Stop Estimating Spikes!
The most common question that teams face when first working with spikes is whether or not to estimate these stories. Luckily the answer is simple...don't.
The whole point of spikes is to help us learn more about stories that we don't yet know enough about to estimate well. This very unknown nature means that estimating the spike itself would be fruitless. Instead, our goal is to learn enough during the spike that we can estimate the associated story in an upcoming sprint.