Will nobbly tyres allow me to grip better on these?

Mildly_Miffed

GervisLooper said:

Yes this has been mentioned in the other thread/s. What genius thought up this 'open differential' thing? "One wheel is spinning, I know lets put all the power to that one wheel"! I suppose there was some logical reason for it but I am yet to hear it?

Draw two concentric circles, one half the radius of the other.

Now look at their circumferences. VERY different, aren't they?

That's what the two wheels on an axle do when you go round a bend. The inner one takes a much shorter route than the other.

That's the job of a diff. If the axle was solid, they would not be able to easily equalise the distance travelled.
On a rear axle, that's a pain in the backside.
On a front axle, it makes it undriveable.
You'd simply go straight on instead of turning.

Limiting the slip in the differential is a trade-off - it allows a smallish difference in those speeds, but one of the downsides is complexity.

Having the diff lockable adds, again, complexity - it allows you to make the axle solid when required, but have the diff open when not required.

https://www.youtube.com/watch?v=yYAw79386WI

GervisLooper

I will also add that I recall one time this slipping has happened even on a 'normal' road. It was very steep mind and a very small, less than well maintained probably, road and wet but just an example of it happening outside of this very specific case.

I was halfway up the hill and then another vehicle was coming down on the single track road so I stopped on the hill.

They were driving a 4x4 so were happy to show off and ramp it up on the grass verge for me to pass but since I was at a standstill and tried to move again the wheels just kept spinning.

I don't think they realized this and thought I was just faffing around but eventually they drove by and I was able to move off again sooner or later.

Perhaps a small bit of evidence that the existing tires are less than ideal even on normal roads?

paul_c123

Nobbly tyres will help because they have a more open tread pattern and (hopefully) a deeper tread. Normal road tyres quickly clog up (fill the tread with compacted mud/dirt) and become "slick", offering almost no grip.

What would also help is contact area - by reducing the tyre pressure (a lot), you increase the contact area and this offers more grip. And if its a 2WD, pumping up the non-driven wheels will help too.

But I think half of it is down to driving technique. You can overcome an open diff (kind of), by simultaneously braking and applying throttle, or 'stabbing' the brake while the throttle is applied. Not all cars will keep the power the same from the engine doing this though, and its very awkward in a manual transmission car. And you can 'clean' the treads by spinning the wheels at a very high rate compared to the ground speed. Off road tyres have a much better "self cleaning" property, this is how its done. But it can damage the surface you're driving over. There is always a compromise between being able to make progress and ground damage in an off road situation, this is why roads are built - to allow sufficient traction, while also being hard wearing.

GervisLooper

paul_c123 said:

Nobbly tyres will help because they have a more open tread pattern and (hopefully) a deeper tread. Normal road tyres quickly clog up (fill the tread with compacted mud/dirt) and become "slick", offering almost no grip.

What would also help is contact area - by reducing the tyre pressure (a lot), you increase the contact area and this offers more grip. And if its a 2WD, pumping up the non-driven wheels will help too.

But I think half of it is down to driving technique. You can overcome an open diff (kind of), by simultaneously braking and applying throttle, or 'stabbing' the brake while the throttle is applied. Not all cars will keep the power the same from the engine doing this though, and its very awkward in a manual transmission car. And you can 'clean' the treads by spinning the wheels at a very high rate compared to the ground speed. Off road tyres have a much better "self cleaning" property, this is how its done. But it can damage the surface you're driving over. There is always a compromise between being able to make progress and ground damage in an off road situation, this is why roads are built - to allow sufficient traction, while also being hard wearing.

I think your suggestions are based on driving in mud wheras this case is not the mud but the rubber tyres spinning on the hard plastic? Wouldn't nobblers be null like other poster mentioned for this use case?

Lol first time I read of these open-diff beating hacks. Yes my van is manual and diesel if that affects anything.

As you note I can't imagine how that would work in a manual especially since I would be starting on an incline so have to hold the clutch to release into gear. Would have to have a third foot for the brake stabbing technique now?

Well the plan is to not get into a stuck position at all but having other techniques to use in case it happens the more the better as it can happen so easily as I found yesterday while still in the experimentation phase.

born_again

On e thing here. A more open off road tyre is going to get it's grip off the matting. Then it is going to put more stress on that & could start ripping it to bits if it has not been installed as per manufacture. Which it seemed from another thread below that they were not.

https://forums.moneysavingexpert.com/discussion/6585047/can-i-get-all-my-money-back-if-seller-claimed-they-would-be-suitable-for-the-job-but-werent/p1

Arunmor

OP your using the wrong vehicle, with overinflated (van) tyres, on the wrong type of terrain with plastic boards that were not designed for the job you want them to do.

Good luck to you.

sheramber

Did you read the installation instructions on the website?

7 - INSTALLING SLABS FOR VEHICLE US

Goudy

Arunmor said:

OP your using the wrong vehicle, 

That's pretty much it.

I've been in your shoes too many times to mention.
A hobby of off road motorcycling tended to take me and my vehicles into the quagmire all too often as that's where all the events were hosted.
I've either been tugging a trailer with a car or had a van (the worst in these conditions).

I've probably done more damage to cars getting them unstuck than I ever did on the road.

Your mats are ok to a certain point, but once you are past a certain incline the weight of your vehicle overcomes traction (and open diffs and two wheel drive has been discussed already so we don't need to go into that).
Throw in they get wet and muddy and you're not going anywhere.

You could try altering the surface with sand/glue but it'll wear off in no time.

You might be able to overcome some of the problem, but it's hit and miss.
Something that works in one set of conditions, won't in another and you could be throwing good money after bad, particularly with tyres.
Even decent 4x4 with mud tyres can struggle if they can't put their power down.
Gaining/keeping traction has as much to do with control of power as it does with things like the tyres and locking diffs.

There are a few tips that might help though.
Reversing a FWD car up a slope means more weight is over the driven axle and usually reverse is a lower gear than 1st which makes it more useful.

Another tip is start up in gear.
I know this sounds brutal but put the car in the lowest gear, take the handbrake off, foot off the brake and crank the starter with the clutch up.
This helps by not overcoming the driven wheels with too much torque setting off.
Diesels are particularly good at this, yes they'll jump and shudder firing up but they tend to chug along without throttle input once fired up and you should creep along, but you really need to be in the lowest gear possible for this.
It's also a neat trick if you get stuck halfway up and need to come back down under some control.

If you can't improve the ground with a proper track, you probably need to think about changing your vehicle.
Something not only 4x4 and can take some mud tyres, but with a locking centre diff and a low gear or range of gears.

I've used winches in the past, even bolted an electric one in the back of a van once.
They are useful but need some care, not just with maintenance but use.

born_again

Now migrated to another section

This quote may peak some interest 😶‍🌫️

 like the studs on s & m bondage gear 

https://forums.moneysavingexpert.com/discussion/6590153/what-can-i-use-to-act-as-studs-to-fasten-on-to-hard-hdpe-plastic-to-give-more-traction#latest

Arunmor

This is becoming a dark matter.