WITHOUT DAMAGING THE CARRIAGE

WITHOUT DAMAGING THE CARRIAGE

The carriage road, and any other bike is perhaps the most loaded mechanism. Therefore, in the carriages with the outer conical bearings at moments of considerable congestion often destroyed bearing cages, often damaged, and ball tracks on the cones of the carriage shaft. Intensive wear of the tracks occurs when operating a Bicycle on unpaved roads because of the dust in the bottom bracket.

The easiest way to restore the mechanism to replace the damaged parts or the Assembly. It is, as a rule, do in repair shops. But such a solution unlikely to be acceptable to a prudent of homebrew, which I will try to return to life staff details.
Carriage shaft it will protocil to 15 mm in diameter almost the entire length, leaving only one side of the place to install the connecting rod from the drive sprocket. This size corresponds to the diameter of the inner hole of bearings series 202. On the shaft until it stops at the collar plant the type bearing 60202 by a protective spacer out (you can use bearings 80202 with protective washers on both sides). The shaft is inserted into the housing of the carriage and to the same press bearing flush with the ends, if necessary, a little rastoci the threaded portion inside the tube housing to the outer diameter of the outer ring. Then with the other hand planted on the shaft and press in the second bearing housing by a protective spacer out. Next, turn the bushing to install the rod, having cut in it a groove for fixing the wedge and napresovuyut it on the protruding end of the shaft.
 
The first method of repair of the Dobby unit
The first method of repair of the Dobby unit:
 
1 — shaft; 2 — ball bearing 60202 (80202); 3 — bushing; 4 — body of the carriage

 
Installing the connecting rod to the shaft through the bushing
Install the connecting rod to the shaft through the bushing:
 
1 — shaft; 2 — rod; 3 — bushing; 4 — clean; 5 — shaft; 6 — nut
 

Repaired thus carriage mechanism often works to “write-off” bike, but too much to eat through, cutting off all cemented layer of the shaft, and a flatted groove under the wedge remains very small. Rod this side of a large load can be loosened, and then have to think about how to fix this place. But the most undesirable in this method of repair that will almost certainly be damaged, special thread 35×1 SPM (one side right, and left) inside the bottom bracket shell of the hull, and the node will become non-repairable.
 
Revision of the shaft of the carriage in the second method, fixation (in parentheses ukochany the radius of the groove and the diameter of the neck for balls with a diameter of 7.14 mm bearings 203)
Completion of the shaft of the carriage in the second method, fixation (in parentheses ukochany the radius of the groove and the diameter of the neck for balls with a diameter of 7.14 mm bearings 203)
 
Repaired bottom bracket Assembly
Repaired bottom bracket Assembly: 1 — the left connecting rod; 2 — shaft; 3 — nut; 4 — the left Cup; 5 — ball bearings 204; 6 — body of the carriage; 7 — the right Cup; 8 — sprocket; 9 — the right rod
 
So I did a little differently, though without turning too, was not. Bored through the damaged tracks cones carriage shaft shallow grooves with a radius of 4 mm for balls with a diameter of 8 mm (more precisely, 7.94 mm) so that the diameter of the shaft neck under the grooves was 14 mm. the Beads are taken from two old bearings 204. Place of groove polishing, although this could not be done — the balls themselves are able to align and even to consolidate the track.
 
The host was collected in this manner. First, heavily coat with grease place a groove on one side of the shaft, recessed in a one-to-one grease balls and put the Cup on the shaft and balls. The shaft is inserted into the housing of the carriage and placed the Cup back until it stops. I did the same on the other end of the shaft (on the opposite side of the carriage), wineva second Cup as long as the shaft body began to rotate without any play, but loose.
 
Instead of the ball bearing 204 and can take from 203. Their balls with a diameter of 7.14 mm is mounted on the shaft on each side of nine pieces. But the groove on the shaft is required to be machined with a radius of 3.6 mm, leaving the neck on the shaft already with a diameter of 15 mm.
S. PALAGIN, city of Morshansk, Tambov region.

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