I'm a bit confused about the whole setup. As a rider for some 45 years, I've only once used a car tyre on the rear wheel (for the purpose of doing Saturday night burnouts in a dull country town in my youth).
Going home through the twisties, I found the handling to be highly compromised during radical direction shifts to the point that it scared me so much I discontinued the practice.
My last serious bike (BMW K100RT) came from a police used bike sale (had < 30K on it) and had a set of OEM sanctioned tyres. I found the traction to be superb and the handling to be faultless.
Bikes are beautiful animals and in good conditions and on benign surfaces can forgive a lot of rider indiscretion.
However........ when the shit hits the fan, you have to rely on every possible refinement that the OEM has made to provide you with a faithful trusty steed, and altering the dynamics can decrease the ability of the bike to perform as the OEM intended. Result, usually tears.
In addition, should you have a bingle (hopefully never) your insurance investigator may refuse cover if your policy requires disclosure of non-OEM equipment fitted to your bike (and you haven't mentioned the non-OEM tyre).
Sorry for rambling on a lot but I just wanted you to get another view from a crusty old biker with many a slide under his belt.
As to the watch!
You won't be wearing it on the bike, so pack it in a Tupperware container in your top box and only wear it as you perambulate around the sights.
The choice therefore will be the watch that you feel you would miss most while on the ride.
Safe Journey.
Cheers
Jim
Click to expand...