Author Topic: Taillight Wire Inside Rear Fender (Mudguard). Thoughts?  (Read 1204 times)

mickeg

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Taillight Wire Inside Rear Fender (Mudguard). Thoughts?
« on: January 27, 2018, 01:11:16 AM »
On my Titanium bike that I built this past spring, I am planning to install a fender (mudguard) mounted taillight and wire that to my dynohub powered headlamp.  That bike is primarily used on pavement (tarmac) with occasional use on well maintained gravel trails.

Plan is to run wiring from the headlamp, down the downtube along the rear brake cable to the bottom bracket, install quick connects there (in case I want to disconnect the wire at that point later), then install the wire on the inside (tire side) of the plastic fender to the taillight.  Taillight is a Spanninga Pixeo Xs.  The wire will be a two conductor wire.  The plastic fenders do not have metal strips in them.  I do not anticipate using that bike in muddy conditions.

In my research on this forum and elsewhere on the internet, I am finding a variety of ways to install the wire on the inside of plastic fenders.  Some people apply tape to hold the wire in place, some people use a hot glue gun, some have used SeamGrip, and some have used Silicone caulk to attach the wire to the fender.  I am inclined to use Silicone caulk.

Some have put the wire in the center of the fender, some have run the wire to the side of the fender thinking that road debris will be less likely to damage the wire at the side.  I will decide later which I think would work best once I have the bike upside down fender cleaned, etc.

This is the best reference I found on this forum.
http://thorncyclesforum.co.uk/index.php?topic=12185.msg89179

If anyone has installed a wire inside a fender and had several trouble free years of taillight operation, I would love to hear how you did it.

And if anyone tried the Silicone caulk method and had a failure, I would very much like to hear what happened?  And if that happened, do you have any suggestions for doing it better?

I am only thinking of doing this on my Ti bike.   I plan to continue only using battery powered taillights on my Nomad and Sherpa.

Thanks in advance for any suggestions you have.

pavel

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Re: Taillight Wire Inside Rear Fender (Mudguard). Thoughts?
« Reply #1 on: January 27, 2018, 01:28:29 AM »
the shop did it that way with my moulton. They used epoxy, and seeing that it's tougher than the fender itself I didn't mind it, but though out of sight it ruffled my sensibilities that neither the wire nor the application of epoxy was straight and smooth enough.  Next time I'd use 1" or so Gorilla tape and then use a spatula to make it permanent with a thin layer of epoxy.  I have no idea how it would turn out.

one point I'd like to mention is that two quick releases may be in order.  On so that the fender can be taken off, and one just before the light so that the rear light can be taken off in the case of damage to either the fender or the light.  The moulton was epoxied right to the very end and I can't remove the light from the now useless fender because even the mounting screws are epoxied, and there would only be 1 cm of wire left exposed from the light - too little to make further use of it.  On my thorn I decided instead to run my wire into a length of aquarium tubing to protect it and tied that on to the underside of the rear rack instead.  I like that better all in all as it's more versatile and a lot less work to install.

mickeg

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Re: Taillight Wire Inside Rear Fender (Mudguard). Thoughts?
« Reply #2 on: January 27, 2018, 03:25:53 AM »
I would not glue my light to the fender.  I have not received it yet, only ordered it today. 
https://www.ebay.com/itm/Spanninga-Pixeo-dynamo-dynohub-tail-lamp-The-most-versatile-we-have-tested/273028783027

The photos suggest that there are two 2.8mm spade connectors that I plug the wires into on the light. It looks like it has a block that holds the wires onto those spade connectors but I might instead be able to use the standard spade connectors.  I would decide later which connectors to use.

I agree that if this light or the wiring does not work out, I want to be able to remove the light from the fender and continue to use the fender.

I better check my inventory of 2.8mm spade connectors, I might be running low.

Danneaux

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Re: Taillight Wire Inside Rear Fender (Mudguard). Thoughts?
« Reply #3 on: January 27, 2018, 05:15:52 AM »
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If anyone has installed a wire inside a fender and had several trouble free years of taillight operation, I would love to hear how you did it.
I've successfully used several methods as described in that Forum link you provided, George. All have been reliable for 30+ years, 20+ years, and more recently (Nomad) 5.5 years. The routing alongside the inner fender lip secured with beta-cyanacrylate (super super glue...the kind that will also glue rubber, wood, and leather) gel proved the most durable for me. The routings down the center of the fender with the foil tape were still working but ultimately removed by me due to a tatty appearance due to impact  by mud and debris. The foil was a mismash to peel off, loose in laces where it had been pierced, tightly adhered elsewhere.
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And if anyone tried the Silicone caulk method and had a failure, I would very much like to hear what happened?
I had both an initial and eventual failure of silicone caulk.
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And if that happened, do you have any suggestions for doing it better?
When new(ish), plastic fenders are both slick-surfaced and may have mold-release compound on them. It is best to remove both or silicone caulk will not adhere to the fender properly and will pull loose (my initial failure). Cleaning the fender with 99% isopropyl alcohol, lightly sanding the track where one intends to route the wire and reapplying the alcohol made for a secure bond for a long time...but (except for ShoeGoo), the silicone caulk was one of the few methods I used that also failed after some years. It simply began to peel at the edges and then pulled free. For that reason, I did not use it again and re-settled on the beta-cyanoacrylate gel which has been most reliable for me in my use (yours may not be the same). I secured the wire with spring-loaded wooden clothespins and waxed paper between the pins and the wire to prevent sticking -- and doing a roughly 5cm section at a time. The gel dries within several minutes, so it is not a great burden to march the clothespins along a section at a time. Of course, it helps to first straighten the wire so it is as flat as possible.

In my experience, plain 2-part or quick epoxy has poor peel strength on flexible fenders over time. I've had better luck with an etching polyamine-polyamide epoxy like JB Weld (the non-quick kind) after the sanding/99% isopropyl application, but still found it less ideal than the beta-cyanoacrylate gel on plastic fenders over time and hard use. It can be incompatible with some wire insulation formulations, causing it to become permanently sticky.

As with Pavel, I would prefer two connectors at the rear fender...one between the fender and bottom bracket so the fender can be readily replaced and a second connector at the taillight so it can be replaced in the event of failure or a desired upgrade.

All good luck, George.

Best,

Dan.

mickeg

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Re: Taillight Wire Inside Rear Fender (Mudguard). Thoughts?
« Reply #4 on: January 27, 2018, 08:11:17 AM »
I do not understand your ShoeGoo reference, are you saying that would be better or worse than Silicone caulk?

I initially thought of trying Shoo Goo, but in my internet research I found a few people using Silicone caulk but nobody suggested Shoe Goo.

The super super glue gel you cited does scare me a bit, I am less than enthusiastic about that as I would rather not glue my fingers to anything.

Sandpaper, what grit do you think would work best?  I was thinking something pretty fine like 400.

pavel

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Re: Taillight Wire Inside Rear Fender (Mudguard). Thoughts?
« Reply #5 on: January 27, 2018, 03:41:04 PM »
Silicone caulk does not hold up well in my experience where there is bending or flexing.  Perhaps though the newer versions are better?  I've always thought it was designed to come off from the bathtub just before nice bicycling weather arrives.  :)

The mechanic who did the setting up of the moulton did not glue the light on, but rather glued the wire on right up to where it turned up to the hole in the fender into the light, which was wired solid.  It was good robust work but I'd have to try to disasemble the light to see if it could be rewired.  I think I still have the fender and light up in the attic, so I'll see if I can find it.  Earlier I concluded a new light was the way to go. 

Off topic, but a while ago my wife backed the Cadillac up, and smashed into my motorcycle.  My bike was fine though the bags and side rack had to be thrown out, but the big problem was that in the process she removed the right side mirror.  There it was hanging by the electric cable.  All I could think was that this was going to cost more than a new Mercury frame to fix, so I took a chance and got a bottle of JB Weld, the same non-quick kind that Dan has mentioned and after crossing my fingers a lot I got it fixed on.  It's held on for about three months now.  Amazing products that we have available to us nowadays.  It works just as before with the electric controls and looks like it will last longer than the rest of the car, likely. 

Danneaux

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Re: Taillight Wire Inside Rear Fender (Mudguard). Thoughts?
« Reply #6 on: January 27, 2018, 05:34:02 PM »
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I do not understand your ShoeGoo reference, are you saying that would be better or worse than Silicone caulk?
I'm sorry I was not clear in my writing, George. Yes, I tried ShoeGoo and no, it did not work well for me long-term. It turned yellow and dried out out, then became brittle and lost adhesion in this application after about three years. In this way, it was about the same result for me as silicone caulk (I used black to match the fender in one case, clear in another instance). Both failed for me after awhile (some few years) but they failed in different ways.
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The super super glue gel you cited does scare me a bit, I am less than enthusiastic about that as I would rather not glue my fingers to anything.
I buy either 5mil or 7mil gloves in bulk from Harbor Freight and wear them while gluing so if I get stuck, it is the glove and not me. For many years, I did not use nitrile gloves for tasks and one day realized I was absorbing a lot of chemicals through the skin of my hands. I was also spending more time on cleanup than on the task, so the change made sense for me and has worked well for minimal cost.

As for the task itself, I made a dry run the first time, arcing the wire along the inner bead edge of the fender and holding it in place with the clothespins. I then removed everything and did the same again with the gel glue. The gel gives a working time of 5-15 seconds depending on humidity and it can be pulled free for up to about 20 seconds. Long-term, it can be peeled off with dedicated effort because the wire is elastic to a degree and the hardened gel is not.
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Sandpaper, what grit do you think would work best?  I was thinking something pretty fine like 400.
That is what I used initially, though in later efforts, I used a 3M green scuff pad because it resulted in less dust that had to be cleaned off. I found it sufficient to simply remove the surface gloss, so a quick swipe or two with the scuff pad was enough. Be sure to clean up the dust afterwards. I find 99% isopropyl works best, but it does temporarily soften the clear cellulose-based coating in ESGE Chromoplast (now SKS) fenders on first application.

I think you should use the materials you are most comfortable with. It is just that having tried a number of materials, the super gel glue is a) what worked best for me on application and b) has held up best over time. There are different formulations, too and this can affect results. Your experience might vary of course. Much of the success is dependent on humidity at the time of application and I found this true for all the adhesive materials I used. This is why I take care to emphasize what worked for me; local conditions do have a marked influence and it can make a difference whether you work inside a house (A/C reduces humidity, a humidifier increases it) or work outdoors/in a garage. Cyanaoacrylates in particular catyalyze in the presence of water and water vapor, moreso in humidity or fog. By the way, if you need to create acrylic plastic to reinforce end-points or do a field repair of some plastic part, baking soda added to liquid super glue works very well as an accelerant/filler and water can trigger catalyzation if humidity is very low and it would not cure so well otherwise. Conversely, vinegar will loosen super glue.

I would suggest you ask a local bike shop for a piece of used/broken fender and then try gluing a piece of the same wire you intend to use to it to see what works best for you before diving into the same thing. Experimentation is worthwhile. I've had good luck using the 2-conductor "zip" wire leads provided by Busch & Muller, the bike-light people. Some other brands of wire have insulation that reacts poorly with some adhesives, becoming ever-sticky dust magnets.

Best,

Dan.

mickeg

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Re: Taillight Wire Inside Rear Fender (Mudguard). Thoughts?
« Reply #7 on: January 27, 2018, 05:47:33 PM »
I am leaning towards Shoe Goo right now.  The super super glue concept still scares me.  But thanks for the comments and advice.

I used to work with toxic chemical cleanups for a couple of engineering consulting firms, later as a state employee overseeing some of that work.  And at times I was a health and safety coordinator for such work.  From that I can say that when you bought nitrile gloves to keep the chemicals from dermal absorption, you bought a very good product, nitrile is very good for that.

I have a bunch of nitrile gloves, every time I go to the dentist or doctors office I ask if I can have a few pair of the disposable ones for emergency bike repairs on the road, they are always happy to give me several pair.

I WROTE THE FOLLOWING BEFORE DAN'S NEW COMMENT THIS MORNING, IT IS STILL VALID:

To elaborate a bit more, I was thinking I would wire it so that I could unbolt the light and lift the light about 3cm from the fender before the wire was taught.  Thus, when the light was bolted in place, I would have some excess wire in a loop on the tire side of the fender.  Then tape that excess down with PVC electrical tape.  Or, maybe some other tape like duct tape, but not a really strongly adhering tape that I could never get off again.

This way I could remove the light later by pulling that tape off (hopefully the tape would not be so strong as to break the wire), unbolt the light and then have enough wire that I could handle it enough to disconnect the wires from the light.

I also planned to tape over the hole in the fender that the wire passes through so that water thrown up from the tire can't get to the light contacts that might corrode.  I was thinking a small dab of grease on the contacts too.

I often use a flashing taillight that is battery powered in daytime on roads.  This new light does not flash, so I still plan to use a battery light on the bike.  Thus, if something in the wiring fails, I should not be stranded out somewhere in the dark.

I looked at the fender yesterday, there is a slight groove at the edge, that probably would be the place to place the wire.

Or, if this entire endevour starts to look too complicated, perhaps instead install the light down by the left rear dropout near the rear disc brake.

pavel

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Re: Taillight Wire Inside Rear Fender (Mudguard). Thoughts?
« Reply #8 on: January 27, 2018, 06:22:45 PM »
So, it would seem that this thread has saved me $ 22.09 USD on a now unavailable stateside tail-light.  I never threw the moulton's 20" mudguard away just in case one day I change my outlook on bike trailers.  It works that the month after I throw something away, I either want or need it again.  Trailers are expensive so I didn't want the cost of a new 20" wheel trailer, plus the cost of a new taillight.  Who says superstitions don't come true.  :)

So I went to the attic and much to my nice surprise, the B&M is not hard wired as I thought.

I don't know which glue the Moulton shop used when they did this job but as you can see from the photos - it's not a job that anyone who cares about details could ever pass off as good enough.  Certainly not one such as Dan and other disciples of "doing it right" here on this forum.  But after three years of medium to light use and several years up in the attic, which is a furnace in the summer - the gluing is in bad shape.  Mostly it's lifted off and it's brittle where a fingernail can crack it off.

Shoe goo stays more supple their website informs us, and yes it would now get my vote too. 

Interestingly, SJS Cycles still caries this discontinued model and it's listed as "4D-Lite Plus Mudguard Fitting Rear Dynamo Light".  The next time it's used, the job will be done to higher standards.  :)
https://www.sjscycles.co.uk/lighting/busch-muller-4dlite-plus-mudguard-fitting-rear-dynamo-light-with-standlight/?geoc=US

mickeg

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Re: Taillight Wire Inside Rear Fender (Mudguard). Thoughts?
« Reply #9 on: January 27, 2018, 08:29:18 PM »
I know that Shoe Goo is more supple that Silicone Caulk or hot glue gun glue, that is why I am re-considering Shoe Goo.  I have used it on several shoes where the sole had significantly worn.

SeamGrip is even more supple, that is also a possibility.  But it is MUCH more expensive, as the tubes of SeamGrip are tiny compared to ShoeGoo.

On my Nomad Rohloff shifter (the round one), I have tried several different options to make it easier to grip when I am not wearing gloves and have sweaty hands.  The three beads of black Shoe Goo that I put on to give it a triangular shape are still in great shape, adhere to the Rohloff rubber shifter just fine.  Photo of the shifter.

I however am concerned that the Shoo Goo might not adhere well to a Planet Bike plastic fender.

Right now I am back and forth on Shoe Goo versus Seam Grip, but I will not do this for weeks or maybe over a month from now.

Danneaux

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Re: Taillight Wire Inside Rear Fender (Mudguard). Thoughts?
« Reply #10 on: January 27, 2018, 08:48:22 PM »
Quote
I however am concerned that the Shoo Goo might not adhere well to a Planet Bike plastic fender.
Last I checked, PlanetBike fenders are made of polycarbonate and thus can be damaged by many common adhesives, including the adhesive backing on masking tape. I would do some experiments first.

My old tubes indicate Shoe Goo Goo contains toluene, which is a solvent for many plastics but is compatible more often with rubber.

Best,

Dan.

mickeg

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Re: Taillight Wire Inside Rear Fender (Mudguard). Thoughts?
« Reply #11 on: January 27, 2018, 09:59:24 PM »
Quote
I however am concerned that the Shoo Goo might not adhere well to a Planet Bike plastic fender.
Last I checked, PlanetBike fenders are made of polycarbonate and thus can be damaged by many common adhesives, including the adhesive backing on masking tape. I would do some experiments first.

My old tubes indicate Shoe Goo Goo contains toluene, which is a solvent for many plastics but is compatible more often with rubber.

Best,

Dan.

Those solvents are quite volatile, would evaporate off in less than a day.  The fender is thick enough that I am not concerned about it causing any long term damage or structural integrity problems.  I would not be surprised if it could etch a polished surface, so I will be careful to only apply to the tire side of the fender which I would have already sanded down a bit.  Actually, if it etches the plastic fender a bit, that would be a good thing as then it would be more likely to adhere.

RonS

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Re: Taillight Wire Inside Rear Fender (Mudguard). Thoughts?
« Reply #12 on: January 27, 2018, 10:28:36 PM »
When I installed my fender mounted taillight I used a latex based household caulk, the type that you would install in a caulking gun. I think it was DAP brand, but your local home improvement store may have something else. I used it because I found it to hold its shape while curing better than silicone (less self levelling) and easy soap and water cleanup of my inevitable mistakes. :) It is still holding fast 3 years on. I have Planet Bike fenders.
As for being wary of super glue, trust the warning about "instantly" sticking fingers together. Don't ask me how I know.

mickeg

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Re: Taillight Wire Inside Rear Fender (Mudguard). Thoughts?
« Reply #13 on: January 27, 2018, 11:18:36 PM »
Interesting.  My tube of Dap brand caulk is labeled Dynaflex 230.  It also cleans up with "damp sponge".  Mine is labeled Premium Indoor/Outdoor  Sealant.  Unfortunately, mine is "Brilliant White" and my fenders are black.  I have a tube like a toothpaste type tube, but Home Depot lists it as also available in a caulking gun type of tube.  And Home Depot lists several different Dap brand caulks.  But I assume for my purpose that a sealant rated for outdoor use would be ideal, especially if it has a name like Dynaflex to suggest that it will stay flexible.

Thanks for posting.  I now have three contenders.  And my experience with Dap is that it has outstanding adhesion which is one of my biggest concerns.  The adhesion issue alone is putting Dap very high on my priority list.

Also, Dap has very little volatile content, Shoe Goo has tens of percent of volatile content.  Thus Shoe Goo has some shrinkage, much more than Dap.


RonS

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Re: Taillight Wire Inside Rear Fender (Mudguard). Thoughts?
« Reply #14 on: January 28, 2018, 01:00:22 AM »
Dynaflex 230. That's the stuff. Mine is also brilliant white, but I figured no one would know except the person who turns the bike upside down and removes the wheel.

It is available in black and clear.