Bongo Fury

When I got my bongo about a year ago it had all 4 tyres the same - 205/65 R15. The problem was the tyres were only rated as 94H so they weren't rated to cope with the rear axle loads. The tyres were almost brand new so I ran them until now with no issues - circa 15,000km and just got a puncture over the weekend - destroying one of the rears.

As I had to buy a new tyre and obviously didn't want two different sizes on the rear axle, I ended up buying two correctly speced 215/65 R15s for the two rear wheels. That still leaves me with 2 205/65 R15s on the front which should be 195/70 R15s.

Do you think it is ok to run with this combination?

I've calculated the diameters, circumferences and revs/mile for each of the tyres: The fronts I have are 133.25, the factory ones were 136.5 and the rears are 139.75.
The fronts I'm running are -2% over the correct rears (probably slightly worse in reality as the fronts are worn slightly) where as the correct fronts are -1.2% over the correct rears.

I hear that a lot of people run with 4 * 215/65 R15s with no issues - this leaves me to believe that the gearbox can at least handle being plus/minus 1.2% from stock and I am proposing to run -0.8% over stock where as a lot of people successfully run +1.2% from stock?

Is my logic sound?

If its 2wd definitely no issues.

If its 4wd I would think that's close enough, but someone with more knowledge will likely be along soon.

We have 4 identical 215s.

Forgot to mention it's 4WD

Your initial sums stack up.
i.e
The standard fronts (195/65R15) rotate about 1% more than the standard rears (215/65R15) assuming equal wear
With 205's on the front, they rotate about 2% more than the standard rears, assuming equal wear. 5mm wear off the front raises the difference to about 2.3%

Have you tried a searching on the forum for the viscous coupling front-rear tolerance?

cmm303 wrote:Your initial sums stack up.
i.e
The standard fronts (195/65R15) rotate about 1% more than the standard rears (215/65R15) assuming equal wear
With 205's on the front, they rotate about 2% more than the standard rears, assuming equal wear. 5mm wear off the front raises the difference to about 2.3%

Have you tried a searching on the forum for the viscous coupling front-rear tolerance?

Had to go quickly, SWMBO was calling TYPO ABOVE: Factory fronts are 195/70R15.

I've found a thread stating 6% here. I thought I had seen 3%. This post talks about 4% causing damage to the VC.

Maybe somebody has a definitive answer.

PS. Was it a craze to shoe Bongos in 205/65R15 94 - mine also had these all round when I bought it?

Thanks for the help, I haven't been able to find anything definitive. Anyone else any ideas?

cmm303 wrote:

cmm303 wrote:Your initial sums stack up.
i.e
The standard fronts (195/65R15) rotate about 1% more than the standard rears (215/65R15) assuming equal wear
With 205's on the front, they rotate about 2% more than the standard rears, assuming equal wear. 5mm wear off the front raises the difference to about 2.3%

...

PS. Was it a craze to shoe Bongos in 205/65R15 94 - mine also had these all round when I bought it?

Mine also came with 205s all round. Over the years I have acquired a number of elsewhere unloved steel wheels with good 215s (never any 195s) so am running those on the back with 205s on the front and as the spare.

Having read just now about the smaller circumference, I won't be be putting 205s on the back again (unless I get a puncture) as I want the best fuel economy and the lowest odometer reading!


Frank