---
product_id: 12975928
title: "Wolf Tooth Components 25mm Long B-Screw for Adapting Old deraileurs When"
brand: "wolf tooth"
price: "€ 12.82"
currency: EUR
in_stock: true
reviews_count: 8
category: "Wolf Tooth"
url: https://www.desertcart.fi/products/12975928-wolf-tooth-components-25mm-long-b-screw-for-adapting-old
store_origin: FI
region: Finland
---

# 25mm length for extra derailleur clearance Precision M4 stainless steel screw Compatible with 40-42T large cogs Wolf Tooth Components 25mm Long B-Screw for Adapting Old deraileurs When

**Brand:** wolf tooth
**Price:** € 12.82
**Availability:** ✅ In Stock

## Summary

> 🔧 Upgrade your drivetrain clearance and never miss a shift!

## Quick Answers

- **What is this?** Wolf Tooth Components 25mm Long B-Screw for Adapting Old deraileurs When by wolf tooth
- **How much does it cost?** € 12.82 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.fi](https://www.desertcart.fi/products/12975928-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

- • **Race-Proven Reliability:** Trusted by mountain bikers to fix bent screws and maintain smooth shifting after tough rides.
- • **Sleek Allen Head Design:** Easy installation and adjustment with a clean, professional finish that fits seamlessly on your bike.
- • **Extended Reach for Big Cogs:** 25mm length gives your derailleur the clearance it needs to handle 40-42 tooth gears effortlessly.
- • **Durable Stainless Steel Build:** Crafted from corrosion-resistant stainless steel for long-lasting performance in all conditions.
- • **Perfect Shimano Compatibility:** Specifically designed to replace and upgrade Shimano B screws with a precise M4 thread fit.

## Overview

The Wolf Tooth 25mm Long B-Screw is a precision-engineered stainless steel replacement screw designed to extend derailleur clearance for 40-42 tooth cogs. Ideal for Shimano derailleurs, it ensures smooth shifting and durability, making it a must-have upgrade for serious cyclists tackling larger gear ranges.

## Description

Need a bit more space for your derailleur to clear a 40 or 42-tooth cog?

Review: Perfect for Shimano B Screw - 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!
Review: Problem solver - Exactly what I needed for a 9 speed SLX derailleur to run a larger 40T granny gear. Nice Allen head with good threads and fit.

## Features

- 24mm M4 Screw: A Little Extra Reach

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Item Package Dimensions L x W x H | 3.8 x 2 x 0.05 inches |
| Package Weight | 0.02 Kilograms |
| Item Dimensions  LxWxH | 4 x 2 x 0.25 inches |
| Item Weight | 4.54 g |
| Brand Name | Wolf Tooth |
| Warranty Description | Limited Warranty |
| Model Name | BSCREW25 |
| Color | Silver |
| Material | Stainless Steel |
| Suggested Users | unisex-adult |
| Number of Items | 1 |
| Manufacturer | Wolf Tooth |
| Part Number | 50-3897-NON-NON |
| Included Components | Miscellaneous Rear Derailleur Part |
| Sport Type | Cycling |

## Images

![Wolf Tooth Components 25mm Long B-Screw for Adapting Old deraileurs When - Image 1](https://m.media-amazon.com/images/I/61DD++TmylL.jpg)

## Customer Reviews

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

### ⭐⭐⭐⭐⭐ Problem solver
*by B***D on July 17, 2025*

Exactly what I needed for a 9 speed SLX derailleur to run a larger 40T granny gear. Nice Allen head with good threads and fit.

### ⭐⭐⭐⭐⭐ For those lower gears
*by A***T on October 8, 2022*

If you want to thumb your nose at Shimano’s claimed largest sprocket size, get this. As long as your derailleur hanger has a large-enough flat for it to bear against, it will work fine for up to 40- or 42-tooth cogs. Some people turn it around, so the head of the screw meets the land to provide support.

## Frequently Bought Together

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

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**Shop now:** [https://www.desertcart.fi/products/12975928-wolf-tooth-components-25mm-long-b-screw-for-adapting-old](https://www.desertcart.fi/products/12975928-wolf-tooth-components-25mm-long-b-screw-for-adapting-old)

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*Product available on Desertcart Finland*
*Store origin: FI*
*Last updated: 2026-03-22*