Topic: CB750 Dual Front Disc Speedometer Drive Mod

[spiritof67]

I remember that the speedo drive on CB750s needs to be modified, but I also dimly recall there was a nice billet replacement available for the twin front disc conversion. Any guidance on either is appreciated.

[spiritof67]

Any help here?

[Don R]

 I milled out the back side of a previously cut rotor so it would capture the tabs on the speedometer drive hub. I had a previously mangled drive hub so I cut it some more so it would fit in the rotor hole and welded the tabs back onto it.
 It ain't pretty from a machining point of view but assembled it's beautiful and works.

[Don R]

 I also cut a drive hub down to fit into the rotor and drilled a roll pin through the drive and into the hub to keep it from turning.

[Don R]

http://forums.sohc4.net/index.php/topic,53532.0.html

 Overall it's a good thread but there is some incorrect information, such as needing a gl1000 axle, use of a 500 speedo drive, etc read it through to get the corrections.

[Godffery]

I remember that the speedo drive on CB750s needs to be modified, but I also dimly recall there was a nice billet replacement available for the twin front disc conversion. Any guidance on either is appreciated.

 I make a modified Speedo drive plate for mounting a twin Disc, and it works without modifying the Disc.
https://godfferysgarage.com/wp-content/uploads/8-Speedo-Drive-Plate.jpg
 It can easily be mounted with Roll / tension pins or count-sink the holes and tap for flat head screws.