Attachment of the wheel.
The wheel is attached with quick releases or confirmed by a simple frame nuts.
The attachment with quick releases has the advantage that the wheel is easy to carry out. This confirmation is also used in combination with rim brakes and derailleurs.
Quick-acting clamps are used in combination with a hollow shaft. For the stretching of the shaft, this is not objectionable because material in the center of the shaft almost does not contribute to the strength.
Hubs with gear hub can not be equipped with quick-release, because the operation of the hub via a hollow shaft expires.
The quick release comprises a pull rod which is inserted through the hollow shaft. On the left side is the tensioner with which the shaft is fixedly put. On the right is provided with the tie-rod with screw thread on which a spindle nut is screwed.
Between the shaft and the quick release feathers are placed in order to assemble the axle easier. Securing the quick release should just require some force. At the moment that the lever is facing to the outside in the extension of the shaft, you should feel resistance.
The lever of the quick release must to be backwards. This is to prevent them from being snagged somehow during cycling.
Using quick releases the ends of the shaft must be approximately flush with the outside of the dropouts.
When they protrude too far the quick release will not press against the dropouts but at the shaft ends.
The space between the lock nut and shaft end should be about the thickness of the patten.
|Regular front hub
Front hub with drum brake
Rear hub with coaster
Sachs three-speed hub without brake
Sachs three-speed hub with brake
Sachs three-speed hub with drum brake
Sachs five speed hub without brake
Sachs five-speed hub with coaster
Sachs five-speed hub with drum brake
Sachs seven-speed hub without brake
Sachs seven-speed hub with coaster
Sachs seven-speed hub with drum brake
Shimano Nexus seven-speed hub
Shimano Nexus four-speed hub
front hub Shimano rollerbrake 100 mm
6-speed mountainbike 126/130 mm
7-speed mountainbike 130/135 mm
8-speed mountainbike 135 mm
7-speed race 130/126 mm
8-speed race 130 mm
9-speed race 130 mm
|Installation width 90 mm
127/ 123,5 mm
For the fixing of the shaft with the shaft axle nuts the axle must have about 8 mm thread. On the shafts are usually also racks, fenders and chain tensioners fitted.
For mounting cap nuts are typically used.
With this the end of the shaft is capped beautiful. Good shaft and locking nuts are ribbed for grip and locking.
If they do not have this, retaining rings have to be fitted between the patten and nuts.
When tightening of the axle in the fork, it is important that the straps are properly parallel.
If that is not the case, they are straightened by the quick release or axle nuts.
hereby you get tensions on the fork shaft.
Especially bending stresses on the shaft are annoying for the bearings because it makes it not running properly and the axis through the extra stress can break.
Also geared hubs with a curved shaft can be very annoying, because it is a risk that this no longer works.
The locknuts should lie against the dropouts without the fork to be bent or bowing. When the fork is too wide the shaft can be filled with shims.
On both sides there has to be placed the same number of spacers.
Optionally, a wider shaft can be put in the hub.
When the fork is too narrow, it must be bent outwards. Especially with the expansion of the number of gears, it may be necessary to bend the rear fork. (See table for any value of the installation width of the hub).
When expanding the number of sprockets and the broadening of the hub, is not necessary to replace the entire hub. It is sufficient to assemble a new free-wheel, to fit a wider axis and to center the wheel. When increasing the number of sprockets the wheel should be more umbrella spoked.
The front axle usually has a diameter of 5/16 “or 9 mm (hollow shaft). The rear axle is usually 3/8 “or 10 mm (hollow shaft).
The material is almost without exception steel.
Shimano has a front hub with aluminum oversized shaft (at the ball bearings 11 mm, at the end 9 mm).
The rear axle of the hub from XTR-group is of titanium. The use of aluminum for axles is hardly useful, because the specific strength of aluminum is approximately the same size as that of steel.
The use of titanium is worthwhile because titanium has a higher relative strength than steel. A titanium shaft with the same strength will be slightly lighter than a steel shaft.
When fitting the wheel, it must be ensured that the right wheel well is in the fork. Centering can be with the eye. The dropouts of the fork are often at bike front derailleur gear fitted with set screws.
By rotating the set screws, the wheel can be perfectly put in the center of the fork. When the wheel is re-mounted, the wheel can be centered without problems by pulling the shaft simple against the set screws and lock in place.
Wheels and axle nuts shall be centered with chain tensioners.By turning on the wheel is pulled on that side backwards. Hereby both the wheel and the chain can be centered when placed with the correct tension.