RK’s sealed-ring chains received the spotlight back in 1977 during 24 hour endurance racing. It was common for riders to change their non-sealed chains at least three times during the race. However, racers riding with RK’s sealed chains achieved the win with only one chain!
Why should I choose an RK’s sealed ring chain?
- Lasts longer
- Improved drive chain life
- Absorbs torque and improves acceleration
An Introduction to Chain Seals
A chain seal helps maintain lubrication as well restrict dirt from entering between the chains inner and outer plates.
There are many chain manufacturers in the motorcycle industry but most (including some Japanese manufacturers) only offer a single type of sealing ring, using a “one type fits all approach” which is used on all their drive chains. This can be inefficient depending on the intended use. Different types of seals for different applications maximises efficiency and performance
Merit Of A Sealed Chain
- Minimum 3 times longer chain life than Non-sealed Chain
- Does not elongate until the end, does not cause pitch error during operation
- Efficient Power Transmission = Minimum Loss of Horse Power
- Able to prevent debris from entering the chain = Maintain performance in muddy or rough road conditions
RK currently has five types of sealed-ring chains and each has its own features and benefits. After several years of development, RK produced the XW seals which drastically improved the chain life and performance. As racing expanded into several different genres, RK added the ultra thin U-Ring and UW-Ring.
Each seal is specifically designed for a particular use to provide the ultimate in rotating efficiency while providing longer wear-life.
RK offers the best O-Ring chains in the industry. All RK O-Ring chains are manufactured with hi-carbon alloy steel for strength and durability. Applying Nitrite Butadiene O-Rings to seal in lubrication and deliver smooth power with minimal ring drag or loss of horsepower.
Seal Ring Cutaway
A summary of each chain seal type
- NS - Non-sealed
- O - Standard O-Ring seal
- RX / Active (X-Ring) - Double barrier, Better Chain Life
- XW (Preimum X-Ring) - Triple Barrier, Best Chain Life
- U - Ultra Thin (0.8mm), Lightest Chain Weight
- UW - Triple Barrier, Improved Chain Life Over "U"
The graph shows how each seal type across the RK range differs in terms of elongation over time
XW Ring (Premium X-Ring)
RK’s flagship model. ZXW Series were developed to meet the spec of the latest models of extreme superbike 1000cc and above.
Designed to be the strongest, long-lasting premium quality XW-Ring equipped chain available on the today’s market, with highest tensile strength of RK series and high rigidity for instant respond on acceleration.
- Developed for Paris Dakar in 1985
- Ultimate sealing performance to endure desert sand
- RK's unique technology
- Used in EXW & ZXW Chains
RX / Active Ring (X-Ring)
RK XSO Series: Designed for Basic Motorcycle Models, lighten chain weight while securing adequate strength required, emphasizes light feeling of acceleration.
Features RX-Ring that have “X” shaped seals and improved metallurgy giving you 2 times longer wear life than standard O-Ring chains.
- Improved seal technology over O-ring seal
- RX ring Developed in 1978
- RX-ring 'X' shaped seal has 2 times stronger ware life than O-ring chains
- RX-ring has one lubrication pool and 2 contact lips, improving the chain life and lowering friction
- Used in XSO chains
UW Ring
One of the lightest Sealed-Ring enduro/motocross chain available on the market today. Made for the professional enduro/motocross racers, Next generation of enduro/motocross racing chains featuring RK’s only technology of Ultra Thin Seal, U-Rings or UW-Rings.
Features UW-Ring which extremely improves the chain life and lower friction, providing high performance under enduro races especially muddy condition.
- Developed for on-road racing in 1999
- Same thickness as U-ring with increased grease pool
- Developed with Suzuka 8H top teams
- Team Honda Seven Stars, won with 520UWR at Suzuka 8H in 2004
- Used in MXU & UWR
U Ring
- Due to weight merit, developed On Road Racing Chain
- Dominating Suzuka 8H since 1997
- Contribute HRC Champion for GP 250cc class at 19997 and 2001
- Used in HRU & TRU Chains
