A-FRAME Goes Legal

Weg
Posts: 808
Joined: Tue Sep 25, 2018 7:30 pm
Location: Huntingdonshire

A-FRAME Goes Legal

Post by Weg » Mon Feb 17, 2020 12:57 pm

I've converted my old A-Frame to be legal by adding an over-run coupling.
Triking brakes are operated by a Bowden cable going from the hitch 'pull rod' link to the M10 thread on the Triking brake pedal arm. One handed connect/disconnect by reaching into the footwell. (Or I could take the bonnet off but that would take far too long). Brakes also operated by the hand brake, especially when the break-away cable is pulled. Stop limiter adjusted on the handbrake lever to prevent overpull on the cable. The orange strap is to prevent the hitch falling to the ground if detached from the tow car.
Credit to Guy Greaves for developing the Bowden cable and the gland going through the front of the footwell to the brake pedal.
Road test to follow.
Attachments
IMG_0184a.jpg

peakrock
Posts: 203
Joined: Thu Sep 27, 2018 4:52 pm
Location: Wreningham

Re: A-FRAME Goes Legal

Post by peakrock » Mon Feb 17, 2020 2:23 pm

Very ingenious Tony!

I'm tempted to build in a similar type of connection to my brake pedal as I'm still at the bare metal stage with my chassis, pedal box etc.

Dave

Weg
Posts: 808
Joined: Tue Sep 25, 2018 7:30 pm
Location: Huntingdonshire

Re: A-FRAME Goes Legal

Post by Weg » Mon Feb 17, 2020 5:20 pm

Much easier to drill the hole in the bulkhead with no body in the way.
No tools needed for fitting/removal of cable.
The lock nut on the adjuster allows quick removal, cable nipple then pulls through the gland.
The nipple holder slips onto cable and screws onto brake pedal M10, one-handed.
Attachments
IMG_0171a.jpg
IMG_0189a.jpg
IMG_0187a.jpg

Weg
Posts: 808
Joined: Tue Sep 25, 2018 7:30 pm
Location: Huntingdonshire

Re: A-FRAME Goes Legal

Post by Weg » Tue Feb 25, 2020 4:15 pm

Final piece completed, socket for connecting car lights to Triking lights.
The only thing that didn't work was the brake lights. I'd spliced into the green/purple before the brake light switch, not after.
Attachments
IMG_0194a.jpg

peakrock
Posts: 203
Joined: Thu Sep 27, 2018 4:52 pm
Location: Wreningham

Re: A-FRAME Goes Legal

Post by peakrock » Thu Apr 02, 2020 4:21 pm

Hi Tony

I've just fitted the pedal box into my new Type 3 build but had to make a different arrangement on the brake pedal as I'm using a Type 4 pedal box. I'm now considering what brake cable to use and am thinking that an appropriate length trailer brake cable would be a good starting point, is that what you used? It looks like you've used an AlKo coupling - is that right, presumably specced for a low trailer weight? I've been looking around and Knott do one for up to 750KG which is the lowest weight I've found, do you know what yours is rated at? I'm curious as to what that black tube with 2 bolts on the side of the coupling does too?

Regards Dave

Weg
Posts: 808
Joined: Tue Sep 25, 2018 7:30 pm
Location: Huntingdonshire

Re: A-FRAME Goes Legal

Post by Weg » Thu Apr 02, 2020 7:23 pm

Dave
You are right about the coupling, AlKo rated 700-1000kg. Perhaps a bit over the top but that seems to be the smallest they do. Relates to the fact that under 750kg does not need brakes. (Civil servant rules)
I didn't come across Knott.
The black angle bolted to the side of the coupling with an adjuster bolt facing forward is a limit for the hand brake lever, it's powered by a gas strut which would put far too much strain on the cable if not limited.
Guy G made up the cable with me just adding the adjuster and nipple at the brake pedal end.

Stay safe. :D

SIG 4643
Posts: 23
Joined: Sun Sep 30, 2018 6:50 pm
Location: Cheshire UK

Re: And here’’s One I made earlier!

Post by SIG 4643 » Fri Apr 03, 2020 7:03 pm

Upon my return to Blighty I resolved to catch up with West End Guzzi on The A frame front. I had already roughed out a design in my head but now had to cut and shape metal in real time. I had already purchased a vastly over rated used ( no thrift was spared) towing hitch and proceeded to cut and weld angle iron to connect it to the chassis. I included a self braking system in the event that the tow bar becomes detached, This is simply operated by the overun brake operating lever being pulled as The A frame angle becomes more horizontal. The front engine mounting nuts were used to prevent the A frame falling too low and hitting the tarmac.
I used Tony’s system of connecting to the vehicle lights but intend to use a simple detachable number plate.

All things considered, I think PC Plod (The Police for our overseas readers) would be hard pressed to find any reason to prosecute,.

I can’t wait to try it out, in the meantime I have already started on my next cunning modification!
Attachments
BEC9716D-3C69-4B20-90B0-6BC8E400D446.jpeg
The auto brake link tightens when A frame drops down
C20A0C73-760E-4E8E-87CF-2DDB536556CA.jpeg
The A frame I made earlier.
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The auto brake link in normal operation

peakrock
Posts: 203
Joined: Thu Sep 27, 2018 4:52 pm
Location: Wreningham

Re: A-FRAME Goes Legal

Post by peakrock » Thu Jun 25, 2020 8:23 am

One of the final jobs with the body off was to sort out the brake pedal connection for the A-Frame. I used a Knott trailer brake cable which come in various lengths with a slotted end and drilled a hole in the bulkhead for the cable to pass through. I'm using a Type 4 pedal assembly and the pedals have a recess in the back and are detachable from their shafts. I had a U shaped bracket in my scrap bin which fitted within this recess so drilled and bolted it to the pedal shaft. I then made up a substantial catch mechanism on this bracket such that the slotted end of the cable drops onto the main part and has a locking catch such that the cable cannot free itself. The cable end has to move backward to lift off the main catch but the recess in the locking part prevents it going back more than a couple of mm so it can't lift the catch.

The cable can also be attached and detached with no tools - hopefully the pictures make it clearer.

Note: this is pre painting and all nyloc nuts etc!
Brake-Cable-2.jpg
Brake-Cable-1.jpg

Richard and Pat
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Joined: Wed Sep 26, 2018 2:44 pm
Location: Biggleswade

Re: A-FRAME Goes Legal

Post by Richard and Pat » Thu Jun 25, 2020 5:37 pm

Superb job David.

Weg
Posts: 808
Joined: Tue Sep 25, 2018 7:30 pm
Location: Huntingdonshire

Re: A-FRAME Goes Legal

Post by Weg » Tue Mar 08, 2022 9:26 pm

It's 2 years since I completed the legal A frame so decided it was time to do a road trial, before towing up to St.Helens in a couple of weeks time.
The sprung loaded handbrake locks the wheels as it should when triggered by the brake-away cable.
On the road trial, nothing seemed to be happening.
Closer inspection when parked up revealed that the cable pulling on the Triking foot brake was too slack.
3 adjustments later, it is now giving a 'gentle assistance' when braking in the tow car.
Job finally ticked off.

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