Author Topic: Attaching wire to inside of fender?  (Read 4054 times)


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Attaching wire to inside of fender?
« on: January 10, 2017, 04:11:55 PM »
I will be doing 3 dynamo installs in the next month. 1 will be on a bike with metal fenders/mudguards and 2 with SKS plastic fenders/mudguards.
Would like some advice on what to use to attach the wiring.


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Re: Attaching wire to inside of fender?
« Reply #1 on: January 10, 2017, 05:47:44 PM »
are u talking glueing the wire to the underside of the rear mudguard ,good trick if you can get glue strong enough to hold it in place.
not much help sorry .



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Re: Attaching wire to inside of fender?
« Reply #2 on: January 11, 2017, 09:58:19 AM »
Seamgrip by McNett is wonderful stuff.
Takes a while to dry/set, but then it stays stuck.


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Re: Attaching wire to inside of fender?
« Reply #3 on: January 11, 2017, 12:45:08 PM »
I used a bead (line) of bathroom silicone sealant in the middle of the underside of the long rear mudguard. I squidged the wire into at and let it dry. Worked for years and was a right bu**er to shift when a crash meant i had to replace the mudguard.

John Saxby

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Re: Attaching wire to inside of fender?
« Reply #4 on: January 11, 2017, 04:18:37 PM »
Quality duct tape will do the job, Anto, so long as you put it onto new, clean mudguards, such as the SKS you're considering.  It'll hold pretty much indefinitely, and you can remove it if & when you want to.  (But it insists on clean surfaces, so if years from now you remove it from the inside of a well-used mudguard, and you later replace it, you'll have to be very careful to cut your new strip to fit into the clean portion of your 'guard. But that'll be an issue for things like silicone, sugru, etc., as well.)

I'd suggest Gorilla brand, heavy-duty black, excellent adhesive.  The thing to remember about duct tape is that it likes to be warmed up a bit bef application.  So, when you're ready to use it, get your roll of tape and rub it well with your hands; and apply it in a warmish room. Canoeists use duct tape to cover cracks (at least those canoeists who don't use trick Royalex boats that bend & absorb the socks from rocks), and I've used small amounts of Gorilla tape to hold my Hebie chainglider halves securely together.


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Re: Attaching wire to inside of fender?
« Reply #5 on: January 11, 2017, 05:40:55 PM »
Installing the wire between the tyre and the mudguard is looking for troubles, or have I misunderstood something about where the wire will be glued?
I use two different sizes of SKS mudguards that I fit on my Nomad depending when I use Schwalbe Marathon Supreme 26 1.6" or Marathon Mondial 26 2.15" tyres, and in both cases there is no much space between the tyre and the mudguard (I like the mudguards seasonable close to the tyre, I think they are more efficient to reduce spray). So I can imagine the odd chip stone passing through the tyre and mudguard grinding whatever is in its path.
Just a thought.
« Last Edit: July 08, 2017, 04:47:35 PM by Javier »


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Re: Attaching wire to inside of fender?
« Reply #6 on: January 11, 2017, 07:07:20 PM »
My experience with wire location has been similar to Javier's...I have had success locating the wire in a rolled or formed bead at the inner edge of the fender blade rather than down the center. I use a beta-cyanoacrylate (all-surface super glue) in *gel* form to secure insulated wire on plastic and metal (aluminum, stainless) mudguards. I've never had it come loose on its own. I use Dean's connectors at either end of the mudguard so the blade can be removed or replaced without affecting existing wiring on the rest of the bike.

In the sort of touring I do (logging roads and deserts as well as deep mud), I've found centerline wiring either becomes rock-impacted or badly scraped over time. Wheel-packing mud or playa has been most damaging to centerline wiring for me because it acts directly to lock the tire against the 'guard. Even in such conditions, I've found edge wiring to be more out of the way and less problematic.

When I did route wiring down the center, I had the best luck using adhesive-backed aluminum or stainless tape, originally intended to seal duct joints in HVAC systems.

On foil-sandwiched mudguards (ESGE, SKS), I've had good luck in the past, tapping into the foil and using it as a conductor. One such effort lasted well over a decade and was still reliable when I removed it to swap in a wider 'guard. I used stainless screw terminals at either end of the blade and eyelet connectors. In the past, ESGE used (what I eventually found to be less reliable) snap-on terminals in OEM applications and tapped into as many as three foil strips for conduction (center frame and stay ground, isolated hot circuits on either side).

One other thought: At least one German bike manufacturer routes their taillight wiring through thin vinyl tubing on the *outside* of the rear mudguard, secured by plastic P-clips to the blade itself, next to Magura hydraulic caliper brake lines. This is a fairly pragmatic approach that values utility and reliability above aesthetics. It can still look very tidy if done well and has the advantage of maximizing clearance between tire and 'guard and ensures the wire is not abraded or impacted in use.




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Re: Attaching wire to inside of fender?
« Reply #7 on: May 09, 2017, 10:28:24 PM »
I used aquarium tubing to make my daughters wiring run impact-resistant. I didn't glue it in, but may do so when I get around to making my wiring a bit more well thought out.