TM SMX 85 [2010-2021]: The Italian Precision Tool for Junior Motocross Warriors

Introduction

The TM SMX 85 represents a decade of Italian engineering distilled into a purpose-built junior motocross machine. Designed for riders aged 12-16 transitioning from mini bikes to full-size competition, this two-stroke screamer has carved its niche as a premium alternative to mainstream Austrian and Japanese offerings. From 2010 to 2021, TM Racing refined this platform with competition-grade components that defy its "entry-level" categorization. Let's dissect why this pocket rocket remains a cult favorite among serious junior MX families.

Design Philosophy: Italian Flair Meets Brutal Functionality

The SMX 85 immediately stands out with its signature blue-and-white livery - a refreshing departure from the orange/white/red monotony dominating pit lanes. But this isn't just cosmetic bravado. The Cr-Mo steel perimeter frame uses ovalized tubes that balance flex and rigidity in a way that makes aluminum frames feel harsh by comparison. At 6 liters (1.59 gallons), the fuel tank is compact but strategically shaped to let riders attack berms without knee interference.

Ergonomics reveal TM's race-first mentality. The 830mm seat height (32.7") might intimidate newcomers, but the narrow chassis and sculpted seat let shorter riders dab feet confidently. Every control - from the Magura hydraulic clutch lever to the adjustable brake pedals - feels like it was milled for a factory GP bike rather than a junior machine.

Engine Performance: Carbureted Fury with Race DNA

Don't let the 85cc displacement (80cc actual) fool you - this liquid-cooled two-stroke packs adult-level intensity. The 46.5x47mm bore/stroke (1.8"x1.9") configuration prioritizes mid-range punch over peaky top-end, making it more manageable for developing riders than its KTM counterpart. The Keihin PWK28 carburetor delivers crisp throttle response, though it demands meticulous jetting for altitude/temperature changes - a small price for avoiding modern EFI complexity.

With the 6-speed gearbox, riders can either short-shift through tight woods or hold gears longer on fast straights. The hydraulic clutch (a rarity in this class) offers buttery modulation even during marathon motos. Expect 28-32 HP depending on tuning - enough to lift the front wheel in third gear when the power valve kicks in around 6,500 RPM.

Chassis & Handling: Pro-Level Suspension Out of the Box

Here's where the TM separates from the pack. While competitors ship with budget suspension, the SMX 85 boasts full Paioli 43mm USD forks and an Öhlins shock - components usually reserved for works bikes. The Paioli setup offers 280mm (11") of travel with 24-click compression damping adjustability. Out back, the Öhlins unit provides 290mm (11.4") travel with high/low-speed compression tuning.

This premium hardware translates to sublime track manners. The front end tracks through braking bumps like it's on rails, while the rear maintains composure on hard landings. For 45kg (99lb) junior riders, the stock spring rates are perfect. Heavier teens might need stiffer springs available through MOTOPARTS.store's suspension upgrade range.

Competition: How It Stacks Against the Usual Suspects

The 85cc class is dominated by three players:
1. KTM 85 SX: The sales leader with superior parts availability but harsh WP suspension requiring immediate upgrades
2. Husqvarna TC 85: Essentially a rebadged KTM with minor ergonomic tweaks
3. Yamaha YZ85: Budget-friendly but stuck with 1990s-era technology

The TM SMX 85 carves its niche with:
- Superior suspension: Öhlins/Paioli combo outperforms stock WP/KYB units
- Hydraulic clutch: Reduces fatigue during long motos vs cable-operated rivals
- Exotic appeal: Stands out at races where every other bike is orange/blue
- Build quality: CNC-machined components vs rivals' cast parts

However, it demands more mechanical sympathy. The 3.5% premix ratio (28:1) requires frequent top-end rebuilds compared to KTM's 40:1 recommendations. Parts availability has improved but still lags behind Japanese brands.

Maintenance: Keeping the Italian Fire Breathing

Owning an SMX 85 is like dating a temperamental supermodel - glorious when maintained, catastrophic when neglected. Follow these MOTOPARTS.store-approved tips:

1. Engine Rebuilds:
2. Pistons every 15-20 hours
3. Crankshaft seals every 30 hours

4. Use MOTOPARTS.store's Vertex top-end kits with upgraded wrist pin bearings

5. Carburetor Care:

6. Clean Keihin jets weekly with ultrasonic kit (MP-UCLEAN)

7. Replace throttle cable annually (MP-TH85-CABLE)

8. Suspension Service:

9. Change fork oil every 40 hours with MOTOPARTS.store's 5W Paioli-specific fluid

10. Rebuild Öhlins shock every 50 hours using genuine seal kits

11. Critical Upgrades:

12. Aluminum throttle tube (MP-ATUBE-85) eliminates stock plastic wear
13. Billet clutch cover (MP-CCOVER-SMX) prevents cracking during crashes
14. Heavy-duty air filter (MP-AF85-HD) for dusty conditions

Conclusion: The Coach's Choice

The TM SMX 85 isn't for everyone. Casual riders might balk at its maintenance demands and premium parts pricing. But for serious juniors eyeing national championships, it's a rolling masterclass in race-bred engineering. The combination of Italian chassis finesse and brutal two-stroke power creates a bike that grows with the rider - something few competitors can claim.

At MOTOPARTS.store, we keep these exotic machines running with our curated selection of TM-specific upgrade kits and OEM replacements. Because every future champion deserves a bike that's as committed to winning as they are.

Specifications sheet