rims + tyres = wheels?

[Jaws]

OK I've read the fact sheets and scoured the forum for information but I still find myself a bit adrift.

Having decided to get some Mazda 6 rims (16 x 7) I am now unsure what tyres will suit my needs. I was aiming for something like 225/65 if possible since there is loads of choice of tyre and even 225/60 gives plenty of high load/speed combinations to think about. I am quite aware of the consequences of changing the overall diameter of the wheels on a Bongo and would actually prefer something larger in the wheel department to bring the speedo into line and reduce cruising RPM.

But the offset of the rims I have acquired is 55mm and offering them up without tyres makes me wonder. There are plenty of posts to say Mazda 6 rims are fine but do they alll have the same offset and what is the ideal tyre profile for this rim on a Bongo? Eyeball suggests 225/anything might rub on the front suspension struts. Before I ask the local tyre dealer to do a trial fit has anybody got first hand experience of this?

[M 80NGO]

Ok fella i've just had a nightmare with tyre sizes but with the help of the very nice people on this site all is now well, i have 18" rims with 245/40 tyres and there's still plenty of roon between the sidewall and the suspension strut, this combo makes my speedo under read by 4 mph, the standard size for a bongo is 215/65 15 this has a rolling radius of 207.50 cm if you use 235/55 16 tyres on your new rims then this will give your combo a rolling radius of 208.88 cm making your speedo overread by 0.7% so when your speedo reads 60 mph you'll actuall be doing 60.4 mph

Hope this helps ya

[scanner]

I use 216/60-16s plenty of choice at a good price and plenty of load carrying capacity. My speedo has a 3-4 mph safety margin, which is just how I think it should be.

If you want good all year round tyres that allow you to keep moving when others slither to a halt go for Vredestein Quatrac 2s or Quatrac 3s.

Try and get Quatrac 2s if you can, I rate them as the very slightly better all round tyres with good cold weather grip.

[Diplomat]

this has a rolling radius of 207.50 cm if you use 235/55 16 tyres on your new rims then this will give your combo a rolling radius of 208.88 cm

These figures don't look right to me as a radius ( a rough measure on my tyres comes up with a radius of about about 33 cm). The above looks more like circumference. (loosely measured at 211cm on mine).

I looked up 'rolling radius' and learned that there is a difference between static and dynamic rolling radii as the tyre deforms under load.

Therefore I would suggest that the most accurate measurement would be distance travelled per revolution at a specified speed. Even that would reduce slightly with tread wear.


Frank

[mikexgough]

The advice you have been given is wise.....

http://www.kouki.co.uk/utilities/visual ... calculator is a good link

[Jaws]

Thanks for some very helpful replies guys! I do like the idea of the Quatrac 2/3 tyres, although I live in Sunny Donny so would clearly only need the winter bit when visitng the alps

My main concern is the different offset of these rims rather than diameter per se. The standard offset is 40mm but these are 55mm. i.e. the mounting face of the rim is 15mm further from the midline. And they are 7" wide rather than the standard 6". As far as I can work out this means the inside edge of the rim will be about 15 + 12.5mm closer to the suspension than a standard rim. Or about an inch. That's why I'm concerned about the profile of tyre I can safely use without fouling on the suspension or body.

BTW I did a little research into weight bearing since I know that there could be concern over using car wheels on a van....


Vehicle Kerb Weight (Kg) Gross Weight (Kg)
Bongo 4wd 1700 2260
Mazda 6 saloon 1485 2010
Mazda 6 estate 1575 2145
Mazdza RX8 1430 1815
Mazda CX7 MPV 1790 2430

Assuming a reasonable margin for safety on the part of the manufacturer I guess the Mazda 6 estate wheels I have should be OK?

[scanner]

Thanks for some very helpful replies guys! I do like the idea of the Quatrac 2/3 tyres, although I live in Sunny Donny so would clearly only need the winter bit when visitng the alps

I hope that wink means you are joking....................?

As you couldn't be more wrong.

Having used Quatracs (of both types) for the past 3 years I wouldn't go back to so called "summer" tyres under any circumstances.
Even with global warming we still get more "winter" than we do "summer" and Quatracs handle it far better than the cr@p Bridgestone Turanzas (at twice the price) I've just dumped from my other car.

[Jaws]

I hope that wink means you are joking....................?

Yep. Definitely joking

[You've Been Bongod]

mazda 6 wheels are perfect for bongo's

i have had 4 sets of them on bongo's and no probs
i used 215 65 16 101L tryes

[mikexgough]

mazda 6 wheels are perfect for bongo's

i have had 4 sets of them on bongo's and no probs
i used 215 65 16 101L tryes

Have you put those lovely chrome rims to bed for the Winter yet Carl....

[You've Been Bongod]

shortly will be mike

[Jaws]

mazda 6 wheels are perfect for bongo's

i have had 4 sets of them on bongo's and no probs
i used 215 65 16 101L tryes

That's very reassuring: thanks.

[Jaws]

mazda 6 wheels are perfect for bongo's

i have had 4 sets of them on bongo's and no probs
i used 215 65 16 101L tryes

That's very reassuring: thanks.

Thank you scanner. Thank you mike. Thank you everybody else on the forum for the endlessly useful contributions. I now have some lovely black mazda 6 rims with Vredstein Quatrac 3 tyres.

Bit nip'n'tuck with the weather mind: had to order the tyres from Germany and they got to Midlands in 48 hours only to be stuck for a week due to snow!

Happy now

[scanner]

mazda 6 wheels are perfect for bongo's

i have had 4 sets of them on bongo's and no probs
i used 215 65 16 101L tryes

That's very reassuring: thanks.

I now have some lovely black mazda 6 rims with Vredstein Quatrac 3 tyres.

had to order the tyres from Germany

Can I ask how much they cost imported?

[Jaws]

The tyres were £120 each delivered. This is about 30% more than when I first checked them out a month or so ago. Then, there were 'local distributors' offering them for less but strangely enough couldn't supply when I tried (in person) to order. "The UK allocation has been exceeded" was the polite way of putting it