Keethos 842 Report post Posted March 10, 2015 Hey all, Another Pro's and Con's question here. I've heard many times that a lil bit of stretch is a good thing as it stiffens the side walls which means less flex which means more positive feel when turning in (is that correct?). But what other good things are there about having stretch tyres? And are the down sides of having stretched tyres? How much stretch is too much? Would fitting a 235/40R18 tyre onto an 18x9.5J wheel equal too much stretch? Below is an image of what Laruen has set up with a bit of stretch and what 235/40R18 looks like, Lauren's setup doesn't look like it's stretch from this illustration but it's enough for her to feel a stiffer, more pointy car. Thanks all. Share this post Link to post Share on other sites
Tareim 343 Report post Posted March 10, 2015 Con's looks stupid seems dangerous higher chance of kerbing alloy less contact patch to the road Pro's are there any? Share this post Link to post Share on other sites
Keethos 842 Report post Posted March 10, 2015 Well yes, as I mentioned in my original message, I see where you're cons are but that's if you stretch them too much, I'm interested to know where that boundary is and what other benefits or con's once I find that medium. Share this post Link to post Share on other sites
Captain G 25 Report post Posted March 10, 2015 Don't know about the pros and cons, have 18 x 8.75 wheels with 225/40 tyres, looks Awsome . My tyre supplier said this was fine, as customers had gone further . Share this post Link to post Share on other sites
rob275 1817 Report post Posted March 10, 2015 I guess the pro's and cons are very preference oriented, i've obviously stretched mine a small amount but it's not dangerous. My wheels kerb easily of course but I don't get as much side wall flex and I think this helps with feel on track, at least for me. Share this post Link to post Share on other sites
Kodename47 446 Report post Posted March 10, 2015 You'd lose ride comfort due to the added stiffness, worth noting for a DD especially if you drive poor roads regularly where a bit of tyres flex helps. Share this post Link to post Share on other sites
smudge 1020 Report post Posted March 10, 2015 I've got 255/35/18 on my 9.5's, perfectly comfortable with plenty of feedback too 1 Keethos reacted to this Share this post Link to post Share on other sites
Keethos 842 Report post Posted March 10, 2015 255? But from your pics, they look like they're still slightly stretched! So is 235 too stretched then? Would 245 be in the limit? Share this post Link to post Share on other sites
Lauren 2259 Report post Posted March 11, 2015 You can find out what a tyre manufacturer recommends in terms of wheel width compared to tyre width. http://www.brick-yard.co.uk/forum/tyre-size-for-rim-width_topic60146.html Or use this as a guide. I tried 225/45/17 on an 8" rim. Too much sidewall flex. So I'm going back to 215s on the same rim as the car was far more responsive which I liked. I will lose a bit of ride quality, that is true, but I think it's worth the pay off. Obviously with all these things you can simply go too far. This can lead to tyres coming off the rims which is not good. Drifters like a rigid sidewall because it makes it easier to drift, well easier to get the car sideways and easier to hold it there. This is to an extent why I like a bit of stretch. Anyone who saw me at the hairpin at Lydden Hill will understand that it just made it so easy to place the car at any angle you want. As soon as you bring sidewall flex in, it gets harder. The other way to reduce tyre flex is to reduce the tyre profile. For example running a 225/40/18 is I think better than running a 225/45/17. The problem is the wheel gets heavier but the upside is the handling remains sharp well you lose a bit due to wheel weight, but everything is a compromise. But as a general rule run a rim width which is at the upper end of the scale in compared to tyre width. Here's a pic of mine from last year with a 215 on an 8" rim: Untitled by Lauren Blighton, on Flickr 1 Keethos reacted to this Share this post Link to post Share on other sites
Deacon 1357 Report post Posted March 11, 2015 The other thing to consider Keith is different manufacturers tyre widths can be different - e.g. The Federals I have to go on are 215/45/17 but stacked up next to the Michelin's (same size) they are about an inch wider (so 5mmish each). 1 Keethos reacted to this Share this post Link to post Share on other sites
Captain Duff 79 Report post Posted March 11, 2015 I really didn't enjoy low profile tyres (which I assume is what stretching does) on my last car. Apart from the kerbing issue and the poorer ride comfort, it was the terrible state of our pot-holed roads that really did the damage (literally - two cracked alloys and numerous flat spots in the rims). These days I like a bit more 'cushion' Share this post Link to post Share on other sites
KevinA 695 Report post Posted March 11, 2015 Some very good points here, I run 9.5 rims and there is a big difference between makes of tyre. My track tyres NS2R's in 235/40/18 have 10mm more contact patch than the same size Conti 5's, ride softness and handling characteristics will all play a part in what set up you have. Very much personal preference and as Lauren said it makes each car feel different, guess it comes down to your own style of driving and what you want from the car. Share this post Link to post Share on other sites
Keethos 842 Report post Posted March 11, 2015 So you've got 235/40R18 Contis on your 18x9.5 rims? Got any pictures? Share this post Link to post Share on other sites
KevinA 695 Report post Posted March 11, 2015 Not the best picture, but gives you an idea. Share this post Link to post Share on other sites
Keethos 842 Report post Posted March 11, 2015 Nice, they look fairly stretched. How do they feel as I'll probably be sticking with Continental again. Share this post Link to post Share on other sites
Lauren 2259 Report post Posted March 11, 2015 Another view of mine: Untitled by Lauren Blighton, on Flickr 1 Keethos reacted to this Share this post Link to post Share on other sites
KevinA 695 Report post Posted March 11, 2015 Are you up at Snetterton, sure Debs will let you sample it for yourself. Share this post Link to post Share on other sites
Keethos 842 Report post Posted March 11, 2015 I'm hoping so but I might not have my 86 by then so will have to let you know, but if I do, I'd love to take you up on that offer! Share this post Link to post Share on other sites
DebbieJ 42 Report post Posted March 12, 2015 Are you up at Snetterton, sure Debs will let you sample it for yourself. Fine by me 1 Keethos reacted to this Share this post Link to post Share on other sites
remal 85 Report post Posted March 16, 2015 Slightly off topic a bit But I have Escort Cosworth Alloys on my kit car which is 8J width and should have 245 tyre on it. The car was built in mind for 205/45/16 wheels on a 7J width alloy But has built the car around the wheels I am running 215/40/16 on the rear and 205/40/16 front to fit under the cycle wing and rear tub. never been a issue and I love the escort cosworth alloys I did not want to change. The only issue I get is trying to find a 205/40/16 profile tyre as there are not that many about Share this post Link to post Share on other sites
Keethos 842 Report post Posted March 19, 2015 This maybe a bit of a crazy idea but what are the chances of the Primacys in wider form still being less grippy? Could I counteract the extra width grip with some Primacy tyres to make the car a lil less grippy while the car is still NA? Thus getting wider rims for the concaved look while still having a relatively predictable loose back end? Share this post Link to post Share on other sites
Lauren 2259 Report post Posted March 20, 2015 You could certainly try it Keith. The thought had crossed my mind, but I don't like the extra sidewall flex running a 225/45 on a 17" rim. Though on 18's on a 225/40 it would be okay I should think. 'Little' Keith, what's all this 'lil' business eh? Share this post Link to post Share on other sites
Keethos 842 Report post Posted March 20, 2015 Little business? You've lost me? Plus I'm thinking of going 9.5J so I'm thinking possibly going 235/40 or 245/35 Primacys, hopefully they'll won't over tyre the car too much. Share this post Link to post Share on other sites
Mike 458 Report post Posted March 20, 2015 I think Lauren wants you to use "little" instead of "lil" Share this post Link to post Share on other sites
Keethos 842 Report post Posted March 20, 2015 Oh right.......cos I'm GANGSTA!......and that I'm lazy.....soz Lauren 1 KevinA reacted to this Share this post Link to post Share on other sites
