The VSS & Computer are far more tolerant than you might think! :lecturef_smilie:
It takes a fairly large tire size difference front to rear before it's even noticeable when ryding, and some pretty hard ryding before the VSS will react to that difference, then somewhat more difference than that before the ECU gets upset!! You can even run on
NO air in the rear tire with full inflation in the fronts & neither the VSS or the ECU will get upset until you try to hang the tail thru a turn or you accelerate so hard the rear rim spins madly inside the (deflated & ruined anyway) tire carcass & you get no corresponding speed increase!! (Do you
really need to ask me how I know this?!?
)
So don't stress too much about the VSS or the Computer/ECU - they really don't care
WHAT black round thing you might be running on your Spyder/Ryker, unless there's a quite large discrepancy between the 'expected rolling speed variation' between the two - and to fit tires that are
THAT different in rolling dia, you'd probably need to do some fairly extensive mods to either the rear swing arm or the rear fenders! :shocked:
