Hello I have a problem which I would like to share so I could hopefully get this issue sorted I have lowered my bus using 2”drop spindles and have put on a set off spax adjustable shocks which I have set at the hardest level. I have adjusted by beam to its max height but I still ground out at the first pot hole. I have tried adjusting both the beam and the shocks but this just makes it worse. When I bought the van the adjustable beam was set at the lowest adjustment, can the leaves in the torsion bar get damaged because it was running at its lowest level. etc. Currently running 175/55/15 front tyres. Thanks.
Either remove the drop spindles or fit coil-over dampers to lift the bus and stiffen the spring rate. Stiffer dampers won’t help, all they’ll do it delay the inevitable bottoming out. Not a fan of narrow low profile tyres personally, what load rating are they?
Pack out the bump stops aprox 25mm to bring them back into play, in my experience nothing else will stop the tyre rub completely
Are you grounding the bus on the floor, or the tyres in the arch? Do you have any bumpstops? 77 Westy, MikeDjames and (I think) Gingerbus all have experience in this area, I read a lot of their info trying to solve my arch/tyre interface. After being let down on a new beam and countless delays I had to find a solution to the previous owners cut and turn beam to get me roadworthy for Vanewst - Gaz Coilovers have raised me up 30mm and stopped most of the banging and rubs in the arches, at the slight expense of a very firm ride.
To stop that you need to limit the travel of the suspension so it cant make contact with the tub. The two suggestions @77 Westy westy makes are a good start. And @PIE is correct too, bumpstops will limit where the wheel can end up, but if you're on a narrowed/adj beam, chances are you have no bumpstops. What's the clearance between the top of the tyre and the inside of the wheelarch?
If the adjustable beam was set at the lowest by the PO I doubt if you have bump stops, but if you do packing them out to reduce the suspension travel might prevent or at least reduce the tyre rubbing. Fitting drop spindles made the situation worse.
mine's running dropped spindles, slightly narrower beam with adjusters set to max height, bigger tyre than yours and doesn't rub. maybe whoever fitted the adjusters put them in already turned so it's low even on max height?
A little bit of usable travel there, about the minimum you'd want! Careful selection of length/stroke of coil-overs will reduce the rub, combine that with Pies bump stop solution (if you can) and you'll be sound. I have no bumpstops, but the Gaz coil-overs have s little 1inch bumper on the shock to stop the harsh bottom out. Sent from my EML-L29 using Tapatalk
When preloaded 25mm on coilovers there is 60mm clearance between the tyre and the outer area of the tub. The damping is set at 6 out of 10. With these settings it just bottoms out when hitting road bumps at 40mph while cornering fairly hard. It is perfectly OK over normal speed bumps at 20mph although the driver and passenger get thrown about .. On one occasion my backside has hit the top of the tub hard while sitting on a stock seat. It did my back in .. it did bottom out.. Conclude- coilovers can help down to 50-60mm tyre clearance.. go lower and you will rub. If you must go low, get air ride.
That completely makes sense as there was no suspension travel before I just at the beam but wanted to have the same right height when putting on the drop spindles but still isn’t correct. I will have a look to see if there are pump stops on but wouldn’t think there is. Was kind of thinkinking that myself as there is not that much spring in the bus even when the shocks are removed to slow down the dampning. Originally thought they were seized as they were on the lowest setting for about 5 years +.
are BOTH adjusters wound right down? ie in both upper and lower beams? i've read some folks have just the lower one right down, and the upper set higher (if that makes sense) sort of like a pre-load. effect should be to make the suspension stiffer i would have thought? worth a try?
Spr Springs dont work like that. They are essentially linear. All you do is risk bending the spring taking more of the load by twisting it more than its partner beyond its elastic limit . This will either give a permanent twist and droop onto the other spring taking more load,or dropping by snapping leaves. Best to drop top and bottom the same on adjusters. Drop spindles are able to make a bus look lowered on totally stock suspension. Once you start lowering by twisting the torsion springs as well you have to consider removing the bump stops or else you are riding hard on the bump stops and the twisting lowering stops working. If you remove bump stops you dont need the drop spindles to hit the wheel arch. Combining both approaches makes it easier to go low but you lose everything in favour of a cool looking vehicle wedged on a speed bump which you have to drive like a paranoid OAP to get there...
yep, agree. i didnt' say it was a good idea, just that i've heard some other folks doing this. mine are equal drop on both adjusters
I think standard spring work just like that, I’m pretty sure one is loaded more than the other , linear perhaps but the further they are loaded the stiffer they get , I think it’s the reason why when you pull the front arms off the spring together, if they were set with identical pre load they would stay the same distance apart
