Your pricey carbon wheels have one job: to get you to the finish line faster during race season. With this knowledge, and since you probably spent a sizeable amount of money on them, we don't blame you for not wanting to take your carbon wheels outside when conditions are less than ideal. Shimano's RS21's won't be the fastest wheelset you put on your bike, but they're solid, capable training wheels that can handle salt on the roads or heavy rain without issue. If bad weather actually forces you inside completely, you can leave your carbon hoops pristine by using the RS21's on your trainer or rollers. They're compatible with 10 or 11 speed cassettes, with a quick release free hub design and a 1620 spoke count, and Shimano includes an indicator to allow you to keep track of how much wear the rims have as you rack up the base miles.