When my speedometer sensor was defective, I mounted a Garman Nuvi on my bike permanently. This model usually reads the speed in the lower left or right corner of the screen. If you touch this reading, the screen changes and the speed shows 5 times larger. Also offers other key information. I mounted my unit inside a waterproof plastic box from a sporting goods store. I don't use it so much anymore, but it has significant value showing "Where am I", when calling AAA or a Towing Co.