The disadvantages road bike in the first place I take them is small compared with the sports speed. But it would be nice to have a universal machine that could confidently move around the track at the same time not yielding at speed on the highway sports. To that end, I put on the bike “Ukraine” of the speed switch (see figures). In the final version of my bike has got five gears: sprocket 48 teeth driven by 21, 19, 17, 15 and 13 teeth. The car has already more than 4000 km of Any of the positive qualities of a road bike she lost, on the contrary, lowering the first transfer of the eased motion on the lane. The speed on the highway has increased significantly.
To make additional details can each owning a plumbing tool. For mounting the switch to the right Peru the rear fork is welded steel plate (Fig. 1). If it is not possible to produce the welding, the plate is made of such form as shown in figure 2, and placed under the nut of rear wheel (in the figure the position of the plate shown in phantom). The switch is secured by a special bolt (Fig. 3) or bolt M8. In the second case, the bolt placed two centering washers, and spacer from the segment tube.
For five-speed Bicycle is necessary to grind an elongated rear axle or clamp the rear axle not the nut, and cone bearing with thread M10X1 (Fig. 5) from a sports bike.
If both options were unacceptable, measure what the stock length is the left part of the rear axle removing the bolts the tension of the chain and washer of minimum thickness. Then cutting the file part of the axis so that the cone that is screwed onto axle until it stops, moved to the left by the amount “x” (Fig. 6).
General view of the bike with the shifter:
1 — switch, 2 — control cable in a flexible sheath, 3 — lever shifting.
Fig. 1. Plate, weld to the right Peru the rear of the plug for mounting the switch.
Fig. 2. Plate that is mounted on the bolts:
A — scan, B — schematic of the rear fork feather.
Fig. 3. Shaped bolt for fastening the switch.
Fig. 4. The scheme of fastening of the switch bolt M8.
Fig. 5. Mount selector plate cone:
1 — rear axle 2 — plug, 3 — mount plate switch.
Fig. 6. Rear hub scheme and the alteration of its axis:
1 — fork, 2 — axis, 3 — plate mounting switch, 4 — unit additional gears.
Fig. 7. The attachment of the cable to the lever:
A — mounting scheme: 1 — the cable in the sheath, 2 — bracket, 3 — lever; B — d-shaped plate.
Fig. 8. Lifting chain (top — bracket).
Fig. 9. Install a pull-up unit from the driven sprocket.
Fig. 10. Extra stars:
A — for regular, B — block stars (instead of regular).
Switch and lever is taken from any sport bike. The cable is best to use a motorcycle, securing it to the frame with hose clamps. To attach the sheath to the lever (Fig. 7) under the lever is enclosed by l-shaped plate, in which is screwed a fitting with a through hole.
In the preparation of the cable should always be remembered that the loop near the switch should be of greater length than the sport bike, because the parallelogram mechanism of the switch operates in a horizontal position.
Sagging of the upper branch of the chain when braking of two-speed bike slightly. To avoid sagging in the five-speed variant, it is necessary to protect the enamel plug with a metal strap or can be put on the upper branch circuit pull-up switch unit (Fig. 8).
Before you put an extra asterisk (“Student”), it is necessary to turn the driven sprocket with the convex side out, folded under the retaining ring seal (Fig. 10). It will serve when welding with strip, which will not allow the stars to get too close. An optional asterisk is placed on the cylindrical part of the sleeve. And since its inner diameter slightly larger than the diameter of the latter, will have to manufacture three steel strip of the same thickness. A block from a sports bike and Bush going on a cylindrical mandrel and welded together.
When traveling on a five-speed bike, remember that braking on 4-5th gear it turns out not effective enough due to the greater gear ratio. Therefore, for braking in advance need go to a lower gear. To increase the braking force you can press the toe of the free foot on the second pedal from the bottom.
Note. Our drawings show only the principal dimensions. The dimensions of the parts can vary depending on the available materials and conditions of manufacture.
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