makes perfect sense and its starting to come together.
When I brought this bike home and started tearing it down I had no experience with the K model bikes because I had just built the F3. When it came time to tearing into the forks and brakes I quickly learned that I had "early style" forks and caliper. When I sent one of my rotors to Godfferys garage he mentioned one of my rotors were from an early K. So having a early hub just makes sense. I didn't know there was a difference but after looking at some pictures of hubs on ebay and the links Godffery and Dream posted its obvious that's whats up. Somewhere along the line my K4 got K0'd.... at least the front end.

So anybody want a powdercoated K0 hub with new bearings?

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Author Topic: Dual discs speedo drive is hitting rotor (Read 6006 times)