|How to Change FLY/Spider Front Hub Bearings|
|We'll help||Call or e-mail with questions.
We are happy to help with this process. All parts needed are
available directly from Nimble. Some, like #12 washers, are
available from other local sources.
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|Parts||The front wire wheel hub consists
of 6 parts:
(1) hubshell forged alloy anodized black
(2) axle spacer alloy
(3, 4) 2 x R4 bearing1
(5, 6) 2 x endcaps black alloy with steel inserts
1Note: The R4 bearing has a bore of 0.250 inches, an outside diameter of 0.625 inches and a width of 0.196 inches (6.35 mm x 15.875 mm x 5 mm).
|Tools||Needle nose pliers
Front QR skewer
Block of wood
Pair of #12 washers2
2Note: These washers need to be flat and press against both the inside and outside race of the R4 bearing while fitting easily inside the 0.625 inch (9.92mm).hole of the hub shell.
|Disassembly||1. Use a pair of pliers to pull
one endcap out of the hub.
|2. Take the nut off your front
skewer and put the skewer partially into the hub from the end missing the
|3. Angle the skewer into
the side of the hub so that it moves the center spacer out of alignment
(the spacer is loose in the center of the hub). Try to deliberately
catch the end of the skewer on the inside race of the opposite side
|4. Hold the hub firmly
against a work table. You will need to hold the hub in a way that leaves
clearance for the bearing to come out and still supports the hub
firmly. Knock the handle of skewer with the block of wood to push
the opposite side bearing completely out of the hub. The opposite
endcap should come out too. This should not be
a difficult high force knock.
|5. Take the center axle
spacer out of the hub from the side missing the bearing.
|6. Turn the hub over and push out
the opposite bearing using the same process.
|7. Remove the skewer.
|Reassembly||8. Load the skewer rod to make a
double-decker sandwich of the old bearings and new bearings with hub in
the center3. This assembly deliberately does not include the hub
endcaps, which are reassembled at the end. The endcaps are left out
because they have a raised center
area that pushes only on the inner race of the bearing and this adversely
affects bearing placement.
In this assembly the washers and old bearings act as a mandrel to ensure the proper
placement and alignment of the new replacement bearings.
A little grease on the bearing exteriors will help in pressing it into the
hubshell. The replacement bearings are symmetrical and can be put in
either side facing the center of the hub. If you are replacing the center spacer as well as the bearings, swap
the new part for the old part in
the middle of the sandwich.
Assemble as follows:
skewer, lever end with rod
skewer end nut
3Note: If you are not changing the bearings or you do not have a second set of bearings, you can use a flat round element (such as a socket tool) that fits within the 0.625 inch hole (15.875 mm) hole - You must make sure that this element is sized to evenly press both inside and outside bearing races of the R4 bearing.
Use repeated closing of the skewer and tightening of the skewer nut to push
the assembly tightly together. Squeeze until the parts appear
aligned and there is no lateral play in the hub assembly.
|10. Remove the skewer end
nut. Pull the skewer out of the assembly, collect the washers. The old bearing
may partially trapped in the hub by this process (since the bearing races have
a small overhang). Carefully work the old bearings out of the
assembly (this may require your pliers.)
|11. Push the hub endcaps