The Sur-Ron Ultra Bee is a fundamentally different machine from the Light Bee X. At ~120kg with 10kW peak power and full 21"/18" MX wheel sizing, it is closer to a proper electric motocross bike than a trail toy. If you own one, maintenance and part sourcing are different from the lighter Sur-Rons — this guide covers what you need to know.
1. Brake System
The Ultra Bee uses Tektro Auriga hydraulic disc brakes — the same caliper family as the Sur-Ron Light Bee X and Talaria Sting. This is good news for parts sourcing: the same aftermarket pads that fit the Light Bee X drop straight in.
Galfer E-Bike Compound ($32.99) — Galfer's e-bike specific formulation is engineered for heavier, more powerful bikes. On the Ultra Bee's extra mass, better heat management and consistent bite at higher temperatures matter more than they do on the lighter LBX. This is the right daily-rider pad.
Galfer Pro Compound ($34.99) — Sintered. Better under repeated hard braking from higher speeds, and in muddy or wet conditions. The trade-off is more rotor wear over time. Right for aggressive trail or any track use on the Ultra Bee.
Unlike the Light Bee X, the Ultra Bee stock setup is 203mm front and rear. A rotor upgrade to 220–223mm is available and follows the same logic as on the LBX: more mechanical advantage at the lever, better heat dissipation.
2. Chain & Drivetrain
This is where the Ultra Bee diverges from the Light Bee X. The Ultra Bee runs a 520-pitch chain — a full size step up from the #420 chain on the LBX. The 520 pitch is standard on 125–250cc four-stroke dirt bikes, which means replacement chains are widely available.
Do not substitute a #420 chain — the pitch and link dimensions are different and a mis-spec chain will fail. When you buy a replacement, match the pitch (520), width, and link count exactly.
Chain tension drifts faster on the Ultra Bee than you might expect given the bike's weight. Check it every 8–10 hours of riding. The heavier the use, the faster it stretches.
3. Wheels & Tires
The Ultra Bee runs full-size MX wheel sizing: 21-inch front, 18-inch rear. This is the same sizing as 125–450cc motocross bikes, which means you have the widest possible tire selection — far more options than the LBX's 19/18 setup.
Common fitments:
- Front: 80/100-21 (MX standard) or 90/90-21
- Rear: 100/90-18 or 110/90-18
Bridgestone Battlecross, Dunlop MX33, Maxxis SI, and IRC VE-33s all fit without modification. If you ride primarily on hardpack, consider a harder compound intermediate tire — the Ultra Bee's weight and power can tear through soft-terrain knobbies quickly.
4. Protection
The Ultra Bee is heavier and hits harder than the Light Bee X, which makes underbody protection more important. A 3–4mm aluminum skid plate is the standard recommendation before riding any terrain with rocks. The battery and motor sit lower on this bike than on the LBX, and the consequences of a strike are more expensive.
5. Suspension
The stock RST forks on the Ultra Bee have more travel than the LBX units — appropriate for the bike's weight and intended use. Riders over 85kg doing significant jumps will still notice the forks working hard. The first suspension priority should be correct sag setup (100–110mm unladen, 75–85mm loaded for MX) before considering spring rate changes or aftermarket units.
Fork seals on the Ultra Bee are 43mm — the same spec as many full-size enduro bikes, keeping replacement cost reasonable. Seal replacement takes 30–45 minutes.
Maintenance Schedule
- Every ride: chain tension check, tire pressure
- Every 8–10 hours: chain lubrication, brake pad thickness check, spoke tension
- Every 20–30 hours: chain replacement if stretched, fork seal inspection
- Every 50 hours: bearing inspection (wheel bearings, linkage, swingarm pivot)
Browse the full Sur-Ron parts catalog on Wired Whips — all parts ship from US warehouses with fitment verified for the Ultra Bee, Light Bee X, and Storm Bee.