Trailing Arm Limit Straps

[stuart]

7 minutes ago, Magz said:

It's just my way of doing things. When I needed an amplifier for my stereo I could have bought a powerful, modern, reliable solid state unit, but instead I built a pair of transmitter valve amplifiers that run at 2.3kV on the output tube anode and terrify my wife. 

But the sound and looks are glorious!

Im with you on the valve amps, so much warmer sound.

Stuart.

[RobH]

8 minutes ago, stuart said:

valve amps, so much warmer sound

That's all the even-harmonic distortion. 

[RogerH]

What we need now is a decent valve with an inbuilt LED instead of the overly hot heater.

That way you get the glow but not the degrees C' temperature..  Great Idea.

Roger

[RobH]

20 minutes ago, RogerH said:

What we need now is a decent valve with an inbuilt LED instead of the overly hot heater.

Theres nowt new under the sun.  Cold-cathode devices were common once Roger, but not much good for amplifiers.  They were mainly switching devices (e.g. thyratron) or displays like neons or nixie tubes. 

Edited April 17 by RobH

[RogerH]

Another invention doomed.

Roger

[dblenk]

i dont have straps but the PO fitted an anti roll bar to the rear fits to the chassis legs and bolts to the hole in the middle of the spring that limits the travel of the TA

i have to remove the anti rol bar to move the TA enough to replace the springs

David

[harrytr5]

17 hours ago, Magz said:

It's just my way of doing things. When I needed an amplifier for my stereo I could have bought a powerful, modern, reliable solid state unit, but instead I built a pair of transmitter valve amplifiers that run at 2.3kV on the output tube anode and terrify my wife. 

But the sound and looks are glorious!

Really gorgeous and in the aircraft world if it looks right it usually is right.

People sometimes ask why did you do that to your TR5! (BECAUSE I CAN)

Love to see the TR6 when finished. I have been toying with the rear brake disc conversion but the consensus is it's not worth it. I would not know as not seen it or experienced it

Regards Harry

[Magz]

5 hours ago, harrytr5 said:

Love to see the TR6 when finished. I have been toying with the rear brake disc conversion but the consensus is it's not worth it. I would not know as not seen it or experienced it

Regards Harry

I went for the rear disks because the drum brakes were badly corroded, and the parking brake was pathetically ineffective. I figured why not just upgrade while I had everything apart?

[Magz]

I received the adjustable limit strap and it was really cumbersome to use for such a short length (too much material in too short a space) so I cut it and had my wife sew it up with fishing line (never knew you could put that through a sewing machine!) to make a 9" strap for test purposes. It seems to do the job effectively (see picture), so I ordered a pair of 9" PRP straps as the permanent solution.

[CK's TR6]

Magz - I am in your camp, fully.  I have built 2 ST-120 valve amps and two valve pre-amps, definitely one way to ……..go or glow. I didn’t have the room for speakers as lovely as yours but still okay, double 8”, metallic cone mid and ribbon tweet, covered in highly figure maple veneer.

As for the other antediluvian engineered thing in the garage, rear discs, front four pots, dual master, anti roll front n rear, CV axles, LSD diff, 5 speed, Dunlop Direzza Diii 205/55r16 stickies. I do have levers but those have the shim pack type valving just like a telescopic shock (Suspension Supplies LTD). 

I was advised by one of my airline Captains, “drive fast, take chances”

Edited April 18 by CK's TR6
spelling

[Z320]

3 hours ago, Magz said:

 

Sorry me Robert,

with your attitude, and the way you present yourself, a textile strap is not your serious soltution?

I would make a „cup“ from aluminium to lift or lower the upper or lower end of the shock absorber.

Ciao, Marco

[Magz]

2 hours ago, Z320 said:

Sorry me Robert,

with your attitude, and the way you present yourself, a textile strap is not your serious soltution?

I would make a „cup“ from aluminium to lift or lower the upper or lower end of the shock absorber.

Ciao, Marco

"Textile" straps made of nylon are the standard for limit straps, used extensively on many different vehicle types, especially for rugged off-road use. They can certainly handle the requirements for protection during maintenance on a lift.

As a side benefit, they have a small bit of stretch to them, so they help avoid the sudden jolt of a hard stop fixture.

I ordered black ones for the permanent installation in case the blue color bothers you...

[Z320]

Its your car

[john.r.davies]

"Suspension limiting" or  "Droop control"  is an arcane feature of some competition cars' suspension.    It's difficult to impossible to find any text that could allow you to design it, or tune it.   What did you base your design on, and do you have a way to tune it?

I've fitted it to the front suspension of my race Vitesse, using steel cable, but chose dimensions almost arbitrarily. I think it helps but would love to know better how it works!

John

[Magz]

2 hours ago, john.r.davies said:

"Suspension limiting" or  "Droop control"  is an arcane feature of some competition cars' suspension.    It's difficult to impossible to find any text that could allow you to design it, or tune it.   What did you base your design on, and do you have a way to tune it?

I've fitted it to the front suspension of my race Vitesse, using steel cable, but chose dimensions almost arbitrarily. I think it helps but would love to know better how it works!

John

Not much of a "design", really. It just needs to prevent the CV axles from drooping to more than 28 degrees below the horizontal (Goodparts spec) while allowing full movement to the upper bump stop. I used the lower bolt hole from the old lever shock mounts and the bolt at the bottom of the rear sway bar end link as convenient, existing attachment points. Since I won't be off-roading the TR6, it's mainly meant to protect the CV joints from overextension when I have the car on my 2-post lift.

I suppose I could "tune" it by varying the strap length or material, but I don't really see the point for my application.

[RogerH]

Hi Robert

I like it.
You have a problem (on the car)  and you engineer a solution.

Not overkill but functional.

Well done

Roger

[john.r.davies]

Ah!  Less tweaking performance, more avoiding excess angulation.      I suppose this would be a higher maitenance component than most, but that's no criticism.

John

[harrytr5]

On 4/17/2026 at 5:03 PM, Magz said:

It's just my way of doing things. When I needed an amplifier for my stereo I could have bought a powerful, modern, reliable solid state unit, but instead I built a pair of transmitter valve amplifiers that run at 2.3kV on the output tube anode and terrify my wife. 

But the sound and looks are glorious!

Yes please I want one. Do I have to sell my house?

Regards Harry

[Magz]

7 minutes ago, harrytr5 said:

Yes please I want one. Do I have to sell my house?

Regards Harry

Probably. Building the pair of amps took a full year of my spare time (pre-retirement) from design to simulation to building to tweaking. I have no plans to build another pair, especially now that I have the TR6 to obsess over.

[harrytr5]

21 hours ago, Magz said:

Probably. Building the pair of amps took a full year of my spare time (pre-retirement) from design to simulation to building to tweaking. I have no plans to build another pair, especially now that I have the TR6 to obsess over.

Many, many years ago I built an amplifier from a set of plans and it never worked. My brother in law had a top secret job at the time in electronics and I asked him to have a look at it. I also built speakers from Kef kit 3s.

He gave it to his apprentices and they found a few dry joints that I had made. Rookie error and never to be repeated so I am full of admiration with your Valve amps and speakers

Being a carpenter I machined 1' thick ply sheets to plans from the tannoy speaker designer for a mate of mine and to date have not heard  them in action due to forgetting all about them till your article came up and I believe he has self built valve amps too. I must make the effort and go to have a listen.

Regards Harry

 

[Magz]

16 minutes ago, harrytr5 said:

Many, many years ago I built an amplifier from a set of plans and it never worked. My brother in law had a top secret job at the time in electronics and I asked him to have a look at it. I also built speakers from Kef kit 3s.

He gave it to his apprentices and they found a few dry joints that I had made. Rookie error and never to be repeated so I am full of admiration with your Valve amps and speakers

Thanks. Yeah, there was a lot of soldering to do, and tons of iron to mount! The amps weigh ~150lbs each, with each output transformer weighing in at 62lbs. Here's a shot of the underside of one amp.

[Phil Read]

On 4/18/2026 at 11:01 PM, Magz said:

"Textile" straps made of nylon are the standard for limit straps, used extensively on many different vehicle types, especially for rugged off-road use. They can certainly handle the requirements for protection during maintenance on a lift.

As a side benefit, they have a small bit of stretch to them, so they help avoid the sudden jolt of a hard stop fixture.

I ordered black ones for the permanent installation in case the blue color bothers you...

I like the idea, where did you buy them?

[Paul Hig]

38 minutes ago, Phil Read said:

I like the idea, where did you buy them?

Phil, Google came up with these https://www.trs-motorsport.com/products/accessories/lashings/suspension-limiting-strap-p5959851 

[Andy Moltu]

If it's just to stop over extension on the 2 post ramp = why not but the lift arms (on the rear) beneath the trailing arms?

[Magz]

1 hour ago, Phil Read said:

I like the idea, where did you buy them?

Summit Racing Equipment:

https://www.summitracing.com/parts/PXC-F9