Anton Posted May 3, 2017 Share Posted May 3, 2017 Up until mid February I was running my Seven (140bhp 1.8K SV) on 16" HPC five-spokes with 205/45/16 Toyos.Severe accident damage means I'll have to replace at least 3 of them, so given that five-spokes are no longer available and following advice that I should get smaller diameter wheels to improve the handling, what wheel diameter/width and tyre size would you recommend for road use only. I don't want to go down to 13" as I already have ground clearance issues! I'd appreciate the experience of any SV owners who've changed from the 16" to a smaller size.What do I need to know to find out if a particular style of wheel from a non-Caterham supplier will fit my car? Link to comment Share on other sites More sharing options...
JNC Posted May 3, 2017 Share Posted May 3, 2017 CC have some black Orcus 15" wheels in their Easter sale, they all have marks but very good saving on new price . Check your PCD these wheels are the latest type and may not fit older cars ! Link to comment Share on other sites More sharing options...
Jonathan Kay Posted May 3, 2017 Share Posted May 3, 2017 What do I need to know to find out if a particular style of wheel from a non-Caterham supplier will fit my car? IIRC there have been problems with insufficient spacing on the inside surface... but I can't remember what made contact. Searching for that in the archives might reveal the required clearance and specs.Jonathan Link to comment Share on other sites More sharing options...
Anton Posted May 3, 2017 Author Share Posted May 3, 2017 John - I don't really like the Orcus - it looks even more fragile than the five spoke. What exactly is PCD? This is the kind of thing I need to know if I go for aftermarket wheels.Jonathan - I've had one search which had about 3,000 hits (!) but didn't seem to give the answers I was looking for. But I'll have another go. Just try a different search query......... Link to comment Share on other sites More sharing options...
TomB Posted May 3, 2017 Share Posted May 3, 2017 15 inch anthracites? OEM Caterham fit if that what you want, or perhaps 14in minilites style? Link to comment Share on other sites More sharing options...
SM25T Posted May 3, 2017 Share Posted May 3, 2017 PCD ..... pitch circle diameter. Link to comment Share on other sites More sharing options...
ScottR400D Posted May 4, 2017 Share Posted May 4, 2017 The PCD is the diameter of the circle on which the mounting studs, and the corresponding holes in the wheel are located, or pitched. In other words, if you drew a circle that passed through the centre of each stud, it's diameter would be the PCD. Link to comment Share on other sites More sharing options...
Jonathan Kay Posted May 4, 2017 Share Posted May 4, 2017 I've had one search which had about 3,000 hits (!) but didn't seem to give the answers I was looking for. But I'll have another go. Just try a different search query.........How about these as a starting point? https://www.google.co.uk/search?q=site:lotus7.club+wheel+clearance https://www.google.co.uk/search?q=site:lotus7.club+wheel+offsetGood luckJonathan Link to comment Share on other sites More sharing options...
paul_w Posted May 4, 2017 Share Posted May 4, 2017 have a play on here to see what tyre sizes match your current to avoid gearing and ride height changes or at least to get an idea of how big a change you're making.http://www.tyresave.co.uk/tyre-size-calculator/your current set up is equivalent to 185/70 R13 as fitted to lots of old school Caterhams. if that size you want around a 19mm offset. you'll find loads new and second hand in this size with a Ford PCD.or on a 15 inch wheel 195/50 15 is near enough and you might find that less of a drastic change from what you're currently running than going to a bouncy tall sidewall tyre.In theory, if all else remains the same, then if you reduce the overall diameter then the offset needs to increase to keep the same geometry - someone more familiar with the newer cars will hopefully know, but I think the newer Caterham wheels that run smaller diameter tyres are about 23mm offset.Hope that helps :-) Link to comment Share on other sites More sharing options...
Wrightpayne Posted May 4, 2017 Share Posted May 4, 2017 I'm not sure 13s look right on an SV - 14" minilights or 15" caterham 10 spokes.Ian Link to comment Share on other sites More sharing options...
DougBaker Posted May 4, 2017 Share Posted May 4, 2017 You would not have ground clearance issues on the 13s with an SV as long as you go for the correct size tyres. The tall tyres are I think also required to get the proportions to look right.Those are Caterham Avon CR322s 185x70 R13 and have virtually the same circumference as the 16 inch wheels I had previously fitted. You lose only 2mm in wheel diameter in changing to the 13" wheels.Rim & Tire Size Calculator. Link to comment Share on other sites More sharing options...
Area Representative Golf Juliet Tango Posted May 4, 2017 Area Representative Share Posted May 4, 2017 AntonDon't fret about clearance. When I got my 21, it was on the 16" HPC wheels (very good looking wheels) which were shod with 205/45 tyres (these were Avon ZZ3). I swapped to the multi-spoke 15" wheels and went to 55 profile tyres (195 front 205 rear) (these were Toyo T1R) and the rolling radius was virtually identical. In my experience the additional sidewall improved the ride. Link to comment Share on other sites More sharing options...
Anton Posted May 5, 2017 Author Share Posted May 5, 2017 Thanks for all the info and hints. Got the PCD and ET, and now worked out the correct profile to get the right rolling radius for 14" and 15" wheels. Link to comment Share on other sites More sharing options...
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