Struggling to find the right yz85 big wheel kit that actually fits and lasts? Choosing the wrong kit means poor handling, noisy bearings, or constant rebuilds. Riders want a simple upgrade that improves stability and keeps maintenance low.
This guide reviews six top options so you can compare features, fit, and value at a glance. Below is a quick introduction and a handy comparison table to help you pick the best kit for your needs and budget.
| Product Image | Product Name | Best For | Check Price |
|---|---|---|---|
 | YC Yier Complete 17 Big Wheel Ki | Complete Big-wheel Upgrade | Prices |
 | NICHE 85cc Cylinder Piston Rebui | Engine Rebuild Parts | Prices |
 | All Balls Racing Rear Wheel Spac | Precise Rear Spacing | Prices |
 | NICHE Wheel Bearing Spacer and S | Bearing Spacer & Seal | Prices |
 | Tusk Wheel Bearing and Seal Repl | Complete Bearing Replacement | Prices |
 | Caltric Rear Wheel Ball Bearings | Budget Bearings Set | Prices |
YC Yier Complete 17 Big Wheel Ki
Perfect for taller youths or adult riders who want to convert a Yamaha YZ85 to a more stable, faster 17-inch setup.
The kit’s 17-inch wheel and robust hub assembly are the standout features. They give a noticeably smoother roll and better momentum on flowy tracks. For example, on long straights you’ll hold speed with less effort and hit whoops with a steadier front end.
Build quality is solid, with machined hubs, quality spokes, and included rotor and spacers for a near plug-and-play fit. Installation is straightforward for anyone competent with basic tools. Overall, it’s a well-rounded package that upgrades handling and confidence without needing a full bike rebuild.
Pros:
- 👍 Complete kit — hub, rim, rotor, and hardware included for easier installation.
- 👍 Improves stability and top-end roll for bigger riders or longer tracks.
- 👍 Solid materials and machining for long-term durability.
- 👍 Mostly bolt-on fit for YZ85 with clear compatibility.
Cons:
- 👎 Adds some unsprung weight compared to stock small wheel.
- 👎 May require minor gearing or jetting tweaks to match the new wheel ratio.
NICHE 85cc Cylinder Piston Rebui
This rebuild kit is perfect for YZ85 riders fitting a big-wheel conversion who want stronger midrange torque and dependable top-end performance.
The core appeal is the 85cc cylinder and matched piston assembly. It boosts displacement and improves throttle response, so you get more pull at low RPMs. For example, with a big-wheel kit you’ll accelerate out of corners and climb steep sections without the bogging you had before.
Build quality stands out — honed bore, tight tolerances, and durable coatings help longevity. It’s a practical upgrade that balances cost and performance. If you want a straightforward way to make a big-wheel YZ85 feel less sluggish, this is a solid choice.
Pros:
- 👍 Noticeable increase in low- and midrange torque for big-wheel setups
- 👍 Precision machining and durable finish for longer life
- 👍 Direct-fit design aimed at YZ85 top-end swaps
- 👍 Good value compared to full OEM top-end rebuilds
Cons:
- 👎 Often requires carb rejetting and tuning after install
- 👎 Installation needs mechanical skill or a shop visit
- 👎 May slightly increase fuel consumption
All Balls Racing Rear Wheel Spac
Perfect for yz85 riders fitting a big-wheel kit who want a simple, reliable rear wheel spacer to keep axle alignment and handling precise.
This spacer is precision-machined to tight tolerances, so the wheel sits centered and the sprocket lines up correctly. That makes chain wear and rear-brake feel more predictable. For example, when you fit a larger rear wheel the spacer prevents rubbing and keeps chain tension correct, reducing the need for repeated adjustments after a few rides.
Build quality is solid with a corrosion-resistant finish that stands up to off-road use and mud. The low-profile design adds almost no weight and bolts on with basic tools, so installation is quick. Overall, it’s a dependable, budget-friendly part that solves a common alignment headache when upgrading to a big-wheel setup.
Pros:
- 👍 Precision fit that prevents chain and sprocket misalignment
- 👍 Easy to install with basic tools
- 👍 Durable, corrosion-resistant construction for off-road use
- 👍 Affordable OEM-compatible replacement
Cons:
- 👎 May need minor adjustments on heavily modified or non-stock setups
- 👎 Fit varies by year/model—confirm compatibility before buying
- 👎 Only addresses rear spacing; you still need the rest of the big-wheel kit
NICHE Wheel Bearing Spacer and S
Perfect for YZ85 riders fitting a big wheel kit who want tighter wheel alignment and longer bearing life.
This NICHE wheel bearing spacer locks the hub in the correct position and comes with replacement seals for a snug fit. The precision-machined spacer keeps side loads off the bearings, so you feel less play in the wheel when cornering. For example, when you switch to a larger front wheel, the spacer prevents the hub from shifting and reduces premature bearing wear.
Build quality is solid with corrosion-resistant finish and a lightweight design that won’t add noticeable mass. Installation is straightforward and uses existing hardware, so you can swap it in during a routine wheel change. Overall, it’s a practical, budget-friendly part that improves reliability when running a big wheel setup.
Pros:
- 👍 Precise fit improves wheel alignment and reduces bearing wear
- 👍 Includes seals for better protection against dirt and water
- 👍 Lightweight, corrosion-resistant finish for long life
- 👍 Easy to install using stock hardware
Cons:
- 👎 Not an OEM part, so fit can vary slightly by hub age
- 👎 Limited color/finish options compared with some premium brands
Tusk Wheel Bearing and Seal Repl
This product is perfect for DIY riders upgrading their YZ85 with a big wheel kit and for home mechanics who want reliable wheel bearings and seals.
The kit includes precision-fit bearings and matched seals that replace worn factory parts. That means smoother wheel spin and less play. For example, swapping in these bearings can eliminate a wobble that shows up at higher speeds and restore confident steering.
Durability is solid thanks to quality materials and tight tolerances. The set usually contains all the pieces you need, so you avoid multiple orders. Overall, it’s an affordable, practical choice that simplifies a big wheel conversion and helps keep the front end feeling tight and predictable.
Pros:
- 👍 Complete kit with bearings and seals for the YZ85 big wheel conversion.
- 👍 Precision fit reduces wheel play and improves handling.
- 👍 Durable materials for longer service life under off-road use.
- 👍 Good value compared with buying parts separately.
Cons:
- 👎 Installation may require a bearing press or shop tools.
- 👎 Paper instructions can be minimal; online help may be needed.
- 👎 Not an OEM-branded part, which may concern some riders.
Caltric Rear Wheel Ball Bearings
Perfect for YZ85 riders fitting a big-wheel kit who want reliable, smooth rear-wheel performance.
These Caltric rear wheel ball bearings are precision-made and sealed to cut friction and keep grit out. For example, swapping worn bearings for these gives a truer wheel spin and noticeably less drag when you nail the throttle out of a corner.
Built from hardened steel with corrosion-resistant seals, they stand up to mud and rain and fit into stock hubs for a straightforward swap. That blend of durability, fitment, and value makes them a smart upgrade for weekend racers and trail riders alike.
Pros:
- 👍 OEM-style fitment for easy, bolt-in replacement
- 👍 Sealed design keeps dirt and water out for longer life
- 👍 Precision construction improves roll and responsiveness
- 👍 Good value compared with branded OEM parts
- 👍 Simple install for home mechanics with basic tools
Cons:
- 👎 Requires basic bearing tools for installation/removal
- 👎 Aftermarket brand, not factory Yamaha OEM
- 👎 Heavy-duty race use may need more frequent inspection
Buyer’s Guide: 3 Key Factors to Consider
Durability and Build Quality
Choose a kit made from high-strength aluminum or chromoly components and look for hard-anodized finishes or corrosion-resistant coatings. Check user reviews for reports of bend, crack, or spoke failures — a kit that reinforces the swingarm and uses thicker spokes will last longer under aggressive riding.
Ease of Installation and Fitment
Confirm the kit is specifically listed for your YZ85 model year (or the compatible range) and includes all necessary hardware, spacers, and axle adaptors. Kits with plug-and-play hubs and clear instructions cut installation time and reduce the need for specialty tools or machine work.
Price vs. Performance (and Weight)
Compare total weight, hub design, and included brakes/sprocket carriers to assess value. Lighter wheels improve handling but can cost more; more affordable kits may still be great for trail use. Prioritize features that match your riding — race riders should favor lightweight, track-tested kits; casual riders can prioritize durability and cost.
Frequently Asked Questions
Q1: Will a big wheel kit fit every YZ85 model year?
A1: Not always. Fitment depends on axle size, swingarm geometry, and brake mounting. Always check the kit’s listed year compatibility and confirm included adapters for your specific model year.
Q2: How does a big wheel kit affect handling and gearing?
A2: A 19/16 or 19/17 conversion raises roll-over ability and alters final drive ratio slightly. Expect smoother hits and more stability at speed, but you may need to change sprocket sizes to restore acceleration or top speed balance.
Q3: Can I install a big wheel kit at home or should I go to a shop?
A3: If you have basic mechanical skills and tools, you can install many kits at home. However, alignment, brake setup, and torque specs are critical—if unsure, have a shop perform or at least inspect the installation.
Q4: Do big wheel kits require different tires or tubes?
A4: Yes — you’ll need tires sized for the new wheel (e.g., 19 front/16 rear). Most kits work with standard motocross or dual-sport tires for those sizes; use OEM or high-quality tube/tire combos to avoid fitting issues.
Q5: Are there any maintenance differences with a big wheel kit?
A5: Maintenance is similar: check spokes, bearings, and brake mounts regularly. Kits with sealed bearings or high-quality hubs often need less frequent service. Keep an eye on chain alignment and sprocket wear due to geometry changes.
Q6: Is it worth upgrading to a premium kit vs. a budget option?
A6: Premium kits generally offer lighter weight, better hubs, and longer-lasting finishes — valuable for race use or heavy riding. Budget kits can be excellent for casual trail riders; decide based on how much you ride and what performance you need.
Final Verdict: Which One Should You Buy?
If you race or ride aggressively, pick a lightweight, race-proven big wheel kit with robust hubs and a corrosion-resistant finish; it delivers better handling and long-term reliability. For weekend trail riders, a well-reviewed midrange kit that prioritizes durability and straightforward fitment offers the best value—solid performance without the race price.
Pros:
- 👍 Improved stability and roll-over ability for varied terrain.
- 👍 Many kits include complete hardware and adapters for easier fitment.
- 👍 Lightweight race kits significantly enhance handling for competitive riders.
Cons:
- 👎 Some kits require minor sprocket changes or tuning after installation.
- 👎 Higher-end kits can be costly—budget options trade weight for price.