ACS Crossfire BB
ACS Crossfire External Bottom Brackets are made from forged and CNC machined aluminium and feature oversized precision sealed bearings that ride on the outside of the Bottom Bracket shell for greater durability.
They are compatible with 2-piece cranks that use a 24mm spindle.
BSA 1.37" x 24T for 68/73mm Shell.
Available in Black, Blue, Red, Gold or White
Box Extremum RacePrep Bottom Brackets
For years, pro racers have modified their bottom brackets for the toughest BMX racing by removing some or all of the seals and replacing the grease with lightweight oil. This results in free-spinning cranks, but also increases the need to maintain and replace bottom brackets.
Enter the Extremum RacePrep™ bottom bracket, the first external BB designed for BMX racing, not mountain biking. Unlike mountain biking where bike parts are exposed to all manner of bad weather, dirt and water crossings, BMX racers typically ride in relatively clean environments. Dust not withstanding.
To protect against the gunk and grime mountain biker’s ride through, designers add layers of seals to bottom brackets. While the seals protect the bearings, they also add drag. And in a 40-second BMX sprint where races are won and lost by hundredths of a second, a little drag can be a huge, well, drag.
Although we didn’t go to the extremes of pro mechanics, the Extremum RacePrep™ bottom bracket features non-contact, titanium-coated SUS bearings, modified low-friction seals and lighter weight lube. The titanium coating results in a low friction coefficient, increased corrosion resistance and smoother rolling bearings.
The result is a BB with less drag that maintains a level of bearing protection more in line with the needs of BMX racers.
Available in anodized red, blue, gold and black to fit all 24-millimeter bottom bracket spindles and 68 or 73 x BC1.37” bottom bracket shells.
Extremum RacePrep™ bottom brackets may require more frequent maintenance, depending on your riding habits. Always have a professional bicycle mechanic install and work on your bottom bracket. Meets or exceeds ENBMX standards.
Promax EX-1 Alloy External Bottom Brackets
EX-1 External bottom brackets feature cold-forged and CNC-machined alloy cups, dual-labyrinth bearing covers and precision sealed bearings. They are the perfect match to Promax CF-2 and HF-2 cranks and ultimate upgrade to the budget BBs sold with most crank sets.
Available in anodized red, blue, gold and black, to fit all 24-millimeter bottom bracket spindles and frames with 68 or 73 x BC1.37” bottom bracket shells.