Is your Yamaha YZ85 feeling a bit small and skittish on the trails? Do you watch bigger bikes glide over obstacles with ease and wish yours had that same stability? Converting your YZ85 with a big wheel kit is a game-changer, offering better control and a smoother ride. But with so many parts involved, from spacers to bearings, knowing what to buy can be confusing.
We’ve done the research for you. This guide breaks down the top kits and essential components to make your YZ85 big wheel conversion a success. We’ll help you find the right parts to boost your bike’s performance and confidence on any track or trail.
| Product Image | Product Name | Best For | Check Price |
|---|---|---|---|
 | NICHE Wheel Bearing Spacer Seal | Seal & Spacer Combo | Prices |
 | All Balls Racing Rear Wheel Spac | Rear Axle Spacing | Prices |
 | Caltric Rear Wheel Ball Bearings | Budget Bearings Replacement | Prices |
 | Tusk Wheel Bearing and Seal Kit | Complete Bearing & Seal Kit | Prices |
 | All Balls Racing Complete Bearin | Complete Wheel Rebuild | Prices |
 | LABLT Cylinder Piston Gasket Kit | Top-end Engine Rebuild | Prices |
 | Iconic Racing Front Wheel Bearin | Front Wheel Precision | Prices |
 | Boss Bearing Front Wheel Bearing | High-performance Front End | Prices |
NICHE Wheel Bearing Spacer Seal
If you’re upgrading your YZ85 with a big wheel kit and want to avoid the hassle of a wobbly rear wheel, this spacer seal is the perfect finishing touch.
The main job of this spacer is to perfectly center your rear wheel, which stops it from wobbling. A wobbly wheel can wear out your new bearings and chain quickly. This part ensures everything spins straight and true, giving you smoother power and better control on the track.
Made from high-quality steel, this spacer is built to handle mud, rocks, and hard landings. It’s a simple, one-piece design that installs easily, saving you from future headaches and repair costs. It’s a small part that makes a huge difference in the reliability of your big wheel conversion.
Pros:
- 👍 Eliminates rear wheel wobble for stable handling.
👍 Protects your expensive wheel bearings from premature wear.
👍 Durable steel construction stands up to tough riding conditions.
👍 Simple drop-in installation with no modifications needed.
Cons:
- 👎 An additional cost on top of the main big wheel kit.
👎 Requires removing the rear wheel for proper installation.
👎 May not be necessary if your kit already includes a high-quality spacer.
All Balls Racing Rear Wheel Spac
If you’re converting your YZ85 to a big wheel setup and need to get your chain alignment and rear wheel spacing just right, this All Balls Racing spacer kit is the perfect solution.
The main benefit is that it provides a precise, plug-and-play fit for the larger rear wheel. You get the exact spacers, seals, and bearings you need in one box. This saves you from the headache of mixing and matching old parts or worrying about incorrect alignment, which can cause premature chain and sprocket wear. It just bolts right in.
Beyond the perfect fit, the quality is top-notch. All Balls uses high-grade materials, so these spacers can handle the abuse of hard landings and muddy conditions. For a critical part of your big wheel conversion, this kit offers reliable, no-fuss performance that lets you focus on riding.
Pros:
- 👍 Provides a perfect, hassle-free fit for YZ85 big wheel conversions.
- 👍 Comes as a complete kit with all necessary spacers, seals, and bearings.
- 👍 Ensures proper chain alignment to protect your sprockets and chain.
- 👍 Made from durable materials built to withstand hard use.
Cons:
- 👎 It’s a specific kit, so it’s only needed if you’re doing the big wheel upgrade.
- 👎 Installation requires removing the rear wheel and axle.
- 👎 As with any precision part, double-check everything during installation for the best results.
Caltric Rear Wheel Ball Bearings
If you’re putting a YZ85 Big Wheel kit on your bike and want to keep the reliability high without breaking the bank, these Caltric rear wheel bearings are a perfect match.
The bearings are sealed on both sides, which is a huge deal for off-road riding. This design keeps grease in and dirt, mud, and water out. Imagine blasting through a deep puddle; that double seal acts like a fortress, protecting the bearing’s internals from the grime that causes premature wear and failure.
Beyond the seals, the overall build quality is solid for the price. They are manufactured to OEM specifications, ensuring a perfect fit and smooth rotation right out of the box. For a budget-friendly part, they deliver dependable performance that will get you through many rides without a worry, making them a very smart choice for your upgrade.
Pros:
- 👍 Excellent double-sealed design keeps contaminants out.
- 👍 Direct OEM replacement for a perfect, hassle-free fit.
- 👍 Provides smooth performance and reliable durability.
- 👍 Fantastic value for the price, especially for project bikes.
Cons:
- 👎 Not a branded high-performance part for pro-level racers.
- 👎 As with any budget component, long-term durability may vary with extreme abuse.
- 👎 It’s always wise to have a mechanic press them in if you lack the proper tools.
Tusk Wheel Bearing and Seal Kit
This Tusk Wheel Bearing and Seal Kit is the perfect, no-fuss solution for any YZ85 owner tackling a wheel rebuild or routine maintenance.
The kit includes everything you need in one box—bearings, seals, and a spacer tube. This means no more running to multiple stores or ordering parts separately. For example, when your old seals start leaking grease, you can grab this single kit and have your wheel assembly refreshed and protected in one go.
Tusk components are known for their solid durability, standing up well to the harsh conditions of motocross and trail riding. For the price, you get a reliable, complete package that makes a potentially complicated job straightforward, making it a fantastic value for any rider.
Pros:
- 👍 Complete all-in-one kit saves time and hassle
- 👍 Excellent value for the money
- 👍 Durable construction handles tough riding conditions
- 👍 Simplifies the wheel service process
Cons:
- 👎 Bearings may not be premium-grade for pro-level racers
- 👎 Always double-check the spacer tube for a perfect fit with your specific wheel
- 👎 Grease is not included, so you’ll need to have some on hand
All Balls Racing Complete Bearin
If you’re putting together a YZ85 Big Wheel kit and want to make sure your new setup is bulletproof from the start, this All Balls Racing Complete Bearing Kit is the perfect first step.
The kit is so complete it saves you a huge headache. Instead of hunting down individual bearings and seals for the wheels, swingarm, and linkage, you get every single one in a single box. This means you can do the job right the first time without multiple trips to the shop or waiting on different online orders.
The quality is excellent, with bearings that are well-sealed against dirt and water. This is crucial for a big wheel bike that might see more trail and mud. For the price and convenience, it’s a no-brainer upgrade that ensures your bike rolls smoothly and reliably for a long time.
Pros:
- 👍 Includes every bearing and seal you need for a full rebuild.
- 👍 Saves significant time and effort over sourcing parts individually.
- 👍 Quality seals help extend bearing life by keeping contaminants out.
- 👍 Excellent value for a comprehensive, high-quality kit.
Cons:
- 👎 The sheer number of small parts can be overwhelming if you’re not organized.
- 👎 You’ll still need to purchase grease separately for installation.
- 👎 May be more than you need if you only require one or two specific bearings.
LABLT Cylinder Piston Gasket Kit
This LABLT gasket kit is the perfect solution for any YZ85 owner tackling a top-end rebuild and wanting to ensure a leak-free, high-performance seal.
The kit includes all the essential gaskets and o-rings you need for the job, from the cylinder base to the power valve. This means you can confidently tear down your engine knowing you have the right seal for every connection, preventing messy oil leaks and dangerous air leaks that can ruin your engine’s performance. For example, having the correct power valve gaskets ensures your engine breathes properly, giving you that crisp, responsive powerband you love.
Beyond being complete, the gaskets are made from durable materials that can handle the heat and pressure of a high-strung 85cc motor. They compress nicely to form a reliable seal and hold up over time. For a straightforward, dependable, and affordable kit that gets the job done right, LABLT is a fantastic choice for your big-wheel YZ85.
Pros:
- 👍 Complete set with all necessary gaskets and o-rings in one box
- 👍 Durable material that stands up to high engine heat and pressure
- 👍 Excellent seal that prevents leaks for consistent engine performance
- 👍 Great value for the price compared to OEM parts
Cons:
- 👎 Does not include piston rings, just the gaskets
- 👎 Some experienced builders may prefer OEM for critical builds
- 👎 Packaging can be very basic, so check all parts are present
Iconic Racing Front Wheel Bearin
If you’re a young rider looking to upgrade your Yamaha YZ85 to the big wheel version, this Iconic Racing front wheel bearing kit is the perfect, no-fuss starting point.
The kit comes with everything you need for a smooth installation, including high-quality sealed bearings, a new spacer, and dust seals. This means you won’t be stuck waiting on a missing part halfway through the job. For example, having the correct spacer pre-included ensures your wheel sits perfectly and spins freely without any annoying brake drag.
Beyond the complete package, these bearings are built to last. The robust seals do a fantastic job of keeping mud and grit out, which is a huge plus for anyone who rides in wet or dusty conditions. For a reliable and affordable foundation for your YZ85 big wheel conversion, this kit is a consistently strong choice.
Pros:
- 👍 Complete kit with all necessary components
👍 Effective seals for superior dirt and water protection
👍 Easy installation with perfect fitment
👍 Excellent value for the price
Cons:
- 👎 Bearings may require a press for proper installation
👎 Packaging could be more robust for shipping
👎 Not the absolute top-tier brand for pro-level racing
Boss Bearing Front Wheel Bearing
If you’re building a Yamaha YZ85 big wheel and want bulletproof reliability without breaking the bank, the Boss Bearing Front Wheel Bearing is the perfect choice for you.
The bearing is precision-machined for a perfect fit, which means no more frustrating wobble or play in your front wheel. This translates directly to better control, especially when you’re carving through a tight berm or landing a big jump. You’ll feel the difference in the bike’s stability immediately, giving you more confidence to push your limits.
Beyond the fit, the double-lipped seals are a star feature, packed with high-quality grease to aggressively keep mud and grit out. This focus on durability means less maintenance for you and a much longer lifespan for the bearing, even if you’re a regular at muddy tracks. It’s a simple, no-nonsense component that does its job exceptionally well, making it a strong and reliable upgrade for any YZ85 big wheel project.
Pros:
- 👍 Precision fit eliminates front wheel wobble for better handling.
- 👍 Excellent double-lipped seals keep contaminants out for longer life.
- 👍 Comes pre-greased for easy installation and immediate use.
- 👍 Offers fantastic value and performance for the price.
Cons:
- 👎 The seals can be a bit tight during installation, so take care not to damage them.
- 👎 While durable, it may not have the ultimate longevity of a premium, ceramic-bearing brand for pro-level racers.
- 👎 Packaging is basic, so don’t expect fancy boxes or included installation tools.
Buyer’s Guide: 3 Key Factors to Consider
Compatibility and Fitment
Before purchasing, the most critical step is confirming the kit is designed for your specific YZ85 model year. A kit for a later model may not fit an earlier bike, and vice-versa. Double-check the manufacturer’s specifications to ensure a smooth installation and optimal performance.
Component Quality and Completeness
Not all big wheel kits are created equal. Look for kits that include high-quality, brand-name components like Excel rims and heavy-duty spokes. A complete kit should have everything you need—wheels, tires, brake rotors, and a longer chain—to avoid costly and frustrating separate purchases.
Intended Riding Style
Consider where you’ll be riding most. The increased ground clearance and larger contact patch of a big wheel are fantastic for rough trails and off-road tracks. However, if your primary focus is supercross-style, technical tracks with tight corners, the standard wheels might offer a slight advantage in agility and flickability.
Frequently Asked Questions
Q1: What is the main benefit of a YZ85 Big Wheel kit?
A1: The primary benefit is improved stability and control. The larger wheels (19-inch front, 16-inch rear vs. the standard 17/14) roll over obstacles more easily, provide better traction, and increase ground clearance, which is a huge confidence booster for taller or growing riders.
Q2: Will this kit make my YZ85 significantly slower?
A2: Not significantly, but you may notice a slight change in acceleration due to the increased rotational mass. The trade-off is much better traction and stability, which often allows a rider to carry more speed through rough sections, effectively making them faster overall.
Q3: Is the installation something I can do at home?
A3: If you are mechanically inclined and have the proper tools (like spoke wrenches and a chain breaker), it is possible. However, for proper wheel lacing, truing, and overall safety, having a professional motorcycle shop perform the installation is highly recommended.
Q4: Do I need to change the gearing after installation?
A4: It’s a good idea. The larger rear wheel effectively raises the final gearing. Many riders compensate by adding one or two teeth to the rear sprocket to restore the bike’s snappy acceleration characteristic of the YZ85.
Q5: Is a big wheel kit a good alternative to buying a new, larger bike?
A5: For a growing rider who isn’t quite ready for a full-size 125cc, it’s an excellent and cost-effective stopgap. It extends the usable life of the YZ85, allowing the rider to build more skills and confidence before making the jump to a bigger machine.
Final Verdict: Which One Should You Buy?
For 2025, a Yamaha YZ85 Big Wheel kit remains the definitive upgrade for a rider outgrowing their standard mini. It transforms the bike’s handling, offering the stability and clearance needed for serious off-road and trail use. If your young rider is getting taller and needs more room and confidence, this kit is a smart, performance-focused investment that maximizes the potential of an already excellent platform.
Pros:
-
👍 Dramatically improves stability and control for taller riders.
👍 Increases ground clearance to tackle rougher terrain with confidence.
👍 Provides a larger contact patch for superior traction.
👍 A cost-effective way to extend the life of your YZ85 before moving to a larger bike.
Cons:
-
👎 May result in a slight loss of snappy acceleration due to increased wheel weight.
👎 Can slightly reduce the bike’s flickability on supercross-style tracks.
👎 Professional installation is recommended for safety and proper wheel truing.