Zongshen Sierra Speedometer drive unit

[ChillRider]

OK, after being on its last breath for the last year or so, the speedometer drive at the front wheel finally gave up the ghost and the speedo needle doesn't move at all. The odometer still *kinda* moves... at a ratio of 100m for every 10 km ridden or so.


In the meantime it went through all phases like e.g. jumping the speedo needle, moving erratically, registering a fraction of kms ridden on the odometer etc., I've also tried everything else like lubricating the cable, replacing the cable, replacing the speedometer itself etc., so that's it for half-measures.


The problem is that my only known source for speedo drive units for this motorcycle, china-parts.co.uk, has it "out of stock" since forever.


The unit itself looks like this:





It is a right-hand unit, BTW. I've tried looking at photos of other speedo drives in online parts shops and eBay and even aliexpress listings to find one that looks close enough, but no luck. Either the notches were incorrectly positioned, or they were left-hand units, or the spindle hole was too small (it should be 12mm), or all of the above.


Any ideas where I could find a source for this speedo, or at least a compatible one from a different make of motorcycle? Even being able to swap out the plastic core gear with a similar one from an otherwise incompatible unit would be enough, without resorting to machining one from scratch.


Edit: FWIW, there seems to be a passing resemblance with the Kawasaki Kaze-R speedo drive unit:





The only obvious difference is that the spindle hole is smaller, but that can probably be swapped out:




Since these are quite affordable, I'll order one and see how it goes from there, reporting back in case this helps anyone.