Rear Mudguards
The rear guards are far more challenging because of the
total lack of mudguard mounting points. I overcame this by fabricating my own
mounting points with tubular aluminium.
Figure 3. rear mudguard.
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The draft bar provides the
rear attachment point for the mudguard frame. The axle and wheel hub provide a
midway mounting point. There is not a front mounting point, but I do attach an
arm to the handcycle frame which acts as a vibration damper. The guard is attached
to the tubular frame at various points with a ¼” nylon "P"clip which can be
purchased from Maplin Electronics. The mudguard frame is attached to the draft
bar and the axle receptor with cable ties, which can be cut to allow easy removal for
transportation. As can be seen from figure 3 the guard is attached to the frame
at four radial positions. This closely mimics the correct mounting of the guard
at the bottom bracket, seat post and provided stays. I have the extra point at the draft bar. This
arrangement ensures that in dry conditions, the guard cannot grab the wheel.
Figure 4. Hub Mount.
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The wheel hub mount consists
of a thin piece of aluminium sheet bent into the shape of a "P" clip with a
30mm long 6mm screw fitted through it into the hex Allen key hole in the axle.
The 6mm screw has a heat shrink sleeve over its thread to provide a good fix
into the axle. The screw can be easily pulled out of the hex Allen hole, to
allow wheel removal.
Figure 5. Mount rotated for wheel removal
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With the wheel removed it can
be seen that the mudguard assembly leans in at the same angle as the wheel.
This is achieved by setting the length of the aluminium bracket to half the
axle receptor diameter.
Figure 6. Wheel removed.
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The mudguard frame was cold
formed around a wood jig as shown below.
Figure 7. Wooden frame jig.
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The trick with the mudguard frame was to make it slightly
narrower than the distance between the inner cable tie mounting point on the
axle and the head of the 6mm screw when inserted into the hex Allen key hole of
the axle. This provides a small inward force that keeps the 6mm screw in the
hex Allen key hole while riding.
The aluminium 6mm tubing was supplied by B&Q as 1 meter lengths (B&Q number EAN: 3232630801000). You need four (3 plus a spare). Any soft aluminium 6mm tubing can be used. To join the tubing I used 4mm rod (B&Q number EAN: 3232630215654). Insert a one inch length into one end of the tube and fix this with epoxy resin glue. After the glue has cured insert and glue into the second tube. The aluminium mudguard stay, at the ¾ position of the wheel radius, was a half section of the mudguard frame bent around the right-hand side of the jig.
The aluminium 6mm tubing was supplied by B&Q as 1 meter lengths (B&Q number EAN: 3232630801000). You need four (3 plus a spare). Any soft aluminium 6mm tubing can be used. To join the tubing I used 4mm rod (B&Q number EAN: 3232630215654). Insert a one inch length into one end of the tube and fix this with epoxy resin glue. After the glue has cured insert and glue into the second tube. The aluminium mudguard stay, at the ¾ position of the wheel radius, was a half section of the mudguard frame bent around the right-hand side of the jig.
