Have you heard of a rim lock? This small piece of equipment may seem insignificant. In fact, most people don’t even see much of it, and what they see, they often mistake for a valve stem. In this article, we’ll take you through a dirt bike rim lock purpose, the best rim lock for a dirt bike, and changing a dirt bike tire with a rim lock.
What’s its purpose?
A rim lock is used to lock the tire of a dirt bike onto its rim, and prevent it from spinning independently from the rim. You might think that a properly inflated tube can seat the tire pretty firmly against the rim on its own, but you’d be mistaken.
In the image below, the threads sticking out of the rim with a nut and washer on it are the rim lock.
You might not be able to spin a dirt bike’s tire against its own rim by hand, but rest assured, the torque from your dirt bike’s engine, after it’s been multiplied by the transmission, is more than capable. Sudden and hard acceleration with a wide-open throttle is one way to achieve this, as is hard braking, and even abrupt cornering.
If you’re running your dirt bike tires at lower pressures, typically to obtain more traction on soft and loose surfaces via increased contact patch surface area, you’re at even more risk of suffering a tire spinning independently of its rim.
Let’s find out why we need a rim lock, and what happens if your tire spins independently of its rim.
Why is a Dirt Bike Rim Lock Needed?
Tires and rims must spin as one single unit in order to work properly. A tire spinning independently of its rim will cause major issues, particularly on those with an inner tube. Even if you’re running a tubeless tire, there are still issues that can ruin your day on the track or trails.
If your dirt bike’s tire spins independently of its rim, the most common outcome is ripping out of the valve stem from the tube, resulting in a flat tire. This is not ideal, whether you’re racing or just in the trails with your buddies. No one wants a flat tire. It sucks.
Problems a Rim Lock can Cause
Rim locks prevent a potentially dangerous issue, but they can also cause problems, especially if care is not taken when installing and removing them. Some of the most common problems include:
- Your inner tube getting pinched by the rim lock due to getting hung over it. This can happen due to hurried or improper installation of the tire, tube, and rim lock. Over time, this will tear your tube, causing a sudden deflation and negating the value of having the rim lock in the first place.
- Mounting hole issues, where the rim lock’s bolt and mounting hole in the rim don’t match up. You might need a washer or a new rim lock of the correct size.
- Incorrect torque. A rim lock typically should be torqued to between 10 and 13 foot pounds. Using a torque wrench for this is highly recommended. Do not finger-tighten and assume it’s enough.
- Tire movement can still happen with an incorrectly installed rim lock. The best way to detect this is to mark the tire and rim with a vertical line in a few places. Once you’ve done this, ride your dirt bike for a bit, gently at first, and periodically inspect to determine if the lines have gone out of alignment.
- Stud separation can occur where the locking stud on the rim lock breaks due to age or improper handling. This can be easy to miss, so ensure that you inspect your rim lock under ample lighting to catch this.
- Bad teeth, where the teeth of the rim lock are crushed or missing. This happens with used rim locks, so if your rim lock has damaged or missing teeth, just get a new one. It’ll save you a lot of trouble later on.
Best Dirt Bike Rim Lock
What’s the best dirt bike rim lock? Let’s look at a few options that are available to you.
Tusk Motorcycle Rim Locks
These are made from cast aluminum to eliminate corrosion, and feature molded rubber to protect your tube. The ribbed aluminum contact area ensures a firm and even seal between your tire and rim.
Motion Pro LiteLock
These are made from nylon composites in a proprietary one-piece design. They are claimed to be super light and impact resistant. A unique contoured shape protects your inner tube from heat build-up, and these are said to be appropriate for use at low tire pressures as well.
Warp 9 Pro Rim Lock
This rim lock features a strong and light titanium main bolt, with an aluminum body. It’s said to be around 50% lighter than typical OEM and aftermarket rim locks.
Dirt Bike Rim Lock Installation Or Changing A Dirt Bike Tire With A Rim Lock
How do you install a rim lock? Here’s the general idea:
- Ensure that your new rim lock is compatible with your dirt bike’s rim before commencing the process.
- If your rim doesn’t already have a hole, which it will if you’re replacing an existing rim lock, you’ll need to drill a compatible hole. Choose a location that’s directly opposite the valve stem.
- Pay attention to where the factory rim weld is, as you don’t want to drill through this.
- Remove the washer and nut from your rim lock and place it, with the bolt passing through the hole.
- Place rim tape over the rim, to cover the spoke nipples. The tape must run over the rim lock as well.
- Line up the hole in the band with the hole for your tube’s stem valve to save you some time.
- Install the rest of your tire as normal, paying attention to ensure that the tube doesn’t get pinched between the rim and the rim lock. You’ll want to check for this a few times before fully inflating your tube.
Frequently Asked Questions About a Dirt Bike Rim Lock
What does a rim lock do on a dirt bike?
On a dirt bike, a rim lock helps keep the tire from spinning independently on the rim. It secures the tire and rim as one unit.
Do dirt bikes need rim locks?
Yes, dirt bikes need rim locks. Small, youth dirt bikes and low-powered bikes don’t necessarily need them, but it doesn’t hurt to have them.
Is a rim lock necessary?
Yes, in most cases, a rim lock is necessary. It may not be necessary on low-power dirt bikes, but it’s good insurance.