Light mount adapter for rear racks

[DarkNewt]

Hi All,

While busily studying away for a security exam I came up with the following:

I am doing away with my dynamo lights and going usb rechargeable letting the dynamo permanently charge a 26000Mah battery that charges the usb lights during the day. The most frustrating part is finding the usb light I want that fits a rear rack mount so this afternoon I made this in my shed. I am calling it version one as a proof of concept. It works really well, costs basically nothing and I know I can make it smaller.

What do you think and any ideas for improvements???

Parts, a piece of plastic water tubing, some reflective tape, two bolts and some spacers. The only work was cut off the required length of pipe, drill four holes, 2 for the bolts smaller than the head size to larger holes directly opposite to allow for a screwdriver/allen key to tighten.

Images are on my blog below:

http://thedarknewt.blogspot.co.uk/2017/01/light-mount-adapter-for-rear-racks.html

[531colin]

As most rear lights come with a bracket to fit your seatpost, one of the old tricks is to mount something onto the back of your rack that pretends to be seatpost and fit the light to that.
I have seen all sorts of things used.....broom handle, an offcut of actual seatpost, and of course alloy tube.....available on line from "Aluminium Warehouse, metals 4U, and such places.

[robgul]

As 531colin is suggesting very few racks have the rear plate in the OP pix.

Here's my take on lamp mounting . . . http://www.beewee.org.uk/index.php?opti ... Itemid=109

Rob

[DarkNewt]

As 531colin is suggesting very few racks have the rear plate in the OP pix.

Here's my take on lamp mounting . . . http://www.beewee.org.uk/index.php?opti ... Itemid=109

Rob

that's a really good idea, however it would interfere with my rack top bag on my mount and the one I made fits the usb light I have bought, but as an alternative for other lights thats simple and very effective!!

[Cunobelin]

All racks have a stay that leaves at the back take a piece of appropriate tubing / wood etc

Cut about an two inches wider than required, cut two grooves so that when the tube is pushed up on the stays it is a tight fit and stays in place

Drill two holes and place a bolt through outside the stays as a security and tightening device

[robgul]

All racks have a stay that leaves at the back take a piece of appropriate tubing / wood etc

Cut about an two inches wider than required, cut two grooves so that when the tube is pushed up on the stays it is a tight fit and stays in place

Drill two holes and place a bolt through outside the stays as a security and tightening device

I have experimented with a variation of my lamp bracket in the link upthread to make a thinner slot and mount it horizontally on one of the stays. Limited success as there is a tendency for the clamp part to move around the stay with the possibility of pushing the lamp into the spokes.

The picture shows quite a bit of tube protruding above the rack frame/bar (and thus potentially fouling a rack bag) - again experimentation shows that with a fairly thick-walled piece of seatpin tube you can get the end of the slot down to about 6mm (that's 1/4" in real measurements!)

Rob

[RickH]

Cateye do a couple of different rack mount for their square fit lamps to fit the mount holes present on some racks (this one & this one). Smart do likewise for their clip in rear lamps (link).

If you aren't a DIY-er, one of these



will clamp on a rack rail or use the 2cm(?) spaced vertical holes on some racks to use a seat post/stay bracket. Bear in mind the end cap is plastic & will crack if you tighten it too hard! (I replaced the cap with a metal plate to use one as a mount for a camera).

[DarkNewt]

Cateye do a couple of different rack mount for their square fit lamps to fit the mount holes present on some racks (this one & this one). Smart do likewise for their clip in rear lamps (link).

If you aren't a DIY-er, one of these



will clamp on a rack rail or use the 2cm(?) spaced vertical holes on some racks to use a seat post/stay bracket. Bear in mind the end cap is plastic & will crack if you tighten it too hard! (I replaced the cap with a metal plate to use one as a mount for a camera).

I tried those previously and found they moved about to much didn't get on with them at all.

[nigelnightmare]

Why would you go from Dynamo lights which are permanently mounted, quite secure and a low theft risk....

....To go to rechargeable lights held on by rubber bands (quick and easy to remove) and rechargeable batteries (expensive and HEAVY)
that are a High theft risk!

Plus you've already stated that the "dynamo" would charge the batteries "during the day".

So you get all the disadvantages of both battery and dynamo systems + a hell of a lot of complication.

Duh!!!

[MikeF]

Hi All,

While busily studying away for a security exam I came up with the following:

I am doing away with my dynamo lights and going usb rechargeable letting the dynamo permanently charge a 26000Mah battery that charges the usb lights during the day.

26Ah battery. How far will you need to cycle to charge that? I believe USB is 500 mA current max, and probably max for the generator as well. If so that would take approx 60 hours or more of pedalling at that rate! Agreed you would not necessarily want that amount of charge unless the battery were flat. Perhaps you could explain a bit more how you envisage this working (and also the logic behind it).

[Stewart H]

I have an alloy seatpost ziptied to the underside of the rack deck, it extends out the back a bit to prevent the panniers from masking the taillights from the side and allows full use of the platform. A satisfactory arrangement.