Yes, side bolsters matter in a sim racing seat, but not for the same reason as in a real race car. In a simulator there is no real cornering force, so bolsters do not fight G loads. Their job is to give your hips, back and thighs a fixed reference point, so your body stays in the same place while your arms and legs work hard on a direct drive wheel and a load cell brake.
That small difference changes how you should judge bolsters. Tall, aggressive wings look fast, but the best bolsters are the ones that fit your body and still let you get in and out without a fight. In this guide you learn what bolsters do, how high and how tight they should be, and which SIMGASM seat shape fits your driving style.
What do side bolsters do in a sim rig?
Bolsters are the raised edges of a seat, and they work as a frame around your body.
Bolsters give your body a fixed reference
Every input you make pushes your body somewhere. A hard stop on a load cell pedal pushes your hips back into the seat. A big steering correction on a strong wheelbase pulls your shoulders to one side. Without bolsters, you slide a few millimetres every time, and your hands and feet lose their exact position on the controls.
Good bolsters stop that tiny movement. Your hips stay in the same spot, so your braking point and your steering angle feel the same lap after lap. That consistency is the real reason sim racers like a supportive bucket shape.
Hip bolsters and thigh bolsters do different jobs
The bolsters next to your back and hips hold your upper body. The thigh bolsters at the front of the seat base hold your legs. Thigh bolsters matter most for heel and toe work and for hard braking, because they keep your knees in line with the pedals. If they are too high, they press into the back of your legs during long races.
SIMGASM | Core Bucket Racing Seat - Black
How tight should a sim racing seat feel?
The right fit sits between loose and tight, and you notice the difference after about twenty minutes.
The simple fit test
Sit in the seat with your normal racing clothes on. Place your flat hand between your hip and the bolster on each side. A snug fit leaves room for about one flat hand. No room at all means the bolster presses on your hips and you get numb spots. Room for a fist means you still slide around under braking. If you are unsure about your size, read our guide on how to measure the right sim racing seat size before you order.
Firm foam beats soft foam behind the bolsters
Bolsters only work when the foam holds its shape. Soft foam feels nice in the first minutes, but it compresses and your body starts to move again. This is also why the question of a soft or firm sim racing seat is so closely linked to bolster design.
Bolsters in the SIMGASM seat range
SIMGASM founder Johan Akkerman treats seating position as a performance factor, not a cosmetic detail, and that shows in how the seats are shaped.
Core Bucket: pronounced bolsters on a steel frame
The Core Bucket has a steel frame and pronounced side bolsters that hold you during braking and steering. The backrest is fixed once it is locked for driving, and it folds only to store the seat in a compact position. Underneath you find a 360 × 385 mm bolt pattern for bottom mounting, so it fits well on aluminium profile rigs with a slider.
Seat comfort is easier to judge when you see it. This short SIMGASM reel shows the seats up close.
Atlas GT: a sculpted shell with memory foam
The Atlas GT uses a sculpted shell that supports your torso and shoulders in an upright GT posture. Washable memory foam cushions fill the shell, and you remove them for cleaning or swap them for another colour. Johan was responsible for the design of the TRX seat during his time at Trak Racer, and the patented Atlas design builds on years of testing seats from across the market.
SIMGASM | Sim Racing Seat Atlas Gran Turismo - Black
Core Recline: softer sides for mixed use
The Core Recline has a leather and suede finish and a backrest that moves to a near vertical position. Its sides are less aggressive, which makes it easy to get in and out. That suits drivers who also use the seat for work, or who prefer comfort over maximum hold. Our comparison of a bucket seat or reclining seat explains that choice in more detail.
When are big bolsters a problem?
More support is not always better, and three situations ask for a softer shape.
Wide shoulders, wide hips and quick swaps
Drivers with broad shoulders often feel the upper bolsters press on their arms when they turn the wheel at full lock. Drivers with wide hips feel pressure points on the outside of the thighs. Shared rigs are the third case: when two drivers of different sizes use one seat, a medium bolster fits both better than a tight race shell.
In those cases a slightly wider bucket, or a recliner with softer sides, gives you better comfort over a full race. You lose a little hold, but you gain hours of driving without numb legs.
SIMGASM | Core Recline Seat - Black
How to choose your seat
Use your main type of racing as the starting point for the choice.
Match the bolsters to your racing
Short sprint races, drifting and rally ask for strong hold, so a bucket with pronounced bolsters is the logical pick. Long endurance stints ask for even support and good padding, which points to a sculpted shell like the Atlas. Casual driving and mixed desk use point to a recliner. You find all three shapes in our sim racing seats range, and every seat bolts to a SIMGASM sim racing cockpit with the matching slider or bracket set.
SIMGASM develops its own hardware from its base in Wijk bij Duurstede in the Netherlands, and every product is tested as part of a complete simulator. That means the seat, the bracket and the frame are checked together, not as separate parts.
Frequently asked questions
These are the quick answers sim racers ask most about bolsters.
Do you need bolsters if you have no motion rig?
Yes. Even on a static rig, your body moves under hard braking and big steering inputs. Bolsters keep you in one place, so your inputs stay consistent.
Are high thigh bolsters bad for long races?
They are fine when they match your leg shape. If they press into the back of your legs, lower the front of the seat a little or choose a flatter seat base.
Which SIMGASM seat has the strongest side support?
The Core Bucket and the Atlas GT give the most hold. The Core Bucket uses pronounced bolsters on a steel frame, while the Atlas GT wraps a sculpted shell around your torso and shoulders.
Can a reclining seat hold you well enough?
For casual and mixed use, yes. For hard braking with a load cell pedal, a fixed bucket holds you more consistently.
Want to learn more? The SIMGASM experts are happy to help.
