BMX Pro XXL

BMX Pro XXL: the size for big builds

The Pro XXL is aimed at riders of 183 to 193 cm, often 85 kg and more once kitted up. At that build the question is no longer just finding room on the bike: the chassis itself becomes the limiting factor, because it absorbs loads on a completely different scale from those of a Pro-sized rider.

Confirming this is your size

One sign never lies: if your BMX Pro XL only works with the saddle pulled as far back as it goes, the size is too short. Conversely, a 184 cm rider with a compact torso can stay on the smaller format, which is easier to place in a corner. Beyond 193 cm, turn to the BMX Pro XXXL.

When stiffness becomes the limiting factor

The longer the tubes, the harder they work. On a 21.75" top tube, a heavy rider putting down full power twists the front triangle: steering goes vague and the line drifts on corner exit. Makers reply with larger tube diameters and thicker walls around the weld zones, generally in 7005 or triple-butted 6061-T6 aluminium. Carbon saves weight and filters vibration, provided everything is torqued properly, particularly at the seat clamp and the stem. A frame that flexes is not dangerous in itself, but it wastes part of the effort put into the pedals, which is precisely what a heavy rider cannot afford out of the gate.

The markers of a Pro XXL frame

• Top tube of 21.5" to 21.75" depending on the maker
• 406 rim in 20 inch, tyres from 20x1.50 to 20x1.75
• Cranks of 177.5 to 180 mm on a three-piece crankset
• Euro, Mid or Spanish shell, according to the frame brand
• Rear end in 10 or 20 mm, hub in 28 or 36 holes
• Long chainstays and raised shell to clear 180 mm cranks

The parts worth oversizing

What survives under a 70 kg rider will not necessarily survive under 95. At this build, favour a 36 hole rear wheel with 14G spokes and a 14 mm rear axle, a crankset on a 22 mm spindle rather than 19, and a handlebar of 720 to 737 mm in thick-wall aluminium or chromoly — 73.7 cm is the UCI maximum (rule 6.1.075), and if you need to adjust the width, only alloy can be cut down, never carbon. Tyres run at higher pressure than a light rider would use, to avoid pinching on landing. The same logic applies to the seat post and clamp, loaded constantly while sitting on the start hill.

Braking and gearing at this weight

More mass takes longer to stop: the disc, with its dedicated tab and an ISO 6-bolt or Centerlock hub, offers modulation the V-brake can no longer match in the wet. On the drivetrain, the power available allows a taller ratio than in Pro, on a 1/8" chain with tension checked after every moto.

The brands in Pro XXL

Not every brand goes up to this size. Inspyre offers it across several ranges built in France, Chase lists it in its triple-butted 6061-T6 aluminium catalogue, Meybo carries it in its longest formats. Stay Strong and Supercross round out the offer, with Pride at the top end. Chainstay length and head angle differ markedly from one model to another, and that is where real handling is decided.

The BMX RACING advice

Give us your height, your inside leg and your kitted-up weight: we check that the frame you have in mind can take it, and confirm crank length and brake choice before shipping. If 24 inch tempts you, compare with the BMX Cruiser range; the full chart stays in BMX bikes and frames. Dispatched within 24 to 72 hours, you can spread the cost over 2 or 3 payments.

For builds that fall outside the standard charts, the full method is set out in choosing your BMX race size.