Hi Gang,
I’m doing my first “open road” triathlon in ages this weekend and wondered what people’s thoughts were on bike lights. I’m tempted to have mine on. But… do you turn them on before the swim and leave them on in transition? Or just turn on in T1?
Cheers
CD
i’ve never used them in a race, but where I to do so, i’d just turn them on at T1… the extra 5 secs in neither here nor there unless you are at the pointy end!
I bet if you leave them on for the swim you will only come back to your bike to find someone has turned them off
I turn it on before the swim. It’s just another thing to remember otherwise; I’m a shocker at transitions!
Only ever had to do this for Helvellyn
I turned it on in T1
Oddly this year for the first time ever I was told ‘you can leave your light on before swimming - it does not count as marking your bike’ in the briefing. Gave me a moment’s worry that it was compulsory ( I wonder if that’s where we are headed for open road tri’s).
I’ve never used a light in a Tri
I’d just turn it on in T1 
I don’t mind either way.
If that is where Tri is heading, so be it.
No grumbles from me.
Anyone got a decent recommendation for a light that can be attached to a GoPro mount? I want to attach it to the bottom of my Garmin out front mount to keep the handlebars free and still be visible without the bike computer blocking any of the visibility.
The Lezyne ones look like they can be easily adapted with the help of a £2 plastic part but anyone else had experience with any better?
Happy to pay around £50-£75 assist only going to be for daytime visibility in low light conditions rather than lighting up dark roads at night.
Some answers in this thread:
Thanks all I turned it on in T1 in the end.
Hope you had a good day out - where was your event? I was at Helvellyn and we had to have rear lights on as well. They had to be turned on before going into T1 - I suppose it means the TOs can check that they’re working.
I was at Reading. Lights were certainly not compulsory but when I did my course recce there were a few stretches of road where it was dark because of overhanging trees so it seemed like a good idea. I was pretty pleased with my result despite the run being tougher than I expected due to rather “ankle breaking” terrain!
How did you get on? Saw some pics on Facebook and the weather didn’t look too bad
rule was changed a few years ago.
Weather was perfect! Cool, calm, and great visibility from the top - a bit different from last year!
Awesome. Very jealous.
You’ll have to share your pics if they had a camera on striding edge
@iaincognito sent me down a bit of a CW rabbit hole with his post on the PEDs thread.
Has anyone had good/bad experiences with radar lights? I was following a cyclist - whilst daytime driving - the other day & was impressed with the randomness & strength of what I guessed was a radar rear light.
Best Radar Bike Lights 2026: Can Garmin be outdone? | Cycling Weekly
A couple of guys I ride with use the Garmin - it’s actually really bloody good at detecting cars. No idea what the light’s like but its radar is excellent.
I have the Garmin radar sans light. I do like the radar and it’s helpful to know if there’s a stealth car crept up behind you in the back roads.
I don’t get the variable light intensity with approaching car distance. Seems utterly pointless. I just have a f@#k off bright rear flasher going constantly.
Whilst I like the radar, I struggle to convince myself that it makes me safer. The super bright flasher is the key. If I were starting over I’d just buy an Exposure Blaze or a Dinotte (in USA), and save my £££.
I have the Garmin radar & light RTL515 and I like it a lot, if it broke I’d but another straight away. The battery is an issue for long days but there are better options now with longer life.