Bike Magazine, Korea: Shuriken Oversized Pulley
When I started my bike for the first time, I used to suppress my desire for high-end parts, saying, "I have more physical strength than a bicycle." However, if you accumulate a certain amount of skill, you will feel yourself as if you are always in place. Then, if you happen to get a chance to ride a good bike, you find yourself looking like something is different, and the 'good parts are different! Bicycle parts brand Token (TOKEN) has studied in detail the parts that affect the performance of the bicycle, and has recently introduced a variety of performance parts. We also introduced an oversized pulley that reduces the resistance that can occur in the driveline, introducing Shuriken that can save watt with ceramic bearings, carbon cages, and large oversize pulleys.
Why do I need a 19-12T oversize pulley?
The oversize pulley has a large size of 17 ~ 19T compared to the conventional pulley made of 11T. The reason for using such an oversize pulley (or big pulley) is that the pulley is a small component of the derailleur that is responsible for the transmission, but it is the part that makes the most rotation in the drive system with a small size of 11T. The parts that rotate in the driveline are pedal axle, BB, hub, pulley, etc. Among them, BB has the same size as the smallest 11T of the cassette sprocket (recently released 10T too). However, since the weight is not directly applied, very low-cost bearings are usually applied, so the resistance against rotation is large. Therefore, when the oversize pulley is applied, the amount of rotation is reduced as the size increases, and the resistance is reduced.However, it is unreasonable to apply a large pulley unconditionally. The tokens are designed so that the gap between the pulleys and the sprockets can be properly maintained by applying 12T to the guide pulleys (upper pulleys) that are directly responsible for gear shifting, so that the transmission performance is not deteriorated.In addition, the tension pulley (lower pulley) which is responsible for the chain tension is designed to be 19T largely, and it is designed to reduce the rolling resistance and smoothly relax the chain tension even if the chain tension changes suddenly according to the shift.
TBT ceramic bearings, rotation is not afraid.
"It's a ceramic bearing on a pulley!" And I think it's too much spec. However, as I said above, it is understandable to think that the most rotating part of a bicycle is a pulley. So, Token has applied the super spec of ceramic bearings to the pulley.
However, accurate understanding of ceramic bearings is also needed. Ceramic bearings are good because ceramic materials are very durable to friction, so they can retain their performance for a long time. However, it should not be forgotten that if a ceramic ball that does not produce precise spheres is applied, it will maintain its abnormal performance for a long time. In addition, even if a precise spherical ceramic ball is applied, if the race surrounding the ceramic ball is not as rigid as ceramic, it is easily broken and the performance is lower than that of a general steel bearing.
In addition to producing very precise ceramic balls, Tokens also feature titanium coatings on races that wrap the ball and form a bearing, allowing it to sustain its performance even during rapid rotation and resistance. This is called TBT ceramic bearing of Token.
Mounting the Token Shuriken
This Token Shuriken oversized pulley is designed to be compatible with Shimano Dura Ace and Ule Tegra (R9100, R9150, R8000, R8050). The cassette sprocket is compatible up to 34T, so if you are a road rider, you can use it freely in cassette size. It can be used just by removing and installing the existing cage. It is better to increase the length of the chain by one or two links because of the larger pulley. If you change to a new size cassette sprocket, you must adjust the gap between the guide pulley and the largest sprocket to make the correct shift. Let's take a look at how to install it.
Reduced noise and power savings with resistors
The disadvantage of the oversize pulleys that were introduced in the past was that the friction noise of the chain and the pulleys was increased when aluminum was applied to make the large size.
But Token added a state-of-the-art coating to the duralumin pulleys, resulting in almost no friction noise between the metals and a smooth rotation. This coating is made possible by PVD (Physical Vapor Deposition) technology and features durability that keeps the coating on for long use.
As Shuriken oversized pulleys are an advanced part, it is not recommended to do it yourself. It is very sensitive because it is made up of lightweight parts, and it is easy to have a skilled mechanic to touch the derailleur directly. Also, since the bearing is exposed to the outside of the wheel or BB, it is recommended to lubricate the bearings after cleaning after riding at a rate of once every 2,000 km or more.
Over-sizing pulleys are relatively expensive parts, and the benefits are only a few watts. However, the few watts needed for long distance riders are not that small. And a few watts that can be obtained from a long uphill split win or loss. "Winter is the season of upgrading," what about raising the expectation of a new season with an oversized pulley upgrade?