Rear light legal requirements

[bigredduke]

Not for the Monster but my Paul Smart. Some time ago I fitted a tail tidy designed and donated by the much-missed Geoff (Buzzbomb).

I fitted a clear-lens LED rear light but I am not completely happy with its appearance.

Anyway, I have come across a round Kellerman LED rear tail/brake light which at 10mm long & 8.9mm diameter is really tiny, but they claim it is sufficiently bright and importantly, E-marked.
https://www.kellermann-online.com/en...integral?c=161

I rather like the idea of a tiny rear light as long as it doesn't compromise safety & satisfies MOT requirements. I would need to come up with a satisfactory way of mounting said light as well. I rarely ride after dark anyway.
So, my question is: is there a legal minimum size and/or intensity for a rear light on a motorcycle in the UK?
I have checked the MOT requirements and it just states that any rear light should show a constant red light but nothing about size or brightness. Before LED's came along the usual bulb for tail & stop light was 5/21W but clearly LED's have presumably made this irrelevant.

Any comments welcomed!

[slob]

I think these are still in force as they’re referenced in the slightly later construction amd use regulations.
https://www.legislation.gov.uk/uksi/...9840812_en.pdf

Don’t forget you need some sort of rear reflector too.

[utopia]

I've got to say, I'm not a fan of tiny lights, be they tails or indicators.
Irrespective of legal specs, I like to be sure that my tail light (and indicators) are bold and unmissable.
And don't forget that your brake light is operational at all times of the day and a small one could compromise its visibility when, for example, you're riding into a low sun on a bright day (and so is the vehicle following you). Rain or fog are other daytime hazards which need a good rear light. You never know when weather conditions are going to change suddenly and catch you out.
My own rear light is the std unit but fitted with an array of red leds on a circuit board which covers the full area of the light unit (ex Capo). This was originally designed to sit behind a clear lens but I replaced that with the std red lens, the result being a really deep, intense red light which I'm confident is unmissable in any conditions.

I'm not saying don't do it, just make sure you don't compromise the light under certain operating conditions.
Trouble is,you only know how good any aftermarket unit is after you've already bought it.
That's why when I fitted led indicators I chose the tried and tested units from a Panigale. ...and coincidentally, Buzzbomb was looking into doing the same.

[Mr Gazza]

I'm with Jeff. There's no substitute for area with a tail light, and indicators come to that.

Regarding brightness it's the difference between tail and stop that's important. If the tail light is too bright it's a nuisance, the same as driving with your fog lights on when it's not foggy. The brake light has to be much brighter and obvious.
I followed someone at the weekender who had a flashing brake light ( Duncan I think?) and that was quite good as it caught your eye. Not sure if it stayed on constant if he held the brake at a standstill?

At that size (8.9mm dia), I would build an array of them in a pattern like a "D" or something, or maybe "V" or 1100 or whatever. To make sure I'm seen.
No matter how bright your brake light is you have to remember how dim most car drivers are.

Remember you also need to show a red reflector facing rearwards and have a number plate illuminator.

[utopia]

Originally Posted by Mr Gazza

I followed someone at the weekender who had a flashing brake light ( Duncan I think?) and that was quite good as it caught your eye. Not sure if it stayed on constant if he held the brake at a standstill?

Actually, the light that Capo fitted to replace the one that I ended up with was an all-singing, all-dancing unit which flashed in a multitude of modes according to how hard you were braking and whatnot.
To be honest, I hated it. The multi-mode flashing was just confusing to my way of thinking, such that instead of instantly knowing (without even thinking) that he was braking, I found myself wasting valuable split seconds thinking "What the fook is happening ?".
In my opinion he gave me the better light of the two and kept the worst one (albeit the most technical) for himself. I once even dared to tell him so.

Flashing rear lights are handy on a bicycle though, I reckon.
Maybe they should be reserved for that purpose.

[Terryphukwit]

Sorry but have to say after having some dumbass run into the back of me, push me onto the car in front with the excuse that they did no see me braking, or the car in front of me braking I would find it hard to see this as a safe option for the road, great for road legal custom but not your everyday ride..

[slob]

Look at the rain lights on race bikes, physically tiny LEDs that are so bright you can’t tell how small the unit is.

[Nasher]

Similar, but not the same at all really, on my 1000SS project I ended up using two tiny rear Rectangular rear lights as I felt one was too little:





They are sold as Road legal, are Very bright, show a big difference when the brake light is active, and my MOT guy confirmed a few months ago that he was happy with them.
Although the bike is booked in with him next week when I'll find out for sure.

Nasher.

[Kato]

While I agree with most of the sentiment above, I disagree with the instant dismissal of this product, as much as it pains me to say it (it’s a German product) Kellerman kit is insanely good, have used myself and seen it used by others it is far superior to a std light, take into account that their stuff is CE marked and TUV approved, TUV being way tougher than a UK MOT! the only down side is it's piggin expensive.
As Slob says though you still have to spoil the look with a silly reflector

[bigredduke]

Thanks everyone for your input, always good to know comments will be thought out and considered as usual on this forum.

Still giving it some thought. Interesting comments about size & brightness, I would have thought that intensity was an important factor to consider. I have Panigale LED indicators fitted and although they are approx. 1/3 smaller than OEM, they are much brighter.

I would also need to illuminate the number plate as the Kellerman one doesn't incorporate one.

[Blah blah]

Originally Posted by bigredduke

I would also need to illuminate the number plate as the Kellerman one doesn't incorporate one.

I use things like this...

https://www.ebay.co.uk/itm/264858261...SABEgKUuPD_BwE

about the same size as a number plate bolt so easy to hide, the Monster has 2 inside the rear light, the Mito has 1 above the number plate

[Mr Gazza]

I binned the huge standard number plate light and stuck a strip of LEDs under the tea tray with double sided foam tape.. Glazing tape I think?

The bullets at the end of the cables must weight more than the whole thing?

[utopia]

And I used the std led numberplate light from a panigale.
Its tiny and in a plastic module, so rot proof.

The pani unit works well, although numberplate lighting is the one area where I'm not too fussed.

[slob]

I used one of these
https://evotech-performance.com/prod...fff64ea3&_ss=r
I also bought a pair of tricolore reflectors,

(because I couldn't find a red one small enough for my liking)
cut the red bits off and glued one either side of the LED on the tail tidy, I'm struggling to find a photo, might have to head for the garage...

[Flip]

I’ve just done the number plate light on my Guzzi so it’s gone from this monstrosity which was as big as the tail light (and oddly the only incandescent bulb on the entire motorcycle):



To this complete with ‘full fat’ Italian Tricorlore reflector:



Using one of these Oxford Aluminium ‘Halo’ bolts:




The Monster also has a Tricolore reflector but uses a BA15s fitting LED in the original number plate lamp holder tucked away under the tea tray: