So much fun.
I have a "hybrid" setup on my 1997 748/853 (Anatra).
It all started last year when ECS
rebuilt and mounted the Ohilns forks from Helmke's race bike on Anatra (it was a 996 or a 748R, I can find out).
At that time we also mounted Brembo 4-Pad calipers.
Since the 748 rotors use a 10mm offset ECS used 5mm spacers when mounting the calipers.
I decided I wanted Brembo T-Drive rotors and was told that I could not get them with a 6-bolt pattern and 10mm offset by a couple of dealers (yea NOW I see them on MotoWheels... Doh!).
So Steve at ECS said we could use 848 wheels so I could get 5-bolt pattern / 15mm offset T-Drive rotors.
The rear wheel is the same for a 748 and 848 so I bought the 848 T-Drive Rotors and a set of OZ Racing Piega for an 848.
I figured we could get rid of the 5mm spacers too.
We could also reuse the front axle though I opted for an exotic one (I think it is 25mm diameter on both but am not 100% on that but the new one I bought was for a 748).
Well ECS and I completely forgot about the analog speedometer pickup. Steve at ECS said he could have his machine shop modify the front wheel to accommodate the pickup. The thing is that the 848 wheel center is wider (amongst other things). For example, when you remove the 748/916 series speedometer pickup for the track you have to replace it with a spacer. With the 848 wheel we did not need a spacer (therefore we would need to machine it down to fit the pickup).
This would all take a lot of time so Steve at ECS suggested we mount a digital bicycle speedometer to use for this season and have the machine work done in the winter. I decided to help by hunting down a speedometer and in my searching I stumbled on one specifically for motorcycles by Koso. It "splices" into the wiring (no little battery inside it) and is back lit illuminated for night.
Sean at ECS fabricated a couple of simple brackets to mount the Koso where I wanted it. I also had go to Pro-Bolt to get one longer fork/axle pinch bolt since the Koso pickup needed mounting point (we used a longer pinch and secured the pickup mount with a nut on the pinch).
In the end, I have decided that the Koso is a permanent addition to Anatra. We also did an 853 big bore on her at the same time so the analog odometer (that no longer works) shows the 748 mileage and the Koso shows the 853 mileage.
I also want to add a +1 to Moto's suggestion on the OZ Racing Piega wheels. I love them!
Here are some pictures... Hope this helps.
This one kind of shows one of the fabricated brackets for the Koso: