You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more
fitting new dynamo lights to my road bike. Both are B&M lights. The front came with a cable to hook up the rear and the spade connectors are super nice and tight. I bought some "B&M connectors" from SJS and they're the correct width I think (2.8mm) but are super loose on the rear light spade - by default its not applying any friction on the connection at all. I figure I have 3 options..
1 - solder the wire directly to the rear light - I'd rather not do this as my soldering is really bad
2 - pinch the connector tight with some pliars - I'd rather not do this as last time they worked loose over time
3 - get the right connector - but not sure where from?
Even if the connector is tight, it dangles out of the bottom of the rear light so always has some friction pulling it down. The front light had short tails to eliminate this - is there a nicer way to connect up the rear?
My rear dynamo light had two options - either spade terminals or just clamps for bare wires - check yours?
its one of these
https://www.bikester.co.uk/busch-muller-toplight-mini-plus-dynamo-rear-light-M325635.html
I think its only spade connections
On the whole, I'd pinch up the spades, then try to make sure the wire was securely supported as close as possible to the connections.
Otherwise, for a proper job, strip back to bare wire , thread and twist through the holes on the spades and solder, then heatshrink each side - for mechanical protection as much as electrical (you did remember to slide the heatshrink on before you soldered, yes? 😉 ) (Oh, and check you've got the wires the right way around and it all works before soldering, too!)
The holes in the spaces are tiny, you wouldn't get more than 2 or 3 strands of the wire though them. Would stripping it back that far not be more liable to break than a connector?
When I had one of those, I just made sure the spades where tight and the looped the wire and cable tied to the rack to make sure zero tension / flapping possible
I wouldn't solder onto the spades - you do not know how close components are inside and you could damage it with heat - its not just a simple LED array - there should be a standlight capacitor in there and some circuitry
I've had to solder vibration broken tabs back onto a B&M Secula board so I doubt soldering a wire to the tabs will cause any damage (provided you can solder quickly and cleanly).
I wouldn’t solder onto the spades – you do not know how close components are inside
Your not MIG welding it . It's a soldering iron.
Aye - I may be being paranoid.
The advantage of soldering is the connection will be much more corrosion resistant. The spade and the spade terminal are probably cheaply tinned steel and will corrode which will worsen the connection. Soldering it up will seal the metal to metal connection in a lump of solder, which will last much longer.
Mine are all just heatshrink over the spade connections.
Get the adhesive heatshrink and it will make a properly waterproof connection.
If using solder (I wouldn't) get the red military/aviation stuff that's lead based. The green/blue lead-free stuff cracks when subject to vibration.
to wrap this up..
I measured the connectors with a set of vernier calipers and it was showing 0.2 or 0.3mm, so I bought a bag of female connectors for 0.25mm male on ebay
https://www.ebay.co.uk/itm/295192356087?var=593403631126
which fit perfectly, however the light itself was dodgy. I returned it and got a toplight line plus, which comes with a convinient "stick your wires here and pull a lever" connection which solved the whole problem. Its also a nicer light in general.
if anyone needs 98 female connectors for BnM lights, lemme know 🙂
Crimp on spades are easiest IMO/IME, use plenty of heat shrink tubing. My mudguard light is (badly) soldered as it's not designed for spade connectors (think I need a new one, but it's refusing to die).
The toplight mounted on the back of my commuting bag uses crimp on nutted washer connections, but has alternative spade connections as an option too.
Spades at headlight and I even had to extend the wire to connect the front light to the hub, so I decided to use in-line male/female spades again so can separate the cable rather than need to pull the connector off the hub.
They're not always the neatest, but they're quick, and very easy to fix if you need to.