We regularly get asked which type of bike would be best for the Methlick Cycle Challenge.
Basically it is up to you. I would say just about any bike would make it but to be honest I would not take my road bike through the woods and over forestry paths normally, so would rather use my hybrid bike which is more suited to this type of terrain.
Our route follows through offroad cycle paths and forestry tracks with some small road sections in between. Most of the surfaces are hard packed but there are sections of loose or rocky ground where you would dread to ride your road bike over with it's skinny tyres.
The most common bike used is the mountain bike. These will easily cope with the terrain but do remember if you are doing the 73 mile route then it can feel a long way on a mountain bike!
Cyclocross or hybrid bikes are an ideal compromise, they should handle the surfaces and be more comfortable to ride on some of the long straight flat sections and have better gearing.
I have heard of some participants coming up with their own solutions depending on what they have in the garage- mountain bike with hybrid tyres, road bike with cyclocross tyres etc.
Saying all that, don't be surprised if you see a shopping bike with basket or a tandem! As we say- it's up you at the end of the day and if you are happy to walk your bike over some of the small technical sections then go for it.
A unicycle might be taking it too far.....