Tubes should not be reused. They should be changed when the tire is changed.
From the the Metzeler website:
When fitting new TT (tubetype) tires, new tubes have to be used. Tubes
become stretched in service. If a used tube is fitted in a new tire, it
can crease and fail due to thinning of the tube rubber.
Tubes in Radial Tires
Tubes should not be used in radial tires.
From the Metzeler website:
Can radial tires be used with tubes inserted?
No. Motorcycle radial tires have different constructions than a bias ply tire so it is not permitted.
Tubeless Valve Replacement
When mounting tubeless tires (i.e. on tubeless rims, with no tube used), always replace the valve.
From the the same Metzeler page:
new TL (tubeless) tires, a new valve should be fitted for safety reasons. Under acceleration and braking, as well as during continuous riding at elevated speeds, the centrifugal forces acting on the valve can bend it down up to 90°. Therefore, short valves should be used. At speeds above 200 km/h, the centrifugal forces acting on the valve insert become so high, that the preload of the valve spring might not be enough to keep the valve closed. Short valve inserts have a higher preload than long ones. Even better are short inserts with a red Teflon-ring. These have further increased spring preload. Whichever type of valve insert is used, it is
very important to carefully tighten the valve cap.
Tire Mounting Orientation
It has long been said that if there's a dot on the tire sidewall, it indicates the lightest point on the tire, and that it should be positioned adjacent to the tire valve.
From a Metzeler page:
Some METZELER tires have a red dot in the tire sidewall to indicate the lightest point which should be positioned next to the valve.
All Dunlop street tires should be installed with the yellow balance dot at the valve.
On the other hand, This article says:
If a tire does feature color dots on the sidewall, one or two dots may be used. A red dot indicates the tire's radial runout high point. A yellow dot indicates the tire's point of least weight, from a balance standpoint.
it also goes on to say:
Times change. With the advent of styled custom wheels, the valve stem location may no longer indicate the wheel's low radial runout spot. In other words, it may no longer be viable to assume that aligning a tire's red dot to the wheel's valve stem will address any potential RFV issues.
California Bay Area
Chris at Wheel Works in Hayward
From local.google: Wheel Works The - (510) 785-4396 - 1957 W Winton Ave, Hayward, CA 94545