Anti-roll bars: choosing uprated, adjustable and rear bars

The short version

• Owners who fitted a stiffer front bar on a car with good dampers and a proper geometry setup were mostly pleased: less roll, a tighter front end and, in one 2017 report, less understeer on track.
• The earliest report here (2009, in the fitting guide) was the opposite: more understeer after fitting. Several owners said that for a while a stiffer bar gives extra understeer until the rest of the set-up catches up.
• Get the geometry and ride height right first. Two owners said that fixed their understeer, not a bar.
• Most owners with an adjustable bar never adjust it, and treat it as a stiffer fixed bar set in the middle hole.
• A rear bar is a separate, argued question. See below.

What owners fitted

Where to set an adjustable bar

• Middle hole to start. Several owners said the middle hole of the Elise Parts bar is a good starting point, and that it is still stiffer than the original there. One ran his one hole stiffer than the middle.
• One owner had the Plans bar on its stiffest setting, which seemed fine on one tyre and set-up, and moved it down one hole with a change to R-compound tyres and said it was then fine. Another ran a 1 inch bar on the stiffest setting, with fairly stiff springs, and said the softest setting felt wrong. A third chose medium to go with medium Nitron Street dampers.
• It isn't very adjustable. Changing the hole means undoing the drop links and applying a good deal of tension to the bar, so it is best done at home, not at the track. An owner said he never adjusted his, and another said most people he knew who had fitted one never did.
• The 2009 fitting report said that bar set to hole three of five gave more understeer on a first dry drive, with the owner planning to try other tyres and settings. See the fitting guide.

Understeer, springs and geometry

• Do the geometry first. In 2007 an owner with a standard NA that was hard to turn into tight corners asked about a lighter front bar. The replies said to get the geometry done first: one said that after fitting dampers it made no difference until the ride height and geometry were set a week later, and then the car "darts" round tight corners and roundabouts. They put the cost at about £80. See Wheel alignment.
• An easy test. To see what the front bar does, one owner suggested disconnecting the drop link on one side and driving, which takes about half an hour. The suggestion was to try it and report back.
• Another variable. One owner said the adjustable bar is one more thing in the understeer/oversteer balance, and that was what had put him off. Another said that most owners who fit one get extra understeer for a while, until they sort the set-up, and might lose a summer of track days over it.
• Stiff bar, soft spring? One owner who tried five front spring rates and three bar settings said that every time he lowered the front spring rate his understeer dropped. He went as low as 225 lb, then back to 275 lb to stop the front bottoming out, and has 450 lb at the rear. Another owner repeated the rule "stiff bar means soft spring", and another said that fitting softer springs would undo the benefit of the stiffer bar and not control pitch. The same owner who said the bar made his turn-in better added that this is because of the extra front roll stiffness. See Shock absorber choice.
• Tyres and wheels. An owner pointed to the standard 175 front and 225 rear tyres, saying you can't run them without understeer, and that changing to a 340R-style geometry and adjusting the dampers would help.

Does it need a rear bar?

The Elise and VX220 have no rear bar from the factory, and several threads (2012 and 2017) asked why.

• Against. One owner who had tried them said they make the car snappy, meaning the back end lets go with little warning, and that it is better without. Another said reducing rear compliance leads to faster breakaway, and that some compliance is needed for progressiveness. Several owners said the race VX220s and Elises cope without one. A 2012 owner said the Lotus subframe has a hole in it to route the exhaust, which he said is why it is as flexible as it is, and that for road use it is fine.
• For. Another owner found a fixed rear bar progressive, not snappy. A 2017 owner combined a 1 inch front bar with a Cornering Force rear bar and called the balance lovely. A suspension supplier's view, quoted in both threads, was that front and rear bars can make a large improvement if they are blended with everything else and set up by someone who knows what they are doing, and that a rear bar is for fine tuning a near-perfect set-up. Fitting a stiffer front bar and a rear bar and nothing else is more likely to throw the car out of balance, even though the flatter cornering feels good.
• The Cornering Force approach is a rear bar plus a new front bar and dedicated spring and damper settings, so the balance is kept. The owner who runs it said it also lets him use softer, more comfortable springs on the road without increased roll.
• Ride comfort. Owners argued about this at length. One said a bar adds an undamped spring to the suspension. Another replied that the bar works through the wishbones and dampers, and only loads up when one wheel is in bump and the other in droop, so it has little effect on ride when both wheels move together. The seller of one bar says it does not affect ride comfort. We don't have a measurement.

Fitting notes from the 2017 and 2018 threads

• How long. One owner took a whole afternoon to fit a 1 inch bar, and said a garage would be quicker. The lower chassis mount bolt is hidden by the wishbone, so it needs a cut-down Allen key once the wishbone is jacked up. The upper one has an access hole too small for a normal socket, so a second chopped key with a 6 mm socket. An annoying riveted panel blocks the way and needs drilling or a Dremel, and the drop links will probably need cutting off. He called the Allen-key bolts a design crime.
• Bush orientation. In 2018 an owner fitted an Elise Parts bar with the bushes butted against the flange, not the metal washer. Two owners said they should butt up to the metal washer, because otherwise the bar can slide sideways. He then checked with the bar's maker, switched them round and said the maker agreed. The retailer's own photo may show it the other way.
• Clearance to the lower wishbone. The same owner found that the new bar seemed to touch the lower wishbone, with little room when on the ground, with the ride height set far too high at about 150 mm. An owner with another make of bar said the same happens on his. Another owner said it only touches in the third hole, and will bottom out whenever both front wheels droop together, and that it doesn't touch in the other holes. Check the clearance through full droop after you set the ride height.

A knocking bar (2016)

An owner had a loud knock from the front near side, felt over cats eyes, and thought it was the bar. The car had a Cornering Force bar fitted in 2011. A garage said the knock came from the chassis mounts, with no visible rubber.

• The mounts on that bar are hard plastic (black Derlin). Owners said they are known to creak if not lubricated, and one said his were dreadful. Lubricate them with copper grease, or if the bar is loose in the mounts, replace them. The maker was described as helpful.
• Check the mounting block bolts. The fitting sheet said 8 Nm, which the owner took to mean about hand tight. Another owner asked whether the gap between the two halves of the mount looked large.
• Worn powder coating on the bar was another suspect, found when he looked closer.
• Drop links. One owner of the same bar kept wearing out the rose joints on the near side, and fitted original drop links instead. Another said the bar has a good degree of free movement from new.
• It may not be the bar. Two owners said a rattle over rough roads that goes away as soon as you touch the brakes is pad and disc rattle, and that some high-friction pads (CL5+ was named) are well known for it.
• The thread ends before the cause was found.