Box Extremum Race External Bottom Bracket
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...... Read More
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 bikers 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.
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 and 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. (100g)
- Lead Time: 0
Choosing the correct bike for your discipline is extremely important, and sometimes for those new to the sport it can be difficult to know or decide, so we’ve broken down the main differences to help you make a decision.
Freestyle bikes are designed for the skatepark, the streets or the trails. They are constructed from strong, hard wearing materials and usually feature Steel or Chromoly frames. This means that the bike can stand up to a certain amount of impacts and hard landings, but remember no bike is indestructible. For riders looking to learn tricks and stunts, then a freestyle bike is the correct choice.
Race bikes are designed specifically with the track in mind, they are nimble lightweight machines for putting down quick lap times. Typically, they are constructed from lightweight materials like aluminium and carbon fibre to keep the weight down and the rider at the front of the pack. These bikes are strong enough for smooth landings on race and pump tracks but will not take the abuse that a freestyle bike would in concrete skateparks. If you’re looking to set fast lap times or begin your competitive career on the track, a race bike is the right choice.
Choosing the correct size BMX bike is very important, bikes that are too large will be cumbersome and hard to manoeuvre and bikes that are too small can feel cramped and hard to keep under control.
Youth freestyle bikes are sized depending on the diameter of the wheel staring at 12” all the way through to 18”, at a 20” wheel the bike is considered an adult size. Adult freestyle bikes are sized on top tube length, a 18.5” top tube is extra small for younger teenagers who have just moved up to an adult bike, a 20” top tube is small, 20.5” a medium and anything over a 21” is considered large.
Race bikes feature 20-inch wheels on all models, but the components and frame are sized dependent on age and height. Youth race bikes start from a Micro size for very young riders and offer a range of sizes through to expert XL. Pro size and upwards are considered adult bikes and are usually offered up to a Pro XXXL or larger for very tall riders.
We recommend consulting our height charts from the link below to help you choose your perfect sized bike:
Choosing the right level bike for your riding ability is important. Components that are not suitable for your level of riding can wear or fail much sooner than expected. Although BMX bikes can look very similar, under the surface components and materials used can vary greatly.
All our bikes are cherry picked from the very best BMX specialist brands, and all our bikes are designed specifically for use at the skatepark or on the track.
For first time riders new to the sport our entry level bikes, priced from £200-£400, are perfect, most of these are made from high tensile steel which means they are still relatively strong, but can be slightly heavier than higher end models. You might find you’ll want to upgrade to something lighter sooner than you’d think. If you are planning on using the bike in rain or bad weather, we do strongly advise choosing a model with fully sealed bearings all round.
If you are already confident on a bike and have some experience in skateparks or performing tricks and jumps then we would recommend choosing a mid-range bike, priced from £400 to £700, with a full Chromoly frame, fork, and bars. This will be lighter and stronger than an entry level model.
For an experienced person that is already capable of performing most tricks and has previously owned BMX bikes then a high-end complete bike, or full custom would be suggested to meet the demands of this rider, these bikes are priced from £700 plus.
Our range of entry level race bikes are perfect for first time racers, usually priced between £200 and £400 most of these are constructed of heavier steel rather than aluminium. These are great to get a feel for the sport but would not be able to keep up in a competitive environment.
Our mid-range race bikes are the perfect for riders who are beginning their path to competitive racing. Priced between £400 and £800 these are not quite the high-end steeds you see at national level races, but they all feature lightweight aluminium frames and are designed specifically with the racetrack in mind.
For experienced riders who are already racing confidently at a competitive level we offer a small range of high-end complete bikes. These are usually priced between £800 and £1500 and feature many aftermarket components like carbon forks, disc brakes and folding tyres. However, at this level we highly recommend building a full custom bike, usually costing between £1500 and £3000 all components can be chosen specifically with the rider in mind. For help on building a custom bike give us a call or drop us an email!
One of our most frequently asked questions in freestyle is, which rear hub do I want, a freecoaster or a cassette? Most experienced riders know their preference, but if you’re new to the sport it can be difficult to know which choice to make.
The main difference between the two is the way the bike performs when going backwards. A traditional cassette hub requires the rider to pedal in time with the rotation of the wheel while travelling backwards, while a freecoaster allows the rider to travel backwards while keeping the pedals level in the same position as riding forwards.
Although this may seem like a brilliant feature, it does come at a price! Freecoaster hubs feature a “Slack” before engagement while pedalling forward. This means that you can turn the crank a set amount (Usually an adjustable amount) before the drivetrain engages. This is referred to as the “Slack”, when riding backwards you must keep your feet positioned within the slack, if your pedals rotate too much the drivetrain will engage and your pedals will start to rotate. The smaller the slack, the harder it is to keep your pedal positioned within it while riding backwards. This means that certain tricks are harder to perform, especially those that rely on pedal pressure, for example Tire Taps.