Thinking about converting your Yamaha YZ85 to a big-wheel setup but not sure where to start? Many riders struggle with finding kits that fit cleanly, avoid extra work, and improve stability without surprises. The wrong parts can lead to wobble, poor alignment, or extra shop time.
This guide reviews the top big-wheel and wheel-bearing kits that fit the YZ85. You’ll get clear comparisons, what each kit is best for, and easy links to check prices — so you can pick the right upgrade and get back on the track faster.
| Product Image | Product Name | Best For | Check Price |
|---|---|---|---|
 | NICHE Wheel Bearing Spacer and S | Exact Spacer Fit | Prices |
 | All Balls Racing Rear Wheel Spac | Rear Wheel Upgrade | Prices |
 | Caltric Rear Wheel Ball Bearing | Affordable Bearings | Prices |
 | Tusk Wheel Bearing and Seal Kit | Complete Repair Kit | Prices |
 | All Balls Racing 25-1168 Wheel B | Oem Replacement | Prices |
 | Iconic Racing Front Wheel Bearin | Front Bearing Fix | Prices |
NICHE Wheel Bearing Spacer and S
Perfect for Yamaha YZ85 riders fitting a big-wheel kit who want a precise, reliable wheel bearing spacer and seal solution.
The NICHE spacer is CNC-machined to tight tolerances so bearings sit square and the axle spacing stays correct. That matters in practice: when you fit a larger wheel the spacer keeps the hub centered and cuts wobble, so you don’t have to retune alignment after the swap. The included seal helps keep grease in and dirt out during trail rides.
It ships with an anodized finish that resists corrosion and handles off-road abuse. Installation is straightforward with basic tools and stock hardware, so you’ll be back on the trail quickly. Overall, it’s a solid, value-minded choice for anyone upgrading their YZ85 to a big-wheel setup.
Pros:
- 👍 Precise CNC fit keeps wheel alignment and reduces play.
- 👍 Anodized finish for good corrosion resistance.
- 👍 Simple install using common tools and stock hardware.
- 👍 Seal included to help protect bearings from dirt and water.
Cons:
- 👎 Fit is model-specific, so double-check compatibility before buying.
- 👎 Installation instructions are basic; novice mechanics may need extra guidance.
- 👎 Slightly more expensive than generic spacers, but you get quality.
All Balls Racing Rear Wheel Spac
Perfect for Yamaha YZ85 riders fitting a big-wheel kit who want a precise, OEM-style rear wheel spacer that makes installation straightforward.
This All Balls Racing rear wheel spacer is machined to tight tolerances and finished to resist corrosion. The precise fit keeps axle alignment true, which reduces uneven sprocket and chain wear. For example, when you swap from a small-wheel setup to a big-wheel kit, the spacer eliminates side-to-side play that can cause vibration at speed. Installation is simple: slide it onto the axle and torque to spec with basic tools, so the swap is quick even in the field.
Built from durable metal, it stands up to off-road knocks and repeated removals. The simple design means fewer failure points and consistent performance over time. If you want a reliable, low-cost part that solves a common alignment headache, this spacer is a solid choice.
Pros:
- 👍 Precise machining ensures correct axle alignment and less drivetrain wear.
- 👍 Corrosion-resistant finish for longer life in wet, muddy conditions.
- 👍 Very easy to install with basic tools—fast swap time.
- 👍 Durable construction handles repeated maintenance and off-road use.
Cons:
- 👎 Designed for specific wheel/axle combos—double-check fitment before buying.
- 👎 Sold as a single spacer, so you may need additional parts for a full kit.
- 👎 Not a visible upgrade—functional rather than flashy.
Caltric Rear Wheel Ball Bearing
Ideal for Yamaha YZ85 riders fitting a big-wheel kit who need a reliable, OEM-style rear wheel bearing replacement that can handle added load and rough trail use.
The Caltric rear wheel ball bearing offers precision tolerances and a sealed design that reduces friction and keeps out dirt and water. In practice this means smoother wheel spin, less heat build-up, and reduced play — for example, after swapping to a larger 19″ rear wheel you should notice steadier cornering and fewer vibrations at speed.
Made from hardened steel with durable rubber seals, the bearing resists corrosion and wears slowly under heavy use. It’s a direct-fit aftermarket part, so installation is straightforward with basic tools or a simple press. Overall, it’s an affordable, durable choice that helps maintain alignment and ride feel after a big-wheel conversion.
Pros:
- 👍 Precision fit reduces wobble and improves handling.
- 👍 Sealed design keeps out dirt and moisture for longer life.
- 👍 Hardened steel construction increases durability under load.
- 👍 Direct-fit and budget-friendly compared with OEM.
Cons:
- 👎 Not branded OEM — verify compatibility before buying.
- 👎 Removal/installation may require a press or specific tools.
- 👎 Limited to specific bearing sizes — double-check measurements.
Tusk Wheel Bearing and Seal Kit
Perfect for Yamaha YZ85 riders fitting a big wheel kit who want a straightforward, reliable replacement for worn wheel bearings and seals.
The kit includes correctly sized bearings and durable seals designed to match OEM dimensions. That means the wheel spins smoothly and with less play right after installation. For example, replacing a noisy front hub with this kit will restore crisp steering feel and reduce wobble on tight corners.
Build quality stands out — the bearings are heat-treated and the seals resist dirt and moisture. The kit also saves time by bundling all needed parts, so you avoid multiple trips to the shop. If you want a cost-effective, long-lasting service solution for a big-wheel conversion, this kit is a strong choice.
Pros:
- 👍 Complete set of bearings and seals for a single purchase
- 👍 OEM-fit dimensions for easy, reliable installation
- 👍 Durable construction resistant to dirt and moisture
Cons:
- 👎 No grease or specialty tools included, you may need extras
- 👎 Packaging may vary by supplier; check contents before starting
All Balls Racing 25-1168 Wheel B
Perfect for YZ85 riders fitting a big-wheel kit who want a straightforward, reliable wheel component that holds up to aggressive trail or track use.
This kit shines with precision bearings and tight-seal shields. The bearings roll smoothly and reduce drag, so acceleration and top speed feel more consistent. The direct-fit design also cuts install time — for example, you can swap wheels between rides without chasing awkward tolerances.
Build quality is solid, with hardened races and corrosion-resistant finishes that resist grit and moisture. That means fewer rebuilds and less downtime. Overall, it’s a practical, cost-effective choice for riders who want OEM-style reliability when converting their YZ85 to a big-wheel setup.
Pros:
- 👍 Smooth, low-friction bearings improve rolling and speed.
- 👍 Sealed design keeps dirt and water out for longer life.
- 👍 Direct-fit, easy to install — saves time at the trail.
- 👍 Durable construction gives good value over time.
Cons:
- 👎 May require specific tools for perfect install.
- 👎 Limited to certain wheel configurations — check fitment.
- 👎 Grease service still needed on heavy-use bikes.
Iconic Racing Front Wheel Bearin
Perfect for YZ85 riders fitting a big-wheel kit who want smoother front-end performance and reliable, long-lasting bearings.
The Iconic Racing front wheel bearing features precision-ground races and a sealed stainless-steel design. That means lower friction and better wheel spin. In practice you’ll notice crisper steering and less drag on the track, for example when accelerating out of turns the front feels more planted and predictable.
It also scores well for durability and easy fitment. The seal keeps grit and water out, so maintenance intervals stretch longer. Installation is straightforward and the tolerances match YZ85 big-wheel conversions. Overall it’s a practical upgrade that boosts handling without a lot of fuss.
Pros:
- 👍 Smooth, low-friction operation for improved handling.
- 👍 Sealed stainless-steel design resists corrosion and dirt.
- 👍 Precision fit for YZ85 big-wheel conversions—easy swap-in.
- 👍 Good value for the durability it delivers.
Cons:
- 👎 Slightly firmer price than generic bearings, but quality justifies it.
- 👎 Not OEM—some riders prefer factory parts for warranty reasons.
- 👎 Requires basic tools for installation if you do it yourself.
Buyer’s Guide: 3 Key Factors to Consider
Durability & Materials
Choose kits that use hardened steel hubs or high-grade 6061-T6 aluminum and reinforced spokes. Check for sealed bearings and corrosion-resistant finishes — these parts take heavy abuse from rocks and jumps. If you ride in muddy or coastal conditions, prioritize corrosion protection and easy-to-replace wear parts (sprocket carriers, spacers).
Fit & Compatibility
Confirm axle spacing, rotor position, and sprocket tooth count are compatible with your YZ85 year and whether you have an electric start or kick-only model. Look for kits that include all necessary adapters, brake caliper mounts, and chain length specs to avoid aftermarket surprises. If in doubt, buy from vendors with clear year-by-year fitment charts.
Installation & Price vs. Performance
Decide how much you want to spend on ease of install versus savings. Plug-and-play kits with pre-spaced hubs and brackets cost more but reduce shop labor. If you do the work yourself, verify torque specs and use a thread locker on critical fasteners. For trail stability and lower maintenance, investing a bit more in quality pays off long-term.
Frequently Asked Questions
Q1: What exactly is a “big wheel kit” for the YZ85?
A1: A big wheel kit replaces the YZ85’s stock 17/14 or 14/12 wheel setup with larger-diameter rims, hubs, and associated spacers/brackets to fit 19″ front and 16″ rear wheels (or similar). It improves stability and gives adult riders easier handling without changing the engine.
Q2: Will a big wheel kit affect gearing or top speed?
A2: Yes—larger wheels slightly change effective gearing and speedometer calibration. The bike will roll farther per engine revolution, which can reduce acceleration but improve top speed and stability; adjust sprocket sizes if you want to restore low-end response.
Q3: Do I need to upgrade the suspension or brakes with a kit?
A3: Usually the stock suspension and brakes work, but performance-minded riders should at least revalve or respring the forks and shock to account for different wheel inertia and rider weight. Upgraded rotors or pads may improve braking feel with larger wheels.
Q4: Is installation something I can do at home?
A4: Many people install big wheel kits at home if they have basic motorcycle tools and mechanical knowledge. Kits that include clear instructions and all adapters are easiest. If you’re unsure about torque specs, wheel alignment, or brake mounting, have a shop handle it to avoid safety issues.
Q5: Are big wheel kits legal for racing or track use?
A5: Rules vary by class and sanctioning body. Some youth classes prohibit big wheels, while many amateur adult classes allow them. Always check class and series regulations before racing with a modified wheel size.
Q6: How do I choose tires for a big wheel YZ85?
A6: Match tire size to the new rims and pick a compound and tread pattern for your terrain (soft-compound for sand/mud, harder for mixed trails). Ensure rim width matches the tire and maintain correct air pressure for the larger circumference to avoid pinch flats and poor handling.
Final Verdict: Which One Should You Buy?
For most riders in 2025, the best choice is a proven, complete big wheel kit from a reputable supplier that includes hubs, spacers, brake mounts, and clear fitment for your YZ85 year — it delivers the best balance of durability, fit, and ease of install. Choose a higher-quality kit if you ride aggressively or in harsh conditions; budget kits are fine for casual trail use.
Pros:
- 👍 Improved stability and confidence for taller/adult riders
- 👍 Longer, more comfortable trail rides with less twitchy handling
- 👍 Many kits include all adapters — fewer compatibility surprises
- 👍 High-quality kits use durable hubs, sealed bearings, and serviceable parts
Cons:
- 👎 Slight loss of low-end acceleration unless you re-gear
- 👎 Some installs require mechanical skill or a shop visit
- 👎 Lower-quality kits may need more frequent replacement parts