*Free shipping on orders over $99

Free Shipping Policy

Free Shipping applies to all orders placed for $99 and above
(pre-tax value). Some restrictions apply:

  • Offer valid in the Lower 48 States only
  • Excludes Complete Bicycles, Framesets, and some other oversize items

Tools & Maintenance Chain Tools

Butter b2 Chain Keeper

Oops they did it again. Changing times and innovation demands new tools and technology to get the job done. In the case of the b2, it's a solution for using the world's best chain keeper with the becoming-a-standard 142mm rear through axle. The 142mm through axle has graduated beyond the early adoption stage and is now enjoying wide spread acceptance, so if you appreciate high quality/purpose built tools, we see a b2 in your near future.

As you would expect from any Butter tool, the quality of the tool is top shelf. Pure precision machining from solid 6000 series alloy billet makes this a lifetime purchase. In the simplicity is profound department, the b2 is remarkably easy to secure onto your bike and operate. Simply insert the leading guide into the dropout and twist the outer knob to secure to the frame. The proprietary Dog Ear Technology automatically orients and locks the b2's position to prevent rotation during use. By solving the issues related to cleaning and maintaining a 12mm thru-axle dropout equipped frame, it's apparent to us that Butter Studios has captured lightning in a bottle. The b2 is a must for any true mechanic's tool box.


  • Purpose built for 12mm rear dropouts
  • Locking Dog Ear Technology
  • Full CNC alloy construction with anodized finish
  • Simple and effective design
  • Superb quality and finish
  • Bombproof durability for lifetime use
  • A must for any serious mechanic or shop
  • Made in Colorado

The Butter b2 is designed for use with the industry standard 12mm thru axle only. It is not compatible with 10mm diameter axles or any other non-standard variants (See the b2 RAT for RAT designs).