Rear lights query, dynamo powered and mudguard mounted

[CamPhil]

My older Seculite is nearly ten years old.  If you are as clumsy as me I would recommend the optional cage to protect the lamp.

I like the the fact that it connects directly to an IQ Fly or IQ CYO front light allowing both to be switched on and off from the a single front switch.  (The standlight persists when the system is turned off).

If anyone has a rear light that does that, I hope they have the means to cover it if they ever take the bike onto a railway station platform.

I consider road spray to be a complete non-issue to the middle of a run of cable (though obviously it's a good idea to put connections somewhere that minimises exposure). 

+1 on that, although I'll add to it as well.
Mechanically strong and flexible cable is a significant benefit.
A single run is better, although any joints I need will be to IP67 or better - I learned my cable jointing when I was working on submersible water pumps, and it's habit now
A common mistake with cable joints is to hold the cable each side of the joint with a fastening, but not the joint itself.  This is always going to be the heaviest part of the cable, and will shake around if not supported.  That will lead to the conductor breaking.
Avoiding those issues will help the wiring have a long and conductive life

[Kim]

Mechanically strong and flexible cable is a significant benefit.

I really rate the Schmidt stuff for that reason.  That it's plain black and has a circular cross-section makes it aesthetically superior to the usual bell wire, too.

A common mistake with cable joints is to hold the cable each side of the joint with a fastening, but not the joint itself.  This is always going to be the heaviest part of the cable, and will shake around if not supported.  That will lead to the conductor breaking.

That's a really good piece of advice, thanks.   

[RJ]

Personally, aesthetics bother me less than functionality - my cable runs along the top tube and the top of the mudguard, to keep it out of road spray as much as possible.

I consider road spray to be a complete non-issue to the middle of a run of cable (though obviously it's a good idea to put connections somewhere that minimises exposure).  The rear light and computer^[1] wiring on my Dawes are normally encased in mud around the bottom bracket - it's not going to hurt the plastic insulation.  What puts me off running cables along the top-tube is the greater risk of mechanical damage when lifting/locking up the bike.

Admittedly my bikes get it relatively easy - I don't do a lot of mileage in winter, and they live indoors, so things don't stay wet for very long.

  One's mileage varies 

All great when it works - but too much of a faff to troubleshoot on a regular basis (n.b. my front lamp and computer need minimal intervention) 

Where does it tend to fail, OOI?

I'm pretty certain the weak spot in my setup is the blade connectors on the front lamp (oval Lumotec).  You can see them pretty clearly in the picture on the B&M website - but mounted on the fork crown of a conventional upright bike, they're in the firing line of spray "blown back" from the leading edge of the front mudguard and/or front tyre if you're going at anything more than running* pace.  I've had other issues with the front lamp getting shaken around in a very front-heavy way on the purpose-built B&M bracket (there's something loose and rattling inside that didn't ought to be like that), but have generally been able to restore rear light functionality by cleaning the connectors.  Last winter I did this and thought I'd done a comprehensive job of sealing everything up - but I guess I sealed some moisture in too  . 

I hope Santa's organising an IQ Fly - I see the rear connectors on that lamp point, well, to the rear ...  In any case, it should run on its own without overheating (and thus no need for a rear lamp).

[Oaky]

(The standlight persists when the system is turned off).

If anyone has a rear light that does that, I hope they have the means to cover it if they ever take the bike onto a railway station platform.

Wow... you learn something new every day... I had to google that after reading it.  The only ref. online I could find stated the following:-

If you ever have reason to take a bicycle on a railway platform, make absolutely sure that all lights, particularly RED lights, are OFF. If your rear light is a standlight with no off switch, cover it securely. It is a serious breach of railway by-laws to display a spurious red light on or alongside the track, and can cause major disruption to services.

I'll have to start carrying a bag when I take my commute bike on the trains in future. (Or work out if it's possible to safely discharge the standlight capacitor without fatal modifications to the light.

I did notice the info page is from Cambridge Cycling Campaign - I assume the "Cam" in your username isn't coincidental? EDIT: I just noticed the article is written by a "Phil"

(I didn't find anything else on line yet - will have to sharpen my search-fu).

[Kim]

I'm pretty certain the weak spot in my setup is the blade connectors on the front lamp (oval Lumotec).  You can see them pretty clearly in the picture on the B&M website - but mounted on the fork crown of a conventional upright bike, they're in the firing line of spray "blown back" from the leading edge of the front mudguard and/or front tyre if you're going at anything more than running* pace.  I've had other issues with the front lamp getting shaken around in a very front-heavy way on the purpose-built B&M bracket (there's something loose and rattling inside that didn't ought to be like that), but have generally been able to restore rear light functionality by cleaning the connectors.  Last winter I did this and thought I'd done a comprehensive job of sealing everything up - but I guess I sealed some moisture in too  . 

Okay, that's certainly a suboptimal bit of design, and probably explains why they've used a short trailing wire for the rear light output on the Cyo (don't know about the Fly).  It's easier to do a decent job of waterproofing an inline connector.

[Crumbling Nick]

The most annoying thing is running cable along the length of a mudguard, for which I've found insulating tape (preferably wider than normal) to be adequate if applied carefully (and replaced if the adhesive gets tired).  Scotchlite tape is retroreflective and has an even better adhesive.  If you keep the run short and go down the first available mudguard stay you may be able to avoid tape entirely.  Does anyone else have any cunning methods that are worth sharing?  I know some mudguards have conductive strips built in for the purpose...

I run my Seculite cable down the lower mudguard stay using spiral cable wrapping & no tape on the mudguard.

The tape holding the cable along the chainstay & under the downtube is Sylglas waterproofing tape. It's clear so is less conspicuous than insulation tape, however minimum width is 50mm so it needs to be cut into narrower strips. (It's also invaluable on tour for repairing transparent items like map cases & damaged lamps.)

[Kim]

I'll have to start carrying a bag when I take my commute bike on the trains in future. (Or work out if it's possible to safely discharge the standlight capacitor without fatal modifications to the light.

Not something I'd thought of when I bought them, but I'll chalk that up as a fringe benefit of the 4DToplight Multi - the 'standlight' is powered by AA batteries, and has an off switch.  I do make sure my lights are switched off on railway platforms.

Being able to discharge (or more sensibly, isolate) the standlight would be potentially useful when locking the bike up, too.  If only to avoid the "You've left your light on." conversation with well-meaning passers-by.

OTOH, a switch adds a point of failure, so I can see why they don't usually have them.

[Crumbling Nick]

The Toplite line plus has a push button to turn off the standlight. However, daily use of the feature during this autumn/winter has been enough to crack the top of the lens of my son's lamp.

[CamPhil]

I did notice the info page is from Cambridge Cycling Campaign - I assume the "Cam" in your username isn't coincidental? EDIT: I just noticed the article is written by a "Phil"

(I didn't find anything else on line yet - will have to sharpen my search-fu).

Yes, that was me too

Most people only find out if a member of railway staff has a go at them about it, but I did some relevant railway safety courses many years ago, and knew about it from then.

[Crepello]

In the past I've superglued the rear light cable to the inside edge of the rear 'guard. I'm thinking of trying a dyno rear light again after reading this and I would do the glue method again. Most mudguards seem to have a thick bead/shoulder along the edges - this ensures that the wire has a good snug fit.  Maybe run something like car underbody sealant over the cable to add protection. Obviously good clearance is a must to reduce any snagging or chaffing.

[andrew_s]

It is a serious breach of railway by-laws to display a spurious red light on or alongside the track, and can cause major disruption to services.

Or work out if it's possible to safely discharge the standlight capacitor without fatal modifications to the light.

The B+M 4D-Lite Plus has a pair of contacts that you can short out with a key to discharge the standlight.
On the left side (of the bike), half way between the guard loop and the bottom.

I wonder what they do in those cases where a road is adjacent to the railway? Prosecute the motorists, not use the line after dark, or rely on the drivers to be able to tell the difference?

[Frere]

In the past I've superglued the rear light cable to the inside edge of the rear 'guard. I'm thinking of trying a dyno rear light again after reading this and I would do the glue method again. Most mudguards seem to have a thick bead/shoulder along the edges - this ensures that the wire has a good snug fit.  Maybe run something like car underbody sealant over the cable to add protection. Obviously good clearance is a must to reduce any snagging or chaffing.

Someone mentioned earlier in the thread that sone mudguards have metallic strips running lengthwise through the guards to avoid running wires on the guard itself - does anyone know which guards have this?

Frere

[Kim]

Someone mentioned earlier in the thread that sone mudguards have metallic strips running lengthwise through the guards to avoid running wires on the guard itself - does anyone know which guards have this?

I've encountered this on the OEM mudguards guards on a bTwin Riverside 7 (a heavy but extremely well-specced Decathlon trekking bike), it was quite neat, with the wiring attaching to the rear mudguard at the bottom bracket.  Unfortunately the mudguards themselves were a bit plasticy and the front one took a permanent kink after being loaded into the back of a car with the wheel removed.  No idea if you can buy them separately.

[andrew_s]

Someone mentioned earlier in the thread that sone mudguards have metallic strips running lengthwise through the guards to avoid running wires on the guard itself - does anyone know which guards have this?

Some of the Esge/SKS chromoplastic mudguards.

They have an aluminium core inside the plastic, and on some of the silver ones* at least this is divided into 3 lengthways with 1mm or so transparent gaps between the central strip and the two sides. All of the mounting hardware is riveted through the central strip, so that leaves one of the edges free to act as the "live" conductor. I've seen shop bikes with wiring to small brass eyelets punched through the edge (just above the BB and near the rear light), but I've not seen the eyelets on mudguards as purchased, even those that came with a (bulb) rear light fitted.

*
3 narrow black stripes plus the two gaps appearing as 5 central stripes on a silver 'guard.

[Crepello]

I bought some SKS P45's some years ago that had the riveted sockets and they came with wire fitted with a plug, along with the rear light all set up for action. I did use this arrangement for a while, but I suspect it's far from perfect, relying on stays and frame to act as the earth. I imagine these junctions would eventually succumb to corrosion.

Twin wire's are best.

[RJ]

I'm pretty certain the weak spot in my setup is the blade connectors on the front lamp (oval Lumotec).  You can see them pretty clearly in the picture on the B&M website - but mounted on the fork crown of a conventional upright bike, they're in the firing line of spray "blown back" from the leading edge of the front mudguard and/or front tyre if you're going at anything more than running* pace.  I've had other issues with the front lamp getting shaken around in a very front-heavy way on the purpose-built B&M bracket (there's something loose and rattling inside that didn't ought to be like that), but have generally been able to restore rear light functionality by cleaning the connectors.  Last winter I did this and thought I'd done a comprehensive job of sealing everything up - but I guess I sealed some moisture in too  . 

Okay, that's certainly a suboptimal bit of design, and probably explains why they've used a short trailing wire for the rear light output on the Cyo (don't know about the Fly).  It's easier to do a decent job of waterproofing an inline connector.

Weird.  Rear lamp has spontaneously begun to work again, but the switch (front lamp) has stopped working.  So probably some sort of internal fault in the front lamp (which I think rattles when shaken in a way it didn't out of the box) ...