


🔧 Upgrade your ride with precision — because every millimeter counts!
The Wolf Tooth Components 25mm B-Screw is a high-quality stainless steel replacement part designed to optimize Shimano MTB derailleur alignment when using large 40 or 42-tooth cogs. It ensures precise derailleur cage positioning for smoother shifting and improved chain management, making it an essential upgrade for riders seeking reliable performance on wide-range cassettes.
| ASIN | B00LMY7BA0 |
| Batteries Required? | No |
| Batteries included? | No |
| Best Sellers Rank | 204,923 in Sports & Outdoors ( See Top 100 in Sports & Outdoors ) 551 in Screws (Sports & Outdoors) 639 in Bike Derailleurs & Parts |
| Colour | Silver |
| Customer Reviews | 4.5 4.5 out of 5 stars (236) |
| Cutting Diameter | 4 Millimetres |
| Date First Available | 15 July 2014 |
| Finish | Uncoated |
| Head Style | Phillips |
| Included components | Miscellaneous Rear Derailleur Part |
| Item Package Quantity | 1 |
| Item Weight | 4.54 g |
| Item diameter | 4 Millimetres |
| Item model number | BSCREW25 |
| Material | Stainless Steel |
| Number of Pieces | 1 |
| Part number | BSCREW25 |
| Pattern | Solid |
| Plug profile | Braze On Mount |
| Shape | screw |
| Size | M4 x 25mm |
| Style | Miscellaneous Rear Derailleur Part |
S**S
It does the job
It is a good screw
N**9
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. 🚴♂️🔩
D**C
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!
B**D
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.
A**T
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.
K**N
Look it's a screw it works perfectly the problem is they just throw the tiny screw in a large envelope and ship it one little hole in the package and goodbye screw and that's exactly what happened to the 1st shipment they sent me another with no questions askef but it took twice as long to get it
Trustpilot
2 months ago
3 weeks ago