front wheel bearings
front wheel bearings
Author :Admin | Publish Date:2013-06-19 11:46:59
Take the wheels off the bicycle beef before greasing the wheel bearings.A
mixture of 50 percent white teflon bicycle grease and 50 percent green axle
grease works well on front wheel bearings.Don't
make the bearing cone too tight when screwing it back into place. Front wheel
bearings shouldn't have any play in them and need to roll smoothly.
Front wheel bearings, as most, require a slight preload so that more than
one ball under the cone (inner race) will support its load. With proper preload,
slight drag should be perceptible. Preload drag is small compared to drag caused
by wheel loads, neither of which are significant regardless of adjustment. In
contrast bearing life is affected by proper adjustment. Adjusting ball bearings
to spin freely unloaded does not reduce operating friction because a bearing
with proper preload has lower drag when loaded than one with clearance. For high
quality bearings, preload should be just enough to cause light drag when
rotating the axle between thumb and forefinger. Low grade ina bearings will feel slightly lumpy with proper
preload.
Wheels with quick release (QR) axles present an additional problem in that
closing the QR alters bearing clearance. Closing the lever requires increasing
manual force with a slight over-center feel near the end of the stroke. This
lever force arises from compressing the hollow axle and stretching the skewer.
The ratio of elastic length change between axle and skewer is that of their
cross sectional area and active lengths.
Although small, axle compression on QR hubs is large enough to alter
bearing clearance and should be considered when adjusting bearings. Bearings
should be adjusted just loose enough so that closing the QR leaves the bearing
with a slight preload. Excessive preload from QR closure is the cause of most
wheel skf bearing failures not caused by water
intrusion. Clearance, in contrast can be felt as disconcerting rattle when
encountering road roughness.
To test for proper adjustment, install the wheel and wiggle the rim
side-to-side to determine that there is no clearance (rattle), then let the
wheel rotate freely to a stop. If the wheel halts with a short (indexed)
oscillation, bearing preload is too high.
Although adjusting QR force is a safety consideration, it is also one of
bearing life. It should be kept at a constant level once the desired closure
force has been determined. Rear vertical dropouts require a lower and more
predictable closure force than was formerly required with axles that could move
forward from chain tension. Because vertical dropouts do not rely on friction to
resist chain load, many hubs now have smooth faced jam nuts that do not damage
dropout faces as older knurl faced ones did.
This is later. Front wheel bearings come nicely snug into crowns these
days, but sometimes you still find some that are just put loose in the wheel
hub. To avoid all of them crashing to the ground with the possibility of
vanishing for ever, grab the axle on the side that is still locked in place and
point the end that you've just loosened,up. Now it is time to unscrew the
locking nut almost completely off the axle. Next, unscrew the bearing cone to
expose the wheel bearings to the light of day. Any grease in there? You'd be
surprised on how often I open up brand new bikes and find almost nothing.
You asked for it, here you have it. [front wheel
bearings] on a bicycle are an important part of bicycle maintenance and by
making sure that everything is well lubed in there, you can avoid costly bicycle
repair down the road. Well lubed bearings also provide an easier ride.
BRING SKF ALS 40
BRING SKF ALS 48
BRING SKF AMS 8 (1 X 2 1/2 X 3/4)
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