Motorcycle Discussions > British Bikes

BSA B40 Headlamp Bulb.

(1/4) > >>

grahamkeen1:
Hi,
My 1966 B40 has been converted to 12V but still runs a 35/35W headlamp bulb which doesn't illuminated very much.
Has anyone used the higher powered 60/55W versions ? Just wondered if there was a problem with the power being drawn and perhaps 'warming' the wiring harness.
Thanks,
Graham.

R:
I fitted a Cibie halogen insert 55/60w (is that the right way around ?) to a Commando some years back, and the result was sorta brilliant ( nearly half as much light as the average car !).  Thats still less power than if your 35w high and low were on together, so "warming the wiring" shouldn't be a concern.

You will likely find that it draws more than the alternator is keen to supply though, all things considered, so unless you ride around in the lower gears a lot (around town), the battery state of charge is likely to suffer. I didn't need to ride far at night on said Commando, or I'd have needed to have fitted one of these higher output alternators ??

mini-me:
You will not"warm" any wires ;) although if you ran a very heavy load via one switch  for a long time the switch will get warm.

for those application thats where relays come into the scheme, but you won't need one.

The standard Lucas  encapsulated alternator will churn out over 110 watts on 12v quite happily, no need to change it.

get yourself one of those 60/55 halogen bulbs it will be more than good enough for your B40, higher wattages are availiable but illegal for road use. [ but by god they make those car drivers with their  blue gas discharge set ups annoyed!!]

iansoady:
I had a 60/55 on my Commando and the alternator (single phase not 3 phase) was capable of running it and keeping the battery charged even when riding through the night on several ACU/BMF rallies.

It wasn't very bright however and I remember having a car following me and seeing my shadow in my own headlamp beam......

mini-me:
exactly.
headlamp 60watts
coil 10watts
rear lamp 12 watts

more than enough to spare for charging.

I used to run a 350 AJS with alternator AND magneto so had over a 100 watts to blast my way down dark roads. DFor continental trips I hung one of theose Cibie Oscar lamps on the badge bar, a falsh of that made even french HGV drivers dip their lamps.

 but as with all these things good earths are essential.

Navigation

[0] Message Index

[#] Next page