jnormandale
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| posted on 26/5/07 at 09:35 PM |
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Locost - Caterham main chasis difference?
I read the 'Build you own sports car for £250' book about a year and a half ago now, and since then have always been interested in
building my own. With the new Chris Gibbs book being released I have a question in need of answering.
I have always been interested in Caterham roadsters rather than any other 7 inspired roadster, however what are the main differences between Locost
and Caterham chasis construction? As with many builders my budget cannot stretch to that of a Caterhams and I am seriously considering in building my
own Locost, however I do prefer the looks of the Caterham Roadsport/R400.
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jos
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| posted on 26/5/07 at 09:48 PM |
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I think Caterhams now have their chassis robotically welded but thats only happened in the last year or so. I think I'm right in saying that
they also sub out the chassis work.
Locost manufacturers weld the chassis' themselves.
Caterhams are also a 7 inspired roadster though - the Lotus 7 was the (only) original
........
and runs for cover
.: Motorsport / motor racing circuit / track wall art Apex Traxs :.
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mangogrooveworkshop
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| posted on 26/5/07 at 09:50 PM |
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Size and the greater use of grp instead of Ali for body work
Cats have purpose made parts
locosts have adapted parts
http://www.locostbuilders.co.uk/upload/archmotors%20catervan%20chassis.jpg
[Edited on 26-5-07 by mangogrooveworkshop]
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StevieB
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| posted on 26/5/07 at 10:02 PM |
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Caterhams are smaller and use a lot more round tube (nearly all of it) and a lot of the triangulation that is now being done by some of the
manufacturers was done by Colin Chapman eons ago.
For me, the Caterham is far better looking - something to do with the proportions. But the cost is a bit prohibitive (though I read in Total Kitcar
this month that you can apparently build a starter kit for £8,500. Sounds a bit optimistic to me!)
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jnormandale
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| posted on 26/5/07 at 10:13 PM |
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£8,500.00 is a ridiculous figure, surely not. So is the Caterham drastically different in size or does it share proportions with the Locost or other
inspired seven roadsters?
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Tralfaz
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| posted on 27/5/07 at 12:30 AM |
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The "Original" Cats are notably smaller (Based on the Lostus Seven Series III.
IIRC they are about 4-5 inches narrower than a "Pre-Litigation" Westfield... which I think is what the original Locost is based on. The
New Cat SV is 4 inches wider,or about the same as the aforementioned Westie. However as stated above the proportions are different.
T
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britishtrident
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| posted on 27/5/07 at 06:43 AM |
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quote:
Originally posted by StevieB
Caterhams are smaller and use a lot more round tube (nearly all of it) and a lot of the triangulation that is now being done by some of the
manufacturers was done by Colin Chapman eons ago.
For me, the Caterham is far better looking - something to do with the proportions. But the cost is a bit prohibitive (though I read in Total Kitcar
this month that you can apparently build a starter kit for £8,500. Sounds a bit optimistic to me!)
Re Triangulation you are talking boswollox, The original Lotus Seven S2 and S3 chassis had practically no triangulation,Chapman cut back on the the
already sparse triangulation he used in the Seven S1 to save costs.
Some triangulation was put back in after S3 had been running a couple of years because practically every Lotus Seven chassis was suffering tube
breakages due to flexing.
If you ever get a good look at the original S2 or S3 chassis without the body work you will see it is frighteningly sparse.
Even after a couple of the original diagonal tubes were put back in the chassis it still continued to suffer breakages, this became worse over the
years as engines became more powerful and tyres improved. Caterham continued wit this chassis for many years however it may have added to the health
Caterhams bank balance as ther monopoly supplier of chassis and parts.
When Westfield started producing a Seven clone and it became obvious that the Westfield MIG welded chassis which was heavier and more complex than
the Seven S3 chassis was stiffer and much less prone to tube breakages. Even then it took more than a decade before Caterham changed thier chassis
design significantly.
The essential differences between a Caterham chassis and a Westfield/Locost are:
The Catherham chassis uses thinner round tubing.
Until recently Caterham used brazing (bronze welding) not MIG welding to join tubes.
Rear suspension --- different systems used
Front suspension on Caterham is Triumph based
Caterham use a front anti roll bar.
Westfield & Locost bare chassis are about 30% heavier.
If I had real money to spend on a Seven chassis I would buy a Birkin.
[Edited on 27/5/07 by britishtrident]
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britishtrident
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| posted on 27/5/07 at 06:53 AM |
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quote:
Originally posted by Tralfaz
The "Original" Cats are notably smaller (Based on the Lostus Seven Series III.
IIRC they are about 4-5 inches narrower than a "Pre-Litigation" Westfield... which I think is what the original Locost is based on. The
New Cat SV is 4 inches wider,or about the same as the aforementioned Westie. However as stated above the proportions are different.
T
Just to point Tiger Cats are not Locosts or Lotus/Caterham Sevens.
The reason why just about every Seven style car increased inwidth by exactly 4" inches is due to the width of available rear axles, an Escort
axle is exactly 4" narrower than a Cortina axle or Sierra rear.
Chapman designed the original Seven around a very narrow track Nash Metropolitan axle for the sole reason he could buy them in well below cost price
after Metropolitan production stopped.
[Edited on 27/5/07 by britishtrident]
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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t.j.
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| posted on 27/5/07 at 06:58 AM |
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Look into my Photo archive.
There are some details about the caterham frames.
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StevieB
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| posted on 27/5/07 at 08:49 AM |
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quote:
Originally posted by jnormandale
£8,500.00 is a ridiculous figure, surely not. So is the Caterham drastically different in size or does it share proportions with the Locost or other
inspired seven roadsters?
I think they might be saying £8,500 if you buy the basic chassis and make the rest yourself (wishbones etc.). Kind of defeats the point of bothering
- if you are going to have to start making loads of bits, save yourself the trouble and build a proper locost!
I'm thinking of building a Catterham when I've finished the Indy - I'm trying to find out if they'll sell me the Classic kit
but withough the K Series and gearbox etc so I can stick a bike engine in there.
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mangogrooveworkshop
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| posted on 27/5/07 at 09:05 AM |
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quote:
Originally posted by britishtrident
If I had real money to spend on a Seven chassis I would buy a Birkin.
The most original seven in the world. Because of aparthied and sanctions the South African way was not to change things for change sake.
Improved the trianglation at the rear to stop tube breakage, replaced the rubber a frame bush with a bearing. And used standard motor company uprights
spitfire and herald modded with a new stub to take mk1 escort carriers and brake discs.
scuttle ali bench seats and long americano clam shell wings. Then they had a new supply of kent engines and boxes with live axels so why mess with a
real classic.
Factory opened by Chapmans wife,Nige Mansell and Deangelos with lotuses blessing.
A bit of back door dealing by Chapman no doubt!!!
Nearn took it real bad........
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MikeR
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| posted on 27/5/07 at 11:18 AM |
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If you like the caterham proportions, looks up the stuart taylor locost (sold to someone else a couple of weeks ago but i can't remember who).
Very similar size.
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britishtrident
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| posted on 28/5/07 at 05:41 PM |
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http://www.georgecushing.net/Lotus7.html
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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jnormandale
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| posted on 29/5/07 at 10:22 PM |
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Is the link above close to the dimmensions of the new model Caterhams such as the R400 and roadsport? I know the website states that they are a
combination of seven models.
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ned
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| posted on 30/5/07 at 06:42 AM |
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The difference in proportions between a caterham and a locost is the size of the cockpit area, in a caterham it is a bit short/smaller which changes
the location of the taper of the chassis to where it evens out, this then affects the bonnet length/line etc and in turn the proportional look of the
car, imho.
Also, most caterhams use smaller wheels and tend to run lower ride heights, they sit quite low, whereas many locosts and derivatives people use
15" and sometimes larger wheels which changes the proportions again.
That's not to forget how high caterham mount the headlights which also appears different to most other sevens.
Ned.
[Edited on 30/5/07 by ned]
beware, I've got yellow skin
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NS Dev
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| posted on 30/5/07 at 04:50 PM |
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As MikeR said, have a look at teh stuart taylor locosts, now under another name, as these are very similar to caterham proportions, though longer in
the cockpit area.
They look much more balanced and pleasing to the eye in my opinion than most of the "sierra based" kits, which to me look bulky and
wide.
The ST requires either a std escort axle or shortened sierra driveshafts, and has a lower bonnet line than any others apart from caterham and pre-lit
westies.
As was mentioned about headlights, most locosts fit them lower than caterham, though i know I am not the only one who has raised the headlights on a
ST car to get better lighting of the road, which again looks more like the caterham idea.
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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procomp
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| posted on 31/5/07 at 08:06 AM |
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Hi the new owners of St locost are LINK.
The only problem with the lower bonnet line is that as with the caterham and modern engines you have an awful lot of sump hanging out the bottom and
then a high chassis ride height to compensate.
And also the later ones have been made wider and a bit more cockpit room given.
cheers matt
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jnormandale
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| posted on 31/5/07 at 06:24 PM |
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What would suggest is the best option as I want the entire locost experience, with building the chasis from scratch. The link a few posts above has
provided excellent dimmensions which have been built up from a variety of lotus chasis models. But on the other hand St locost seem a very viable
option and look fantastic propotionally, however as i want to construct the chasis myself what do you think is the best option?
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t.j.
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| posted on 31/5/07 at 09:12 PM |
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I'm building my own chassis by using the AVON-book and the 250 book.
My chassis is longer and wider in the cockpit, less widht bonnet as the avon. wheelbase 2380 mm
But if i knew all the things a know now a would build a mc-sorly.
[Edited on 31/5/07 by t.j.]
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