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Post by nznick on Jun 13, 2018 12:34:29 GMT
We are running 145/70R12s on Rover minilites 4.5"x 12" .
Our JDM 1000cc is quite low geared overall, so I reckon we could run a taller tyre to help the gearing a little and reduce revs at 60mph
Local tyre shop has offered us 155/70R12s which are 15mm bigger diameter or 155/80R12s which are 45mm bigger diameter. Both are a bit wider but still narrower than a 165/60R12
Question? ....can we go taller without clearance issues to the firewall, inner fender, suspension?
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Post by mra-minis on Nov 10, 2020 20:03:42 GMT
We are running 145/70R12s on Rover minilites 4.5"x 12" . Our JDM 1000cc is quite low geared overall, so I reckon we could run a taller tyre to help the gearing a little and reduce revs at 60mph Local tyre shop has offered us 155/70R12s which are 15mm bigger diameter or 155/80R12s which are 45mm bigger diameter. Both are a bit wider but still narrower than a 165/60R12 Question? ....can we go taller without clearance issues to the firewall, inner fender, suspension? I can be contacted on martin@kmprecisionengineering.com Ok so its a little oldish.... However there is no simple answer, the width has an effect on the overall diameter due to the aspect ratio, for example:- 145/80-12 are calculated as such:- 12 x 25.4 = 304.8mm 80% of 145 = 116mm x 2 = 232mm Total diameter = 304.8 + 232 = 536.8mm 165/60-12 and :- 12 x 25.4 = 304.8mm 60% of 165 = 99mm x 2 = 198mm Total diameter = 304.8 + 198 = 502.8mm 175/50-13 13 x 25.4 = 330.2mm 50% of 175 = 87.5mm x 2 = 175mm Total diameter = 304.8 + 175 = 505.2mm But also what a wider tyre can do is create a larger wheel movement radius which can then connect with the wheel arch, when you also factor in the wheel dish depth then this can all change again. |
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Post by nznick on Nov 11, 2020 7:55:15 GMT
Thanks
Yeah I get the relationship and had crunched the numbers too. I was hoping someone had tried 155/70s or 155/80s and knew if the bigger diameter would rub anywhere on full lock, but looks like no-one has..🙁
I ask around every now and then if either size in stock, and let the group know if I have any luck.
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Post by notamini on Nov 11, 2020 17:21:24 GMT
Hard enough for me to even find 12" tyres. So I just get whatever is available. 145/80 R12 for now. Think I'd like something wider. Better still, I wish I could find some white walled radials. Everyone on this continent starts at 13". all that is out there is a set of cross ply 12's. Oh well. At least this is what was original on the car when new so I might get them just for shows. My Atlas Portawhites are eating my sidewalls!
Mark
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Post by mra-minis on Nov 11, 2020 22:01:53 GMT
Thanks Yeah I get the relationship and had crunched the numbers too. I was hoping someone had tried 155/70s or 155/80s and knew if the bigger diameter would rub anywhere on full lock, but looks like no-one has..🙁 I ask around every now and then if either size in stock, and let the group know if I have any luck. I can be contacted on martin@kmprecisionengineering.com I have used 165/60-13 on a mini and they fitted ok but did need the front area of the front wheel arch to be cut away and the rear inner section to be "manipulated" due to the rolling diameter, I found them to be better than expected better than my 175/50-13 I think due to a little more flexibility on the side wall in the vertical mode but not lacking in the cornering and especially turn in. I now have 225/45-13 abd they are not good in the wet but on a dry road excellent. |
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Post by mra-minis on Nov 11, 2020 22:04:00 GMT
Hard enough for me to even find 12" tyres. So I just get whatever is available. 145/80 R12 for now. Think I'd like something wider. Better still, I wish I could find some white walled radials. Everyone on this continent starts at 13". all that is out there is a set of cross ply 12's. Oh well. At least this is what was original on the car when new so I might get them just for shows. My Atlas Portawhites are eating my sidewalls! Mark I can be contacted on martin@kmprecisionengineering.com Have you tried Mini Mania ? they ship container loads over from the UK |
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Post by notamini on Nov 12, 2020 16:55:57 GMT
Does this include white wall radials?
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Post by mra-minis on Nov 15, 2020 23:16:37 GMT
Does this include white wall radials? I can be contacted on martin@kmprecisionengineering.com The math can be applied to all Radials, however it is a "ball park" guestimate because in reality you should be using the rolling radius at 30mph which can be different to static, often these figures are not easy to find but first port of call should be the manufacturer. |
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