Rear mudguard mount lights - battery options?

General cycling advice ( NOT technical ! )
hercule
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Joined: 5 Feb 2011, 5:18pm

Rear mudguard mount lights - battery options?

Postby hercule » 4 Feb 2019, 2:27pm

I’m wanting a mudguard fit rear light for my recumbent trike. Whilst I am aware that there are battery versions available I’m wary of putting too much mass on the end of the mudguard - although solid, it doesn’t have a fixing in the usual brake bridge position (because there isn’t one), instead it has 3 pairs of stays and a bolt on attachment down by the chainstays.

Does anyone have any experience of the Busch und Muller Secula rear light? It comes in two versions, battery and dynamo. Is the battery version reasonably light? Might it shake the mudguard to bits (I don’t use this trike on particularly rough roads)? Would it be possible to run the dynamo version off a remote battery pack?

Any other suggestions much appreciated!

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andrew_s
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Re: Rear mudguard mount lights - battery options?

Postby andrew_s » 4 Feb 2019, 2:56pm

It will be as light as any other 2 x AAA light.
If you are thinking of an external cable to the dynamo version, I'd be inclined to recommend using the battery version instead, by putting two dummy batteries inside, instead. The dummy cells can be as basic as 2 x 40 mm lengths of 1/4" dowel, with drawing pins in the end and the ends of the power lead connected to the appropriate pins
a) You get to retain the 2 x AAA option as backup
b) If you put DC into an AC dynamo light, there is the potential for problems such as diodes seeing a 100% duty cycle rather than 50%, and overheating as a result.

I used to use a dynamo Secula - it's a good bright light. However, the end of a mudguard is a place where a light is prone to getting knocked against things when parking etc.

An alternative for a rear light that's light enough for mudguard duty would be a USB rechargeable light such as a MOON Comet (or one of the Aldi/Planet X clones). You would probably have to do some mount bodging to get it to point backwards properly.

AndyK
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Re: Rear mudguard mount lights - battery options?

Postby AndyK » 4 Feb 2019, 6:54pm

The PDW Fenderbot is another option.
Review here.
It's currently available from Sportpursuit.com (registration needed) for just £6.99.

hercule
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Re: Rear mudguard mount lights - battery options?

Postby hercule » 4 Feb 2019, 8:27pm

Thanks for both suggestions. The Fenderbot looks worth a go at that price, I’ve put in an order!

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gaz
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Re: Rear mudguard mount lights - battery options?

Postby gaz » 4 Feb 2019, 8:48pm

I use a Spanninga Pixeo, 2xAAA version. The mudguard has definitely become more rattly since fitting.

AndyK
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Re: Rear mudguard mount lights - battery options?

Postby AndyK » 4 Feb 2019, 11:33pm

hercule wrote:Thanks for both suggestions. The Fenderbot looks worth a go at that price, I’ve put in an order!

Let us know how it goes. I do have a PDW rear light but it's a strap-on model* rather than mudguard-mounted. It's well-made but has some odd choices of operational mode: the only options are steady beam, s-l-o-w alternating flash, or early '80s mobile disco light show.

*Insert Carry On joke here.

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[XAP]Bob
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Re: Rear mudguard mount lights - battery options?

Postby [XAP]Bob » 5 Feb 2019, 1:23pm

I have secula dynamo light and two of the battery version for my trike...
Though I was using them on the front guards, so mass was less of an issue. They aren't too heavy, but they are really not very weather resistant in my experience (one set of batteries - i.e. a week) and the inside was a mess.
A shortcut has to be a challenge, otherwise it would just be the way. No situation is so dire that panic cannot make it worse.
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slowster
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Re: Rear mudguard mount lights - battery options?

Postby slowster » 5 Feb 2019, 2:12pm

An alternative option might be to use an L shaped metal bracket to fix a light to the top of the mudguard, where it might cause less mudguard sway than on the rear of the mudguard, and the higher position of which might also improve the lights' visibility a bit.

The battery versions of the B&M rear lights with a reflector, which are designed to be bolted to the standard light fixing point with 50mm centre bolt holes on most Tubus and similar rear racks, would probably provide the best visibility, e.g. https://www.sjscycles.co.uk/lighting/busch-muller-toplight-flat-s-permanent-rear-light/. If you did not have a suitable piece of metal to use to make a bracket, you could use the one Tubus make to fasten a mudguard to the light fixing point on their racks - https://www.spacycles.co.uk/m2b0s215p3028/TUBUS-Mudguard-Holder-T70025.