anti roll bar

[freeman41]

Hi all, New to the forum. My father in law has started to build his sammio spyder and getting on very well with the build. He was wondering, has any one put an anti roll bar to the rear of the car. The converted car for the build is a triumph vitess 2.0l.

Thanks

[The 1958 Rocker]

High freeman41,
welcome to the not a kit car club forum. Don't hang around your father in law for too long, or you will become infected too. There have been some discussions regarding rear roll bars, but I have forgotten which threads they were in. Sorry, but that's what Sammio ownership does Ha ha. Someone will soon let you know what you need to know for sure. In the mean time welcome aboard. Where abouts are you located by the way?

Regards
The 1958 Rocker (Simon)

[freeman41]

Thanks, for that. Where in Leeds. I'm getting quite involved already. I do alot of the internet stuff and the lifting and lugging. He did build me a kitcar 4 years ago. It just for him this time.

Dave

[Mister Towed]

Welcome aboard Freeman41, don't forget to post some progress pictures of your dad's Spyder.

As for the rear anti roll bar question, light weight and a very low centre of gravity mean rear roll isn't an issue in these cars. Phil J swears by a heavy duty front anti roll bar though, which he says really improves front end grip. Mind you, his first Sammio started its life as a courier van which had a front anti roll bar the thickness of a bootlace. I'm going to run mine with its standard Vitesse suspension (albeit dramatically lowered and fitted with new dampers, polybushes, etc) for the time being and see how it fairs on the road. I can always retro fit alternatives later in its life. Good luck and I'm looking forward to seeing another build progressing.

[oxford1360]

Hi Freeman41,

I looked into this a fair bit - there is a lot of info on the Triumph forums. I have not followed-up on roto-flex so the text below is only relevant to Heralds and MkI and 2.0l Vitesses.

Consensus seems to be -
Fitting a rear antil roll bar on the conventional Herald spring can help a little, but you will almost certainly have to make something yourself.

Beefing up the front a/r (Spitfire MkIV or later) is the move of choice (you will need to widen the holes at the mounting point) but some people seem to think that this should be done only when fitting a swing spring from a similar car (this is an easy swap).

As Mr T says, going lower by at least an inch front and back will also help handling a lot.

Canley provide swing spring kits (link below) but you can buy the bits yourself for about a quarter of the cost.
http://www.canleyclassics.com/?
xhtml=xhtml/product/swingspring.html&xsl=product.xsl

The link below is a useful site to start with as it introduces the "camber compensator" which are not easy to come by -
http://herald-tips-tricks.wikidot.co...and-tuck-under

As always there is a fair amount of contradictory chat out there. The link below has contributions from those that have tried rear a/r and camber compensators and most could feel very little difference with an a/r (and not much with a CC).

http://club.triumph.org.uk/cgi-bin/f...?m-1179261525/

One interesting suggestion is to increase the rigidity of your chassis. Get that welder out!

Oh, and make sure that all your bushes are in sound condition. That's sound advice for any man.

Good luck.

[davecymru]

Wotcha matey, good to hear there is another Vitesse build under way

I can confirm that quite a few of us have gone down the route of:
Swing Spring conversion, 1" rear lowering block, stiffer front anti-roll bar, lowered front spring.
And with that set-up on mine i have no issues whatsoever

For all the faff fabricating and locating a rear anti-roll bar would entail, I'd say do all of the std upgrades first and then see how it handles, and i suspect that he'll more more than happy.

Dave

[MoriniMan]

All other things being equal an anti-roll bar reduces the grip on the end to which it is fitted. They transfer weight from the inside wheel to the outside wheel and although a tyre produces more grip with more weight it's non linear, so you're losing grip on the inside wheel faster than you're gaining it on the outside. They do of course reduce roll and if excessive roll is lifting the tyre tread off the road due to camber change in the suspension, then the anti-roll bar may well indeed increase grip (or in fact stop if from falling so much). The wider and lower profile the tyre the more likely this trade-off is.

The reason for the very thick anti-roll bar on swing-spring equiped Triumphs is becuase the whole point of the swing-spring is to reduce to roll resistance at the rear end, so you need to control it at the front. A more common approch in the USA is to fit a camber compensator, or Z bar. They may at a glance look similar, but while an anti-roll bar tries to make both wheels rise and fall together a camber compensator does just the oposite.

My Moss Monaco (Herald based) had a re-tempered and as I recall 'de-leafed' rear spring because it certainly didn't have a lowering block and the rear camber was pretty much neutral at static ride height. I fitted some quite soft front springs (might have been less than 100lb/in) and it never had a front anti-roll bar.

With the Triumph-Standard 145/13 remoulds it never had much grip, but the handling was fantastic. You could four wheel drift it in the dry and the steering wheel was nearly an optional control in the wet. A friend who regularly drove it nearly crashed the Moss cars demonstrator (equipped with 185/70-13s and a 1" front anti-roll bar) because it understeered so badly.

My Moss Roadster with a 120bhp Ford 1700 X-flow on MKII Vitesse (rotoflex) suspension and 165/70-13 tyres (actually all it really needed) didn't run an anti-roll bar either. It too was softly sprung and both cars had the engines further back than the Sammio, but I'll try running without the front bar and then think about fitting one only if necssary. The Mazda V6 is lighter than the Triumph 4 pot, but things are obviously different if you're using the Triumph 6 pot. If I were using it, I'd consider doing the suspension tower swap and moving it back. Thinking back to the Moss Monaco, I didn't have to touch the chassis rails, You just unbolted the gearbox mount from it's recesses and mounted it on top of the rails further back. A taller transmission tunnel wasn't a problem.

[oxford1360]

Did you make up a new propshaft or is there an existing Triumph shaft that is shorter by the width of the suspension tower? I have a few different ones knocking about and I think it would be a good move to shift the lump back even though it is only a 4 pot.

[MoriniMan]

Originally Posted by oxford1360

Did you make up a new propshaft or is there an existing Triumph shaft that is shorter by the width of the suspension tower? I have a few different ones knocking about and I think it would be a good move to shift the lump back even though it is only a 4 pot.

I'm not sure, I probably had one made since Reco-prop are local. You might find that an overdrive or Spitfire/GT6 shaft would do the job. You could always space the mounts a little to suit the prop.

[freeman41]

Thanks Guys for all the info and advice, I will past in on to my father in law and I will put up some picks soon.
Cheers
Dave