1991 M100 Steering instability -15" 205 50 R15 Tyres?

[Twayblade]

Hi all, I've only had my 1991 Elan since March and I've had limited opportunity since then to seriously drive it but when I have , I noticed a tendency for the steering to be a little unstable( constant need to make micro adjustments) at higher speeds!
I read through a lot of steering related posts on the forum relating to play in the steering column UJ'S and concluded on my car as best I could, that the UJ'S were fine, as were the tie rod ball joints etc and the small amount of free play i could detect was actually within the rack itself. I haven't as yet attempted to adjust this.
I discussed this issue with a mate of mine who has experience of sprint racing Mini's, and his response was to check wheel alignment and Tyres, which set me off looking at the posts in this section and the references to tramlining.
Now, titter ye not, on checking my cars tyres I found that the two TOYO Proxes T1R'S on the rear were different vintages one 2016 and one 2006, and both FIRESTONE FIREHAWK TZ200's fitted to the front were 2002. All four tyres have4-5 mm of tread.
I am inclined to replace all four tyres as a first step but wondered if anyone could advise on tyre choice in the first instance (15" wheels) or anything else that may be relevant to my issue?
thanks in advance
Tony G

[Rambo]

Driving on 19 yo and 15 yo tyres is definitely NOT recommended by me, despite the tyre depth

Whilst this may not be the source of your problem, I'd recommend you change all 4 asap, for peace of mind, if nothing else. Michelin, Pirelli, Goodyear, Yokohama, Toyo... you won't go far wrong

PS are you sure your brakes aren't binding ie caliper stuck on one side ?

[par]

both FIRESTONE FIREHAWK TZ200's fitted to the front were 2002.
Tony G

Is this not the vintage of Firestone tyres that ruined their reputation back in the day?

I would follow Rambo's advice and get 4 new tyres. I would also recommend checking the pressures as the Elan appears to be quite sensitive. My car felt horrible when I set them all to 32 psi but after research on here dropped them to 27 psi which made a massive difference.

[Graaf]

Driving on 19 yo and 15 yo tyres is definitely NOT recommended by me, despite the tyre depth

Whilst this may not be the source of your problem, I'd recommend you change all 4 asap, for peace of mind, if nothing else. Michelin, Pirelli, Goodyear, Yokohama, Toyo... you won't go far wrong

PS are you sure your brakes aren't binding ie caliper stuck on one side ?

Quite a few years ago I bought a Japanese in port Eunos. The tyres were about 15yrs old if not more. Driving home was like driving on ice, terrifying.

[KenCarson]

Look at Toyo Proxes 1 tyres. £70 each fitted.

[HJ2]

What happens if you drive, say 150 kilometers an hour and firmly press the brakes?

[sideways]

What happens if you drive, say 150 kilometers an hour and firmly press the brakes?

You stop?

I have old (and hard) tires on mine and the only reason I haven't replaced them is because I don't drive at 150KM/h any more and I am selling the car - leaving the choice of rubber up to the new owner.

[Rambo]

What happens if you drive, say 150 kilometers an hour and firmly press the brakes?

You stop?

I have old (and hard) tires on mine and the only reason I haven't replaced them is because I don't drive at 150KM/h any more and I am selling the car - leaving the choice of rubber up to the new owner.

Yes, but do you stop on a straight line? Or does it dive violently to one side?

[lotusflasherman]

When I acquired yet another M100 7 years ago I lined up my collection of wheels and tyres to decide which were best for what was going to be my daily drive. I've always had a preference for the same (make and model of) tyres all round so there is no inconsistency between wet and dry handling but this was reinforced when it became obvious there were different profiles across manufacturers whilst all marked as 205 50 R15. The new acquisition had come on 4 different 'budget tyre' which had significantly different profiles. (I might have posted a photo on this forum but it was a long time ago...)

Tyre manufacturers and dealers consider tyres to be “new” and fit for retail up to 5 years from the date of production shown on the sidewall. This is an industry standard based on the German BRV. When in use, it is recommended that tyres are replaced when they reach 7 - 10 years old.

Get a set of 4 Toyo Proxes and you'll have eliminated any instability from tyres ... and you can enjoy wearing them out before they 'time out' . Some favour other tyres but my experience on Proxes has been very good, can be got for a good price too.

[lotusflasherman]

You stop?

I have old (and hard) tires on mine and the only reason I haven't replaced them is because I don't drive at 150KM/h any more and I am selling the car - leaving the choice of rubber up to the new owner.

That surprises me as you're the man who is also proud he drives on old brake fluid ... "In almost 60 years of driving in a multiplicity of cars, from the mundane to the magnificent I have changed brake fluid only once in one car."

Old tyres, old brake fluid ... an accident waiting to happen.!

[dapinky]

Old tyres, old brake fluid ... an accident waiting to happen.!

Ah, but it will give the new owner a choice of whether they want to car to drive and stop properly......

.... as long as the price is adjusted accordingly.

#ArthurDaley

[sideways]

What happens if you drive, say 150 kilometers an hour and firmly press the brakes?

You stop?

I have old (and hard) tires on mine and the only reason I haven't replaced them is because I don't drive at 150KM/h any more and I am selling the car - leaving the choice of rubber up to the new owner.

Yes, but do you stop on a straight line? Or does it dive violently to one side?

The "You Stop?" was a bit glib so apologies for that

Straight as an arrow, no pulling to either side etc, tires are old but not ancient and to my mind a little on the hard side but lots of tread. No ABS was a bit of a surprise when I locked them up, forgetting there WAS no ABS - mine are completely stock and feel perfectly fine.

Back to the original, if indeed the car is being driven as it should and on old tires - ditch them and get the best quality ones out there.

[Twayblade]

Thanks for all the input, lv'e ruled out binding brakes, l have to admit the brakes are not brilliant, that's another job l guess!but the car does pull up straight.
Once l checked the age of the tyres l did realise having read other posts that irrespective and as a first step they would have to be replaced, so were booked in Sat morning for 4 new Toyo TR1's.
I'll report back?

[Twayblade]

Well, what a difference four new tyres have made!! Instantly felt more grippy and stable . 26psi all round? Haven't gone on a long run yet but the car definitely feels a lot better

[HJ2]

I had the same experience, hence my question concerning braking behaviour.