it is to my understanding that the reserve is simply the lower portion of your petcock, and is simply used to alert the rider that the gas level is low and it would be wise to fill up... as for riding with reserve on all the time there will be no warning and you will simply run out of gas with other option than to start pushing your bike to the next gas station.... i always ride with reserve on that is because i know how many miles i can get on one tank.... i hope this helps