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Richard Treacy
Grand Master
Username: richard_treacy

Post Number: 2098
Registered: 4-2003
Posted on Tuesday, 30 March, 2010 - 16:40:   Edit PostDelete PostView Post/Check IP

I am considering having a batch of antiroll bars made up in 30, 32 and 34mm if SY and SZ owners are interested. I already have a source for the solid-type ball joint antiroll bar links as shown in the picture below. The type I have had made may be set to suit handed or parallel use, eliminating the need to but two or three different types.

Background

If you have ever wondered why your Silver Shadow or Rolls-Royce SZ leans a little too much in corners, and wallows and corkscrews over twists in the road camber, just have a look at its front antiroll bar. It is too small for the job, a compromise to suit certain markets. Road testers always complained bitterly of the suspension behaviour when the cars were released.

Below is a picture two antiroll bars for comparison: the skinny standard type and a 32mm Turbo R type. The skinny one is of all SYs and SZ Rolls-Royce cars, and to Bentleys until SZ Chassis 13833. That bar is part number UR15403, a 24.5mm bar. Turbo Rs and later Bentleys have the UR27110 32mm bar, except for the Continental T Mulliner which has the UR96450 34mm bar.

Incidentally, the stiff coils on an Australian car leave them skittish at the rear despite Crewe having deleted the rear antiroll bar as part of the AUS package. If you have ever inadvertently done a 180° on a wet road in your AUS SY you will know what I mean. Those cars are crying out for increased front suspension antiroll.

Many cars have already been upgraded, and some have the Harvey-Bailey kits of course. The improvement is astonishing. Cornering is almost roll-free and the ride is far more pleasant. Gone is that sickening lurch into corners, and the vehicle feels far more relaxed to travel in at all times. If I drive our upgraded SBH13247 then another SY, the difference is very marked indeed. I do not think that the ride is any harsher, rather simply more comfortable.

The heart of the Harvey-Bailey kits to fit revised coil springs and antiroll bars. Those kits are mainly centred upon Export-specification SY coils as fitted to Australian-specification cars from new, and an uprated antiroll bar up front. New dampers (shock absorbers) complete the kit, but those are standard-fare Bilsteins or Boges as designed for the cars.

To complete the upgrade, not usually part of the H-B kits or others, solid ball joint linkages between the antiroll bars and the suspension control arms are fitted. These are standard on Turbo R and late Bentley cars. For SYs and early SZs (until chassis 2550), the unhanded linkage from the rear antiroll bar of a Turbo R are best fitted to the front replacing the rubber-injected originals. For later cars, the handed Turbo R linkages are preferred. These linkages all bolt straight on to replace the squishy rubber-injected ones.

Turbo R cars all have the solid-type links, and they are handed: the links are attached at 90°, whereas the SY and early SZ cars have parallel attachments. See the picture below.

My message: there is a relatively inexpensive upgrade to achieve almost all that the expensive conversions offer.

As Australian-spec SY cars have no rear antiroll bar, a 30mm front bar and solid links make a good compromise, although I am very happy with the 32mm bar on ours. For UK-spec cars, a 32mm bar is ideal along with the linkages front and rear. Even then, a UK car ends up softer than an Australian car despite the UK’s antiroll bar. For my Turbo R, I may opt for a 34mm bar shortly.

Bar thickness...........Roll Stiffness Increase..........Recommended for
24.5mm...........................Normal...................Standard uneasy ride
30mm..............................50% stiffer.............All SY and SY cars, Medium: ideal for Australian-spec SY cars (no rear antiroll bar, stiff coils). May be preferred by Rolls-Royce owners for softness.
32mm.............................70% stiffer..............All SY and SZ cars, sporty on Australian-spec cars
34mm..............................96% stiffer.............sporty for Bentley, especially Turbos


Also required: four solid ball joint antiroll links, except on AUS-spec SYs (two). Note that these links increase the stiffness a little over the figures quoted above.

SY-SZ standard bar compared to a Turbo R bar


Standard Turbo R ball joint antiroll linkage - note that it has a 90° offset. Left and right hand units differ as they skew in opposite directions (UR27358,9).


Brand-newly-made ball joint antiroll bar linkage on T-Series SBH13247. These may be set locked to parallel as shown (functionally identical to UR27357 standard Turbo R rear antiroll bar link, replacing original UR13778 rubber unit), or to +/-90° (functionally identical to standard Turbo R UR27358 or UR27359) for SZ cars from chassis 2550.
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Omar M. Shams
Prolific User
Username: omar

Post Number: 125
Registered: 4-2009
Posted on Wednesday, 31 March, 2010 - 02:14:   Edit PostDelete PostView Post/Check IP

If I lived in Oz i would opt for the upgrade for my Wraith IIs...........
Incidentally, how much do you think they will cost?
Thanks
Omar
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Richard Treacy
Grand Master
Username: richard_treacy

Post Number: 2099
Registered: 4-2003
Posted on Wednesday, 31 March, 2010 - 07:18:   Edit PostDelete PostView Post/Check IP

Omar,

The links are about A$150 each ready to bolt on, and an antiroll bar probably $250, all including GST Value Added Tax. I bought the last 32mm bar new for less than $200 to pattern as a guide. When I arrive back in Oz in two weeks, I'll price them all up. We have no problem having leaf springs, coil springs and antiroll bars made to pattern in Oz.

Also, almost all of the rubber antiroll bar links I have seen are at least partially shot after a few years. They look and seem OK until they are tested on the bench. That explains the slightly wiggly ride of most cars. Just fitting the upgraded links alone makes a marked improvement.

For those concerned about ball joints and bush stresses, I must point out that all SYs and SZs share the same ball joints, and that includes Continental T Mulliners. The other bushes are the same dimensions from 1972 onwards with compliant suspension, are interchangeable, and all are supplied with the slightly stiffer Turbo R bushes by Crewe as replacements these days. In any case, the suspensions are exceptionally strong and long-lived, but simply let down by the standard antiroll settings and tuning. Due to improved tyres over the years, I certainly find that the pre-compliant SYs win hands down on front suspension.

You may well think of an upgrade where you live. It transforms the cars in the city on roundabouts especially in Canberra, and tight city corners are so much more negotiable. On the highway, you wonder why Crewe took until 1985 to wake up, even though that was only for the Bentleys until the Silver Seraph came along.

As to wheel alignment, the standard SY/SZ specs are:

Front wheel toe-in 0° 12’ +/- 5’ (this equates to a half toe-in of 0.10” +/-0.04”; 2.5mm +/-1mm – double the numbers to measure the difference tyre centre to tyre centre, called the total toe-in)
Camber Angle 0° 30’ Negative +/- 15’
Caster Angle 3° 0’ +/- 30’

This is acceptable, but does not take into account road cambers and turn directions. It is also not ideal for tyre wear, especially on the edges, nor for steering response. The cars respond particularly well to increased negative camber. In practice over the years, we have found that the settings are better set on all SY and SZ cars, regardless of steel-belted radial tyre type and roll stiffness tuning, to:

Front wheel toe-in half toe-in of 2.9mm +/-1mm, or a total toe-in of 5.8mm +/- 2mm
Camber Angle - Drive on Left cars (UK, Australia, Japan, Hong Kong etc):
1° 30’ Negative +/- 15’ left hand side
1° 0’ Negative +/- 15’ right hand side

Camber Angle - Drive on Right cars (USA, Continental Europe etc):
1° 0’ Negative +/- 15’ left hand side
1° 30’ Negative +/- 15’ right hand side


Caster Angle 2°20’ +/- 30’

Rear Wheel Alignment:
Toe-in 5’ +/- 2’ (Total toe-in 2.6mm +/- 1mm)
Camber -30’ +/- 15’
Thrust angle 0.00° +/- 10’
Set back 0.00° +/- 10’

RT.
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Kevin Lagden
Experienced User
Username: kevin

Post Number: 23
Registered: 7-2009
Posted on Wednesday, 31 March, 2010 - 08:56:   Edit PostDelete PostView Post/Check IP

I too would be interested for my 75 Shadow SRH 19305 as I will be having some mods done in the near future, so would appreciate costs at some stage

Kevin
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Richard Treacy
Grand Master
Username: richard_treacy

Post Number: 2107
Registered: 4-2003
Posted on Wednesday, 31 March, 2010 - 09:21:   Edit PostDelete PostView Post/Check IP

Sure, Kevin, I'll let you know mid-end April.

To convince yourself, I do recommend that you badger a drive in an uprated car !

I had our T-Series nearby you in Beecroft and Dural two weeks ago. If I drive it to Sydney again soon I'll give you a demo.

RT.
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James Feller
Prolific User
Username: james_feller

Post Number: 138
Registered: 5-2008
Posted on Wednesday, 31 March, 2010 - 11:25:   Edit PostDelete PostView Post/Check IP

RT,

I too would be interested to see the $$ for my SZ 86 Spirit. While its fairly good re handling its nowhere near as firm and secure as my Turbo.
Let me know if you are seeing Kevin, I live very close to Beecroft, and I wouldn't mind, if its ok with you blokes, coming along too.

Cheers

J
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Richard Treacy
Grand Master
Username: richard_treacy

Post Number: 2146
Registered: 4-2003
Posted on Sunday, 20 June, 2010 - 18:49:   Edit PostDelete PostView Post/Check IP

I shall be in Sydney with the T this week. There is a story to write on why the mainshaft of the Turbo R's new transmission snapped after 2'000km.

Anyhow, if there is interst, I may come by for a demo.

RT.
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Kevin Lagden
Experienced User
Username: kevin

Post Number: 26
Registered: 7-2009
Posted on Tuesday, 22 June, 2010 - 09:45:   Edit PostDelete PostView Post/Check IP

Richard

Unfortunately I am in Noosa until next week, perhaps another time.

Thanks
Kevin
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DWoodworth
Unregistered guest
Posted From: 75.80.96.196
Posted on Thursday, 10 February, 2022 - 09:01:   Edit PostDelete PostView Post/Check IP

I apologize for resurrecting such an old thread. I am in the process of collecting parts for the setup Richard Treacy has outlined here. They are getting hard to find, and the only solid links (UR27357) I can find are used. These joints have approximately 10mm of travel/play in all directions with little to no resistance. Is that how they would have been new? Just want to make sure there isn't anything worn out in the ball joint that will cause handling issues.

BTW I'm a member of the RROC in USA. I'm not registered here as the website won't accept my email address.

(Message approved by david_gore)
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DWoodworth
Unregistered guest
Posted From: 75.80.96.196
Posted on Thursday, 17 February, 2022 - 17:49:   Edit PostDelete PostView Post/Check IP

Not sure if/when anyone will see my posts in this ancient thread in the miscellaneous section.

I found a NOS tie rod UR27357 and it had the same range of motion/travel and resistance. So the used ones I bought should be fine.

For anyone looking for a similar tie rod, the few suppliers I could find who have them are charging $300+ USD each now.

I found a supplier in the USA, who are making what appears to be a replacement part to similar specs for $180 each. They have both the handed ones and the inline version.

https://shop.rareparts.com/search?year=1991&make=BENTLEY&model=TURBO-R

I think I am going to order a set and try them on my rear anti roll bar to see if they indeed a correct fit.

(Message approved by david_gore)
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DWoodworth
Unregistered guest
Posted From: 75.80.96.196
Posted on Friday, 18 February, 2022 - 10:33:   Edit PostDelete PostView Post/Check IP



Duplicate post deleted by Moderator.



(Message approved by david_gore)
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Alan Dibley
Frequent User
Username: alsdibley

Post Number: 344
Registered: 10-2009
Posted on Friday, 18 February, 2022 - 20:03:   Edit PostDelete PostView Post/Check IP

Yes your post has been seen. It has reawakened my interest in a new, thicker anti-roll bar for my '71 car. Thanks.
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DWoodworth
Unregistered guest
Posted From: 75.80.96.196
Posted on Saturday, 19 February, 2022 - 18:16:   Edit PostDelete PostView Post/Check IP

I can't seem to sign up here with an account as my email addresses don't qualify (gmail and hotmail). So I also can't send a PM.

Moderator comment: I have referred your problem to our Administrator for attention.

Alan, not sure where you are located, but you might try contacting Richard Treacy on this board via PM and alerting him to this thread being resurrected. For those of us doing this modification, it would be good to know if he still has reproduction anti roll bars and/or the tie rods he mentioned in this thread years ago still available. Those parts are getting very hard to find, and expensive if one does find them. I will post back here with my experience with the reproduction tie rods once I have them installed.

Richard can be contacted direct using the following link:

https://www.spurparts.com.au/

(Message approved by david_gore)
}
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Dwoodworth
Unregistered guest
Posted From: 75.80.96.196
Posted on Monday, 21 February, 2022 - 18:08:   Edit PostDelete PostView Post/Check IP

David, thank you for passing that along to the administrator, and for contact info for Richard.

I have a question for anyone who has used the solid ball joint tie rods in place of the stock (for RR at least) rubber bushing type. I am wondering if they are noticeably noisier or have any other downside as compared to the rubber ones. I suppose I will find out as soon as I get them installed on my Shadow.

(Message approved by david_gore)
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Dandridge Woodworth
Yet to post message
Username: palladio

Post Number: 1
Registered: 02-2022
Posted on Saturday, 12 March, 2022 - 18:45:   Edit PostDelete PostView Post/Check IP

I tried contacting Richard at the business link posted, but didn't hear back.

Still finishing up some other work on my Shadow, but hope to have it back on the road in a week or so. I will install the 32mm front anti-roll bar. At the advice of my mechanic, I am now thinking about using new/OEM original spec rubber joint end links in front, and the solid ball joint end links in the rear.

Other than what Richard mentioned in this thread, I don't know anyone who has used the ball joint links. I wonder if they may introduce some unwanted noise or vibration into the super smooth steering feel and isolation of the stock Shadow setup.

Today I had a new OEM rubber type end link in a vice and there is barely any motion in the joint, even when using a box wrench to try to move it.

I want to decrease the body roll, but otherwise I'm not looking for a "sportier" feel on my Shadow. The wafting and the isolation from the road is part of the charm of the car for me. If I want to feel the road, I have an old 911 that communicates every imperfection.
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Jim Walters
Frequent User
Username: jim_walters

Post Number: 359
Registered: 01-2014
Posted on Monday, 14 March, 2022 - 04:14:   Edit PostDelete PostView Post/Check IP

The suspension is already riding on several other ball joints, so I doubt very much you would feel any difference between the rubber links and the ball joints that replace them.

SRH8505 SRC18015 SRE22493 NAC-05370
www.bristolmotors.com
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Dandridge Woodworth
New User
Username: palladio

Post Number: 2
Registered: 02-2022
Posted on Monday, 14 March, 2022 - 16:59:   Edit PostDelete PostView Post/Check IP

Jim, thank you for explaining that.

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