ET, connecting the bolts to the wires

Looking at Overland's pic thread I have noticed many trucks on the 70's have steer wheels very forward, similar to a SAR, be it bonneted or cab over. Europeans trucks are set back a little in comparison.

I'd like your thoughts as I drive narrow windy roads. My current cab over which I bought because a sizeable competitor uses them, appears to have an overhang of 1.37m bumper to centre of steer wheel. I initially felt cab overs were shorter so better for purpose, but have since noticed bonneted tractors are 7.5m long as well.

Do you think position of the front axel (more forward) plays more of a role in manoeuvrability than being set back? Or does chassis length from steer axel to rear bogies is whats important. Just pondering if a tractors length is 7.5m regardless of cab shape, if the steer axels are more forward it should do windy roads better, and have less overhang to deal with on tight blind corners.

No doubt a forward positioned steer and short chassis is best, but that cost another 10k to achieve. There may well also be a down side that isn't clear (to me anyway) for a short tractor be mated to a 37T trailer to travel down a windy hill.

thoughts

Axle position is more to do with weight distribution.
The Volvo F88/89 were a very common/popular truck in Europe but we got the set forward axle G88/89, to prevent front axle overloading, as we had lower limits than Europe.

Thanks Ian, "prevent overloading" can you expand on that a bit please.

Obviously the matter is complex. I have a body fitters guid here and the math around everything it is quite impressive let alone mind boggling. But in truck drivers terms,

I had concluded after possible turning benefits ride comfort was the main purpose for location. More weight for of the axel probably makes suspension work better especially when empty.

I thought permissible weight on the front axel was basically where the load was positioned on the tractors bogies. If load was distributed correctly it would make the front suspension work correctly regardless of where the front axel is positioned. But your saying front axel position plays a part in preventing overloading. I'm interested.

In my case the load is the same every load. This 14.5m over all length restitution is one thing, but if I have a choice, a shorter tractor that spins around the corners and has better manoeuvrability on the edge of the double limes makes life easier. I have plenty of blind corners with cars and bikes trimming corners on a daily bases. You can see the whites of their eyes when they realise where they are and have to correct. As you well know truck are blamed for everything, so if I can make my life easier and the ride comfier its worth pondering.

The set forward axle was to meet "bridge formula" regulations which required the longest possible distance between front axle and last axle of trailer to get max payload. Similarly, spread axle bogies on trailers came from the same portfolio. As the old timber bridges got replaced the regs died a death. There has been a lot of nonsense written about ride and axle position, for example the G88 Volvo was reckoned to ride harder than the F88 because of the shorter (looking) springs when in fact their springs have the same part number.
Ride quality is a factor determined by the manufacturer. To deal with tight mountain roads cabover short wheelbase is the way to go. At it's extreme Fiat at one time made their big prime movers with right hand drive so the driver could get real close to the edge to facilitate passing. Think of coaches with front axle set 2 metres back on mountain passes - on hairpins the front is virtually travelling sideways.
It used to be fashionable to have turntables which could slide up and down a bit to adjust weight distribution, however don't see them these days, and again there is a sweet spot for best handling characteristics (250mm forward of centre???). Pulling a heavy trailer with king pin at or behind centre is "interesting". Their is a bloke running roof trusses out of Tamworth with such a setup as he is single drive with a decent hiab crane behind the cab.