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Tiny · Joined: 10 Apr 2006 Posts: 502 Location: London, UK

I had the rear tyres replaced two days ago as the old ones were cracked and duff.

I only realised at the tyre garage, that the PO had put 195/70/14 rubber on the back.....and I had the stock size of 185/70/14 rubber on the fronts (which i replaced last november).

They went ahead and put 185/70/14's (h-rated) on the back so I was correct all round. The rubber was a make called "corsa." The guy said they were made by pirelli....cheap and cheerful.

Anyhow....I left there happy with a warm fuzzy feeling, until I entered the first country road bend/twisty....and when I turned the steering wheel...all of a sudden the back felt much "looser" and it felt like there was more body roll. It feels much more wibbly wobbly at the back....wtf!

I carried on driving and thought I'd do a proper test.

Cornering at speed feels more unstable...but does not actually let go at the back.. it feels like the back wants to come round more....or at least that there is more body roll.

I confess I am a noob with tyres...I don't know too much about tyres and characteristics....but am thinking that logic says that this would indeed happen with a narrower footprint at the back.....yes?

I put new boge shocks on the rear couple months ago...and handling was more "stable" ....with 195's on the back. Whats going on?
Tiny

ps. side-rant -On the weekend...I lost my backed up data on my PC with norton ghost (the backup file corrupted)...and with it...the pics of all my seat re-upholstery went bye bye...all done with my sisters sewing machine...so I am annoyed coz I wanted to post my pics!! grr!!
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*****1981 - 924 - Auto - London, UK******

924RACR · Posted: Thu May 15, 2008 1:36 am Post subject:

Realize also that the different tyre type front/rear will impact handling substantially, perhaps more so by far than the small size change. Best to match 'em up.
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Vaughan Scott
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'79 924 #77 SCCA H Prod racecar
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Tiny · Joined: 10 Apr 2006 Posts: 502 Location: London, UK

hot damn! hadn't thought of that. thanks man.
At least I know now....what Im buying next!
reckoning to a new full set of 195/65/14 Yokohama AVS Sport
tiny
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*****1981 - 924 - Auto - London, UK******

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

Also give them a few miles to wear in before expecting optimal handling. Shaggy was very squirrelly at first as well, and is now a slot-car-esque beast. . .had two C4S's get out of my way during a club backroads event last weekend!
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Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

Neil924 · Joined: 18 Mar 2003 Posts: 4225 Location: Canada

Also the taller the tire, the more flex it will have resulting in that instability in the turns. You can try a lower profile tire next time.

As Rasta said, the tires needs to be scrubbed in a hundred miles or so.

924RACR · Posted: Thu May 15, 2008 3:58 am Post subject:

Actually it's more a matter of sidewall stiffness - which, admittedly, is usually less for a taller sidewall, but can still vary substantially across different tyre constructions.
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Neil924 · Joined: 18 Mar 2003 Posts: 4225 Location: Canada

Smoothie · Posted: Thu May 15, 2008 5:42 am Post subject:

Also double check the tire pressures. With more pressure in the rears than in the fronts, the rears will behave more like stiffer sidewalled tires and you might get it back to feeling more like it did before.
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"..it's made in Germany. You know the Germans always make good stuff."

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Eturbo924 · Joined: 09 Nov 2002 Posts: 2212 Location: Londonderry NH

It is best to go with a tire that you know... was recomended to you.

As noted above the side wall stiffness is key. The speed rating frequently can indicate this but not a definate.

I had the same thing happen back when I was 17. Ohy dating myself again. Anyway I needed new tires and had nice tires on (but worn) and went to Sears Auto Center. Got a pair of "Road Handlers".... right... anyway same thing from the sales guy... made by Pirelli (sp?) and H rated. Thought wow these should be great.

Nope... first corner I went into I thought I was going to roll over! Way to much slop in the side wall stiffness. It was terrible. Lucky for me Sears gives you (or gave at the time) a 1000 mile 30 day money back offer. So I took the car to Town Fair Tire and described the issue to a guy. He was actually quite good. I got a set of Swedish tires. Gislaved (or some thing like that). These were only T rated but man what a difference. I loved those tires! You could push and push and push the car and then when it finally began to loose traction all 4 tires would begin to easily side together. No rear end or front end snap... just perfect.

Anyway moral of the story. Know what you are getting. I never go for the "made by" crap. Do some research on line and talk to others with your car.

I have some recomendations if you like... other than the Swed tires.
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1992 968
2003 C4S
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Tiny · Joined: 10 Apr 2006 Posts: 502 Location: London, UK

Thanks folks,

I grabbed her back end and gave it a good jiggle observing for sidewall squishiness....which is apparent....but they do look like they could do with a bit more air too.

I'll check and possibly increase rear pressures a wee bit.. during the scrub in....and see....but I think Im suffering in my hastiness to buy poop.

If mine don't get any better... they're coming off. ATM I see a fair amount of peeps on here praising the yokos.

Yeah Eturbo, tell me what lubber you like and maybe i'll lub it longtime too.

thanks guys
Tiny
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*****1981 - 924 - Auto - London, UK******

Eturbo924 · Joined: 09 Nov 2002 Posts: 2212 Location: Londonderry NH

I like Mich MXV4

And Falken 512

Have tried them both and they are good performers in dry and wet.
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1982 924
1992 968
2003 C4S
Parts Parts Parts and More parts.
E-mail me for parts you need!
Drive Fast!

skytrooper · Joined: 29 Aug 2007 Posts: 461 Location: Canandaigua, NY

I put Fuzion HRi 205/60/15's on my S last month. I love 'em ! They hold on to the pavement like a dog with a bone. Next week I get to try them at Watkins Glen

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Matt

1987 - 924S "Black Pearl"
1982 - BMW 633CSi
1984 - BMW 528e
1983 - 944 N/A "Blue Max" (Gone)
1981 - 931 "Scarlet Harlot" (Gone)
1976 911S Targa (Gone)

Tiny · Joined: 10 Apr 2006 Posts: 502 Location: London, UK

hey guys,
wonder if these alloys will fit/bolt on and be correct?
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=290229616840

what details would i need to know, in order to find out??

tiny
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*****1981 - 924 - Auto - London, UK******

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

Mike924 · Joined: 12 Aug 2004 Posts: 2601 Location: IoW UK

+1 on the Yokos. I had a set on the old wheels and I was very pleased with the level of grip.

On those Ebay wheels, Tiny, you need to check that the bolt spacing, "PCD", is 108 mm or 4 1/4 inches. I have a vague recolloction that Escorts do use that pitch...

Then there's the question of offset. FWD and RWD set-up normally have quite different offets...

Lastly, you'll most probably also need spigot adaptors. (I don't know what diameter(s) Ford favour).
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