A surprising (to me) number of people compare the FX Mountain Moto to trials motorcycles, probably because both are at the light end of performance-off-road motorcycles.
The most obvious difference is that trials motos don’t have seats…it’s stand-up riding all the way. FX has the geometry and footpeg-seat-handlebar triangle of a full size enduro motorcycle.
But you might be surprised at the amount of difference between the claimed “dry weight” of bikes and their actual ready-to-ride weight…it can be 20-40 lb+ (10-20kg)! (See this article on dry vs wet weights)
If you get 2 bathroom scales with a wheel on each (or a more accurate setup!) your typical ready-to-ride Gas Gas will be 165 lb, maybe more. Nothing against the Gas Gas…for what its designed for, competition trials, you couldn’t get much better.
FX starts at 132 lb ready-to-ride, so 30 lb lighter than a ready-to-ride trials bike, which is a big difference in agility and portability.
But the main differences are in the geometry and layout, e.g.
Trials bikes have a very steep fork angle so they can be balanced on the front wheel. This becomes unstable and twitchy at higher speeds.
FX has a raked out fork angle, similar to an enduro bike, so it is very stable on steep terrain and is very comfortable on faster singletrack.
Trials footpegs are positioned to the rear of the bike for easy balancing on the back wheel, which is fine when standing up but not for longer distance seated riding.
FX footpegs are central like an enduro, keeping both wheels firmly on the ground and comfortable for stand up or seated riding.
Trials fuel tanks are about 1 quart / 1 litre with much thirstier engines than the 100mpg+ FX, which has a 2 gallon / 7 litre fuel tank.
For these reasons, any trials-based bikes that have tried using small seats have had to change their layout and end up more like enduro bikes with trials tires, with ready-to-ride weights over 190 lb.
From our experience, riders who enjoy FX the most are riders of enduro bikes AND trials bikes AND mountain bikes. If someone is a purist, only enjoying one type of 2-wheeler, they sometimes can’t adjust to the unique riding experience of FX, which really is a crossover of all these.
Another example of the differences between trials and FX: Look at the wheels on trials/enduro…a rear trials tire weighs 22lb or so, with the heavier rim to match…around double the FX wheel weight…this is spinning unsprung mass which makes a proportionately-major difference to handling.