catastrada Posted November 25, 2009 Share Posted November 25, 2009 I'm about to order new wheels : 7x13 ET24 front and 9x13 ET24 rear. Michelin slicks will be fitted on them. I've already checked on a track that those slicks are not rubbing at all. For my test they were fitted on CC 8 spokes wheels, 6 ET24 front and 8 ET24 rear. My conclusion is that there is space enough for those tyres. As a result I guess that same tyres, on wider wheels with the same offset (ET24) should be OK no ? (I checked visually that there is more than half an inch space each side of the wheels, I mean near the rear springs, near the rear ARB, near the front wing stay...) Do some of you have experience with 7'' front and 9'' rear, and can you confirm ET24 is the right offset ? Link to comment Share on other sites More sharing options...
Irrelevant Posted November 25, 2009 Share Posted November 25, 2009 As a result I guess that same tyres, on wider wheels with the same offset (ET24) should be OK no ? (I checked visually that there is more than half an inch space each side of the wheels, I mean near the rear springs, near the rear ARB, near the front wing stay...) Yes, no I mean, if the 8" wheels left half an inch (which is close) and you use 9" wheels with the same ET, they will be almost touching as they will stick out half an inch more each side. What Michelins you thinking of anyway? 160/530R13 and 230/570R13? What's "Munster & Riesling"? Guess it might be abroad, but on the off chance it's not, and it's anywhere near J4 of the M3; I have a load of wheels with different tyres, inc. 230/570R13s on 9" rears (that are fine) 250/570R13s on 10" and 9", 180/550R13 on 7"(ET24), 170/530R13 on 8" . .. plus others. Link to comment Share on other sites More sharing options...
catastrada Posted November 25, 2009 Author Share Posted November 25, 2009 "Munster & Riesling" is the region in France where Munster (the cheese) and Riesling (the wine) are produced, close to the german border. Thank you for your very kind offer but unfortunately I need to decide without trying your wheels. And yep the Michelin I'm having are 16/53/13 and 23/57/13 (Formula Renault 2.0). I measured more than half an inch each side, that's why I think it should fit. You mentionned "230/570R13s on 9" rears (that are fine)" but you did not precise the offset ? Edited by - Catastrada on 25 Nov 2009 15:21:24 Link to comment Share on other sites More sharing options...
Irrelevant Posted November 25, 2009 Share Posted November 25, 2009 You mentionned "230/570R13s on 9" rears (that are fine)" but you did not precise the offset ? They're split rims and use spacers so I'm not sure. I will try to remember to measure them tonight. Link to comment Share on other sites More sharing options...
catastrada Posted November 25, 2009 Author Share Posted November 25, 2009 😶🌫️ Link to comment Share on other sites More sharing options...
Pendennis Posted November 25, 2009 Share Posted November 25, 2009 ET+12 Want to rent an 18th century Farmhouse in Rural Somerset? Link to comment Share on other sites More sharing options...
catastrada Posted November 25, 2009 Author Share Posted November 25, 2009 Thank you for your feedback Pendenis. With ET24 the rear wheels are already filling the arches. See here and here Any technical reason to explain ET12? Edited by - Catastrada on 25 Nov 2009 20:07:32 Link to comment Share on other sites More sharing options...
Pendennis Posted November 25, 2009 Share Posted November 25, 2009 No real reason apart from they offer similar clearance for rubber from watts linkage to the 8.5" variant. The 8.5" is ET+21. I have 9" rears with MOG extra wide arches and they sit inside them normally, if you know what I mean (don't protrude like yours) Want to rent an 18th century Farmhouse in Rural Somerset? Link to comment Share on other sites More sharing options...
catastrada Posted November 25, 2009 Author Share Posted November 25, 2009 Yep I see, thank you Link to comment Share on other sites More sharing options...
Pendennis Posted November 25, 2009 Share Posted November 25, 2009 Look at page 2, Yellow and black Caterham number 8 http://www.semsec.org.uk/gallery/200912septbh/index.html Want to rent an 18th century Farmhouse in Rural Somerset? Link to comment Share on other sites More sharing options...
Irrelevant Posted November 25, 2009 Share Posted November 25, 2009 Catastrada: The wheels I have 23/57/13 Michelins on are 9.5 Madins. Here are some photos of the wheel on a standard winged s3 Caterham. . . . I measured the distance from the mounting face to the outside of the tyre. On the front, it's 125mm. On the back, 145mm (there's 15mm extra each side for the tyre in these measurements). So that gives you 20mm offset. Have a look at this website which may help you. Edited by - Epimetheus on 25 Nov 2009 22:21:36 Link to comment Share on other sites More sharing options...
catastrada Posted November 26, 2009 Author Share Posted November 26, 2009 Hey Epimetheus, you are a king! Thank you for your help 😶🌫️ Link to comment Share on other sites More sharing options...
Irrelevant Posted November 26, 2009 Share Posted November 26, 2009 Hey Epimetheus, you are a king! Thank you for your help It's a pleasure . . . but I am not a king, I'm a God Link to comment Share on other sites More sharing options...
catastrada Posted November 27, 2009 Author Share Posted November 27, 2009 One more question God, Are you using -2° De Dion ears ? Link to comment Share on other sites More sharing options...
Irrelevant Posted November 27, 2009 Share Posted November 27, 2009 Are you using -2° De Dion ears ? Don't know I'm afraid . . . I followed the advice I got from BMTR at the time (which did involve getting new ears). Whatever BMTR said, it was not right for me as the tyres were getting unevenly warm. I fitted some shims to adjust the rear camber and set the toe and eventually the heat was even. Whether this is the correct procedure or not, I don't know. . . . And I don't know what camber I have as I didn't measure it. So not much help I'm afraid 😳 Link to comment Share on other sites More sharing options...
simonpa Posted November 27, 2009 Share Posted November 27, 2009 Hmm - is that a matt paint finish on your car? Link to comment Share on other sites More sharing options...
catastrada Posted November 27, 2009 Author Share Posted November 27, 2009 @ epimetheus: it's ok for this time... @ simonpa: yep matt black Link to comment Share on other sites More sharing options...
catastrada Posted December 4, 2009 Author Share Posted December 4, 2009 Order for news wheels is placed. For budget reason I went for monoblock wheels. I wanted to keep ET24 to keep the standard position of the wheel (bearing aligment...). I was not able to find 13x9 wheels with ET24 (asked to KN, Compomotive and MB, Mad'In). As a result I ordered 7x13 ET24 front and 8,5 ET24 rear, Compomotive CXR. Link to comment Share on other sites More sharing options...
Area Representative Richard Price Posted December 4, 2009 Area Representative Share Posted December 4, 2009 As a result I ordered 7x13 ET24 front With standard hubs and wing stays, I don't think 7" wheels with ET24 will fit. I think you'll need to use something like a 10mm spacer to get clearance on the wing stay. Link to comment Share on other sites More sharing options...
Pendennis Posted December 4, 2009 Share Posted December 4, 2009 Not sure why you think wheel bearing alignment is involved in this I think your referring to scrub axis of tyre, which in my experience is a waste of time worrying about. Edit, sorry got it wrong way round , your gunner need a decent spacer as mentioned, circa 8mm Want to rent an 18th century Farmhouse in Rural Somerset? Edited by - Pendennis on 4 Dec 2009 21:32:00 Link to comment Share on other sites More sharing options...
catastrada Posted December 7, 2009 Author Share Posted December 7, 2009 Yesterday I measured how much I have between my wheels and my wingstays. There is at least 16mm, I think it shoul be OK then. (there is much less between the tyres and the wing stays, but with the same offset as the current wheel this shouldn't change with the new wheels). Link to comment Share on other sites More sharing options...
Pendennis Posted December 7, 2009 Share Posted December 7, 2009 Surely, the backspace of a 7" or 9" with ET24 will be roughly 12mm MORE than a 6" or 8" with ET24 So as you have been advised, that additional backspace would need filling with spacers Is you car different or am I missing something here Want to rent an 18th century Farmhouse in Rural Somerset? Link to comment Share on other sites More sharing options...
Area Representative Richard Price Posted December 7, 2009 Area Representative Share Posted December 7, 2009 Yesterday I measured how much I have between my wheels and my wingstays. There is at least 16mm, I think it shoul be OK then. Is that with existing wheels, or the new wheels 🤔 but with the same offset as the current wheel this shouldn't change with the new wheels I think you're missing the point here ❗ As rim width increases, if the offset stays the same, then the back space will increase! When going wider than the standard caterham wheel widths, all the additional width needs to go outwards, unless you're going to have custom wingstays (at the front that is). If you're really that concerned about the extra loading on the wheel bearings, then don't fit wide and sticky tyres at all! Edited by - Richard Price on 7 Dec 2009 14:31:30 Link to comment Share on other sites More sharing options...
catastrada Posted December 7, 2009 Author Share Posted December 7, 2009 Is that with existing wheels, or the new wheels 🤔 With existing wheels I think you're missing the point here ❗ As rim width increases, if the offset stays the same, then the back space will increase! I'm OK with that. What I try to explain (not always easy for me in English) is that it seems there is enough place for half an inch added on both sides of the front wheel. Link to comment Share on other sites More sharing options...
Pendennis Posted December 7, 2009 Share Posted December 7, 2009 Castrada, I don't want you to waste your money on a nice new set of wheels which won't fit your lovely Caterham I know I certainly would not want to use spacers especially after just buying new wheels. If I was buying wider wheels for my car, I would measure the backspace I currently have with the existing wheels and ensure that those measurements remains the same for the new wheels. Ultimately, the offsets will change. I already stated that ET12 is perfect for a 9" rear on an S3 with watts linkage, fronts probably going to be ET18 Want to rent an 18th century Farmhouse in Rural Somerset? Link to comment Share on other sites More sharing options...
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