Home > Wheels & Tyres > Wheel and tyre choice |
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shropshiredefender Member Since: 05 Jun 2017 Location: Shropshire Posts: 834 |
My target when changing wheels was to improve the turning circle to an acceptable level for everyday driving/parking.
Like you I am not keen on spacers. Standard ET is 33, I settled for ET10 wheels giving a 46mm wider track by moving the rim 23mm away from the radius arm, which is the limiting factor to the turning circle, and adjusting the steering stops accordingly. I felt that a -25 ET would give a 116mm wider track and this was too much. Anyway after a couple of years use I'm happy that I can get into tight parking spaces (for a 110) and take tight mountain hairpins in one whereas before I'd taking 2 or 3 swipes at it on the standard wheels. Just had a new set of 235/85/16 BFG AT fitted as the wider 265/75's have no obvious benefit in real world driving, I know because I had them fitted with ET0 modulars on my 300tdi 110. Click image to enlarge |
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27th Apr 2018 5:31pm |
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Cupboard Member Since: 21 Mar 2014 Location: Suffolk Posts: 2971 |
Wide tyre are good on cars that need lots of high speed lateral stability.
They're completely pointless on a Defender unless you like the look of them. Another option would be the Cooper AT3, I personally think they look pretty good. |
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27th Apr 2018 6:50pm |
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r21 Member Since: 25 Apr 2014 Location: Merseyside Posts: 77 |
cheers, think I’ll rule out the challenger ones then, cheap modulars or expensive bowlers it is then, guess I’ll have to see how much is left in the budget and how much I can sell the dual finish ones for.
I’ll check out the AT3 as well |
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27th Apr 2018 7:47pm |
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L110CDL Member Since: 31 Oct 2015 Location: Devon Posts: 10728 |
As a couple of you have mentioned that 265/75/16 BFG's are no good for the real world driving and only for fast cars, i would have to disagree with you there and your saying that the 235/85/16 will do the job as good or better than the 265/75/16 ?
Please enlighten me on these comments 1996 Golf Blue 300Tdi 110 Pick up. Keeper. Clayton. |
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27th Apr 2018 9:06pm |
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shropshiredefender Member Since: 05 Jun 2017 Location: Shropshire Posts: 834 |
What I said was "Just had a new set of 235/85/16 BFG AT fitted as the wider 265/75's have no obvious benefit in real world driving" ie there is no difference other than looks - and that's a matter of personal choice.
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28th Apr 2018 11:09am |
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r21 Member Since: 25 Apr 2014 Location: Merseyside Posts: 77 |
I've decided to go with the Bowlers, the tyre choice is between
BFG AT 235/85/16 265/75/16 Performance for both is listed as identical, Fuel (F), Noise (74), Wet (B) 235's are about £20/wheel & tyre less so nothing really in it Since I want a better turning circle and handling, what would be the better choice - am I correct that the 235 would be better for turning.... bowler wheels are ET10 so -23 in comparison to the dual finish at ET33 235 tyre width divided by 2 is 117.5 so inside tyre face will be 23mm futher from radius arm than current 265 tyre width divided by 2 is 132.5 so inside tyre face will be 7mm futher from radius arm than current Is that right? |
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30th Apr 2018 8:10am |
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r21 Member Since: 25 Apr 2014 Location: Merseyside Posts: 77 |
Just rang Bowler, they recommend the 265s - they said they wouldn't recommend using 235s with their wheels
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30th Apr 2018 8:50am |
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Cupboard Member Since: 21 Mar 2014 Location: Suffolk Posts: 2971 |
Sadly my normal go to web links with people that are better at explaining things than me seem to no longer exist. The link I'd love to share is this: http://www.expeditionswest.com/research/wh..._rev1.html Tall, narrow tyres have a lower rolling resistance. That's why bicyles with taller tyres are easier to pedal. In off road driving in soft conditions, a wider tyre needs to move more goop out of the way to make progress. This is the first factor. Second factor is that traction corresponds with the length of the contact patch. For a given pressure the narrow tyre will have a longer contact patch. Letting air out of a tyre does little to the width (unless you're going round corners which we'll come to later) but primarily makes the patch longer which is one reason why letting air out of a tyre inproves traction (and that's something that's done by drag racers on hard concrete too). The other reason you want to run at reduced pressures is so that the tyre can flex around the terrain, a tyre that's wrapped around a rock will grip it much better than one that's perched on top of a rock. That conformability is something that's completely irrelevant to drag racing If you are just running at standard pressures on the road then the skinny tyre still has benefits. The maximum force through friction that a tyre can support is calculated with the formula F=μR, with F being the friction force, μ being the coefficient of friction (defined by the stickiness of the rubber and deteriorating with age which is another reason to change your tyres regularly) and R being the force pushing the tyre in to the ground - i.e. the tyre pressure. Skinny tyres run at higher pressures than wider tyres so up until the limits of the rubber disintegrating they will stick better. Finally, a skinny tyre is lighter so less rotating mass which is easier to start and stop, less unspring weight so the suspension can do a better job, less load put on all the vehicle components. This is also a good reason to use alloy wheels which should be lighter than the steel equivalent. The advantages are more surface friction, lower rolling resistance and a longer contact patch for a given ground pressure. And because the tyre is narrower you get a better turning circle and less mud up the sides of your car which for most people are good things. For an off road vehicle you want a lot of sidewall because it means you can lower the tyre pressures more, it protects the wheel and provides more comfort (the tyre is springier). Now, there are disadvantages to skinny, high profile tyres. In the same way that the long front to back contact patch gives you front to back traction, a wide contact patch gives you side to side traction. For the same pressure you can't have both long and wide. When you go round a corner, the side wall flexes and picks the inside edge of the tyre up. Effectively, this reduces your tyre width. To limit the effect you need a wide tyre with a short sidewall running at a high pressure. Where you are seriously at risk of sinking without trace you need a lower ground pressure. You can usually go lower with a wider tyre before you can problems with running out of sidewall or loosing a bead. This is why you see arctic vehicles with balloon tyres and beadlock wheels. Look at military and commercial off road vehicles (e.g tractors), they are almost all running things with a long and narrow contact patch. The exceptions are things that need flotation without much in the way of traction like crop sprayers which usually have wide tyres unless working between rows. Tesla, interestingly, give their vehicles equiped with 19" wheels a longer range than the ones with 21" wheels. There are reasons to run wide tyres but none that are relevant to what I use my Defender for and what a Defender is really good at. |
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30th Apr 2018 11:48am |
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r21 Member Since: 25 Apr 2014 Location: Merseyside Posts: 77 |
thanks for the very detailed response, the thinner tyre definitely would appear to be the better choice (turning circle wise) however when I spoke to Bowler they were pretty clear that they don't recommend 235s on their wheels, I wasn't buying them directly from Bowler so it wasn't a commercial decision to suggest more expensive 265s
So I bit the bullet and ordered 265s based on Bowler's advice, the 7mm extra clearance and maybe whatever I can tweak from the steering lock will hopefully improve it enough. |
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30th Apr 2018 12:25pm |
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Cupboard Member Since: 21 Mar 2014 Location: Suffolk Posts: 2971 |
It might just be that the wheel is too wide for a 235.
Enjoy your new boots |
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30th Apr 2018 7:56pm |
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L110CDL Member Since: 31 Oct 2015 Location: Devon Posts: 10728 |
No worries 1996 Golf Blue 300Tdi 110 Pick up. Keeper. Clayton. |
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30th Apr 2018 9:43pm |
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L110CDL Member Since: 31 Oct 2015 Location: Devon Posts: 10728 |
Many many thanks for the great information Cupboard
I read the info, will have to read it again to get my head round it so the way i see it ( i'm most probably wrong ) that 265's are good for going around corners and letting the pressure down for off road use ? what you use on your landy, suits your choice, i get that but do you think that the 235's would be as good or better than the 265's that i have got on and what i use my landy for ? once again, many thanks 1996 Golf Blue 300Tdi 110 Pick up. Keeper. Clayton. |
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30th Apr 2018 9:57pm |
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Arierep Member Since: 12 Apr 2013 Location: Portugal Posts: 258 |
Just my 2c.
Iv'e gone progressively bigger in wheel offset over the years. +33, +8, -9 and now -25mm. The Land Rover community is culturally very adverse to big wheel offsets, which is not always justified. At each increase in track width I found a decrease in steering self centering and increase in road camber following, but an increase in stability, safety, traction and body protection in narrow offroad tracks, with no discernible increase in bearing problems. This includes a 11.000km Africa expedition with a loaded roof rack, tough (ish) offroad and some rally style driving. I've settled at -25 and wouldn't use anything different now. I've since installed torsen diffs front and rear which corrected the self steering issue. If you go offroad or carry a load in your roof you should consider a large wheel offset. Regarding improving the turning circle, don't forget you get this at the cost of a less favorable CV angle. Again, this is mostly a consideration if you go offroad. In my case, I've adjusted the steering stops to not use full steering lock potential in order to protect the CVs. |
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30th Apr 2018 11:19pm |
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plumpmoose Member Since: 14 Dec 2015 Location: North Devon & Oxon Posts: 114 |
Can this be made a sticky? Common sense for most LRD owners. |
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3rd May 2018 11:19am |
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