Tyres again

Technical questions and answers about the Mazda Bongo

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nightjar

Tyres again

Post by nightjar » Wed Oct 06, 2010 11:06 pm

I met a nice man in Aldeburgh ...

Sat in my new love, a guy came up and said he'd just installed 225x70 all round, and it handled beautifully. Thanks chap. Money pit!

Studied the forums.

I upped the pressures to 40 all round (much higher than the factory spec, but I've had it converted, so it's heavier).
Handled fine - comfortable at a clocked(?) 100mph down a long hill I know :-)

I knew my tyres were past their sell-by (front were worn at edges and rear were cracking - my mechanic just sucked in when he saw them). They were factory-original sizes, but had been changed in previous lives I think.

Went to local tyre shop ... discussed. Got 195x70 all round. They recommended a pressure of 50 (uppable to 65 when loaded)! Heavier load rating - small van type.

Steering is lighter (as it would be with that width and pressure!) and it seems to handle better than before on small lanes. Did a few wiggles at speed (60mph+), but only a few (no motorways tried yet).

Definitely stable so far. but I look forward to load/speed testing later (brick-dynamics understood).

Roll on winter!
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Re: Tyres again

Post by David Edwards » Wed Oct 06, 2010 11:14 pm

My bongo is an unconverted 96 flat top, I would be very wary with big changes in tyre pressures, this can make one hell of a difference to the safety aspect of the bongo, both at speed and during general handling and could also be a major point should you at any time ( heaven forbid) be involved in a bump and your vehicle gets examined, it may also have insurance repercussions. I may be wrong here but I am sure and indeed relying on other peoples findings and opinions here. Just speaking from experience of accidents dealt with during my police career I know that tyre pressures are examined carefully and have been deemed a contributory factor in some accidents.
nightjar

Re: Tyres again

Post by nightjar » Wed Oct 06, 2010 11:24 pm

Much appreciated 'caution'!

I presume(d) that the specified pressure for the tyres' safe operation would be the correct setting (even in law, but I'm more concerned about safety!).

I shall proceed with caution ... and invite advice.

Thanks
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Re: Tyres again

Post by scanner » Wed Oct 06, 2010 11:33 pm

But why have you gone undersized on the rear if you say you have a conversion and it's heavier?

Wouldn't it have been better to have gone for 215's all round instead?

What if you have an accident and the undersize rears are noticed?
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Re: Tyres again

Post by mister munkey » Wed Oct 06, 2010 11:43 pm

nightjar wrote:

Went to local tyre shop ... discussed. Got 195x70 all round. They recommended a pressure of 50 (uppable to 65 when loaded)! Heavier load rating - small van type.

Never heard of that in all my time on here.


Heavier load rating than what? 92 front 96 back is minimum anyway. Most Bongos have 100s on them. More than that is not only rare but excessively unessacary & expensive.


This sounds like the speak of someone with absolutely no idea of what they are talking about. No wonder the steering feels light, there's probably only 15% of the tread actually touching the road :shock:

Surely you have drifted into an Alchamists establishment not a tyre shop . . .

Drop back down to 40 & fettle from there.
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Re: Tyres again

Post by Scott » Thu Oct 07, 2010 9:09 am

Are you sure your van is heavier with a conversion?

I suppose it depends on what conversion you go for mind you.

The original seats weigh a ton and I'm pretty sure my van is lighter with its full side conversion (vohringer ply) and R&R bed then it would have been with those seats in.

Any of the converters like to put me right?

:D
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scanner
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Re: Tyres again

Post by scanner » Thu Oct 07, 2010 9:39 am

mister munkey wrote: there's probably only 15% of the tread actually touching the road :shock:
I certainly wouldn't want to be in front of you if you had to stop quickly in the wet.

And the centre of your tread is going to wear very, very quickly.

Drop back down to 40 & fettle from there.
Good advice.
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Re: Tyres again

Post by Ron Miel » Thu Oct 07, 2010 10:50 am

Scott wrote:Are you sure your van is heavier with a conversion?

I suppose it depends on what conversion you go for mind you.

The original seats weigh a ton and I'm pretty sure my van is lighter with its full side conversion (vohringer ply) and R&R bed then it would have been with those seats in.

Any of the converters like to put me right?

:D
Agreed. Eight seats and the full design load of (even Japanese) passengers will be heavier than most conversions.
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