[Jeep]

Hi St. Anger

Not sure if my post is too late. Anyways:

I upgraded the stock tyres in my 1996 M800 (145/70/R12) to 165/60/R12. Kept the same rims. The tyres are tubless Bridgstone Potenza. Driven for about 20K kms since then and no punctures yet (touchwood). You will be amazed to feel the difference in road grip. Expect 1 kmpl reduction in mileage in city drives as well as on long drives (make sure you fill air to 30 psi). The ride quality at the back seats improved (or so I felt). This is probably true because the stock ones were worn out when I made the replacement, otherwise there is against logic.

However, now I feel I should change those to 155/70/R12 for better mileage and comfort (however as the profile will increase the city driveability will reduce due to the effective 'taller gearing')

[humyum]

Its just getting used to it.Ram sir and me have 145/80/r12s in our 800s since more than a year now.
Ram sir has a 5 speed mpfi 800 so the pickup factor loss is less noticable to him
Where as i have carburated 1998 800 and the pickup factor was initially noticable but now i have got used to it.
So go ahead with the swap.U ll get used to it in no time and there is a very minute noticable difference which will not hamper city drivablity

[biju]

Yesterday my M800 car tyre had nail on it and it went flat. This is first time that I have experienced such a thing after I bought my car. Immediately I changed the type with a new tyre.

My Question is ..Should I replace the tyre again after repair or should I continue with the new tyre and keep the repaired on as an extra tyre ?

Biju

[sumeethaldankar]

Hi,
guys one day the local air pump attendant,while filling air in my tyres noticed that the front right tyre had lesser air pressure than the remaining ones.He asked me to get the tyre checked for punctures.

I took the car to the near by tyre puncture shop and on removing the
wheel we discovered that there was no puntcure in the tube but the
tube itslef had been deformed.It was narrow at certain places and at other places had become wider than normal.

The tyres are MRF Zigma's 12" Radials.I had recently ie aroud 10 Months
back had upgraded to Neo Alloys (12").Did this had any adverse affect on
the tube.

Gurus need to know your suggstion on what could be the cause of the problem

Thanks.

[sureshshanmugam]

Hi I have just replaced the foot wear for my M800 5 speed to Bridgestone Turanza ER60 - 145/80 R12(Alto's Size). The steering vibrates above 90KMPH. I doubt that it is not the right set of tyres to be fit for M800. I have balanced the front tyres. Will this be a problem because of not balancing the rear wheels. I ride on the Aura 12" alloys.
Also please let me know the Tyre Pressure that can I can keep. The tyre shopwala recommended me 27 Psi. id thid right.

Experts please provide me suggesstions to improve my ride quality.

[humyum]

Originally Posted by sureshshanmugam

Hi I have just replaced the foot wear for my M800 5 speed to Bridgestone Turanza ER60 - 145/80 R12(Alto's Size). The steering vibrates above 90KMPH. I doubt that it is not the right set of tyres to be fit for M800. I have balanced the front tyres. Will this be a problem because of not balancing the rear wheels. I ride on the Aura 12" alloys.
Also please let me know the Tyre Pressure that can I can keep. The tyre shopwala recommended me 27 Psi. id thid right.

Experts please provide me suggesstions to improve my ride quality.

Ram sir and me have 145/80/R12s in our 800 since about 2 years now.He has no vibration problems at all,and i had vibration problems due to faulty mrfs which is sorted now.
Nope the vibration wont be because of rear wheels not balanced.Try fixing the back tyres front ( after balancing) and the front ones back and see.
Also is your steering,suspension and bearings in order ?
27 or 28 is the right tyre pressure(cold)
145/80/R12 is perfect for the 800.No problems with the size at all.
Also the steering vibrates above 90 till what speed does the vibration last?Seems to me like an overinflated tyre or a balancing not done properly.

[ramie2400]

The correct size for M.800 is

145/70 R12
165/60 R12
155/60 R12

[sureshshanmugam]

Thanks Humyum. when my wheel was balanced, the techie set the balancing mode to inner instead of inner and outer. when I asked him, he said my alloys cannot be balanced for outer balance as balancing weights cannot be hammered to it. Will this be the reason by any chance. More over what makes the difference in inner balancing and outer balancing in a wheel

[kpzen]

Suresh
Did u get the alloys with the tires or u had them before with stock tires?

[humyum]

Originally Posted by sureshshanmugam

Thanks Humyum. when my wheel was balanced, the techie set the balancing mode to inner instead of inner and outer. when I asked him, he said my alloys cannot be balanced for outer balance as balancing weights cannot be hammered to it. Will this be the reason by any chance. More over what makes the difference in inner balancing and outer balancing in a wheel

Well high end sophisticated balancing machines do have that inner/out balancing selecting option which our local tyre wallas dont.
Morever was this vibration problem present even remotely before u got the new tyres fixed ? If not,then go to another balancing fellow and get it rebalanced and check it out.

[sureshshanmugam]

Hi kpzen,
I had the alloys in my old stock Ceat 145/70 R12 tube type tyres itself. I used to touch 110Kmph effortlssly in those tyres even at 56000Kms, they were good except for the rubber got integrted and started cracking.

Hi humyum,
I think this is the right solution that would help. How ver my car is now 59000Kms in the odo, I will wait till 60000Kms and after the service i will take to another Tyre expert in chennai LAL Enterprises and do a re-balancing. Does any expert have opinion on LAL enterprises or any other good place in chennai to consult this.

[sumeethaldankar]

Hi Guys ,
My marutis fitted with Neo Alloys (12") and MRF Zigma Radials (tube) tires.I have a couple of problem ever since i have switched to the
alloys.
1- On the day i got the alloys fitted the read tire punctured because of large nail.When i inspected the read tire on noticing the
puncture i found that there was no valve sticking out of the value outlet.I took the car back to the guys who fitted the alloys and
had the tire removed.We found that the tube inside the tire had moved around and hence the valve was not found where it was suppose.Is this normal??
2-Problem,my front right tire after almost 10 months of ftting the alloys showed loss of air pressure.When i had the tire removed for inspection the repair guy fount that there was no puntcure in the tube,but the tube had lost its shape.It was wider at some places
than normal and at certain places it was narrower.

Now my question is this happening because of alloys?Are alloys wheels more designed to work with tubless tires rather than
tube type ones?

[Ram]

Originally Posted by sumeethaldankar

Hi Guys ,
My marutis fitted with Neo Alloys (12") and MRF Zigma Radials (tube) tires.I have a couple of problem ever since i have switched to the
alloys.

1- On the day i got the alloys fitted the read tire punctured because of large nail.When i inspected the read tire on noticing the
puncture i found that there was no valve sticking out of the value outlet.I took the car back to the guys who fitted the alloys and
had the tire removed.We found that the tube inside the tire had moved around and hence the valve was not found where it was suppose.Is this normal??

This most likely happened because of moving the car with a flat tire.

When the car is driven, even twenty to thirty feet on a completely flat tire, the tire distorts cyclically.

This distortion can suck the inner tube to a different position within the tire cavity, especially if the valve stem is a loose fit in its hole in the wheel rim.

Is the valve hole in your alloy wheel-rim, large enough for the valve stem to fit loosely, while deflated?

The churning action of the deflated innertube can yank the valve stem into the tire cavity and shift around.

Originally Posted by sumeethaldankar

2-Problem,my front right tire after almost 10 months of ftting the alloys showed loss of air pressure.When i had the tire removed for inspection the repair guy fount that there was no puntcure in the tube,but the tube had lost its shape.It was wider at some places
than normal and at certain places it was narrower.

Now my question is, is this happening because of alloys? Are alloys wheels more designed to work with tubeless tires rather than
tube type ones?

No. It sounds like your inner tubes are either defective or the wrong size, for that tire. This can happen if you upsized your tires, but used the same old innertubes from your old small tires.

Alloy wheels are just truer and less malleable than conventional pressed-steel wheels.

Alloy wheels have been used with tubeless as well as tube type tires.

My Ford Taunus had OEM alloys and tubeless tires, with tubes in them.
The car was regularly maintained by Ford of Nederland. No problems. No complaints. I have also had a flat tire more than once with no such problem of valve stem getting sucked into the toroidal cavity.

That being said, I would still recommend you change to tubeless tires at the next opportunity.

[Ravi Yadav]

Recently I upgraded the tyres on my '97 model 800 to 145/80 R-12 tubeless. Replace all the rims with new ones.
To my surprise i have noticed that i am unable to cross the 100 kmpl limit. Before the upgrade i used to achive it quiet easily. Is this due to the change in tyres.

[Ram]

Originally Posted by Ravi Yadav

Recently I upgraded the tyres on my '97 model 800 to 145/80 R-12 tubeless. Replace all the rims with new ones.
To my surprise i have noticed that i am unable to cross the 100 kmpl limit. Before the upgrade i used to achive it quiet easily. Is this due to the change in tyres.

Ravi Yadav:
By going to 145/80R12 from 145/70R12, you have increased the rolling diameter by 5.71%

The overall diameter has increased from 507.8 mm to 536.8 mm. This means that your speedometer and odometer now indicate readings 5.7% less than actual.

When your speedometer indicates 94.6 km/hr, your car has actually already attained 100 km/hr !

See post #7 in this thread.

Ram