I get dull ache in the lower back. It is especially worse on singletrack such as Cragg Quarry.
I found the solution is to do group rides with frequent stops. If I go on a ride that has lots of stops, I don’t get back ache. It is only riding continuous that does it.
I even managed to get round the Mary Townley Loop by stopping a lot, and the back pain was not there for the majority of the ride.
My back pain is worse if I try and ride as fast as I can. If I just tried to do a lap of Cragg Quarry in 20-25 minutes my lower back would be killing.
I don’t know what it is, it’s really frustrating but it doesn’t stop me from riding altogether provided I take breaks. It just prevents me from doing a certain type of riding. i.e. fast pace.