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The Baroque-Gear, the gear that makes the ideal pedaling possible by adjusting the gear ratio, the most notable characteristic of the non-circular gear, to each athlete’s characteristics or to an event that the athlete competes in, can be produced in various forms with three dimensional CADCAM and high-speed machining center.

 

What is “Baroque-Gear,” the non-circular gear that Smith Co., Ltd is proposing?

Smith’s Baroque-Gear does not have a circular or oval shape but a unique non-circular shape which changes the gear ratio according to the crank angle when pedaling.  The shape of the Baroque-Gear is not limited to just one pattern, but is available in four patterns.
The reason for this is because the vector generated while pedaling is different in each individual and also in each event that an individual competes in.
Also, though we suggest four different shapes in Baroque-Gear products, it is possible for us to make a custom made gear adjusted to an athlete’s individual characteristics based on the measurement results from the Pioneer pedaling monitor.

History of Non-Circular Gears

Up until now, many gears that were not shaped perfect circular have been on the market, starting with Shimano Biopace in the 1980s, oval shaped gears from companies like Rotor, and unique shaped ones like O,Symetric that Tour de France champions, Wiggins and Froome have used. One thing in common in these gears was that the companies offered an existing, particular shape which would assist the athletes to obtain the advocated effect. However, the responses from the users that actually bought those gears were both positive and negative.

Drawing 1
The drawing above shows the data on the change of pedaling power on a perfect circular gear and a non-circular gear (SMITH Baroque-Gear 39T). The green straight line shows the data of a perfect circular gear 39T, which shows no change. On the other hand, the data with the quadratic curves is the one from the non-circular gear. Thus, the non-circular gear changes the assumed gear ratio by changing its shape, and makes it possible to produce changes in pedaling torque.

What We Began to See from Visualization of Pedaling Vector

Around 2013 when the pedaling monitor from Pioneer became widespread, interested users began to observe their own pedaling vector in details. What became clear is that the pedaling vector is different from individual to individual and that even with the same person, there is a big difference on the tendency of pedaling vector depending on the event that the individual competes in, his or her exercise intensity, or the saddle position of the bicycle that he or she riding.

Drawing 2
The drawing above shows the torque curves of right legs when we measured ten athletes pedaling. The dark gray zone in the back shows the ideal curve. The red part of the measurement results shows when the torque was at its peak, and the light blue part shows when the torque was negative. Though it is ideal that the peak torque is exerted at crank angle of 90 degrees, it was observed that eight out of ten athletes reach the peak torque between 90 and 120 degrees.

The Limit Seen in the Production Method of Ready-Made Non-Perfect Circular Gears

Previously, the perfect circular gears produced a big loss by not being able to adjust to the pedaling effort that drastically changed according to the crank angle. In the effort to solve these problems, companies suggested various oval shaped gears. However, since all the companies tried to apply one shape to everybody, there were many cases where the users whose vector distribution did not fit into the shape could not get the effect. The reason that the suggested shapes of various oval gears had to be uniform as ready-made products is because of a restriction in the means of production for those gears. In other words, the shape had to be the same in order to mass-produce them. We had to wait for the appearance of a means of production like the three-dimensional CADCAM and 3D printer in order to prepare several different shapes and adjust the shape to each athlete’s vector individuality.

Drawing 3
The drawing above is an expansion of the dispersion range when the torque is at its peak during pedaling. With the previous means of production, each company decided on one shape pattern at the angle that the company thinks is the best and mass-produced the gears. We, Smith Co., Ltd, are able to manage a wide range of shapes with a means of production where the designing process (three-dimensional CADCAM) and the production process (high-speed machining center) are directly linked together, and also making it possible to produce custom-made gears.




Drawing 4
The drawing above shows the crank position on each product when the change of the gear multiples (imaginary gear ratio) has reached its peak, which is the characteristic of the non-circular gear. By having four different patterns of gear angles, they can match the torque curve on a wide range of users.

Advantage of Production Using Three-Dimensional CADCAM and High-speed Machining Center

At Smith Co., Ltd, as we engage in the development and support of car companies, we have also come to own a program development technology to efficiently use three-dimensional CADCAM and high-speed machining center. As of 2015, we are currently capable of processing 9 different gears in different shapes all at the same time with one machine. With this technology, we are able to put on the market the “Baroque Gear,” the non-circular gear that can adjust to each athlete’s pedaling vector individuality.

SMITH Baroque-Gear Production Information

                    
Baroque-Gear 〈PCD 110〉
Number of Teeth Shape Angle

Price

(Tax Not Included)

 
34 ±2 90° $175
34 ±3 90° $175
36 ±2 90° $175
39 P1 90° $175
39 ±2 100° $175
39 ±2 110° $175
39 ±2 120° $175
5arm34 2-1 90° $175
5arm36 ±2 90° $175
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