The BSA A7-A10 Forum

Technical => Lucas, Electrical, Ignition => Topic started by: tiggy on 28.11. 2014 17:04

Title: How to correctly fit a lucas hf1441 horn
Post by: tiggy on 28.11. 2014 17:04
Hi, following on from an earlier post confirming the correct type of horn originally fitted to my machine, (thanks for the replies), I have managed to find a working HF1441 horn and period bracket/laminates which I believe to be the type used by BSA. (I believe numerous other manufacturers used the HF1441). I thought my restoration was about to be completed but I can't get the thing to fit!
The bike is a 1958 model with a nacelle and shrouded forks. I have located the two tapped holes in the lower yolk, and the small angled bracket matches up to these holes. The four laminates also match up to the tapped hole in the angled bracket. The problem is with the angled bracket drop facing forward, the horn is almost entirely proud of the forks and looks odd. With the bracket reversed, the horn is almost entirely within the nacelle but touches the fork/headlight shroud, which doesn't seem right.
Does anyone know the correct way to fit these horns? Looks like I will have to put spacers/shims in to to keep it from vibrating against the body work.
I have searched the internet for hours and cannot find a photo of a bike with one of these fitted and looked at all the members bikes on this site. A lot of lovely machines out there but couldn't see one with this type of set up.
Thanks
Title: Re: How to correctly fit a lucas hf1441 horn
Post by: Angus on 29.11. 2014 13:25
A bit hard to take a picture but here is the A10's horn in head light. Looks to me like quite big spacers under the bracket. I took it off early this year but can not recall it the spacers are fixed to the bracket of loose.
Title: Re: How to correctly fit a lucas hf1441 horn
Post by: Angus on 30.11. 2014 12:36
Hi Rob
Thought I would put our conversation on here so others can comment and potential benefit from the info


Saw there was no replies today so just dropped the headlight off to have a look.
Yes I really struggled earlier in the year when a wire cam off the horn to get anywhere near anything in there.
So
Assuming the A10 is standard
The tone disk is at the front
The bracket bends back towards the tank
the front of the horn is flush with the fork legs
The spacer between the bracket and the yoke is approx 10mm

It is however, as above, very full in there is you want to do anything up or undo anything. I could not put the wire back into the horn and screw the wire tight with the horn fitted, had to undo bracket from bottom yoke then put in wire and tighten screw and then put horn and bracket back in place.

picture from the back (really hard to do would not flash and then would not focus)

Title: Re: How to correctly fit a lucas hf1441 horn
Post by: tiggy on 30.11. 2014 15:22
Thanks Angus for going to the time and trouble. I was convinced I must have the wrong bracket!
 I will make a temporary spacer out of wood until I know I have the correct distance then fabricate something more permanent.
Much appreciated.
Title: Re: How to correctly fit a lucas hf1441 horn
Post by: warmshed on 30.11. 2014 22:12
I would be pleased to turn up a stainless spacer and send it to you if you don't have access to a lathe. (free of course.)  Going on holiday on Friday so if you get the size Ill post it before I go. Dave
Title: Re: How to correctly fit a lucas hf1441 horn
Post by: tiggy on 01.12. 2014 16:16
Thanks for all the help and advice Angus & Dave
 I made two small wooden blocks to test the size of the two spacers required. For anyone else with this issue the diameter is 2cm,  the length or drop is exactly as Angus estimated, i.e. 1cm, and the centre hole to take the bolts is 6mm.
Very generous offer from Warmshed, (Dave), typifies what this site and it's members are like.
Rob.
Title: Re: How to correctly fit a lucas hf1441 horn
Post by: warmshed on 03.12. 2014 09:01
Of course being a British bike with imperial threads it is most likely to be a 6.35 (1/4") bolt.
Title: Re: How to correctly fit a lucas hf1441 horn
Post by: tiggy on 03.12. 2014 16:23
Got there in the end thanks to this site, particularly Angus and Warmshed with their knowledge and engineering skills. A couple of pics. with the horn in situ in case anyone else has trouble with this unusual set up.
p.s. Warmshed was correct about the bolt hole diameter. As I mocked up a couple of blocks of wood to test the thickness requirement for the spacers, it was easy to push the bolts through a soft material but would be impossible with a metal spacer.
Thanks guys.
Title: Re: How to correctly fit a lucas hf1441 horn
Post by: Angus on 03.12. 2014 17:04
Tiggy

Sorry look at my pictures again, the horn goes inside the nacelle (behind the headlight lens) if it is the same as mine. It should be out of sight.

Title: Re: How to correctly fit a lucas hf1441 horn
Post by: warmshed on 03.12. 2014 20:18
Wouldn't it muffle the sound (already like a bee under a bucket) if the horn was behind the lens? Or is it facing downwards? hard to see.
Title: Re: How to correctly fit a lucas hf1441 horn
Post by: trevinoz on 03.12. 2014 20:47
It sits on top of the bottom yoke!
Title: Re: How to correctly fit a lucas hf1441 horn
Post by: Beezageezauk on 04.12. 2014 11:00
Hi Tiggy,

Here are are few shots of the horn on my '58 Alternator Model B31.  The set up is the same as yours and FYI..... this horn has never been touched since it left the factory.

(http://i109.photobucket.com/albums/n80/beezageezauk/BSA%20Close%20Ups/DSCF4957_zpsc2ae75e8.jpg) (http://s109.photobucket.com/user/beezageezauk/media/BSA%20Close%20Ups/DSCF4957_zpsc2ae75e8.jpg.html)


(http://i109.photobucket.com/albums/n80/beezageezauk/BSA%20Close%20Ups/DSCF4959a_zps087a4420.jpg) (http://s109.photobucket.com/user/beezageezauk/media/BSA%20Close%20Ups/DSCF4959a_zps087a4420.jpg.html)


(http://i109.photobucket.com/albums/n80/beezageezauk/BSA%20Close%20Ups/DSCF4960_zps275991d4.jpg) (http://s109.photobucket.com/user/beezageezauk/media/BSA%20Close%20Ups/DSCF4960_zps275991d4.jpg.html)




Beezageezauk (http://s109.photobucket.com/user/beezageezauk/media/BSA%20Close%20Ups/DSCF4960_zps275991d4.jpg.html)
Title: Re: How to correctly fit a lucas hf1441 horn
Post by: tiggy on 04.12. 2014 19:15
Thanks for the additional comments and pics.
 I have got the idea now, but what a nightmare to get good access to this area. I have removed the headlight, nacelle, speedo drive, and light switch etc. ready to connect it all back up at the weekend. Held the horn in position by hand and it all fits fine which surprised me. Looking at the bike on its stand there doesn't look like there is enough room to accommodate so much behind the headlight.
Live and learn!
Thanks everyone,
Rob
Title: Re: How to correctly fit a lucas hf1441 horn
Post by: Angus on 05.12. 2014 11:04
Yep  *angry*
When the wire came out of the horn I could not get it back in and done up with the horn fitted  *angry*. I refused to remove the nacelle so spent hours (well is seamed like hours) with fingers jammed in though the front with just the headlight removed. I removed the horn and replaced it that like that but only able to move a spanner about 1/8 turn so lots of putting spanner on and off and turning over to get the angles.
It may have been better your way  *smile*
Ps the good old BSA twin restoration book page 112 states that from 1958 models with the nacelle had the horn fitted inside it.
Title: Re: How to correctly fit a lucas hf1441 horn
Post by: tiggy on 05.12. 2014 17:19
Had another go today. Hopefully the second and last time!
I have gone as far as I can for now due to damaging the speedo. rubber when removing the nacelle to get better access., (it was already cracking although almost new).
Anyway, horn fitted and working thanks to you guys, just waiting for the mounting rubber to arrive to finish off.
Not likely to frighten any pedestrians with it though.
Thanks again
Rob
Title: Re: How to correctly fit a lucas hf1441 horn
Post by: trevinoz on 05.12. 2014 20:22
Have you tried adjusting the tone, Rob?

Trev.
Title: Re: How to correctly fit a lucas hf1441 horn
Post by: tiggy on 06.12. 2014 17:42
Trev., I have given it my best shot after finding a copy of the Lucas Workshop Instructions on-line. It can certainly be well heard above the sound of the engine running. I was comparing it to a modern horn that came with the box of bits when I bought the bike, probably very unfair for a 56 year old horn! Having said that the cheap modern one looked cheap and the chrome showed signs of rust after two weeks out of the packet. I am very happy with the end result and appreciate the help of all concerned.
Thanks
Rob
Title: Re: How to correctly fit a lucas hf1441 horn
Post by: trevinoz on 07.12. 2014 07:54
Hi Rob,
                        The hardest part to adjust on the HF1441 is the armature travel. That is loosening the clamp band and try, try, trying to get the diaphragm with the correct clearance and getting it to stay there while the band is tightened!
Congrats if you got it right.

Trev.
Title: Re: How to correctly fit a lucas hf1441 horn
Post by: Angus on 07.12. 2014 10:34
Hi Rod And Trev
You mean it could be louder. The A10 horn in the Nacelle is currently very quiet, compare to the A7 (new repro) external by the exhaust.
Damik now I have another job on the A10 list
Rob a link to the Lucas instructions would be useful
Title: Re: How to correctly fit a lucas hf1441 horn
Post by: tiggy on 09.12. 2014 16:15
A link to the Lucas Workshop Instructions (H.F, 1440, 1441, 1444), for anyone thinking of having a go. The small brass locking ring turns anti clockwise to release which I managed using the points of cir-clip pliers.
https://www.britishonly.com/pdf/lucas/sectionL7partB.pdf (https://www.britishonly.com/pdf/lucas/sectionL7partB.pdf)