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Having spent (don't) drive it day finally re-uniting  the body  tub and the chassis for the first time in nearly ten years, my thoughts turned to next steps  - which will involve positioning the windscreen fixing points and fitting the hard top for the first time.  Having read Hamish's discussion on fitting hardtops, I dug out a roll bar that I bought from someone somewhere back in the mists of time to see how that might also need to  fit in the 3-d jigsaw.

The roll bar is an unused (still in its wrapper) but old, and discontinued  Safety devices model No.34 which is a vertical hoop with inclined braces at the rear.  My problem is that the feet on the bottom of the legs are very flat (as are the corresponding  stiffening plates) whereas the wheel arch is very curved. I assume that I either have to bend the feet and plates which will be challenge (as well as being flat, they are also quite  meaty) or that I need a set of curved and tapered packers to go above and below the wheel arch which I suspect would be an even greater challenge.  (I'm not sure where I'd start to fabricate something like that given the curvature).

 I have contacted Safety Devices who have confirmed the bar was designed for a sidescreen TR, but they do not have any fixing instructions.  I therefore wondered if anyone had any experience of fitting such a roll bar and perhaps had a photo. 

As ever, all help gratefully received.

Cheers

Dave.

 

Edited by Dave Herrod
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Dave

Firstly I would establish that said frame will even work inside a hardtop.....

I think I would be fitting the screen, hardtop and  sidescreens, adjusting to get a perfect fit and then testing the roll bar for fit inside the HT and seat obstruction....they can restrict reward movement. If the RB fits OK then it will work inside the soft top which can be fitted to match the windscreen/ sidescreens positions found by fitting the HT.

Iain

 

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Whilst the feet on my rollover bar weren’t flat, they weren’t curved to match the wheel arch either. 

I placed the bar in the position where it  fitted best and drilled holes through the wheel arch so that I could bolt up the anchor / stiffening plates under the wheel arch as tight as I could get them. 

I then tack welded the stiffening plates into position before removing the bar and hammering the wheel arch into shape onto the plate. 

After checking that the bar still fitted and was in the right place I fillet welded the stiffening plate to the underside of the wing all round. 

Job done. 

Rgds Ian

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Hi

i think I would take Iain’s approach.

the important parts for the car is the screen - with straight stantions  
then fit the hardtop.

i had enough issues with just the hardtop !

i think in your circumstances the roll bar is the last on the list. 
 

push comes to shove the roll bar can be test fitted under a well fitting hardtop and if too tall cut the legs down and re weld the plates. 
 

the main hoop should not lean forward on the arches. 
 

H

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I'm pretty sure my roll bar came from Safety Devices (via Revington) and the best position for it was one where it sat with the anchor plates approximately aligned with the wheel arch, the front bar vertical and the rear support just in front of where the rear firewall would fit.  I don't have a hard top so that wasn't an issue but I did check that the hood frame could be erected with it in place.

My point was that once I had decided the best place for it, I didn't worry about the plates not being curved, I adjusted the wheel arch to suit.  Once the arch had been trimmed the small flat areas where the roll bar is bolted weren't an issue.

Rgds Ian

Edited by Ian Vincent
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Thanks guys...as you say the hard top/ windscreen fit is the most important thing, the roll bar can be "adapted" if necessary.

Ian's suggestion makes sense,but the thought of taking a hammer to the beautifully double curved piece of steel that a friend made and let into the wheel arch when he was working on the tub did make wince a bit!  A bit more thinking required!

Dave.

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Hi Dave

Picture attached shows a Safety Devices RB fitted to OGB by Revingtons. The feet on the RB and the reinforcing plates have been bent to fit the curvature of the wheel arch. Its not the neatest of jobs as they are pretty substantial as you say. Looks as if they might have been either bent in a vice or hammered over an anvil. The reinforcing plates aren't welded on to the inside of the wheel arch as perhaps they should be, bit late now the arches have been trimmed. If you have the opportunity I recommend you do that then drill through the feet, wheel arch and plate to make bolting on an easy job. As they are, it's a right fiddle to do the bolts up in the right order to get everything in place.

No idea what the model number of the RB is. It was fited about 20 years ago so it might be a similar vintage to yours but I can confirm that it does fit under the soft top and under an original metal hard top. The fitting of the latter is an ongoing project and having issues like Hamish

The photo was taken last summer as we did some work on the car. Since then the RB has had a harness bar welded across the rear two struts to give a better mounting point for the harnesses that were previously bolted to the floor behinf the seats. I bought a length of cold drawn tube from Safety Devices, cut and shaped it to fit round the tubes and got it professionally welded. Looks just llike the ones now being advertised!

I'm just the other side of the Forest to you. When restrictions ease, we must get together and compare notes

Phil

 

DSC_1636 Brian Aug 19 - 3 V2.jpg

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9 hours ago, Ian Vincent said:

I'm pretty sure my roll bar came from Safety Devices (via Revington) and the best position for it was one where it sat with the anchor plates approximately aligned with the wheel arch, the front bar vertical and the rear support just in front of where the rear firewall would fit.  I don't have a hard top so that wasn't an issue but I did check that the hood frame could be erected with it in place.

My point was that once I had decided the best place for it, I didn't worry about the plates not being curved, I adjusted the wheel arch to suit.  Once the arch had been carpeted the small flat areas where the roll bar is bolted weren't an issue.

Rgds Ian

Revington’s current and (for some while) RB’s are built to a Revington design. They fit very easily and have multiple options. 

Iain

Edited by iain
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9 minutes ago, iain said:

Revington’s current and (for some while) RB’s are built to a Revington design. They fit very easily and have multiple options. 

Iain

You are right Iain, it is a “Caged” bar and fitting it was straightforward but the feet aren’t curved they are thick plates that have been bent in straight lines (if that makes sense) so when you put the bar in place, they fit where they touch. 

Rgds Ian

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1 minute ago, Ian Vincent said:

You are right Iain, it is a “Caged” bar and fitting it was straightforward but the feet aren’t curved they are thick plates that have been bent in straight lines (if that makes sense) so when you put the bar in place, they fit where they touch. 

Rgds Ian

Most odd......I’ll have to check mine I don’t remember this issue. I will revert.

Iain

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My 2016 revington bar with harness bar and removable diagonal has bent rather than curved foot plates and under wheel arch plates. 
 

but once you drill the pilot and then big bolt holes It all clamps together well. Just do it as tight as you can. You can’t over do it as access won’t allow long strong arm bars. And you may need extensions. I found some of the bolts a bit difficult to get to with sockets etc around the bars .

i cut away the inner wheel arch trim so it’s metal to metal,  then took off the trim when I had to move the bar to fit the hardtop the bar was too far back.
 

once all fitted I did add some mastic sealer around the edge of the plates in the wheel arch to prevent water and crud getting in any gaps. As I haven’t welded the plates. 

 

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I am surprise at the relative weakness of the mounting area for the feet, but I suppose space is limited. I hadn`t seen a roll bar fitted before and was thinking of putting one on my 3a, my previous experience with roll bars in various rally cars had them picking up on reinforced points where possible, and I had assumed that the main hoop would have somehow mounted on the floor at the body mounting point where the load would have been shared between the inner sill and the chassis, then squeezed up between the seat and the quarter panel.

Anyway, better than no roll bar at all.

6 hours ago, PhilipB said:

 

 

DSC_1636 Brian Aug 19 - 3 V2.jpg

 

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On 4/28/2020 at 8:24 AM, Ralph Whitaker said:

I am surprise at the relative weakness of the mounting area for the feet, but I suppose space is limited. I hadn`t seen a roll bar fitted before and was thinking of putting one on my 3a, my previous experience with roll bars in various rally cars had them picking up on reinforced points where possible, and I had assumed that the main hoop would have somehow mounted on the floor at the body mounting point where the load would have been shared between the inner sill and the chassis, then squeezed up between the seat and the quarter panel.

Anyway, better than no roll bar at all.

 

.

Edited by Guest
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They may not be a thing of beauty but they are there to fulfil a function. The photo above is as brutal as it could be, no screen, no seat and in the workshop. However put a driver in the seat and put the car in an appropriate environment and it don't look too bad . .

Phil

Castle Combe #1 V2.jpg

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Hi Ralph.

I bought some years ago a Safety Devices cage for my TR2 (not fitted and not sure if I will) but the pick up points were the floor to chassis mounts and the middle of the arch. The diagonal runs full width from low behind driver to top diagonal above passenger. That way driver doesn't bash the napper going over speed bumps.

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2 hours ago, RoyM said:

boy oh boy! don't they make more discrete roll over bars these days, they all look so industrial, big and ugly, the mounting points ruin the interior trim look, they also look especially worse with aero screens fitted and seem to stick out like a sore thumb, just a personal opinion mind you.

Yeah...as PhillipB says function definitely wins out here over beauty but even a modest off at less than 20 mph where the tyres hit grass first will topple the car complete with squealing occupants. The difference is with a roll bar you get to ruefully look at the car and be glad you've got one fitted. Try this double hoop version from JimG in the US is that more to your taste ?

683911637_TR4JimG.jpg.e3f07334c11ccd109d24e4ea0c08b599.jpg  

Or a similar version being tailor made for a sidescreen car

1168549399_TR3rollbar2.jpg.000fdf6dc784c359beffdf1543f25822.jpg

This shows how you have to work to get the bar mounting onto the chassis and shell mounting points, from memory the car of Mr Andrew Uprichard (yes) in the US also.

Mick Richards 

Edited by Motorsport Mickey
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Hi Mick,

Sorry but no matter which way you look at those they are pretty (UGLY).

I like to look of the TR2 with aero screens and rollover bar.

Edited by Rodbr
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Those double hoop ones almost never include a rear strut, so are intrinsicly weak, and unacceptable for competition use.    Or road use, IMHO, as they are then just bling, however heavily built.

Ralph noted thast  the TR3a bar above was mounted on "relatively weak" panels.    That the wheel arches are doubly curved adds greatly to their strength.    Philip didn't mention, but that strength is further increased if the mounting is reinforced by a backing plate, preferably welded underneath, but bolted will do, that is wider than the foot plate.     The MSA (now Motorsport UK) Blue Book provides all the detail needed for secure installation.  See Section K: https://www.motorsportuk.org/wp-content/uploads/2019/11/1-8-Title-Page-and-Contents.pdf

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19 minutes ago, john.r.davies said:

Those double hoop ones almost never include a rear strut, so are intrinsicly weak, and unacceptable for competition use.    Or road use, IMHO, as they are then just bling, however heavily built.

Ralph noted thast  the TR3a bar above was mounted on "relatively weak" panels.    That the wheel arches are doubly curved adds greatly to their strength.    Philip didn't mention, but that strength is further increased if the mounting is reinforced by a backing plate, preferably welded underneath, but bolted will do, that is wider than the foot plate.     The MSA (now Motorsport UK) Blue Book provides all the detail needed for secure installation.  See Section K: https://www.motorsportuk.org/wp-content/uploads/2019/11/1-8-Title-Page-and-Contents.pdf

Agree about the rear strut John but these do include 2 angled struts trianglising the 2 separate hoops, just not easily seen when painted, try this different angle unpainted

516386067_TR3rollbar.jpg.5d6cf1a770729fb3d04a492e623fc10c.jpg  

admitted they would be better if angling upwards nearer to the individual radii hoops and have another couple of bars from the lower across car bar which I believe ties into the shell supporting the rear lower cross tube but as a roadcar it makes a reasonable attempt at stiffening the rear of cockpit shell whilst still tipping a hat at aesthetics. I think there are better attempts available commercially but personally I'm always keen to acknowledge somebody trying to second guess luck with a roll bar fitment. I think the thought of "I'd rather have a torso which looks like the Sontaran from Doctor Who"

 

1314680918_SontaranDrWho.thumb.jpg.8d6352762772a4c72c1ede81209d0fa1.jpgrather than fit an ugly roll bar is somewhat shortsighted.

Mick Richards 

Edited by Motorsport Mickey
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50 minutes ago, Motorsport Mickey said:

Yeah...as PhillipB says function definitely wins out here over beauty but even a modest off at less than 20 mph where the tyres hit grass first will topple the car complete with squealing occupants. The difference is with a roll bar you get to ruefully look at the car and be glad you've got one fitted. Try this double hoop version from JimG in the US is that more to your taste ?

 

7 minutes ago, Motorsport Mickey said:

Agree about the rear strut John but these do include 2 angled struts trianglising the 2 separate hoops, just not easily seen when painted, try this different angle unpainted

516386067_TR3rollbar.jpg.5d6cf1a770729fb3d04a492e623fc10c.jpg  

admitted they would be better if angling upwards nearer to the individual radii hoops and have another couple of bars from the lower across car bar which I believe ties into the shell supporting the rear lower cross tube but as a roadcar it makes a reasonable attempt at stiffening the rear of cockpit shell whilst still tipping a hat at aesthetics. I think there are better attempts available commercially but personally I'm always keen to acknowledge somebody trying to second guess luck with a roll bar fitment. I think the thought of "I'd rather have a torso which looks like the Sontaran from Doctor Who"

 

1314680918_SontaranDrWho.thumb.jpg.8d6352762772a4c72c1ede81209d0fa1.jpgrather than fit an ugly roll bar is somewhat shortsighted.

Mick Richards 

  well to be honest these roll bars make the car look like a dodgem some thing you would find on a pier or fairground and also if you need them fitted because you may turn the car over then i would suggest not driving like an idiot, as well as adding unnecessary extra weight to a light weight car therefor forcing you to fit a more powerful engine to compensate and making it go faster with the possible result in a crash, catch 22:D

Or a similar version being tailor made for a sidescreen car

1168549399_TR3rollbar2.jpg.000fdf6dc784c359beffdf1543f25822.jpg

This shows how you have to work to get the bar mounting onto the chassis and shell mounting points, from memory the car of Mr Andrew Uprichard (yes) in the US also.

Mick Richards 

2 hours ago, PhilipB said:

They may not be a thing of beauty but they are there to fulfil a function. The photo above is as brutal as it could be, no screen, no seat and in the workshop. However put a driver in the seat and put the car in an appropriate environment and it don't look too bad . .

Phil

Castle Combe #1 V2.jpg

 

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I have to agree, they are all ugly, however, faced with a choice of safety or ugliness, there is no choice.

I fitted a Revington RB for two reason

I wanted a) seat belts and b)was not prepared to be "beheaded" in a role.

In the past I felt less mortal and roads were less busy; i drove for years with no belts at all.......but only ever it the TR !?

Now I feel less immortal am more aware of the potential for others stupidity and accept the poor aesthetics for feeling slightly safer.

An RB with integrated Harness bar, with a removable diagonal made sense for road/ track use.

Revington have recently introduced a harness bar which is aesthetically great, but offers no protection in a role, however it might suit some.

Iain

 

 

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16 minutes ago, iain said:

Revington have recently introduced a harness bar which is aesthetically great, but offers no protection in a role, however it might suit some.

Iain

Iain

The advantage of the harness bar is not protection in a roll but a better placed anchorage for a harness.

Previously, my shoulder straps were anchored on to eyebolts through bolted to the floor directly behind the seats. God forbid, in a head on collision, because of the angle,  that would have allowed forward travel of me towards the non-collapsable steering column heading in the other direction towards me at a rate of knots. Any measure to keep me as far away from that as possible is a good thing.

Because the shoulder straps are near horizontal from my shoulders, this limits forward travel of me in those circumstances as far as possible

The MSA gives guidance on this, from the 2020 Blue Book

"2.1.10.The anchorage points to the rear should be positionedso that the strap from the shoulder is as near horizontal as possible. It should not be located on the floor directly behindthe driver/co-driver."

Competition or no, that's good enough for me

Phil

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7 hours ago, RoyM said:

"if you need them fitted because you may turn the car over then i would suggest not driving like an idiot"

Roy,

I've seen 3 TRs roll over and all 3 were doing less than 30mph and 2 were doing less than 20 mph! how much slower do you need drivers to go to not to meet your definition of "driving like an idiot".

All these cars were racing and had suffered a spin and then the cars traversed across the track at very low speed under 20 or 30 mph onto the grass the wheels tucked under when it hit the green stuff and a ton of car oh so slowly went up and over (twice on one car). Apart from the initial cause being racing and losing it, the actual speed involved in the rollover was low (under 20mph with two of the cars) something similar to yourself driving down the road and a driver enters from a sideroad without looking causing you to swerve onto a grass verge...that's all it takes. Inertia and soft surface works really well at tripping up cars.

If you don't fancy a roll bar because you can't stand the intrusion into the "classic lines" of the car that's fine, your car your choice. 

Mick Richards

Edited by Motorsport Mickey
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Whilst I understand these safety roll bars may detract from the original aesthetics it’s unfair to suggest that those with them drive like idiots !

whilst driving our old cars I suggest the threat is from the other road users. 
 

Have a look at this video and  assess the worth of a roll bar if this classic triumph had gone all the way over. A roll bar may have given added protection to side impact regardless.
 

 

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