Millie antiroll bar

[cabrioman]

Re: Millie antiroll bar

Take a look at this Paul

https://www.rhocar.org/index.php?/forums/topic/32640-compression-struts-tie-bar-installation-help/&do=findComment&comment=246683

Could this be the solution, using a cut arb to create a compression strut that retains the rubber bush on the TCA but provides castor adjustment. I think I would have preferred to put a male thread on the Arb that took a female collar and rod end like the compbrake struts you had fitted.

Maybe it could solve the chassis stress issues seen on the Cabrios, the curve in the strut would reduce the transfer forces into the chassis aided by retaining the original oem bush on the TCA.

The orientation of the Cabrio arb mount would be even better as the rose joint would be in the vertical plane as opposed to horizontal as on the example shown in the link.

[milliemarlin]

Re: Millie antiroll bar

Take a look at this Paul

https://www.rhocar.org/index.php?/forums/topic/32640-compression-struts-tie-bar-installation-help/&do=findComment&comment=246683

Could this be the solution, using a cut arb to create a compression strut that retains the rubber bush on the TCA but provides castor adjustment. I think I would have preferred to put a male thread on the Arb that took a female collar and rod end like the compbrake struts you had fitted.

Maybe it could solve the chassis stress issues seen on the Cabrios, the curve in the strut would reduce the transfer forces into the chassis aided by retaining the original oem bush on the TCA.

The orientation of the Cabrio arb mount would be even better as the rose joint would be in the vertical plane as opposed to horizontal as on the example shown in the link.

Thanks again John,
It’s very interesting to see how others have tackled this problem.

I had not realised the ARBs are hardened I find that surprising. You would expect them to be tough not hard.

I have considered cutting my ARB in a similar way turning the cut off end down and adding an external 22m thread to match that of the compression strut, as you suggest. That would allow the use of Ford bushes at the TCA end and rose joint at the chassis end and would include the compression strut adjustment. I decided against it because removing the bar between the two sides is possibly part of the original problem. I also felt the contoured compression strut would twist in the rubber bush and not keep the rose joint in the mid position which could make it rattle and possibly wear. Finally I think the rubber ARB bushes will dissipate the energy in a better way than the hard rose joint.

You are right to say this is a potential in this fix but I think I am reconciled to having an ARB.
Paul

[cabrioman]

Re: Millie antiroll bar

Yep I may take a look at reverting to an ARB, but to be honest I tend to feel the problem is probably more related to the positioning of the ARB mount on the Cabrio chassis. Its design potentially allows the mount to pivot around the chassis leg, as the inner corner is sort of floating inside the chassis line.

I think the work you have already done to beef up the chassis will have already resolved any further problems regardless of whether you go with an ARB, split ARB or Compression Struts.

There are probably hundreds of Sierras and Escorts out there using struts given the number of companies manufacturing strut kits and Ford themselves fitted struts to the Sierra on the Cosworth WRC cars, so I am sure it is all about the strength or lack of in the chassis and brackets.

I wait with interest to see what you end up with, I agree an ARB with adjustable Caster would be great, even if the adjustment was by spacers on the end shoulders.

[milliemarlin]

Re: Millie antiroll bar

If it involves, preferably using only two pieces of string, a plank of wood and a school rule, can you please explain how I can measure camber, at home in the garage?

Advice much appreciated, Colin B.

Pretty basic. As I can’t change it I just look at it and think why one side is positive and one side is negative. You could mark it up with calibrations. Note that camber changes as you steer.

Img_8707s.jpgImg_8709s.jpg


My castor gauge is a little better.
Img_8697s.jpgImg_8698s.jpg

Paul

[milliemarlin]

Re: Millie antiroll bar

I refitted the compression struts and set the castor to 3°. I did a little local circuit that tested a range of conditions. I then turned the adjuster through one whole turn which makes is about 1.5° change to the castor angle. Repeating this process for 3, 4.5, 6, 7.5 degrees. I checked the toe in after each change adjusting as required.

First some general observations about the difference between the ARB and Compression Strut (CS): Over rough surfaces, like a cattle grid, the CS transmits every vibration. Over undulating surfaces where only one wheel is going over a bump the CS scores absorbing more of the bump. I can see no discernible difference in roll. The Cabrio has very little roll.

Over a range of road conditions, smooth tarmac, heavily patched, patched and undulating roads there was very little change between castor angles the on driving experiences. A rough road is just as rough at 3° as it is at 7.5°. No jumps were made.

3°: I was quite surprised that this had quite a good feel. Very light. The self centring was still there. The steering has a progressive feel to it where there resistance is almost nonexistent straight ahead but increases as the steering wheel is turned. Even with this little castor the self centring is strong on full lock. When the steering wheel is about 30° either side of centre the wheel will not centre itself. At high speed (60mph) there is a weak feel of the straight ahead position. On one fairly sharp reasonably fast corner I felt some evidence of oversteer. I felt that in the wet this could become a problem. I can see that a rally driver, who is totally focused on the drive ahead, would be comfortable with this angle.

4.5°: The feel at this angle was close to that at 3° except the feedback was slightly stronger. This suited a relaxed style of driving imparting a confidence and solidity to the drive. I would be quite happy driving the car with this set up.

6°: This gave an even stronger more solid feel to the drive. It was close to the feel of my power assisted faux by four. The steering still did not self centre close to straight ahead but there was a definite sense when off centre. The difference between this and 4.5 was simply a greater feeling of solidity.

7.5°: This too was a perfectly reasonable drive but the steering felt heavier without really improving the overall feel. I would still be happy driving this car.

I had planned to make additional tests to try to pinpoint the exact point at which the drive is sweetest. If I was on a racing circuit consistently driving the same route close to the ragged edge I might be able to detect small changes. On my highway based test route so many other variables are present that it would be a waste of time.

The drive at any point from 4.5 to 7.5 is excellent; one heck of a lot better than the drive at 12°. I lived with odd castor angles of about 17° one side and 8° the other that I certainly will be very happy with 6°. The unmodified CS was holding the wheels at 8° and I was more than happy with that.

All of which is a very long winded way of getting to the conclusion that 6° is my target castor.

I should have just copied Mike.
Paul

[greyV8pete]

Re: Millie antiroll bar

Interesting data Paul to add to the knowledge base. I had a good run over Exmoor yesterday in brilliant sunshine and am very happy with my new found 6degrees castor, so agreement there.

For completeness of the record what wheels are you using? Rim size (Diameter, width and offset) and tyre size and make of tyre, as all these have a significant bearing on handling. Peter.

[milliemarlin]

Re: Millie antiroll bar

... For completeness of the record what wheels are you using? Rim size (Diameter, width and offset) and tyre size and make of tyre, as all these have a significant bearing on handling. Peter.

Wheels: Excite RO2: 15” Dia width 6.5” 35mm offset
Tyres: Runway – Enduro-656: 195/65 R 15 91V
Inflated 24psi

[milliemarlin]

Re: Millie antiroll bar

Yep I may take a look at reverting to an ARB, but to be honest I tend to feel the problem is probably more related to the positioning of the ARB mount on the Cabrio chassis. Its design potentially allows the mount to pivot around the chassis leg, as the inner corner is sort of floating inside the chassis line.

Although the compression strut scores on undulating ground it’s not so good on ruts. Given the same castor angle I’m inclining to the ARB being a better option for road use. Racing drivers and rally drivers being made of sterner stuff.

I think the work you have already done to beef up the chassis will have already resolved any further problems regardless of whether you go with an ARB, split ARB or Compression Struts.

Let’s hope so!

There are probably hundreds of Sierras and Escorts out there using struts given the number of companies manufacturing strut kits and Ford themselves fitted struts to the Sierra on the Cosworth WRC cars, so I am sure it is all about the strength or lack of in the chassis and brackets.

To be fair, the Sierra chassis does a better job of supporting the ARB or strut by mounting it on an angled face. Not really a practical option with the Marlin design. Also the struts were really designed for competition use where the suspension would be inspected after every race. I was also going to say a track is smooth but then the Cosworths were rallied too.

I wait with interest to see what you end up with, I agree an ARB with adjustable Caster would be great, even if the adjustment was by spacers on the end shoulders.

On a road car I can’t see much need for adjustment. Although there was a discernible difference it was not as significant as the road conditions. On the rally spec sheets the type of course made a difference but a road car has to be a jack of all surfaces.

I’ve set up the struts to be accurately set at 6°. I’ve had a couple of beautifully sunny days and covered a few miles, enjoying routine driving. After a bit of experimenting, with apologies to local traffic, I have found self centring to be better than I had first thought. Even at speeds as low as 20mph she will return to a straight line. Low speed manoeuvring can seem a bit hard.

Yesterday it was raining and I reverted to the faux by four. Its electric power steering was; I would have to say, every bit as good in a straight line. In fact I would only rate it better at low speed steering extremes.
Paul

[milliemarlin]

Re: Millie antiroll bar

Well I have “machined down the old ARB from the Estate and fitted it to the car. My cunning plan to use a v-belt take off from the back of my small lathe failed miserably because an intermediate belt kept slipping. Resorting to turning it by hand it took the best part of an afternoon to modify the ARB. The longer estate car ARB required about 20mm removing on one side. The other side, being bent, only required 7mm. Partly because I forgot to allow for the nearside mounting difference and partly due to difficulties measuring accurately I ended up with a n/s castor of 5.5° and o/s of 7°.

Tool.jpg

The tool

n-s.jpgo-s.jpg

The “turned” ARB

n-s spacer.jpg

The n/s required a substantial spacer to avoid the nut becoming thread bound.

Good weather has allowed me to clock up a few miles and she is a pleasure to drive. The rubber mounted ARB does absorb shocks better than the struts. There is a discernible harshness to the ride over rough ground but not enough to bother me. I ought to find some quite road and check how it deals with squealing tyres but I can’t see that happening anytime soon.

Using corrected measurements I have machined down the Sapphire ARB. I removed 14.5 and 11 from the o/s and n/s respectively. Measuring as previously described the lengths of the o/s arm is 305.5mm and the n/s 309mm.
It will be a while before I can fit the Sapphire ARB. I’m not in any hurry because I don’t think I will be able to discern a difference.

I thought this thread would be two posts long it’s turned into quite an epic. To think this all started with a perished steering rack boot. In hindsight I wish I had made these changes years ago but not by such a tortuous route.

My thanks, to everyone who contributed; especially those that crawled under their cars to take measurements, photos and the like.
Paul

[cabrioman]

Re: Millie antiroll bar

Glad to see you got it sorted out Paul.

I have dropped you a PM on a related matter.

John

[ggrum]

Re: Millie antiroll bar

Well done Paul. Worth all the work in the end.

[danny_nelson]

Re: Millie antiroll bar

Hi Paul, Another Cabrio found with the same condition. This car was for sale on Car and classic and when I contacted the owner he had no idea that anything was not correct. What he had heard was a scraping/ grinding sound coming from the NS. however nothing was found on a recent MOT test (the torn metal was under the powder coat ) and could only be found when I told the gentleman how to test . He was horrified at what he found and immediately removed the car from sale. This man is a classic car fan and has sent me photos of a heavy duty repair that has since been carried out. To my knowledge there are at least two more cars fitted with these struts one of them being the ex Lee Hunter car.

[danny_nelson]

Re: Millie antiroll bar

The ex Simon Gregory Cabrio is advertised for sale on this website (which was the first car I found with the ARB mounts ripped out of the chassis.) Any prospective buyer should contact me to discuss the (repair) Danny 07976 836 374. thankyou.

[danny_nelson]

Re: Millie antiroll bar

I should have stated in the above post that we have now found five Cabrio cars fitted wiith these compression struts with this serious damage, and Dave Clutterbucks car with the same damage but with the ARB fitted. Danny.

[milliemarlin]

Re: Millie antiroll bar

Danny, thanks for the update. I believe that the MOC has saved lives with information. Just one more, very important, reason to be a member. I can’t thank you enough for drawing my attention to it.

Even with an ARB fitted I will be checking this area regularly. I strongly recommend everyone else does too. The MOT is a good thing but it’s never going to check vehicle specific problems.
Paul