Hey chaps!

I did my first off-road session today just riding along an 8-mile green lane. The speed was anywhere from 10mph in 1st to 20mph in 2nd (it felt fast enough to me!!)

However, the fan was on most of the time. Even when I stopped to catch my breath and take a photo, the fan stayed on.

Is it OK and normal for the fan to run so much when riding off-road?