---
product_id: 65684652
title: "Wolf Tooth Components 25mm long B-Screw for adapting old deraileurs when using a by Wolf Tooth Components"
brand: "wolf tooth"
price: "£18.62"
currency: GBP
in_stock: true
reviews_count: 6
category: "Wolf Tooth"
url: https://www.desertcart.co.uk/products/65684652-wolf-tooth-components-25mm-long-b-screw-for-adapting-old
store_origin: GB
region: United Kingdom
---

# 25mm precision length Premium 18-8 stainless steel Optimized for Shimano MTB derailleurs Wolf Tooth Components 25mm long B-Screw for adapting old deraileurs when using a by Wolf Tooth Components

**Brand:** wolf tooth
**Price:** £18.62
**Availability:** ✅ In Stock

## Summary

> 🔧 Small Screw, Massive Shift: Upgrade Your Ride’s Precision!

## Quick Answers

- **What is this?** Wolf Tooth Components 25mm long B-Screw for adapting old deraileurs when using a by Wolf Tooth Components by wolf tooth
- **How much does it cost?** £18.62 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.co.uk](https://www.desertcart.co.uk/products/65684652-wolf-tooth-components-25mm-long-b-screw-for-adapting-old)

## Best For

- wolf tooth enthusiasts

## Why This Product

- Trusted wolf tooth brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Lightweight Yet Strong:** At just 5 grams, it delivers maximum strength (550 MPa shear) without adding bulk to your setup.
- • **Seamless Derailleur Adjustment:** Ensures optimal B-limit screw replacement for cleaner shifts and superior chain management.
- • **Precision Fit for Wide-Range Cogs:** Specifically engineered to perfectly adapt Shimano derailleurs when paired with Wolf Tooth GC 40 & GC 42 large cogs.
- • **Durable Stainless Steel Construction:** Crafted from high-grade 18-8 stainless steel for corrosion resistance and long-lasting performance on every ride.
- • **Easy Installation with Phillips Head:** Designed for quick, hassle-free upgrades to keep you rolling faster and smoother.

## Overview

The Wolf Tooth Components 25mm B-Screw is a premium stainless steel replacement screw designed to optimize Shimano mountain bike derailleurs when using Wolf Tooth’s GC 40 or GC 42 large cogs. Engineered for precise derailleur alignment, it enhances shifting performance and chain management, making it an essential upgrade for serious cyclists seeking flawless drivetrain efficiency.

## Description

When using the Wolf Tooth GC 42 (50-3898) or GC 40 (50-3899) replacement cogs with a Shimano rear derailleur, a longer B-screw will be needed for proper adjustment. High quality 18-8 stainless steel screw is compatible with most Shimano mountain bike derailleurs. Replaces stock B-limit screw on Shimano MTB derailleurs Use if you are using Wolf Tooth GC 42 or GC 40 large cogs High quality stainless steel

Review: It does the job - It is a good screw
Review: Wolf Tooth 25mm B-Screw – A Small Part with Big Impact - The Wolf Tooth 25mm B-Screw might seem like a tiny, unassuming component, but it makes a huge difference in your bike's drivetrain setup. If you’ve got a Shimano derailleur and are looking to ensure proper derailleur alignment, this B-screw is a must-have. Made from durable materials, it’s designed to provide precision adjustment for your derailleur cage, giving you cleaner shifts and better chain management. It’s especially helpful if you’ve recently swapped to a wide-range cassette or if your original B-screw has worn down. Final Verdict: 9/10 – Simple, effective, and well-made. A small upgrade that improves your bike's performance. 🚴‍♂️🔩

## Features

- Replaces stock B-limit ************************************************************* on Shimano MTB derailleurs
- Use if you are using Wolf Tooth GC 42 or GC 40 large cogs
- High quality stainless steel

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B00LMY7BA0 |
| Best Sellers Rank | 70,358 in Sports & Outdoors ( See Top 100 in Sports & Outdoors ) 210 in Screws (Sports & Outdoors) 228 in Bike Derailleurs & Parts |
| Brand Name | Wolf Tooth |
| Colour | Silver |
| Compatible Groove Diameter | 4 Millimeters |
| Customer Reviews | 4.5 out of 5 stars 236 Reviews |
| Drive System | Bicycle Derailleur Drive System |
| Exterior Finish | Stainless Steel |
| Exterior finish | Stainless Steel |
| Fastener Size | M4 x 25mm |
| Fastener Type | Screw (M4 thread size) |
| Finish Types | Uncoated |
| Global Trade Identification Number | 00812719020152 |
| Grade Rating | Premium |
| Head Type | Phillips |
| Head style | Phillips |
| Included Components | Miscellaneous Rear Derailleur Part |
| Item Diameter | 4 Millimetres |
| Item Dimensions | 10.2 x 5.1 x 0.6 centimetres |
| Item Weight | 5 g |
| Item dimensions L x W x H | 10.2 x 5.1 x 0.6 centimetres |
| Manufacturer Part Number | BSCREW25 |
| Material | Stainless Steel |
| Material Type | Stainless Steel |
| Maximum Shear Strength | 550 MPa |
| Metal | Stainless Steel |
| Model Number | BSCREW25 |
| Number Of Items | 1 |
| Number of Pieces | 1 |
| Point style | cylindrical |
| Screw Head Style | Phillips |
| Screw Point Style | cylindrical |
| Set Name | Single Screw Set (M4 x 25mm) |
| Set Screw Thread Type | M4 x 0.7mm |
| Size | M4 x 25mm |
| Thread Class | standard |
| Thread Coverage | Fully Threaded |
| Thread Size | 4mm |
| Thread Style | M4 |
| Thread Type | Metric |
| Thread size | 4mm |
| UPC | 812719020152 |
| Unit Count | 1.0 count |

## Product Details

- **Exterior finish:** Stainless Steel
- **Head style:** Phillips
- **Item dimensions L x W x H:** 10.2 x 5.1 x 0.6 centimetres
- **Material:** Stainless Steel
- **Thread size:** 4mm

## Images

![Wolf Tooth Components 25mm long B-Screw for adapting old deraileurs when using a by Wolf Tooth Components - Image 1](https://m.media-amazon.com/images/I/61DD++TmylL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐ It does the job
*by S***S on 4 September 2022*

It is a good screw

### ⭐⭐⭐⭐⭐ Wolf Tooth 25mm B-Screw – A Small Part with Big Impact
*by N***9 on 2 February 2025*

The Wolf Tooth 25mm B-Screw might seem like a tiny, unassuming component, but it makes a huge difference in your bike's drivetrain setup. If you’ve got a Shimano derailleur and are looking to ensure proper derailleur alignment, this B-screw is a must-have. Made from durable materials, it’s designed to provide precision adjustment for your derailleur cage, giving you cleaner shifts and better chain management. It’s especially helpful if you’ve recently swapped to a wide-range cassette or if your original B-screw has worn down. Final Verdict: 9/10 – Simple, effective, and well-made. A small upgrade that improves your bike's performance. 🚴‍♂️🔩

### ⭐⭐⭐⭐⭐ Perfect for Shimano B Screw
*by D***C on 5 July 2024*

I used this to replace the B limit screw on my Shimano derailleur after it was bent in a particularly muddy mountain bike race. It works perfectly!

## Frequently Bought Together

- Wolf Tooth Components 25mm B-Screw
- Wolf Tooth Components Roadlink
- Wolf Tooth GoatLink for Shimano

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*Product available on Desertcart United Kingdom*
*Store origin: GB*
*Last updated: 2026-06-28*