Total front wheel speedo drive conversion.

[pfenig]

Not sure this is the right place to ask but I will start here.

I'd like to put a 4LS front drum brake on my W650 for racing purposes, so think the following.

https://victorylibrary.com/graphics/RC181.jpg

However in doing so I will lose the speedometer function on the W650 (which I'd very much like to keep) because the speedometer drive is located on the original front wheel.

Does anyone know of a solution for this? To complicate matters further the speedo clock has a digital input (but there are converters for this).

[stinkwheel]

What sort of a W650?

I'm guessing not the late 90's kawasaki on the basis that you'd be replacing a disc brake with a drum and I can't see anyone racing a kawasaki W650.

There are a couple of places that do self-contained GPS speedos. various styles, some of which are a good swap for a smiths. What does your current speed look like?

A lot of old brits had the spedo drive on the rear wheel and a rediculously long drive cable.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[RhynoCZ]

Well, maybe you will be able to use the original speedo drive mechanism (worm set) with this drum brake. If not, I think the best idea would be a GPS speedo or a bicycle computer (cheap).

Something like this would be lovely to have:
https://i.pinimg.com/originals/aa/df/38/aadf38c7faba85546cb63914a7449230.jpg
____________________
'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[wr6133]

[stinkwheel]

In which case a smiths chronometric would be the thing to have no? They can be direct driven from a cable, electronic sensor triggered or GPS. Does the Hub have a speedo drive at all?
https://www.smiths-instruments.co.uk/motorcycles

https://www.smiths-instruments.co.uk/documents//dials/bikes/bikechrono-mph-speedo-web-652.png
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[pfenig]

People do indeed race Kawasaki W650's and W800's.

The original worm drive is on one side of the front disc brake. I have no idea how it could be modified to fit the 4ls brake I've shown, I doubt it's possible.