Head light cowl fractures

[tlmark]

Hi Guys

I was just upgrading the headlight bulb to LED one at the weekend.
when I noticed the lower two mounting bolt hole sections had cracked, also a crack was running up the side of one side.

have any of you seen anything like this before?

My mate is going to try welding them back on, and when he looked at it he said it looks like it has happened before and been repaired on the opposite to the main split.

[RDfella]

I've suspected for a while that the A series front downtubes are the frame part which vibrates in harmony with the engine (given the propensity for them to fracture close to the headstock). Could this be another manifestation?

[Jules]

yep, mine is the same, re re repaired.....

[Jules]

I'm interested to know how you get on with the led bulb on these machines - I've always "heard" that led's cant handle variable voltages, that they end up flickering???

[Greybeard]

I'm interested to know how you get on with the led bulb on these machines - I've always "heard" that led's cant handle variable voltages, that they end up flickering???

I've heard that although LED headlights are bright they don't have a penetrating focused beam.

[Black Sheep]

When I tried an LED headlight, it lit up everything except the bit of road I needed to see.

[KiwiGF]

Hi Guys

I was just upgrading the headlight bulb to LED one at the weekend.
when I noticed the lower two mounting bolt hole sections had cracked, also a crack was running up the side of one side.

have any of you seen anything like this before?

My mate is going to try welding them back on, and when he looked at it he said it looks like it has happened before and been repaired on the opposite to the main split.

Those cracks are annoying, but commonplace, I have had to weld mine up too.

Going a bit off topic, I am in the luddite camp and have a 6v headlight, it’s not blown a filament yet, I don’t use the headlight in daylight and I rarely ride at night and keep the speed down if I do, generally I am all for improving safety by buying good tyres, brake linings etc but ultimately these bikes cannot be made anywhere near as safe as modern bikes so each of us have to draw the line somewhere.

If I did fit an LED it would be an additional “driving light” and on all the time. The headlight LED are not legal in NZ anyway and they usually get picked up by the beam testing machine at WOF (aka MOT) time. I’m thinking a really bright parking light LED in the reflector might work, if a 6v one was available.

I have not looked much into it but there are some oddities in the NZ laws eg driving lights must be on all the time and not switchable on/off. No parking light is required (on bikes anyway). A while back I watched a modern honda owner go livid when the WOF inspector basically passed his bike, but then asked if he could demo the extra driving lights he had fitted could be turned off, he turned them off and promptly failed the WOF 

[BSA_54A10]

Weld the broken bits to a mudguard washer ( or smlilar then weld it to the cowl, trim where necessary then paint or you will be re-repairing the re-repair of a repair
Welds are castings and as such nowhere near a s strong as the original .

[Black Sheep]

My welding course instructor stated that a good weld is stronger then the surrounding metal. It's the surrounding metal that will give you problems.

[Swarfcut]

 May be a trick if the light, but that hole for the speedo looks a little different. Great shame that any hot repair will ruin the finish. From scratch a gas weld (a true fusion weld) to the sheet metal and a braze on of support reinforcing washers would be my choice. Tack welding with mig won't give the same strength, but could save the majority of the finish. Bolt on hidden subframe is an alternative. I used a cross bar here to mount a modern horn.

 As to the cause, there are support washers under the cowl, and the lower mounts are slotted, all in order to ensure the cowl is mounted without strain. Make sure the repair lies flat against the lower yoke with the forks finally set straight, again to avoid any strain on the cowl as the lower yoke bolts are tightened.

 Swarfy.

[RichardL]

Interesting, but not surprising that the break occurred right along the circumference of both washers. When welding back together, I believe it would be a good idea to distribute the stress over a wider area, maybe by putting down some braze after the weld. I will now wait for more weld-savvy members to correct me.

Richard L.

[bikerbob]

To me that has all the hallmarks of a vibration fracture, and I would fit a thin nylon or rubber washers either side of the cowl when refitting it to reduce the chance of it happening again. My A65 mudguards were prone to cracking around the mudgaurd stay holes, I fitted rubber washers either side of the mudguard and they have been good now for about 10 years.

[Greybeard]

To me that has all the hallmarks of a vibration fracture, and I would fit a thin nylon or rubber washers either side of the cowl when refitting it to reduce the chance of it happening again. My A65 mudguards were prone to cracking around the mudgaurd stay holes, I fitted rubber washers either side of the mudguard and they have been good now for about 10 years.

When I removed the front guard on my bike I found the (presumably original) squished remains of a rubber packing between the underneath of the guard and the U shaped bracket it bolts to. I used some large tough rubber washers to replace the original packing. The idea seems to have worked so far.

[tlmark]

The LED is a projector type and is
6-12 volt compatible also positive or negative earth. I’ll post some pix in another thread tomorrow.

I think I’ll try some sort of rubber isolating once I have it repaired
Sadly I think it is powder coated so once it’s fixed I’ll have to have it blasted and re coated

[Kickaha]

The headlight LED are not legal in NZ anyway and they usually get picked up by the beam testing machine at WOF (aka MOT) time

Fully legal in NZ if you fit an entire assembly and not just a bulb, it's to do with the reflectors not working with the led bulbs hence the incorrect beam pattern