I know artics are carrying alot more weight than Class 2s but how come they come past on the level and downhill? Do they not have engine braking that cuts in to stop you going above 56mph regardless? If Im going downhill with a full load my truck still won`t go any faster
The only thing I’ve ever driven that wouldn’t go faster downhill when fully loaded (without manual intervention )was a coach with cruise control and a Voith retarder which worked together.As to ‘on the level’----well,where do I start? There are a few threads on here regarding fuses,wires and magnets. 
I must stress though,that nowhere here will you find a ‘how to’.(Not that I think you would want to!)
its all about the power and gearing when on the level and even going uphill…downhill just the pure weight pushing us along…
well my old scany 420 will do about 58 on the flat full loaded, and if i let it go down reigate hill i could if i wanted to get it off the clock, just purely letting the weight push me. but wouldn’t, never know what numpty going to pull out on you, and there would be no way of stopping 44 tonne at that sort of speed 
peteandbrenda:
and if i let it go down reigate hill i could if i wanted to get it off the clock
Reigate Hill, I know its on the M25 but where abouts is it?
i’ve drive many a different rigids dif makes/tyre depths at our place and all though they all read 90kph on the tacho no matter which one im driving artic drivers still pass like your parked up - never get rigid drivers overtaking but always the artics overtaking on the flat - surely not all artic driver run on the wire? do they? 
DAF95XF:
peteandbrenda:
and if i let it go down reigate hill i could if i wanted to get it off the clockReigate Hill, I know its on the M25 but where abouts is it?
J8 to J7 anti-clock
DAF95XF:
peteandbrenda:
and if i let it go down reigate hill i could if i wanted to get it off the clockReigate Hill, I know its on the M25 but where abouts is it?
Hi Stu,
It’s a hill near Reigate. 
Sorry mate, I couldn’t resist that. 
I know when I drove 6 and 8 leggers the double drive rear ends created a drag on speed and fuel consumption compared to an artic.
Not all trucks are limited to 56, some are fast and some are slow, one day you’ll be passing everybody the next you’ll be the one chokeing on the fumes. As for going downhill it depends on the weight and how much your willing to let go
There’s some crazy speed limits in this country, two examples…
Firstly, why can a coach travel at 70mph fully loaded with humans, surely the most precious cargo of all? But, trucks are limted to 56mph (ish) A fully loaded artic could do more damage than a fully loaded coach but hopefully you see what I`m trying to get at?
Secondly, a 51 plate 7.5T came past me this week, must have been doing 65mph. A friend of mine said that before a certain reg they are`nt limited? WTF! What has the year got to do with anything, 51 plate, 57 plate, still weigh the same
Dakota:
… A friend of mine said that before a certain reg they are`nt limited? WTF! What has the year got to do with anything, 51 plate, 57 plate, still weigh the same
Your mate is right, but it was a good few years before 51 plate.
I remember TNT having limiters fitted to thier existing fleet of ‘N’ reg MAN’s while I worked there.
Dakota:
I know artics are carrying alot more weight than Class 2`s but how come they come past on the level and downhill?
Dakota:
Do they not have engine braking that cuts in to stop you going above 56mph regardless?
Err. No.
To go back to the first question, it is a matter of basic Physics. Momemtum = Speed x Weight. Hence the greater the weight, the more the ‘momentum’ of the vehicle which will continue to provide a ‘speed’ advantage even though the gradient has seemingly ‘bottomed out’.
In relation to 7.5 tonners. When the EU proposed the Legislation, the UK campaigned for the limit to be set at the same level as Coaches. Perhaps recognising that a fully loaded 7.5 tonner, when reaching an upward gradient, would present an ‘overtaking hazard’, whereas one with an inbuilt speed advantage, would be less likely to do so.
But the EU, being the EU, declined to respond to those representations.
Darby Flyer:
Dakota:
… A friend of mine said that before a certain reg they are`nt limited? WTF! What has the year got to do with anything, 51 plate, 57 plate, still weigh the sameYour mate is right, but it was a good few years before 51 plate.
I remember TNT having limiters fitted to thier existing fleet of ‘N’ reg MAN’s while I worked there.
IIRC, the limiter came in the mid-90s, and spookily I was also on TNT at the time.
I was on nights on the Lever contract out of Port Sunlight.
The trucks were all “H” reg ERFs, but they had to be retro-fitted with limiters.
IIRC (again) I seem to remember something about the retro-fit going having to go back about as far as “E” or “F” reg.
Somebody with a better memory might put me out of my misery and correct me. (Please. 
)
dieseldave:
Darby Flyer:
Dakota:
… A friend of mine said that before a certain reg they are`nt limited? WTF! What has the year got to do with anything, 51 plate, 57 plate, still weigh the sameYour mate is right, but it was a good few years before 51 plate.
IIRC, the limiter came in the mid-90s, and spookily I was also on TNT at the time.
Somebody with a better memory might put me out of my misery and correct me. (Please.
Was it? (We were talking 7.5 tonners here originally weren’t we?) 7.5T speed limited information, DfT
Anyway the new/old speed disparity is at the consultation stage at the minute: DfT Consultation on Heavy Goods Vehicle and Passenger Carrying Vehicle motorway speed limits and the proposal is to tidy things up.
If we’re talking heavier, yes, dates of introduction depending on vehicle were 1 January 1994 to 1 January 1996 and retro-fitting back to 1 January 1988. (SI 1946 of 1993) The Road Vehicles (Construction and Use)(Amendment)(No. 1) Regulations 1993. (see 36B)
Edit: Actually, the thread is jumping about a bit. 7.5T was mentioned in the middle by the OP, and Class 2 at the start. It might be clearer to chuck the obsolete Class 2 expression out of the window, then talk category C1, C and CE and D and D1.