RK Racing Chain Universal Chain Tool UCT2100(50) for 40/50 Series — Break, Press-Fit & Rivet

The RK Racing Chain UCT2100(50) is a compact universal chain tool that breaks, press-fits, and flares 40 and 50 series motorcycle chains for clip or rivet link installation.

This precision shop-grade tool combines a chain breaker, press-fit holder, and rivet flare pin in one compact unit so you can shorten, join, and finish 40 and 50 series chains with accurate, repeatable results. RK redesigned internal components to lock into the body and added a larger pressure bolt and a sure-grip handle to make one-handed setup and operation easier. The tool also includes a reversible holder plate for switching between clip-style and rivet-style side plates, plus a flare guard to prevent over-riveting.

How does this tool handle chain breaking and reassembly?

The UCT2100(50) removes and installs pins cleanly on 40 and 50 type chains, including O-ring variants, by guiding the pin press and limiting travel for consistent pin depth. Use it to remove excess links, then seat sideplates to the correct dimension for clip or rivet links.

• Breaks 40 and 50 series chain pins without damaging rollers or links
• Press-fits tight tolerance O-ring sideplates to the correct depth
• Reversible holder plate for clip or rivet link alignment

Can this tool flare and rivet links reliably?

Yes — the included rivet flare pin expands RK’s pin-hole rivet links to the proper outer diameter so sideplates sit securely. A built-in flare guard limits the amount of material displaced, reducing the risk of over-riveting while giving a consistent finish.

• Flares RK rivet pin holes to secure sideplates
• Flare guard prevents excess deformation of rivet pins
• Works with rivet links designed for 40 and 50 series chains

What improvements make this version easier to use than older tools?

RK updated component retention so parts lock into the tool body during use, and increased the pressure bolt diameter to lower operator effort. The handle has a textured sure-grip overhaul, and the part number is laser engraved for quick identification in a busy toolbox.

• Locking components prevent dropped parts during setup
• Larger pressure bolt requires less torque for the same force
• Ergonomic sure-grip handle for better control and comfort

Are there any chain types or accessories required?

The UCT2100(50) is built for 40 and 50 series chains, including O-ring types; it cannot rivet 420/428 chains without additional parts sold separately. RK lists compatible accessory items for 420/428 rivet work, so check compatibility before attempting smaller chain rivets.

• Compatible with 40 and 50 series chains (O-ring friendly)
• Not suitable for riveting 420/428 without FP428JP and PH428 parts
• Limited lifetime warranty on tool body material and workmanship

Who is this for: The RK UCT2100(50) suits home mechanics, road racers, and professional technicians who service motorcycles that use 40 or 50 series chains and want a single compact tool for breaking, press-fitting, and flaring rivet links. If you frequently shorten chains or prefer doing reliable rivet or clip link installations yourself, this tool reduces fiddly setup, keeps components captive for fast workflow, and delivers consistent rivet sizing. If you work on smaller 420/428 chains, plan to order the listed adapter parts before attempting rivet finishes.