Leadership Team Midas Posted February 28 Leadership Team Share Posted February 28 We had a lot of questions at the Webinar from members asking what Caterham was doing to replace Avon tyres on our cars. Simon Lambert has been back in touch and kindly provided the following table showing a read a cross from Avon to Toyo - the new favoured tyre brand going forward. Simon produced the following table Caterham - New Tyre Table Here is an Avon-to-Toyo table that was requested by several. Please note, some tyre sizes have changed due to an exact equivalent not being available; most notably the Academy 185/70R13. Avon Size Toyo Replacement Toyo Size ZZS/ZZR 185/55R13 Proxes R888R 185/60R13 ZZS/ZZR 215/55R13 Proxes R888R 205/60R13 ZZS/ZZR 195/50R15 Proxes R888R 195/50R15 ZT7 185/60R14 Proxes Comfort 185/60R14 ZT7 175/65R14 Proxes Comfort 175/65R14 ZT7 155/65R14 Nanoenergy 3 155/65R14 Academy 185/70R13 Proxes CF2 185/60R13 CSR Tyres As the CSR is still a product for Europe, selecting which of the Toyo options will be appropriate has a homologation impact which again makes things less straight-forward you would hope, so this remains TBA. 2 Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted February 28 Member Share Posted February 28 Thanks, both. That's very helpful. Does anyone know about wingstay clearance for any of these? Jonathan Link to comment Share on other sites More sharing options...
7 wonders of the world Posted February 28 Share Posted February 28 no issue with 185/60 x 13" using the race stays even using 6.5" front rims Link to comment Share on other sites More sharing options...
Ainsley Posted February 28 Share Posted February 28 I may be missing something, but if the tyre height changes, the diameter changes, so will the speedo be out ? Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted February 28 Member Share Posted February 28 19 minutes ago, 7 wonders of the world said: no issue with 185/60 x 13" using the race stays even using 6.5" front rims Thanks. Please keep them coming. Jonathan Link to comment Share on other sites More sharing options...
Area Representative bluenose Posted February 28 Area Representative Share Posted February 28 From the Nova Motorsport website: Nova Motorsport has secured all the residual stock from the Avon & Cooper Motorsport business. This valuable inventory is now located in our newly established UK Distribution Headquarters. Our new factory is already operational, marking the beginning of an exciting journey. Starting from March 2024, we will begin the process of manufacturing the Avon Motorsport range. With the first tyres anticipated to hit the market in the second half of 2024, these selected product lines will showcase our unwavering commitment to performance, heritage and quality. Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted February 28 Member Share Posted February 28 11 minutes ago, Ainsley said: I may be missing something, but if the tyre height changes, the diameter changes, so will the speedo be out ? Yes. For electronic speedometers that means entering s different calibration factor. That can be derived by calculation or by measuring real speed on the road, which is now best done by GPS rather than motorway markers! For mechanical speedometers it is possible to change the gearing. but I'm not expecting many to do it. Speedometer Guide. Jonathan Link to comment Share on other sites More sharing options...
Ainsley Posted February 28 Share Posted February 28 My recently delivered 420R kit came with the Toyo tyres, which are 60's as opposed to 50's on the original Avon's. So I just need to calibrate my speedo then, as I assume its electronic being a new build. Bigger tyres = greater rolling distance = non calibrated speedo, so would that mean I show a speed slower that real ? Link to comment Share on other sites More sharing options...
7 wonders of the world Posted February 28 Share Posted February 28 ....you may also need to re set ride heights, castor, camber toe and rake etc too Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted February 28 Member Share Posted February 28 (edited) 4 minutes ago, Ainsley said: My recently delivered 420R kit came with the Toyo tyres, which are 60's as opposed to 50's on the original Avon's. So I just need to calibrate my speedo then, as I assume its electronic being a new build. Bigger tyres = greater rolling distance = non calibrated speedo, so would that mean I show a speed slower that real ? As above: I'd do it by comparing the displayed speed to a known steady speed measured by GPS. Then change the calibration factor by that ratio. And repeat to check. Jonathan Edited February 28 by Jonathan Kay Link to comment Share on other sites More sharing options...
Ainsley Posted February 28 Share Posted February 28 OK, will do. Thanks. Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted February 29 Share Posted February 29 (edited) 5 hours ago, Ainsley said: I may be missing something, but if the tyre height changes, the diameter changes, so will the speedo be out ? It is only a nominal 1.6% diameter difference between the 205/60-13 Toyos vs the 215/55-13 Avons, 9.5mm diameter difference overall (although the actual value may be 17mm compared with the nominal value, from the listed specs). The R888Rs only have a tread width of 185mm vs the 200mm of the ZZSs, though. Edited February 29 by aerobod - near CYYC Link to comment Share on other sites More sharing options...
W33SVN Posted February 29 Share Posted February 29 Tyre size conversion calculator with speed variance; https://www.willtheyfit.com 2 Link to comment Share on other sites More sharing options...
Miker7 Posted February 29 Share Posted February 29 Do we know if the tyres have been selected because they're the same size or similar / better grip levels? I'm specifically thinking of the 14" as I've got 14" wheels on my road car and "comfort" tyres doesn't inspire confidence. Link to comment Share on other sites More sharing options...
Ainsley Posted February 29 Share Posted February 29 Ah, that's a great website, thanks for that recommendation. So I will be going 0.99 mph slower and gain 4.75mm in ride height. All in all that's actually a good result, I probably wont bother re-calibrating the speedo then and drive faster at speed bumps 🙂 Link to comment Share on other sites More sharing options...
7 wonders of the world Posted February 29 Share Posted February 29 R888R are most certainly performance based and not in the comfort category... By not means are they a harsh tyre but they are a road legal track tyre. Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted February 29 Share Posted February 29 The R888Rs are comparable to the ZZS with OK wet grip and good dry grip. For the better dry grip of the ZZR, but limited wet grip, the Nanking AR-1 is the comparable tyre. Link to comment Share on other sites More sharing options...
Miker7 Posted February 29 Share Posted February 29 I didn't realise until now you could get r888r in 14" - now that does create a dilemma when it comes to replacing tyres. Link to comment Share on other sites More sharing options...
John Vine Posted February 29 Share Posted February 29 19 hours ago, Ainsley said: My recently delivered 420R kit came with the Toyo tyres, which are 60's as opposed to 50's on the original Avon's. So I just need to calibrate my speedo then, as I assume its electronic being a new build. Bigger tyres = greater rolling distance = non calibrated speedo, so would that mean I show a speed slower that real ? With luck, CC may have already calibrated the speedo to match the supplied tyres. Have you asked them whether they did this? Out of interest, can you tell us what size your Toyo tyres are, and what 6-digit pulse code you have at the moment? That would be useful info for the Speedometers Guide. (Part C of the Guide explains how to display the code.) JV Link to comment Share on other sites More sharing options...
John Vine Posted February 29 Share Posted February 29 21 hours ago, Midas said: We had a lot of questions at the Webinar from members asking what Caterham was doing to replace Avon tyres on our cars. Simon Lambert has been back in touch and kindly provided the following table showing a read a cross from Avon to Toyo - the new favoured tyre brand going forward. Simon produced the following table Caterham - New Tyre Table Here is an Avon-to-Toyo table that was requested by several. Please note, some tyre sizes have changed due to an exact equivalent not being available; most notably the Academy 185/70R13. Avon Size Toyo Replacement Toyo Size ZZS/ZZR 185/55R13 Proxes R888R 185/60R13 ZZS/ZZR 215/55R13 Proxes R888R 205/60R13 ZZS/ZZR 195/50R15 Proxes R888R 195/50R15 ZT7 185/60R14 Proxes Comfort 185/60R14 ZT7 175/65R14 Proxes Comfort 175/65R14 ZT7 155/65R14 Nanoenergy 3 155/65R14 Academy 185/70R13 Proxes CF2 185/60R13 CSR Tyres As the CSR is still a product for Europe, selecting which of the Toyo options will be appropriate has a homologation impact which again makes things less straight-forward you would hope, so this remains TBA. Very useful info -- thanks. Did Simon happen to provide the related speedo calibration (pulse) codes? JV Link to comment Share on other sites More sharing options...
Red B Posted February 29 Share Posted February 29 Thanks for this post - really helpful, as I was getting very confused about what tyres to fit. However, I can't find any Proxes CF2 185/60R13 in stock anywhere. Has anyone found any?? If not, someone had suggested Yokohama A539 - has anyone used these before or know anything about them? Link to comment Share on other sites More sharing options...
StevehS3 Posted February 29 Share Posted February 29 I still feel unsure about fitting 205 width R888R tyres on 8x13” rear wheels. It is outside of Toyo’s Approved Rim Width and it seems 6x13” would be a better match. Link to comment Share on other sites More sharing options...
7 wonders of the world Posted March 1 Share Posted March 1 205 tyres have been used on 8" rims since Ford Anglia days... 1 Link to comment Share on other sites More sharing options...
Miker7 Posted March 1 Share Posted March 1 14 hours ago, Red B said: Thanks for this post - really helpful, as I was getting very confused about what tyres to fit. However, I can't find any Proxes CF2 185/60R13 in stock anywhere. Has anyone found any?? If not, someone had suggested Yokohama A539 - has anyone used these before or know anything about them? IIRC A539 are the control tyre in a number of race series - eg locost.I believe they're a good tyre .I've got some on capri laser alloys i'm about to try fitting to see how they go once I stop panicking about wheel stud length. 1 Link to comment Share on other sites More sharing options...
David_Stamp Posted March 1 Share Posted March 1 (edited) I have the feeling that this thread will run for a very long time .... Edited March 1 by David_Stamp Link to comment Share on other sites More sharing options...
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