Condensed answer: Hub guards aren’t mandatory, but they can be very helpful if you do a lot of grinding on concrete ledges and rails. If you ride primarily on ramps and jumps, however, the need for a hub guard is low.
What Is The Function of a Hub Guard?
The hub guard is an add-on that slides onto the front and rear axle. Its job is to protect the hub shell, the lock-nuts, the axle, and the insertion points of the spokes during BMX grinds done on ledges and rails.
How Can Grinding Hurt The Hub?
In a perfect world, grinding involves only the pegs of the bike. However, even experienced riders have a hard time getting on a ledge or rail without occasionally hitting the hub area, especially when trying a new combination of tricks.
Very often a rider would bunny hop onto a ledge and hit it first with the outer part of the hub before sliding onto the peg. Or in other words, the sequence is hub -> peg.
The initial hit can inflict a lot of damage on the hub. The aftermath may include a destroyed cone mechanism, bent spokes, dented hub shell…etc.
On some occasions, the wheel will even seize due to stuck ball bearings.
In What Situations Are Hub Guards Useful?
Hub guards can be very helpful in the following situations:
1. Beginner stages
If you’re just learning how to grind, chances are that you will smash your hubs a lot until you get the technique down and develop more finesse.
If you’re new to the sport, and you don’t have sponsors, it’s highly advisable to get a hub guard because it will protect your bike and therefore save you money in the long run.
2. Lots of Riding on Ledges and Rails
A hub guard is truly needed only when you do lots of grinding on ledges and rails.
However, if you’re riding primarily on ramps or do street riding but without grinding, then a hub guard doesn’t have a lot to offer you.
It wouldn’t hurt, aside from adding a dozen extra grams to the bike, but it’s not indispensable since the hub area is a lot less likely to get smashed.
What Are Hub Guards Made Of?
Hub guards are available in three main materials – plastic, aluminum and Chromoly steel. There are also hub guards made of two parts. E.g., An aluminum body combined with a steel shell.
The plastic models have better sliding properties and tend to be lighter. Their downside is that they aren’t as durable as steel ones and can break without a warning.
The aluminum versions are light but aren’t the most tenacious either because the alloy is softer and lacks elasticity.
The steel ones are a bit heavier, but they’re the strongest and usually bend instead of braking because steel is compliant.
Also, steel hub guards don’t slide as easily as the plastic ones due to extra friction.
Conclusion: If you’re looking for durability, the Chromoly hub guards are a good choice as they can take the most abuse and have the longest lifespans.
On Which Side Of The Bike Do I Need a Hub Guard?
The hub guards should match the side on which the pegs are installed. If you have pegs only on one side, you need hug guards on it. If you running 4 pegs, it’s necessary to have a hug guard on every side of the wheel to get max protection.
Are Hub Guards Universal?
Many hub guards are designed for specific hubs and are therefore not universal. In order to use them, your hub will have to be on the list with supported models.
Check the description of the product before buying to see if your hub is listed there. If you can’t find enough information, contact the seller.
Alternatively, you could also post a picture of your hub and the guard on a forum to receive advice from other riders.
If you’re not a fan of online communication, you could also go to your local bike shop.
Having said that, there are also universal hub guards designed to fit most standard BMX hubs.
The downside of some universal hubs is that they may throw your rear wheel off-center. To get it centered again, you will have to re-dish it. The procedure requires experience as a wheel mechanic as well as extra equipment – a spoke wrench and a truing stand.
If you can’t do the procedure yourself, you will have to pay a bike shop to do it for you.
A List of Universal Hub Guards
Below you will find a list of universal hub guards that should work on most bikes:
|Tree Bicycle Modular Hub Guards||Chromoly (heat-treated)||Front – 43g|
Rear – 53g
Rear (drive-side) – 70g
|GSport G.L.A.N.D. MKIV||Plastic||Front – 28g|
Rear – 45g
|GSport Uniguard||Chromoly (heat-treated)||59 grams|
|Kink Universal Driver guard||Chromoly (heat-treated)||59 grams|
|Mission Universal BMX Hub Guard||Chromoly (heat-treated)||56 grams|
|Eclat Servo Universal Front Hub||Chromoly (heat-treated)||85 grams|
|Kink Universal Rear Freecoaster Hub Guard||Chromoly (core) |
Moulded Nylon (outer)
|Cinema VF Front Universal||Nylon||25 grams|
|Federal Universal Rear Hub Guard||7075-T6 Forged Aluminium||68 grams|
|Rant Strap On Front Hub Guard||Fiberglass High Density Composite||28 grams|
|Salt Plus Universal Rear Hub Guard||Nylon + Chromolly||81 grams|
|Salt Plus Universal Rear Hub Guard||Chromoly + Aluminum||104 grams|
|Merritt Tension Front Hub Guard||Plastic||25.5 grams|
My Dropouts Are Too Narrow For Installing a Hub Guard. What Are My Options?
First, see if the hub guard that you have supports your hub. Second, make sure that the hub guard is installed correctly. (Some models require you to remove the locknut.)
If everything is in check, the other possibilities are:
1. Cold set the frame.
Up to a point, steel can be bent without losing structural integrity. Thus, steel frames can be spread to accommodate a hug guard that wouldn’t otherwise fit. You shouldn’t need more than 1-3 extra millimeters to get the hub to fit.
If you’re not comfortable doing this, take the frame to a mechanic.
2. Use a Hub Guard Attaching To The Drop Outs or The Spokes
Models like GSport Uniguard can be mounted on the external side of the dropout and thus eliminate the need to spread the frame.
You could also try using a hub guard that attaches to the spokes via zip-ties or a shoelace.
Why Are Hub Guards “Bell-shaped”?
Hub guards have a wide base and a body decreasing in width to ensure a smooth transition to the peg.
When you land on the guard, the bike would slide back down to the pegs which should be the contact points for grinds.
What’s Better – Partial or Full Hub Guards?
Some hub models allow you to rotate them once a section gets damaged.
The models that have a 360 degrees rotation allow you to do that more times than the partials and should therefore have a longer life.
That said, a partial hub guard is not necessarily worse than a full one. You also have to take into consideration the material, the design, and the craftsmanship behind the product.
Homemade Hub Guards
It’s possible to make your own hub guards from items that you may already have at home.
For example, some people make hub guards out of tennis balls. The downside of this method is that it takes some time to cut the ball to the necessary dimensions. If the piece isn’t sized properly, it will rub and slow down the wheel.
Another possibility is to 3D print a hub guard if you have access to the technology.
Note: It’s recommended to buy a stock hub guard at least for your drive side (if you grind on it) because the guard needs a cutout for the chain. Coming up with a homemade solution could be a bit frustrating.
Besides, many companies offer affordable hub guards which lower the incentive to waste time making your own.
My Chain Broke. Did It Happen Because I Don’t Have a Hub Guard?
If you are grinding on the drive side, then it’s quite possible to damage the chain when sliding on concrete ledges and rails. The hub and the sprocket area are the most vulnerable.
There are two ways to mitigate the damage:
1. If you grind only on one side, you can move the drivetrain to the other. That way the chain will be fully protected.
2. Install a hub and a sprocket guard.
The sprocket guard mounts onto the chainring and protects it from impact. It lowers the bike’s clearance a bit, but it’s not the end of the world.
- If you plan to do lots of grinding, it’s highly advisable to install hub guards as they increase the longevity of the hubs, the chain, the axles, and the spokes.
- Some hub guards are hub specific. If your hub isn’t supported, look for a universal model.
- Steel hub guards are heavier and don’t slide as smoothly as the plastic/nylon models but are the most durable.