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Shimano RD-M3020 Acera rear derailleur SGS black 8 speed

• Reliable 7-8 speed shifting performance - Shimano Acera-level engineering delivers consistent, dependable shifting across 7-speed and 8-speed drivetrains, providing practical gear range for commuting, recreational riding, and light trail use

• Long-cage design for wide-range gearing - Extended cage accommodates larger cassette cogs and greater gear range, making it ideal for hilly terrain, touring, and riders who need low gears for climbing or carrying loads

• Durable construction for everyday riding - Robust build quality withstands the demands of daily commuting, recreational cycling, and light off-road use, offering reliable performance over thousands of miles at an accessible price point

• Shadow design for improved ground clearance - Low-profile Shadow technology positions the derailleur closer to the frame, reducing the risk of damage from obstacles while improving chain stability and creating a cleaner appearance

• Easy setup and maintenance - Straightforward adjustment and tuning make it accessible for home mechanics, while Shimano's proven design ensures compatibility with 7-speed and 8-speed Shimano shifters and cassettes

Brand: Shimano

Type: 7-8 Speed

Availability: In stock Out of stock

Delivery: 2-3 working days

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Regular price: £28.89
Sale price: £28.89
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Description

Acera mountain bike rear derailleur with light action operation and over-size pulleys for a wide gear choice

Oversize 13-tooth tension and guide pulleys to reduce noise and wear

Extension spring and low-friction fluorine-coated link pivot bushing result in a light shifting action

Top normal spring for use with Rapidfire shifters

IG and HG chain, 7- and 8-speed compatible

Product Type Rear Derailleurs

Speed 8 Speed

Speed 7 Speed

Discipline MTB

Colour Black

Size SGS - long

Di2 No

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FAQ

Q: Can I use this derailleur with both 7-speed and 8-speed systems? A: Yes, the RD-M3020 is compatible with both 7-speed and 8-speed drivetrains. Shimano's 7-speed and 8-speed mountain bike systems use the same cable pull ratio and cog spacing, so this derailleur works seamlessly with either setup. Just ensure you're using matching 7-speed or 8-speed shifters, cassettes/freewheels, and chains for your specific system.

Q: What is the maximum cassette or freewheel size this derailleur can handle? A: The RD-M3020 long-cage derailleur can accommodate cassettes or freewheels up to 34 teeth on the largest cog, making it suitable for wide-range gearing needed for hills and touring. Common compatible ranges include 11-28T, 11-32T, 11-34T, and 14-34T. Check your total drivetrain capacity (difference between largest and smallest gears front and rear) to ensure compatibility.

Q: Is this derailleur compatible with 9-speed or higher systems? A: No, the RD-M3020 is designed specifically for 7-speed and 8-speed drivetrains and will not work properly with 9-speed, 10-speed, or 11-speed systems. Different speed systems use different cable pull ratios and cog spacing, so mixing components will result in poor or non-functional shifting. Always match your derailleur speed rating to your shifters and cassette/freewheel.

Q: What does the Shadow design do and why is it beneficial? A: Shadow design positions the derailleur body closer to the frame and lower profile compared to traditional derailleurs. This reduces the risk of damage from rocks, roots, curbs, and other obstacles, improves chain stability by keeping the chain path more direct, and creates a cleaner, more protected appearance. It's particularly useful for mountain biking, touring, and urban riding where obstacles are common.

Q: How do I set up and adjust this derailleur? A: Basic setup involves: 1) Setting the high limit screw so the chain doesn't shift past the smallest cog, 2) Setting the low limit screw to prevent shifting past the largest cog, 3) Adjusting cable tension for crisp shifts across all gears using the barrel adjuster, and 4) Setting the B-screw to control the gap between the upper pulley and largest cog. Regular maintenance includes cleaning the pulleys and lubricating pivot points. If you're new to derailleur adjustment, Shimano's manuals or a bike mechanic can help ensure proper setup.