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14 inch vs 15 inch
darren(SA) - 22/11/03 at 04:18 PM

Hi guys, trying to decide on the above, ignoring costs, do i go for 14" with 60 profiles or 15" with 50 profiles?

I'm well aware of the diff in road cars as I moved my golf from 14's to 15's.down to better handling vs better comfort i suppose. How many guys are running 15's? I would be keen on these but I have heard some rumours that 15's are a very hard ride for a locost, any opinions?

thanks
darren

[Edited on 22/11/03 by darren(SA)]


Stu16v - 22/11/03 at 05:00 PM

Ok, you asked.....

13's. Smaller, lighter, cheaper, and more suited to the car type IMHO....

Saying that, mine is on 15's, but for different reasons. My car is slightly bigger, so I thought 15's would look more 'in keeping' with the scale. And I dropped on some alloys at the right price


Metal Hippy - 22/11/03 at 05:13 PM

I'm told an inch makes all the dfference....


theconrodkid - 22/11/03 at 05:16 PM

so em keeps saying


ChrisW - 22/11/03 at 05:52 PM

15s all the way. You know it makes sense. Who wants comfort in a Seven??

Chris


craig1410 - 22/11/03 at 06:33 PM

I will have to go for 15's on mine as I am using Sierra rear disc brakes and they won't fit in 13's or 14's (They will fit in 14" steel wheels due to them having thinner walls than equivalent alloys but I don't want steel wheels on my wagon thanks very much...)

I would have gone for 13's to take advantage of cheaper tyres as I expect my Rover V8 will probably eat tyres but as I said they won't fit. The other advantage of 13's is that I understand they are quite a bit lighter (wheel and tyre) than an equivalent rolling radius 15" (wheel and tyre again) and this can affect acceleration in the lower gears. If you are planning on drag racing or sprinting then 13's would be much better I'd expect due to the smaller rotational inertia and also the taller aspect tyre should give more grip off the starting line, especially if crinkle walled tyres are used.

HTH,
Craig.


Mark Allanson - 22/11/03 at 07:22 PM

I am going to use 185 70 13's, because they are cheap, easily available and as has been said before, they suit the car.

The biggest advantage is that you still have handling. lower profile tyres do increase the grip, but at the expence of feel. The difference between being on the limit and upside down in a ditch is far less with low profiles. The 70 series will squeel, kick, thow tantrums and generally give you loads of warning before they let go, and when they do it is more progressive, easier opposite lock and easier regain of control. 45 series are lethal, everything is fine at high cornering speeds until they aren't and then your dead.


Mark Allanson - 22/11/03 at 07:24 PM

Forgot to mention, the 70's put a lot less strain on the suspension components and chassis brackets.


craig1410 - 22/11/03 at 08:07 PM

Mark,
What brakes are you using on the rear? Drums I'm guessing?

Don't take this wrongly, I got a Sierra disc setup virtually for free so I used that and was too far down that path before I realised the problem with caliper clearance. Drums are fine (on the back anyway...) and will probably give you a better handbrake which as you know is very handy for stopping the car rolling down hills when out shopping

I may end up with 14" steel wheels initially due to lack of funds and this may prove to be a happy compromise. If I can find some alloys which will clear my calipers then I'd be more than happy with 14" wheels (same for 13's but much less likely due to clearance). I know what you mean about 45 series tyres as I have some on my Rover Vitesse Turbo (215/45 17) and they have never even chirped a hint of a squeal before letting go. Fortunately (in this case) the car is front wheel drive so at least I get to see what I'm about to hit and have a chance to back off and avoid it!!

Cheers,
Craig.


Mark Allanson - 22/11/03 at 08:17 PM

My back end is capri, so I am using capri RS wheels. I do have a set of 14" sierra pepperpots which you could have FOC except for the 1600 mile round trip to collect them!


craig1410 - 22/11/03 at 08:26 PM

Ah that's less than a 10 hour trip for my trusty Vitesse...especially if I tweak my turbo boost up a few psi...

Are Sierra pepper pots alloy then? If so, do you happen to know if they can accommodate disc brakes?

I had a nice set of Capri Laser alloys which are more or less the same style as the RS ones but when I tried them on with the sierra discs I couldn't even get my little finger between the disc and the wheel and had absolutely zero chance of getting a caliper in there. I sold them to another builder from the forum a while back. A shame because they would have been ideal...

Cheers,
Craig.


Mark Allanson - 22/11/03 at 08:33 PM

They are off my donor, equipped with drums, so I cannot say for sure, I am sure that someone can confirm


steve m - 22/11/03 at 11:40 PM

Just for info I have the 7 spoke 13" rs style wheels on my car at the moment , I also have 5 capri pepperpots that used to be on it, and neither style will fit on a k reg sierra, as the front brakes were to big

my next plan is to fit 14 or 15 wheels

Also what might be a silly question but,

If I was to fit larger discs with my existing 4 pot calipers would my brakes be better ?


craig1410 - 22/11/03 at 11:52 PM

I'm no expert but my logic goes something like this:
If you have the same friction pad area (size of pad assuming it still contacts disc correctly) and the same contact pressure (same caliper, master cylinder and pedal setup) then using a larger disc will increase the maximum braking torque for the same pedal effort due to the increased "leverage".

I don't know how far you can stretch this though because eventually the design of the caliper will restrict the size of disc as the disc will tend to hit the top and bottom of the caliper body and thus the pad area will not be fully utilised near the centre of the pad. Diminishing returns will result once you get to this stage.

HTH,
Craig.


darren(SA) - 23/11/03 at 10:06 AM

quote:

15s all the way. You know it makes sense. Who wants comfort in a Seven??



I think you got a good point, i dunno if you saw I had a post going a little while back where I was moaning about my rear suspension floating all over the show, so it is evident that I'm going for handling, its still a bit of a debate tho. In SA there are so many diff types of mags and the diff btwn 14's and 15's could be as low as R200, tyres not bad either, good set of dunlops ( 50's ) for around R500 each, so the cost factor doesn't play a major part.

check this picture out, set of mags from a golf VR6 on a picture that I 'borrowed' from who knows where (greatest compliments), these are 15's and i could get hold of a set quite easily for around R2000. Rescued attachment lotus7.jpg
Rescued attachment lotus7.jpg


ChrisW - 23/11/03 at 11:05 AM

Bigger wheels = better looks

I'm going to be running 18" alloys with 35 profile tyres

Chris


paulf - 23/11/03 at 03:48 PM

Mark are you sure about the easy availability of these tyres? i want to use them for much the same reasons but as i have mentioned elsewhere there appears to be little choice of quality tyres in this size the best choice of 13 inch tyres is 60 series which does not give good gearing.I have tried to obtain used tyres but all the local suppliers have told me that 185-70-13 is now an obselete size. There is some choice of 175-70-13 as it is still a commonly fitted size but i think they would be to narrow.
Paul.

quote:
Originally posted by Mark Allanson
I am going to use 185 70 13's, because they are cheap, easily available and as has been said before, they suit the car.

The biggest advantage is that you still have handling. lower profile tyres do increase the grip, but at the expence of feel.


Mark Allanson - 23/11/03 at 10:12 PM

I checked with my tyre supplier (the one selling the Formula 27). He offered me several types of 185 70 13's, varying from budget at £20, to michelins at £39. I am going to fit budgets first until I get the suspension set the way I want it, as I am sure they will be ripped to shreds in about 2 months.

The 185's are easily available, but he had none in stock, but could get them in at 24 hours notice.


Peteff - 23/11/03 at 11:27 PM

I bought 4 Vredestein 165/65x13 for my car to get the gearing right for SVA speedo check, but they look like roller skate wheels. I like them on the front but would like some 185/70's for the rear. They are good tyres and look the part, nice square profile. I got a discount for buying 4 at once so it's worth asking round unless you know the dealer.

yours, Pete.


mackie - 24/11/03 at 11:59 AM

Craig, we got 5x 14x5.5 inch alloy wheels with our Ghia 4x4 Sierra so I can definately say they fit over the rear brakes.
They are fitted with 195/60 tyres which should be fine I think.


Bob C - 24/11/03 at 12:13 PM

Go up to 17 inch rims for looks but unsprung weight suffers. A 7 on a truck axle is already iffy on unsprung weight. 13" and 15" give best tyre choice, I'm using 14" & you simply can't get some tyres in that size.
Solifworks say's I can use 10.5" discs in the 14" wheels - I look forward to seeing whether real life agrees....
Cheers
Bob C


craig1410 - 24/11/03 at 12:56 PM

Bob,
Ah but does solidworks know about the caliper??? I got my Sierra rear discs inside the 13" capri laser wheels but there was no room for the caliper to wrap around it...

Interesting point about the tyre availability for 14" being lacking. I may rethink my intention to go for 14" in favour of 15". Thanks for that!

Cheers,
Craig.


craig1410 - 24/11/03 at 01:02 PM

quote:
Originally posted by mackie
Craig, we got 5x 14x5.5 inch alloy wheels with our Ghia 4x4 Sierra so I can definately say they fit over the rear brakes.
They are fitted with 195/60 tyres which should be fine I think.


Thanks Mackie, I will keep an eye on the local papers for any such cars being scrapped although as Bob was just pointing out, tyre choices may be limited and may warrant me moving to 15" wheels.

One other thing which I have come to accept is that I don't believe that I need to stick to the standard offset for my wheels (ET18/19) and will most likely use a 38mm offset as the choices are much greater. I have more than enough body clearance on the back to allow these to fit and on the front I already have more scrub radius than I want so handling may even be improved. I don't want to trigger another scrub radius argument but just wondered if anyone else has decided to broaden their choices by going for wheels with a more common offset such as 38mm and whether they had any issues which I have not considered.

Cheers,
Craig.


mackie - 24/11/03 at 01:17 PM

I personally haven't noticed a problem with tyre choices for 14inch wheels. I guess it depends on what you are after but it should not be at all difficult to get good value, good performing tyres on 14in rims. For example Pirelli P6000s or Yoko A539s.
I think we're just going to keep it locost and use the sierra alloys, they are the same as the ones on conrod's car and don't look too shabby for effectively free wheels. The tyres on them seem virtually new but are budget items.


mackie - 24/11/03 at 01:19 PM

You may want to ease up on the old avatar sizing there craig!

[Edit]
Ah, you did

[Edited on 24/11/03 by mackie]


blueshift - 24/11/03 at 01:22 PM

quote:
Originally posted by ChrisW
Bigger wheels = better looks

I'm going to be running 18" alloys with 35 profile tyres

Chris


quite subjective. I think the viento in your signature looks silly with those wheels. plus the handling and ride may suffer, for our car I want nice squealy progressive tyres to practise rwd antics in.


Bob C - 24/11/03 at 01:28 PM

re 14" tyre choice - my other car is a mx5 & they come with 14" wheels standard. When the bridgestone SO2 was the best tyre around you could not buy it in 14". I'm pretty sure it's not the only one, I guess they reason that wrt performance tyres, performance motors tend to have big wheels.
And I do have the caliper in the solid model too!!! I've measured the wheels & downloaded a pdf of my caliper of choice & reckon I have about 1.5mm clearance, have to breathe in when I fit the wheels..
Nice looking de- dion in the pics - how does the axle weight compare to an escort one?
cheers
Bob