I recently bought two Smart Lunar R1 lights. They are small, lightweight devices but extremely bright. I got them for two purposes:
- Putting on my winter bike which I will occasionally be riding in fog at this time of year
- As a backup light for my best bike. I can unclip and put them on the best bike before an event
When I got them out of the box and looked at how they worked I was impressed at the “modes” available. The light has some small LEDs and one large big LED. The 3 modes, which are selected by pressing one switch are big light, small lights only, alternate/flash big/little. The big LED is too powerful for group riding but is impossible to miss, even in daylight. The little lights are good for group riding and the batteries will last longer. So being able to select big or little as alternatives is great.
The “big” and little lights modes
The pair of lights, fitted on the rear stays of the bike
I put them on the bike about a month ago.
The bad news
However, the lights were too good to be true. During the second of two wet days/nights out one of the lights refused to switch off after use. Later in the same ride the other light refused to switch on. I left them over the fireplace overnight, they dried out and started working again.
I asked around and apparently this is a known problem with this type of light. The design flaw is that the switch is placed at the bottom of the light. Any water that penetrates the seal pools near the switch and causes it to go wrong.
The “smart” (see what I did there) thing to do at this point would have been to return the lights to the retailer as unfit for use. Apparently Astrum and Radobot lights have the switch in a different place and do not have this problem. But sadly I am not sensible enough for this.
To try and mitigate the design flaw I have taken the following counter measures
- Remove the gasket seal and coat it with silicon grease
- Apply silicon grease around the switch
- Apply silicon grease on the seal on the switch cover
- Wrap red insulating tape around the join of the two halves of the light
- Mount the lights upside down so that the pooling occurs away from the switch
Will it work and render the light reliable in rainy weather? I don’t know. I suspect I will be finding out quite soon though.