SKS rear light

I've just bought a set of SKS P50 mudguards for my hybrid. I'm pleased with
them overall. They look good and I suspect the durability claims might be
valid. However, the rear has a light unit that I can't fathom out. I can
find neither an easy way to get at the innards nor a switch, so I assume
it's meant to be powered by an external source (dynamo or power pack). That
said, there doesn't seem to be a way to run wires to the light without
ruining the look of the mudguard.

So, how are you supposed to use this light, and if externally-powered how
are you supposed to run the cables?

TIA

"Will Cove" a écrit:

I've just bought a set of SKS P50 mudguards for my hybrid. I'm
pleased with them overall. They look good and I suspect the durability
claims might be valid. However, the rear has a light unit that I can't
fathom out. I can find neither an easy way to get at the innards nor a
switch, so I assume it's meant to be powered by an external source
(dynamo or power pack). That said, there doesn't seem to be a way
to run wires to the light without ruining the look of the mudguard.

So, how are you supposed to use this light, and if externally-powered
how are you supposed to run the cables?

The mudguard is a plastic/aluminium laminate, with the central aluminium
strip electrically insulated from the sides. You can run current through the
aluminium layer to the bulb. I forget exactly how the contacts are arranged.
The lamp is intended to be driven by a dynamo, but of course you could rig
up a battery system if you prefer, or simply ignore it. There aren't any
innards as such. Pop off the red lamp cover, and you'll find just a bulb
underneath.

James Thomson

"James Thomson" wrote in
:

The mudguard is a plastic/aluminium laminate, with the central
aluminium strip electrically insulated from the sides. You can run
current through the aluminium layer to the bulb. I forget exactly how
the contacts are arranged. The lamp is intended to be driven by a
dynamo, but of course you could rig up a battery system if you prefer,
or simply ignore it. There aren't any innards as such. Pop off the red
lamp cover, and you'll find just a bulb underneath.

Many thanks. I'm gobsmacked by such a neat idea as using the mudguard
itself as the "cable". Makes me want to investigate having my front wheel
rebuilt with a dynohub just to use it grin

James Thomson wrote:

So, how are you supposed to use this light, and if externally-powered
how are you supposed to run the cables?

The mudguard is a plastic/aluminium laminate, with the central aluminium
strip electrically insulated from the sides. You can run current through the
aluminium layer to the bulb.

I forget exactly how the contacts are arranged.

GOOD! It involves dissimilar metals*) and will corrode soon. Use wire
instead, and you might have a chance that the light will keep on working.

Open the light and you'll probably find a brass spring or something you
can feed the wire in. The exithole for the wire is probably in the base

*) as recommended in the Universal Cycle Design Guide
--
---
Marten Gerritsen

INFOapestaartjeM-GINEERINGpuntNL
www.m-gineering.nl

M-gineering writed in
:

James Thomson wrote:

So, how are you supposed to use this light, and if
externally-powered how are you supposed to run the cables?

The mudguard is a plastic/aluminium laminate, with the central
aluminium strip electrically insulated from the sides. You can run
current through the aluminium layer to the bulb.

I forget exactly how the contacts are arranged.

GOOD! It involves dissimilar metals*) and will corrode soon. Use wire
instead, and you might have a chance that the light will keep on
working.

Open the light and you'll probably find a brass spring or something
you can feed the wire in. The exithole for the wire is probably in the
base

*) as recommended in the Universal Cycle Design Guide

Which is exactly how I have used these for the last 25+ years. I've never
been able to get the inbuilt conductors to work reliably.

Will Cove wrote:
I've just bought a set of SKS P50 mudguards for my hybrid. I'm pleased with
them overall. They look good and I suspect the durability claims might be
valid. However, the rear has a light unit that I can't fathom out. I can
find neither an easy way to get at the innards nor a switch, so I assume
it's meant to be powered by an external source (dynamo or power pack). That
said, there doesn't seem to be a way to run wires to the light without
ruining the look of the mudguard.

So, how are you supposed to use this light, and if externally-powered how
are you supposed to run the cables?

TIA

Glad someone else couldn't fathom it out.We have one on the tandem.Even
the LBS who built it didn't know.

I just ignore it.

Sam Salt