Any time you have two dissimilar metals in contact, you run the risk of creating a 'battery' and the oxidation that can occur could lead to problems
As anyone that has worked on a motorcycles has found, they are assembled with many kinds of dissimilar metals, steel bolts holding aluminum parts and clamps, i.e., fork triple clamps, pinch bolts on the base of the fork holding the axle, aluminum axle surface mating with the steel bearing surface, the steel bearing surface meeting the aluminum hub housing, and the list goes on.
Magnesium or aluminum engine parts being held together with steel, aluminum or even titanium bolts, i.e., the side covers over the clutch, flywheel or water pump assemblies.
Don't forget the rear suspension linkage, bearings or bushing pressed into aluminum linkage parts and steel bolts holding the assembly together.
I'm sure if you look over your Trials machine you will find many locations with dissimilar metals that are in contact with each other.
To help combat some of the corrosion effects of bolts and nuts on a motorcycle I use an anti-seize compound, applying a light covering of the threaded surface with the mixture. Don't forget to apply a small amount to the flat surface of the bolt or nut that butts up against the surface the bolt or nut is being threaded through.
To give the anti-seize compound a little more stickiness and spread ability I mix my anti-seize compound with equal parts of water proof grease. This gives a thick honey like texture to the compound making it a little more sticky and easy to work into small threats.
If you want to save yourself some grief in future bike maintenance, while you are doing your normal weekly, monthly and yearly maintenance of the bike, remove and coat bolts and nuts that could need removal in the future. If you have the time, don't forget to to remove the bearings in your front and rear wheel hubs and give the mating surfaces between bearing and hub a coating of anti-seize compound.
I have found that the smaller the bolt the better the chances of the bolt seizing, mostly due to the smaller surface area and less bulk of the head where the removal tool fits, i.e., the small bolts holding exhaust guards in place, metal bolts screwed into aluminum threats.
The next time you do some bike maintenance, take a little extra time to apply an anti seize compound to your bike's bolts, nuts and other surfaces, you will be glad you did when future maintenance is needed.