Are you after an original replacement chassis or one of the tubular versions with the double wishbone rear suspension?
If it’s the tubular version that you are after then there are some considerable differences between the Spyder and Banks chassis.
All fit in the same space as the original.
The Spyder version is closer in layout to the original Lotus design and most of the original hardware swaps straight across (*Steering rack is mounted using original clamps*) - notably the rear Y design follows pretty close to the original layout but is obviously adapted to be manufactured from tubing. I can’t see any reference to it from a quick look but they used to offer basically the same tubular chassis with the option of either the original trailing arm rear suspension setup OR their double wishbone option.
Spyder double wishbones consist of a long lower wishbone and a pretty short upper wishbone with their own upright, the upper wishbone length being dictated by the space available which is fairly limited due to the similarity in layout to the original chassis which wasn’t intended for double wishbones. - One slight disadvantage of this is that the rear wheels see a fair bit of camber change as they move up and down which is something to consider if you intend to use your car on track for example.
The Banks version is also similar to the original Lotus design at the front (*with the exception of the rack mounts being of their own design so that bump steer could be adjusted out by use of shims*). - the differences really start at the rear of the backbone, the whole rear end was designed specifically to be of tubular construction for a double wishbone setup along with their own upright (never offered a trailing arm version) and as a result is quite different in comparison, the upper wishbone is longer whilst the lower wishbone is shorter (than the Spyder version) the resulting geometry is such that there is no rear camber change.
Again, the majority of the original hardware can be swapped straight across but there are options, such as the gear change mechanism, that have been reworked and are worth considering.
You could also option a roll cage (mounting points added as chassis is manufactured), either part or in full, that adds considerably to the torsional rigidity of the chassis whilst offering the obvious improvement in protection.
Both versions make for a nice road car and deal with the well documented driveshaft/rear upright/wheel bearing/hub etc wear issues.
If you are looking to spend more time on track or update the running gear then I would recommend you towards the Banks version as there are many more options and it was quite comprehensively re engineered (more than I have mentioned) to bring things up to date so to speak.
As BDA mentioned, the Banks chassis is not listed on the Lotus Supplies website (the twin link kit is for use with the original Lotus chassis only) and after speaking to them this morning they informed me that he is still manufacturing them but it is best to ring Richard directly to discuss availability and price etc.
Worth noting that, as mentioned, it’s hard enough getting hold of anyone when I live in the same country as them so it will take a bit of perseverance to get a response I’m afraid.
