Premium 520 Chain Sprocket Kit – Hyosung GT125R GT125 GT250
⛓️ 520 PREMIUM CONVERSION | TOURING DURABILITY🛣️
Stop the stretch. The stock 428 chain is overworked on a 180kg 125cc V-Twin. Our 520 Conversion Kit moves your bike to heavy-duty hardware used by 600cc machines, offering sharper acceleration, reduced maintenance, and a massive jump in tensile strength.
As for you 250cc owners , it is not fun being 100 miles away from home due to a snapped china MTX chain!
- 🚀 Optimised Gearing: Specifically ratioed for better “zip” without stressing the valves.
- 🇯🇵 Japanese & EU Chains: We use RK, EK, DID, DC Japan or JT as an alternative. ❌Absolutely no rubbish china MTX chains.
- ✨ ✅ Free Stainless Hardware: Includes Stainless Rear Sprocket Bolts for a permanent shiny finish.
- 🔐✅ Front Locking Washer included: Don’t allow the front sprocket to fall off with a bad old lock, so we also include it for you!
- 🛣️ Touring Ready: The choice for long-distance 125cc/250cc riders.
Cheaper kits on other websites use Chinese industrial chains (MTX/CHOHO). On a heavy Hyosung, these stretch instantly and can snap. We sell Mechanical Insurance—proven brands you can trust at 10,000 RPM. #GoFaster!🛣️⚡
Description
The Hyosung GT Series are “Big Bike” chassis machines. At nearly 180KG, they are far heavier than a standard 125cc commuter. Using a 428 “Moped” chain is the weak link in the factory setup. This 520 Conversion Kit is designed to bring your drivetrain up to the standard the chassis deserves.
⚙️ Why the 520 Conversion Works
Many riders ask: “Why not stick to 428?” The answer is Physics. A 520 chain has larger rollers and thicker plates. While the 520 hardware is slightly heavier, the Optimised Internal Gearing in our kit more than compensates, resulting in:
- Increased Surface Area: Distributes the load better, meaning the chain stretches less over time.
- Improved Circumferential Torque: Our specific sprocket pairing ensures the engine stays in the “Power Band” longer.
- Better 0-60 Performance: Especially on the 125cc, you’ll feel the bike “wake up” between gears.
| Quality Sprockets Precision engineered, no “soft” steel. |
Japanese/EU Chains DC, RK, EK, DID, etc or JT Branded. |
| Stainless Bolts Included Stay shiny and rust-free. |
Safety Lock Washer Ensures your front sprocket stays put. |
| Chain colour will be generally “black or dark grey” | Looking for a Gold 520 Chain or specific kits for another bike? Contact us here |
🏍️ Performance Expectations
GT125 / GTR 125: Expect a noticeable boost in acceleration. While it helps you reach top speeds (80+ mph) more efficiently, we advise against sustained redlining to protect your valves. This kit is about getting there smoother.
GT250 / GTR 250: The benefit here is longevity. The 520 chain handles the V-Twin torque with ease, providing a much longer service life than stock Korean parts.
📜 Confirmed Fitment:
| GT125R & GT125-RC (Up to 2021) | GT125 Naked & GT125P (Up to 2021) |
| GT250 (All Years) | GT250R (All Years |
🔧 Chain Sprocket Kit Installation Tips
- Sprocket Alignment: Ensure your rear wheel is perfectly aligned using the swingarm marks to prevent “side-wear” on the new chain.
- Thread Locker: Use a drop of blue thread-locker on your sprocket bolts to fight V-Twin vibrations.
- The 20mm Rule: Always allow roughly 20-30px of “slack” when the bike is on its side-stand to allow for suspension travel.
- Clean & Lube: A good chain will last more miles if kept clean. Avoid “Sticky” lubes that attract grit.
Additional information
| Weight | 3 kg |
|---|---|
| Dimensions | 30 × 30 × 4 cm |
14 reviews for Premium 520 Chain Sprocket Kit – Hyosung GT125R GT125 GT250
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GARAGE PICKS // ADD TO BUILD
-
Anodized Gear Shift Linkage Rod [Shifter Bar] – GTR 125 250 RC Hyosung
Price range: £20.00 through £24.00 -
Anodized Short Gear Shift Bar [Shifter Linkage Rod] – GT125 Naked & GT250 Comet Hyosung
£21.00 -
Front Engine Sprocket Nut – Hyosung GV125 GT250 GT125R GV250 RT125D
£12.99 -
SwingArm Spool Kit {Race Stand Bobbins Sliders} – Hyosung GT125 GT250 GT125R GT250R
£34.99
EXPLORE // RELATED PRODUCTS
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Fast X-Ring Upgrade Chain & Sprocket Kit – Hyosung GV300S [Aquila 300 Bobber]
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Premium X-Ring 525 Chain & Sprocket Kit – Hyosung GT650 GT650R
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Japan Front Rear Wheel & Sprocket Bearing Kit – Hyosung GV GT 125 250 650 & ST7
£33.99 -
![Engine Front Sprocket Washer [Safety Lock] - Hyosung GV300S](https://i0.wp.com/hyoriders.club/wp-content/uploads/2022/09/hyosung-gv300s-sprocket-washer-lock.jpg?fit=362%2C362&ssl=1)
Engine Front Sprocket Washer [Safety Lock] – Hyosung GV300S
£9.99
Your Hyosung parts hub genuine & aftermarket parts + upgrades with UK & worldwide shipping.
shane (verified owner) –
Made a improvement to my 125 got abit more top end aswell
Mick (verified owner) –
Fantastic pieces of kit cheers marcel they work a treat
Jason (verified owner) –
Once again amazing service and delivery they look good too
Daryn (verified owner) –
Instant gains from this kit amazing worth every penny
Lee Bartlett (verified owner) –
Fantastic service from marcel.
Brilliant bit of kit and would recommend anyone looking to upgrade to buy this kit.
Jake Carter (verified owner) –
Fast delivery and straightforward fitment
Andy Elias (verified owner) –
Easy to fit and instant gain, quick service too. cheers Marcel
Matt (verified owner) –
Bought a couple of weeks ago and finally fitted last week. Made a good improvement to gearing and acceleration.
Jed (verified owner) –
Bought to replace my 428 set. Big improvement in gearing and it’s lots smoother now! Bigger sprockets, chunkier chain = better looks. Really happy with the purchase, thanks Marcel!
Andy (verified owner) –
Easy simple fit.
Kevin Barrier (verified owner) –
Straight swap, easy fit. Looks great. Will post pictures later. Bigger front and rear sockets, longer thicker chain. I am perfectly happy with my purchase and hand delivered by Marcel. Excellent product, great store. Will be using again
Owen –
Definitely worth it, Bike now drives much smoother, gearing is way better. I would highly recommend to switch to this kit
dufferdave (verified owner) –
Much better quality than oe items, fitted perfectly, much smoother and performance gains noticeable instantly, well worth the money. thanks Marcel.
Stu (verified owner) –
Bought for 2016 GT. Straight forward swap out. Bike feels better geared in all gears. No massive top end gains but worth it for the increased rideability!!