Can you fix flat spots?

[Jack]

I'm a bit of as newbie to classics and the reulting issues.
Could anybody help me out here?
The Spider I now own was to the best of my knowledge parked for a bit more
than a year in storage.
I've have the wheelsa balanced but still get a big vibration at aroung 90km.
Funny thing was it felt like an up/down vibration rather that steering wheel shake.
The tyres are Malaysia made, not top qual.
On jacking the car and spinning the front wheels there is a very definite flat dip on the tread.
I doesnt seem to be the rim as it spins vaguely round, but look at the tread as
it's spinning and there's this visual blip,blip of the line of outer circumference.
I dont know anything about flat sopts created from long term inactivity.
Could this be that?
Is it fixable?
Cheers

[lance]

G'day Jack,

Thought someone may have replied to your vibe question already, but it seems not. Sounds like if your car has stood for a year or so without turning a wheel the tyres will definately be ....ed. Alot of cheaper tyres are out of round even when new and just get worse as they age. Some tyre shops have facilities to buff the tread on the case to true them up but if, as you've suggested, they're not good quality to begin with maybe it's time for a new set.

Most tyre/rim balance probs. present at around 80-100 k's or thereabouts and if it's the front you'll usually feel it thru the steering wheel, if it's the rear thru the seat etc. If they're flatspotted or separated you'll often feel a bumping sensation at really low speeds too. Good luck with the Spider, might catch you (and him) on the Sept. 17th  EMR.

[Beatle]

Jack,

You could try inflating the tyres to about 45/50PSI for a while to see if that helps.

***   SAFETY SAFETY SAFETY   ***

Only inflate them to this pressure after checking that the rubber isn't perished or cracked.  If it is, throw them away and buy new tyres.

When inflating the tyres, don't stand to the side of the tyre.  If it lets go it will be out the sidewall. The tread is the strongest section.

Don't drive in the wet with the tyre inflated so high, and only leave them at 50PSI for a few days.

[Jack]

Hey Lance ,Paul
thanks for your replys.
Firstly I'd like to say what a great drive I had on the EMR up in the hills. I have not ran the car so hard or far and really enjoyed the drive. I wish I had been closer to your car Lance to compare how my was running on the road. I was behind the silver Duetto for a fiar way and I must say how smooth he looked. Never out of shape, unlike me!
Interestingly I seemed to have used about half my engine oil on that run although my Spider never blows smoke, or not that I notice.
On the tyres, I have tried as I said Lance to deflate the tyres to about tewnty and run them on the freeway so as to get them nice and hot and then I went up to about 39 and freewayed them again.
To no avail so far. They still are a bit bumpy. Hate the idea of them shaking and vibrating the front half of the car about as I've got a few rattles and clunks anyway. Lance , I meant to ask you about vibration and shakes over bumps with your Spider, knowing that you've had yours for so long. I am getting a bit of windscreen and dash shake over bumps. I realise it's a thirty year old car and wont be "tight" by any stretch of the imadgination but i wondered if that was part of the beast?
Would a chassis stiffener be of much benefit? Are there any tricks to tightening them up apart from an extensive rebuild?
On the tyres, I'll try going up to maybe high fourties as the tyre states a maximum pressure of fiftyone on the side wall.
The condition of them is really quite good with at least 90% tread if not more and no sign at all of perrish or cracks.
If i have to go for a new set, got any leads on a dealer for a decent price? I am unimpressed with the guys Ive been going to.
Thanks again for the replys. The Spidwer owes me so much money I'm duty bound to stick with it and make improvements.
Not to mention, It's too much fun at the moment!
Cheers
jack

[lance]

G'day Jack,

Yeah the Sept 17 EMR was good, thanks again to Damian for organizing a fun morning for all who attended. You used half your engine oil??!! Sounds a bit excessive, it can only really leak on the ground or blow out the tailpipe. Might be time for a check up?

Sounds like your tyres aren't going to fix themselves then. Maybe some of the Alfa track guys could suggest a tyre shop that has the means to buff the tread so you can at least get some use from your current set of "wobblies".

The high tyre pressures can't be helping the cowl shake issue either, which all topless cars suffer from to some degree. If it's any consolation I've driven several mid 70's Benz roadsters and they were just as bad as the Spider! I always find it interesting how two identical models of a particular marque can sometimes be so very different to drive due to the aging process, lack of maintenance etc.
Have a drive of another Spider, you may find yours is pretty good after all.