Member Since: 04 Feb 2017
Location: Falkirk
Posts: 360
Weight is your enemy off road. D3's are heavy. So only fit what you really need and no more.Series one 1949 - in bits, chassis is strapped to the ceiling in my garage (beside the canoe)
LR 90 - In bits
Disco 3 - currently in bits
13th Nov 2020 8:49 am
Kenny57
Member Since: 12 Apr 2020
Location: Essex
Posts: 173
Breg90, would you be kind enough to elaborate on why you feel its my enemy?
This is a genuine question as, for example, one mate of mine says weight is your friend when dealing with mud because it makes your tyres sink down to firmer ground where they get more grip. Another mate says it's your friend when crossing rivers because it makes you less likely to lose grip on the bottom and get washed away. These both seem to make sense, but I can also see that weight might be your enemy when dealing with a steep slippery slope or a soft surface with no firm base.
And is it just about weight, or is it as much about tyre choice? By that I mean that narrow, low volume tyres would seem better for digging through surface mud, or making you less likely to float away in a river. On the other hand huge, wide "balloon" tyres might be much better for soft bottomless surfaces such as sand or bog (as in, if your tyres are big enough you can actually drive on water). And that's not even accounting for tread type and tyre pressure.
So, is it as simple as just vehicle weight or does it depend on what you want to do? Just a thought... is a Challenger tank worse off road than a Defender 110?
13th Nov 2020 9:58 pm
Breg90
Member Since: 04 Feb 2017
Location: Falkirk
Posts: 360
I've done a lot of winch challenges and other events. My brother (used to be my navigator) has completed in the Ladoga Trophy and in Ultra 4 events. I have been to California to watch king of the hammers 5 times and spent days marveling at the engineering of the cars in the pits (and watch poor performances from heavy cars). I have got 'stuck' and used winches 100's of times.
Ladoga, winch challenge, LR club trialing & Ultra 4 experience - weight is every thing. That's why the Russians spend ££££ on making lightweight 4x4's. That's why Randy Slawson wins KOH in his bare bones car design.
I have never wanted a heavy vehicle. I have always wanted a lighter one.
You can work around it by using wider tires to an extent to get lower ground pressure. But when you run out of traction - heavy is heavy. The car slides more further and faster in which ever way gravity is pulling it most. When you try and recover your self the winch works harder, you need a better anchor point or your mate has to snatch tow you harder, etc. You need more power to get up that big hill. That means you have to use more momentum, bigger risk of damage. More power means bigger axle components to handle it - you get heavier again.
There is always some one with a heavy car with its own gravity field who claims it helps. There wrong in my view. If your floating in water - open the door & add weight using the water or don't drive that deep. If your claiming that heavy axles helps lower your center of gravity - you have to much weight high up - redesign your car. Never add weight for the sake of it.
However that is my view as an engineer (strongly held). But it's a free world and your car to do with what you want. As long as your smiling at the end of the day your doing something right.
AdrianSeries one 1949 - in bits, chassis is strapped to the ceiling in my garage (beside the canoe)
LR 90 - In bits
Disco 3 - currently in bits
13th Nov 2020 10:31 pm
Kenny57
Member Since: 12 Apr 2020
Location: Essex
Posts: 173
Thank you Adrian for taking the time to tell me your background and your views.
As an ex-sports cars racer and retired engineer I know a reasonable amount about weight vs performance. I also know in the real world its not always that simple (unless you're Colin Chapman in which case its always that simple!) I also know my circuit racing knowledge counts for nothing off-roading a D3 but constraints such as budget, and compromises for reliability and component redundancy still apply. Chapman notwithstanding, adding some weight in the right places can nearly always be beneficial overall. Hence my request for advice.
In my current situation I'm stuck (I mean blessed) with the vehicle I have, and I'm not trying to win any competitions. I'm just after advice on the point where fitting or carrying "just in case" kit stops being beneficial and starts being counter-productive. For example, I guess carrying a big heavy land anchor makes it more likely I'll sink and get stuck in some mud, which is bad. But adding 20kg to a 2500kg car probably only increases that chance by a couple of percent, whereas having it on-board might increase my chance of getting out of the mud again by 100% if there's no handy trees, which is good.
I take all your points and thank you again for sharing your experience. I will avoid any unnecessary weight, and stretch my budget to higher-grade lightweight kit where ever I can. And whatever happens, I'll make sure to have fun!
Cheers,
Ken
14th Nov 2020 7:49 am
RRSTDV8
Member Since: 07 Apr 2014
Location: Here
Posts: 13538
Kenny57 wrote:
Breg90, would you be kind enough to elaborate on why you feel its my enemy?
So, is it as simple as just vehicle weight or does it depend on what you want to do? Just a thought... is a Challenger tank worse off road than a Defender 110?
My RRS gets around when I'm feeding pheasants. But it makes more mess than the buggy/quad does. That's because it's heavy, it slides on any cross slope which can be interesting in gateways and that's because of weight. Of course, more aggressive tyres would help there but then they'd also do more damage to the surface. The quad/buggy doesn't do the damage and gets around in soggy conditions that would stop a 4x4 on anything other than mud tyres. And that's because its weight is tiny for the size of it tyres.
A Challenger tank is better off road than a Defender because it's got huge tracks that spread the load, and huge tracks that maintain ground contact at all times, and huge ground clearance, and... Visiting from rrsport.co.uk
2012 RRS SDV6
2008 RRS TDV8
"When you fire that first shot, no matter how right you feel, you have no idea who's going to die! You don't know who's children are going to scream and burn. How many hearts will be broken. How many lives shattered. How much blood will spill, until everybody does what they were always going to have to do from the very beginning: SIT DOWN AND TALK!"
14th Nov 2020 8:43 am
Kenny57
Member Since: 12 Apr 2020
Location: Essex
Posts: 173
LOL, I get your drift, but is it a fair comparison between your quad bike and your RRS? While you're quite correct the bike benefits a lot from it's light weight, would you want to go to Wales for a weekend camping on it? (assuming "Here" isn't in Wales of course!).
I'm interested in what you say about tyres. I had the impression that ordinary road tyres do a lot of damage exactly because they slide around on slopes, spin up when you try and move, and have generally poor grip. Would a heavier car on a decent set of M/T's not still be better than a lighter car on ordinary tyres?
PS. I mean a heavier car on M/T's driven sensibly with just enough right foot, not a monster truck driven by someone with lead feet.
PPS. the avatar pic was taken after 6hrs of green-laning after lots of rain. I'm using A/T's. I think I broke traction once... briefly... and never slid off line. Although admittedly Essex is pretty flat.
14th Nov 2020 9:51 am
Breg90
Member Since: 04 Feb 2017
Location: Falkirk
Posts: 360
Kenny57 wrote:
Thank you Adrian for taking the time to tell me your background and your views.
As an ex-sports cars racer and retired engineer I know a reasonable amount about weight vs performance. I also know in the real world its not always that simple (unless you're Colin Chapman in which case its always that simple!) I also know my circuit racing knowledge counts for nothing off-roading a D3 but constraints such as budget, and compromises for reliability and component redundancy still apply. Chapman notwithstanding, adding some weight in the right places can nearly always be beneficial overall. Hence my request for advice.
In my current situation I'm stuck (I mean blessed) with the vehicle I have, and I'm not trying to win any competitions. I'm just after advice on the point where fitting or carrying "just in case" kit stops being beneficial and starts being counter-productive. For example, I guess carrying a big heavy land anchor makes it more likely I'll sink and get stuck in some mud, which is bad. But adding 20kg to a 2500kg car probably only increases that chance by a couple of percent, whereas having it on-board might increase my chance of getting out of the mud again by 100% if there's no handy trees, which is good.
I take all your points and thank you again for sharing your experience. I will avoid any unnecessary weight, and stretch my budget to higher-grade lightweight kit where ever I can. And whatever happens, I'll make sure to have fun!
Cheers,
Ken
Ken,
A good debate! Its all a compromise. If you are after the ultimate off road capability you would not start with a D3. But if you can only have one car that will transport the family in comfort with loads of gear, tow 3.5 T and go off road its an excellent starting point. But its heavy.
Perhaps what I didn't say was 'do you really need that protection given the weight it brings?'. Only you can answer that question. But assuming your D3 is not just an off road toy for abusing, then you need to be able to drive home/get to work. So are you really going to push it that far?? If not then my opinion is that you don't need 250 KG of protection.
I never fitted much protection to my 90 for winch challenge events, in fact 2 diff pan guards, a bit of bent scaffold pole welded to the chassis to protect the steering box drop arm and a roll cage. Nothing else. We destroyed wings, but never damaged anything underneath. Do you really need that under body protection??
Adrian
Series one 1949 - in bits, chassis is strapped to the ceiling in my garage (beside the canoe)
LR 90 - In bits
Disco 3 - currently in bits
14th Nov 2020 10:03 pm
Kenny57
Member Since: 12 Apr 2020
Location: Essex
Posts: 173
Well after this conversation the answer is "probably not"
Having said that, I have removed the original steel front bumper and underside guards so guestimate is the extra protection is more like 100kg (or not much more than an extra passenger and their overnight bag!). It'll be interesting to see who's closer when I get to the weighbridge.
My mate with a similar D3, in spite of his underside damage so far, is resisting significant protection. Instead of fixing his air compressor he's taking it off and fitting springs. Be interesting to see if the minimalist approach bears fruit. If his lighter less protected car continues to suffer damage I'll keep my armour plating, but if I get stuck more than him it may have to go. I'll come back to this thread at some point and let you know
A D3 on springs? Is he mad? It's not just a variable height thing - at low speeds, air suspension allows air to transfer across an axle to improve articulation and grip.
Half the computers will complain; he will need a very sympathetic insurer.
2015 Volvo V40
2014 D4 HSE
2006 RRS - C'est mort. Fin... ...It's alive! Oh no, it's not - scrapped.
2019 Suzuki Kingquad 400
2017 RamRod Taskmaster 1150
1977 John Deere 2130
15th Nov 2020 9:05 am
Kenny57
Member Since: 12 Apr 2020
Location: Essex
Posts: 173
Not sure if you're aware, but springs was the standard offering on the base model D3 with air rams only an option. I'm not sure if his is specifically a base model with the option fitted, but either way its all standard D3 parts and an easy retrofit. For the same reason I think someone with the right kit can just tell the computer the car doesn't have air suspension.
My mate is partly doing it to simplify the car for off-roading, and partly because its cheaper than sorting his air suspension out after ripping his air compressor off on a rock!
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