How best to mount a Magicshine MJ818 rear light

daniel_b

...when your seatpost is obscured by this:

Which is excellent by the way.

This is the light I have:


I have a Topeax Supertourist rack thing, and this has a place to mount a reflector.
Looking at the magicshine, it seems like it is only designed to fit around a seatpost tube, which are generally 27.2mm - is that right?

So my idea is to either get another seat post (Though these are all going to be rather too long) or another piece of tubing, yet to be decided, but would need to be of the correct, or similarish diameter to that of a seatpost.

My idea is to permanently mount this bit of tube onto the rack, via clamps, cable ties or whatever works best, and then I will drill up through the box, so the batterypack can sit comfortably in there, and I can remove the light from the tube when I get to work.

Any suggestions as to what pipe I could use instead of buying another seatpost?

Cheers

Dan

DrLex

The problem with mounting this light on a seat post using 'O' rings is that the light won't be horizontal. I recall one suggestion of using a length of plastic (uPVC) overflow pipe (22mm) or small bore (34mm) plastic waste pipe lashed to the back of a saddle. With this in mind, how about a length of this pipe, coupled with a pair of brackets epoxied to either the underside of your rack, or perhaps the rear of your rigid pack? Hardest part might be finding a plumbers' merchant who stock it in black.

daniel_b

Thanks for the reply Dr L, and yes a very valid point there, the light would be pointing severely downwards if I could mount it on the actual seatpost.

I have just found an American post where the guy used an old flat bar grip on his seatpost to provide a horizontal mount, but I will try and adapt this (As I have two old grips from my gf's ex commuter bike) perhaps with a bit of tube inside to 'make them more solid' and then lash this to the rear area of the rack somehow, and put one on the right hand side, and maybe invest in a second one in the future for the other side.

I plan to mount one or two smarts on the rear stays as well, as the mounts are adjustable you can get them horizontal or facing down slightly etc.

DrLex

FWIW, I have a Topeak beam rack on which I detached the reflector and used the mounting point to screw on an old CatEye rear light. You may be able to do something similar, then run the cable under the rack to the battery pack on the seat post/stay bridge. I think Bails87 has the same MS light, so pm him if he doesn't see this thread & post.

vermin

Just a thought on the point that the light would not be horizontal; I have a Hope District, which I believe is similarly bright. I always direct the beam downwards to the ground behind the bike, where is creates a large and very visible pool of light on the road, in addition to the lamp being highly visible directly. If you shine that thing directly into drivers' eyes, you may not win many friends.

redvee

MJ818s come with 2 o-rings, the smaller is good for 22.2mm handlebar tube. My solution was a 4" section of handlebar with a hole drilled all the way through both sides and a bolt through the bar and through the reflector mount on the rack.

daniel_b

Thanks for all those replies chaps, liking your solution there redvee, not sure I would have the diy prowess to drill through a metal tube, or indeed the required drill bits, but we'll see.

No worries re blinding drivers, I just, meant more horizontal, although appreciate it was a misuse of the word, and something is either horizontal or not!

Anyway, I'm an regular motorist also, and will make sure they blind no one.

Up until now I have only used a smart of blackburn on the back as only has a 2 mile commute, mostly on bridleway, that has now gone up to nearly 100% road, and a round trip of 37 miles, so I decided I needed some serious lightage to see me through the year.

bails87

I've got an MJ818 mounted on the seatpost. It's way brighter than a 'horizontal' Smart R1 or Cateye LD610. As said, it illuminates a massive patch of road behind you with bright red light.

Mine has been flawless, but make sure you have two rear lights on at any one time, you don't want to be in the dark without realising!

kiwimatt

Here is another idea using an old reflector clamp - unscrew the mount it comes with and replace like so. I'm going to do mine like this with a dab of something round the screw silicon grease etc to ensure it's watertight

fossyant

I've done something similar with 25mm plastic pipe. Covered it with black heavy duty tape and cable tied it to my Topeak MTX bag light loop. Both magicshines are then just attached with the rubber bands. This also means the light comes off with the pannier, so saves time. Batteries are located in the pannier.

I have also changed the battery packs for 6x AA units as most of my lights take AA or AAA and have chargers at home and work. The spare batteries are used for the 808e I have on the MTB.

vorsprung

I mounted a small light on the seat stays
That doesn't sound very remarkable except the bike is a Specialized Roubaix and the stays are sculpted and curved carbon fibre. Details of metal putty etc here http://audaxing.wordpress.com/2011/08/0 ... g-for-pbp/

Mark Elvin

So, why did I look at this thread, it's just cost me £25 as I found myself "needing" a Magicshine rear light..... :oops:

fossyant

This is how I mounted mine

daniel_b

Mark Elvin wrote:

So, why did I look at this thread, it's just cost me £25 as I found myself "needing" a Magicshine rear light..... :oops:

Sorry! I may have to buy antoher one actually - pretty good value all told.

fossyant wrote:

This is how I mounted mine

Ah fossyant, is was your setup I was thinking about from last year when I bought this, as at the time it was for my gf who did sommute with a rack bag.

Anyway, at the weekend I found a random piece of metal tube (Not bike related) that is pretty much handlebar size, and was wide enough to cover the distance pretty much from pedal to pedal.

I forced two old rubber grips onto it (Incurring blisters), which happened to leave a space in the middle that was the exact width of the mounting plate on the rack - I bound this area with some chopped up innertube, in the way you might wrap your bars, or put a new handle on a tennis reacket, and tucked each end into one of the grips to geep it secure.
I then used three cable ties to affix it, and whilst it is not rock solid, it's certail well fixed.

I took it for a ride this morning into work, and all good, light remained solid, and so far so good, just thinking about getting another one now to balance it up with one on the other side.

Not sure whether to go for a light and a Y splitter, or just for a whole additional set, as otherwise if the battery runs out I could be out of rear lights at a critical time, and yes of course I will have a helmet lightetc, but even so.

My plan could be with two batteries, to run one light on constant, and one on flash, the idea being then that the constant one will run out first, but that the flasher (!) will always have some juice left in it, and that way I can also keep a charger at work.

Good idea?

daniel_b

So rumour has it that I may have just ordered another one of


And one of these badboys (To partner my 4 year old Ayups)


I do have a good 7 miles of totally unlit country roads, and the adjustable power on the move appeals to me.
Planning to direct the Ayups close down, and the Magicshine further afield, going for more power as and when there is no oncoming traffic.

kiwimatt

So have rigged mine up and it has survived two return commutes in monsoon like levels of downpour so I am happy with my waterproofing. I am also happy that it takes my 18650 packs of which I have an endless old laptop based supply

But it's not quite the retina searing experience I was hoping for - it seems bright and gives off a lot of light but it's a kind of orangegy red that seems less intense than my Smart or Cateye when they have minty fresh AAA's installed which are really painful to look at the flashing of. Especially the central section seems a bit anaemic.

Do i have a duff one or is this a function of a bigger/broader output light compared to the small LED units?

bails87

Sounds a bit off to me, I can film my MJ818 and a Smart R1 or Cateye LD610 side by side if you want?

Edit: video uploading here http://youtu.be/ES5iOSJh4tk

The red spread at the end of the video is all from the Magicshine, it's a big area that's bathed in red light, I think the Magicshine is a lot less specific than the Cateye. So if you're 'off centre' the Magicshine is still as bright, whereas the Cateye gets noticeably dimmer.

kiwimatt

Mmm thanks for that. I think I have a problem. The central LED in particular doesn't look anywhere near as bright as the other shots. Photos are tricky but think this shows what I'm on about. If I hadn't butchered the mount etc I might be asking for an exchange...ho hum

kiwimatt

Still not happy with centre LED brightness opened the unit up and found this

Yeah I know Magicshine in dodgy QC shocker :shock:
Unsoldered the burnt wire and replaced with a better quality bit - hasn't brought up the centre LED brightness but I've done everything I can now.
Contacted the supplier (UK) to see if they will do anything for me although might be on a hiding to nothing having fettled with it

Choccy

I know it's late but how about this.

http://www.xcracer.com/shop/viewproduct ... ductid=235

redvee

Choccy wrote:

I know it's late but how about this.

http://www.xcracer.com/shop/viewproduct ... ductid=235

Too low down IMHO plus I've got nutted axles on my SS.