Technical Bald front right tyre

[ralphnz]

I got a warrant on a mk1 45 just a month ago with 4 good tyres. I had a look tonight and the inside half front right tyre is completely bald. Probably only after 300km. Uno's are very very light cars, so would it be possible that my weight would cause the tyre I sat nearest to to wear down like that?

 

[Jai]

you'd have to be this big:

and a balding tyre would be the least of your worries, i'm a good (or bad) 18 stone, so no, you are not a tubby in a tub

as for your tyre pattern baldness issue....traking and balancing all good?

 

[ralphnz]

Hey, where did you get that photo of me from?

Thought I 'd ask the not so obvious before going to a garage. Cheers.

 

[alexGS]

Seriously, I think it's most likely to be a toe-out problem. That chews out the inside edges of the tyres, but often more the right tyre than the left.

You want neutral toe (zero toe, wheels parallel) on a standard Uno, which is possible to set yourself using a tape measure between the tread blocks, front and back of the wheel.

I had a strange tyre wear problem on my old Uno 60 when I had too much toe-in. The left front tyre would wear, evenly, more than the other three.

I believe that a wheel alignment is a worthwhile investment whenever you buy two or more new tyres.

Also I believe that with tyres, you get what you pay for. More expensive tyres, in the correct size (155/70 for an Uno, 175/60 for the Uno Turbo), give a more precise feel to the steering, are quieter, and last longer. I think that spending up to about $100 per tyre is perfectly acceptable for something that's so important.

If you do lots of k's, it's a waste of money to buy second-hand tyres, too. You save a bit over the new price (I bought a nice matching set of Bridgestone 155/70s for $260 recently) but you get something that's already part-worn - and part-aged - tyres have a useful life of about six years before they get perished and hard.

-Alex

 

[ralphnz]

Ah right. That makes sense. I'll check the other tyre. Cheers Alex.

 

[Chas Uno]

Definitely a tracking problem. Or if the car has been in an accident the suspension geometry could be out. Get it checked by a garage with the correct equiment and that should sort it out.

 

[ralphnz]

Is tracking/alignment something you can do yourself? I understand the bit about the toe in. But what if it's pulling to the right as well, what does one adjust or do you need a special machine. I mean if you know it's pulling one way, without a machine or whatever it is they use, is there a rough adjustment that I could do to test just by seeing if the steering straightens up after i've adjusted it.

 

[alexGS]

Is tracking/alignment something you can do yourself? I understand the bit about the toe in. But what if it's pulling to the right as well, what does one adjust or do you need a special machine. I mean if you know it's pulling one way, without a machine or whatever it is they use, is there a rough adjustment that I could do to test just by seeing if the steering straightens up after i've adjusted it.

The toe-in is the only adjustable angle on an Uno, so start with that. Camber (the amount that the top of the wheel leans inwards, inwards=negative) is sort-of adjustable if you use a round file to enlarge the strut bottom bracket upper bolt hole. But that isn't normally necessary.

Funnily enough, I was just contemplating a quick tracking/alignment check myself. I did this on an Uno in the past, then had it subsequently aligned (on a proper machine) and it was well within tolerances. So, here's how:

- The car must be on the ground, having been driven or at least rolled 5m back and forward and bounced several times, to bring the suspension to the correct height. You can't check alignment with the wheels hanging in the air.

- Use a tape measure to measure between the edges of tyre tread blocks. Do this as far back as possible, so that the tape measure just touches the exhaust pipe. Then do this at the same distance forward of the wheel centre.

- Since the tread blocks are not at the wheel rim, and since the measurement points are not 9'o'clock and 3'o'clock, the measured difference is NOT the actual toe. But with the Uno, you are aiming for neutral toe (0mm difference). So it is sufficient to measure no difference (within an accuracy of +/-1mm.) You'll need a good tape measure and possibly an assistant...

- To make an adjustment, begin by slackening the locknut on the tie-rod end. This is often much harder than it sounds, due to corrosion in the threads! Of course, you have to try and do this from under the car... or, you have to jack-up, make the adjustment 'blind', lower the car and roll it, bounce, etc. before you can re-check.

For the locknut you'll need a 21mm open-ended spanner (does everyone have one of those?), and to stop the tie-rod from rotating, you should use a 12mm spanner on the special flats included in the tie-rod. Or, you could just rely on the balljoint to stop the tie-rod from rotating. I always do that and it hasn't caused me any problems.

- With the locknut slack, turn the tie-rod relative to the balljoint. Half a turn is about half a millimetre of toe adjustment - so you often don't need much.

- The adjustment also affects the steering wheel angle. If that started out as straight-ahead, then you would need to adjust both sides equally. More usually, the steering wheel is off-centre; lengthen the tie-rod on the side that the steering wheel pointed towards.

- If the steering wheel is slightly off when the alignment is deemed correct, it is probably easier to take the steering wheel off and re-fit it straight.

---
The above lets you get pretty close to correct after, say, changing the steering rack, and you save the $65 cost of a wheel alignment if you know the rest of the suspension is still OK after a previous alignment. $65 seems quite a lot to pay for just a simple toe adjustment, compared with the same $65 to have all four wheels adjusted on, say, an Alfa Romeo 166 which has toe-out specified at the front and toe-in specified at the back, adjustable camber, etc.

But if the car is new-to-you, it is probably worth paying out the $65 so that you know if there are other wrong angles (e.g. camber, caster) as a result of suspension damage. This can then be remedied properly by parts replacement over time. Also, you can then give someone else the job of shifting the locknut that hasn't moved in ten years (an oxy-acetylene torch helps...) which suddenly makes the $65 seem much better value.


-Alex

 

[ralphnz]

"$65 seems quite a lot to pay for just a simple toe adjustment"
Absolutely.

"But if the car is new-to-you, it is probably worth paying out the $65 so that you know if there are other wrong angles (e.g. camber, caster) as a result of suspension damage."
I'll do this after trying the above. You always feel better about trying it first before paying the garage.

It's anal but i keep the costs in my head of pretty much everything, so after a year or something i can say, this car cost me this much per km...

Another quick question. Would having tyres on the front that have a larger diameter than the back cause any steering issues?
(I have 155/70/13 on the back and 155/80/13 on the front of my MK2. The steering does feel a little too responsive, ie it wanders compared to my MK1.)

And why do the 175's necessarily go on a turbo and not a standard uno?

Cheers.

 

[Chas Uno]

Another quick question. Would having tyres on the front that have a larger diameter than the back cause any steering issues?

No. Unless they were vastly different in diameter in which case the car would look silly

And why do the 175's necessarily go on a turbo and not a standard uno?

Cheers.

The turbo has more power and stiffer suspension so was given wider tyres than the less powerful models. However, 175 tyres are an old size and hard to find now. They were more popular in the 80's, but you'll find it easier to find 185/ 55 (I think) that will give you the same rolling radius. They will also be cheaper than 175's as they were more common.

 

[alexGS]

The turbo has more power and stiffer suspension so was given wider tyres than the less powerful models. However, 175 tyres are an old size and hard to find now. They were more popular in the 80's, but you'll find it easier to find 185/ 55 (I think) that will give you the same rolling radius. They will also be cheaper than 175's as they were more common.

Chas is certainly right about the 175 size being hard to find! But in NZ, I doubt that 185/55 13 will be available either - in fact I'm certain they won't be There aren't many new small cars on the market, or at least, the small cars that are around have big wheels - 15" is normal!

You have to go to a real tyre specialist (i.e. not Firestone Direct, Beaurepaires, or Tony's Tyre Centre) to find 13" tyres (apart from 155/80 'budget' tyres - see below)

For 175/60 there's only one brand left (Hankook?) - jjhepburn bought some of the last and also bought Toyo RA1s in 185/60 13, which seem like a good choice for a Turbo - the widest you can go before you rub the gearbox with standard Turbo alloys. Also, the Toyos are just about the last 185/60 13 available since the Bridgestone Conselfa bit the dust a few years back.

175/60 or 185/60 will not fit onto standard Uno steel rims (4.5"). Well, they will go on, but it's not ideal - too much sidewall flex so you won't get the benefit of the wider tread. They only suit the Turbo alloys (which are wider: 5.5").

165/70s are pretty easy to get but they're also too tall (not low-enough profile), being designed to replace 155/80s. They'll rub the arch liners on an Uno and 165 is still a little bit wide for a 4.5" rim. Remember that 135 was the original fit for the base-model Unos - on the same 4.5" rim. 165/70 is OK on a 5" rim and that is what FIAT X1/9 wheels have. Incidentally it can be about the same price to buy a set of alloys + tyres as it is to buy 13" tyres!

Really the only 'proper' tyre for Uno steel rims is the 155/70. You can get these new - Nankang (Taiwan), about $80 each - and they also seem to be coming off certain small Jap imports - Suzuki Alto, Diahatsu Charade? - so luckily, supplies seem reasonably secure. I recently bought four used "Bridgestone Sneaker - Made in Japan" 155/70 tyres - 6mm tread each - for $260, almost certainly off a Jap import. These tyres are designed for shopping-cart wheels, but I'm happy to say that the Uno steering feels 'correct' and there's a surprising amount of grip - tested that today. However, the tyre noise is a bit high. You can't have everything...

On the other hand, 155/80 13 tyres have the 'budget status' of the market, since they fit a few old Toyota Corollas and Ford Lasers (student-transport ) At $50 each brand-new, you don't get much of a tyre. It's not just the profile (height) difference, it's the fact that they're made to be cheap. Often they use a hard compound (for durability) that has next-to-no grip in the wet. The sidewalls don't have the complex bracing of expensive tyres, so the responses (and steering feel) change at different speeds and loads. It doesn't surprise me in the least that you mention more of a wandering feeling (Ralph), I've experienced it myself and even a horrid wobbly feeling on other budget tyres. I won't risk them.

I guess I'm a bit picky these days - I've had some amazing tyres in the past - retreads that came apart, 15-year-old rubber that should have stayed at home when it rained, 185/70 tyres on 4.5" rims, an original Pirelli P1000 135 tyre that blew out, fortunately when I was driving through roadworks near Kaikoura, etc. etc.

The tyres I remember most fondly are Barum (a Czech brand owned by Continental), they seemed to be a quality product: low noise, good grip, fair price. Let's face it, if a budget tyre is $50 and a Barum tyre is $80, that's $30 difference - $120 if you're replacing all tyres at once. What price for safety?

If anyone thinks $80 per tyre is excessive - all four tyres were shot on that Alfa Romeo 166 I had in March. The cheapest replacements I could find (in the 225/45/17 size) were $260 each. The most expensive were $900 each (Michelin). Part of the problem is that these 17" tyres really ARE better, but they are developed for the sort of 200km/h+ speeds that we can only dream about in NZ...

My suggestion would be to put those 155/80 tyres on the back - though, I was having this discussion just the other day with some people, and the conclusion was that the best tyres should always be on the back of a FWD car, because the back end is hard to catch when it comes around in the wet.

Oh and thanks for the thanks, Ralph I'm pleased you're going to check/adjust the toe setting yourself - I think you'll notice a difference and it has to be better than wearing out more tyres!

-Alex

 

[ralphnz]

Yeah i've got a 175 on the standard spare and it looks like it's about to pop right off!!!