mossy7 Posted August 11, 2016 Share Posted August 11, 2016 I know it's been covered in other threads but I am still a bit confused. I am currently running 14 inch wheels and as part of my tinkering wonder whether a change may bring improvements. What is the collective opinion of changing to 13 inch or 15 inch wheels in terms of ride and handling feed back? Do 13s bring an improvement in acceleration that's noticeable? Should I have 6 inch wide all round or 6 front and 8 rear? What is best tyre for road use?And if I change, is it just a straight swap? For info I have an S3 Roadsport 140 Sigma so not huge power, running 185/60 14s. Thanks in Advance,Andy Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted August 11, 2016 Member Share Posted August 11, 2016 Only ever road use or a few trackdays as well?How high a priority is performance in the wet?What's your current clearance under the sump and how low would you go?Jonathan (14", A021Rs as soon as I heard they were going) Link to comment Share on other sites More sharing options...
mossy7 Posted August 11, 2016 Author Share Posted August 11, 2016 Hi Jonathan,wet performance not really an issue. I may do the odd track day but 90 percent road use. As for clearance I manage ok with speed bumps with my 14s so don't want to go much lower. Its on Avon ZV3 tyres. ( not at home so can't check profile) Link to comment Share on other sites More sharing options...
DJ. Posted August 11, 2016 Share Posted August 11, 2016 I have 14 inch wheels with Uniroyal Rain Expert tyres on a Sigma 125. I find they are excellent for road use in all weathers, but they are obviously not as fast as less treaded tyres. If I was to swap wheels, I would definitely go to 13s even though I would lose some ground clearance. I have a friend with more power and zzs tyres on 13s and he has been happy with grip, but did have some aquaplaning in really bad Scottish rain while my Uniroyals didn't give me any nasty moments. Definitely stick to 6 inch rears with your power it'll be more fun. Link to comment Share on other sites More sharing options...
Tony Whitley Posted August 11, 2016 Share Posted August 11, 2016 I don't know about 14" except that there is less choice of tyre. I've used 13" for years but last year bought a set of 15" as an experiment. I can't say whether it's the wheel size or the tyre (Toyo T1R) but they spoil the feel of my car on the road, cause armfuls of understeer on track, and so I'm going back to 13". Jonathan has a good point about wet weather - I'm much happier on A-021Rs in winter (I didn't think they were available in 14"?) and have vivid memories of acquaplaning in rush hour traffic on the M3 on worn A-032Rs :o Link to comment Share on other sites More sharing options...
Tony Whitley Posted August 11, 2016 Share Posted August 11, 2016 Definitely 6" rears with that power. Link to comment Share on other sites More sharing options...
glasgow Posted August 11, 2016 Share Posted August 11, 2016 Well, I have similar power and went for 8" rear in order to stop over-steering. Ahmed Link to comment Share on other sites More sharing options...
Tazio Posted August 12, 2016 Share Posted August 12, 2016 , ,Stop oversteering?, why?, isn't that the point of our wonderful little cars?, having a little fun?, and to answer the question, 13s for fun, 15s if you do touring. Link to comment Share on other sites More sharing options...
mossy7 Posted August 12, 2016 Author Share Posted August 12, 2016 People, thanks for the comments. I think the answer is 13s. Final decision yet to be made on tyres though. My conversion from 125 Roadsport to 140 Supersport shall soon be complete. And I've saved money too! Link to comment Share on other sites More sharing options...
Mrp Posted August 12, 2016 Share Posted August 12, 2016 I run mine on 13" and zzr tyres 215 on the back and 185 on the front. I went for minilights with a different offset which in my view looks much better. Post if you want more details or pictures. My 2009 Sigma car has undergone the same transfomation as yoursMrp Link to comment Share on other sites More sharing options...
L7 FST Posted August 12, 2016 Share Posted August 12, 2016 You won't experience much difference between 13 and 14" - the main factor to think about is what kind of tyres you want (sticky like ZZRs or R888s, or harder road tyres like Toyo T1R) which can give huge variations in ride as well as handling.Generally I think Caterhams are at their best on 13" wheels - light and nimble handling, and the tall profile of eg R888s makes them very comfortable for touring too.. Some people fit 15 or even 16" wheels with uncomfortable low profile tyres because they fill the wheel arches and look good but the ride is usually terrible.I agree about sticking with 6" wide rears if you have around 140hp. Link to comment Share on other sites More sharing options...
Dave Rayner Posted August 13, 2016 Share Posted August 13, 2016 Spot on choice with 13" wheels, I run 6" and 8" with CR500 on road and have spare set with R888R for competition use. The advantage of course is if you upgrade to even more power the boots are sorted!! Link to comment Share on other sites More sharing options...
mossy7 Posted August 13, 2016 Author Share Posted August 13, 2016 Decision is 13 inch Apollo wheels in black with ZZR tyres. Going to order direct from Caterham. Just need to sort a flat floor set up now to make the best of it.Thanks for the advice everyone. Link to comment Share on other sites More sharing options...
Mrp Posted August 13, 2016 Share Posted August 13, 2016 All 6" or 6 & 8" ? Link to comment Share on other sites More sharing options...
mossy7 Posted August 13, 2016 Author Share Posted August 13, 2016 Ah... Now that's the next question !!!! Link to comment Share on other sites More sharing options...
Andy Watson Posted August 13, 2016 Share Posted August 13, 2016 ....just as an aside, does anyone have any thoughts/experience of Nankang Sportnex NS-2Rs? They seem to do a 185/60 R14..... Link to comment Share on other sites More sharing options...
Leadership Team Toughie Posted August 13, 2016 Leadership Team Share Posted August 13, 2016 I'm still very new to 7s, so attended their introductory Get To know Your Seven course recently at Caterham South. If I have taken my notes correctly, we were told that 13" were far better for handling (though they can "look a little lost on an SV") and preferably with ZZS tryres, which were better in the wet, though ZZR were also said to be very good. Link to comment Share on other sites More sharing options...
Mrp Posted August 13, 2016 Share Posted August 13, 2016 Two sets of wheels !!!! zzr & zzs Link to comment Share on other sites More sharing options...
Leadership Team Toughie Posted August 13, 2016 Leadership Team Share Posted August 13, 2016 Does that require a towbar and a trailer to carry the spare set? Link to comment Share on other sites More sharing options...
mossy7 Posted August 13, 2016 Author Share Posted August 13, 2016 MrP, you have mail. Link to comment Share on other sites More sharing options...
pensioner Posted August 21, 2016 Share Posted August 21, 2016 I have 16 inch wheels on my Roadsport. The standard fitment according to the manual is 14". If I was to change, what would happen to the speedo as this over reads already? Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted August 21, 2016 Member Share Posted August 21, 2016 What fraction does it currently overread, and what tyres would be on the before and after wheels?JonathanPS: What type of speedometer... it might be easy to recalibrate. Link to comment Share on other sites More sharing options...
pensioner Posted August 21, 2016 Share Posted August 21, 2016 assuming I followed the manualcurrent are 205/45 vr16 which would change to 185/65 hr 14According to a chart on the net the 205s are 577 and the 185s are 591 od so I suppose there is not a huge difference on ODWhere would I get the speedo re calibrated? It is a standard caterham speedo from a 2003 roadsportAccording to my sat nav, the car is doing 60 when the speedo reads 70. [i wondered wht everyone overtook me when I was driving at an indicated 70] Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted August 21, 2016 Member Share Posted August 21, 2016 Current display is 1.167 x true.577 to 591 is 1.024. That would take the display to 1.140 x true, or 61 mph displayed at 70 mph.Is that an electronic or mechanical speedometer? I don't know when they changed.On some (? all) electronic speedometer recalibration is a matter of pressing buttons. On factory mechanical speedometers I think the repairers can change the gearing but i'm not certain. A cheaper option is to add lines at the speeds of interest using something like Letraset.Jonathan Link to comment Share on other sites More sharing options...
pensioner Posted August 23, 2016 Share Posted August 23, 2016 Thanks Jonathan. I will have to think about it Link to comment Share on other sites More sharing options...
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