Grimeca 4LS brake parts?

[Jordan]

The double sided front brake with 4 shoes is well known as standard fitment for certain models of Ducati single.
For example, it is on the Silver Shotgun model.
Each side has a single leading shoe design - one leading, one trailing.
Less well known is the variation with four leading shoes, which uses the same hub but with a twin leading shoe brake on each side.
I have that type of brake on my non-standard single.

Mine needs a replacement speedo drive part - the gear piece within the right side backing plate.
I thought it would be the same as for the normal 4 shoe brake, but evidently not.
The connecting link rod between the brake cams, as normally seen with TLS system, necessitated a change to the angle that this gear's shaft exits from the brake plate. It's at a slightly greater angle, to clear the rod.
When I bought the brake, it was not supplied with the gear but it wasn't obviously different so I just installed one from another brake.
That seemed to work fine, but eventually the speedo stopped working, and investigation revealed a chewed up drive gearbox at the wheel, and then I discovered the cause.
I have no idea how to obtain a correct factory replacement, which may involve changing the bigger worm gear on the hub as well.
If anyone knows who sold these 180mm 4LS Grimeca brakes, I'd be grateful for a lead to a possible supplier of the proper gears.

[blethermaskite]

Jordan, have you checked out the speedo drive from the 230mm 4ls grimeca brake? its the same brake only bigger.......maybe the drive bits are the same? worth a look.
Cheers,
George

[Jordan]

Good thought, George.
I did study photos of the larger 4LS brake, and concluded that it won't have the parts like I need.
On that brake, clearance for the link rod is provided by having the cable run positioned to go under the rod, with a shallow angle for the speedo gear shaft.
On my 180mm brake, the cable goes over the rod, and has a steeper exit angle for the shaft.

[blethermaskite]

Moto Morini 3 1/2 sport?

[Jordan]

Moto Morini 3 1/2 sport?

Nope - again, not enough angle.

I'm looking into getting a gear made.
For metal, I'd need a universal mill.
Maybe a plastic gear would work, as found in some speedo drive gearboxes.
I can't do 3D printing or design, but I can buy beer so maybe there's a chance there.

https://www.youtube.com/watch?v=b4c9pSZvTzw