I don't suppose anyone has had a go at fitting Rogers bump stops to an ARP4, with coilovers instead of leaf springs, have they? When loaded my springs do bottom out, with quite a bang too. The alternative is harder rear springs, but that will harshen the ride too or get some longer springs and wind up the clearance a bit.
Have you spoken to Dan at SSL Paul? His company offer dual rate coil overs with adjustable pre-load and damping for the factory 5 link Roadster, basically the same as previously used on the ARP4 I understand.
My experience with them nearly three years in is despite being softer over rough surfaces they also cope well with severe undulations two up, full tank and with humungous suitcase on the back. Almost surprised mine don't bottom out sometimes but the gentle way they stiffen up as full bump is approached must put them at a higher spring rate than factory single rate coil overs, which has extra dividends in improved roll control. All I add is a few extra psi in the rear tyres and a couple of clicks on the damping for such touring. Even then I have the option of increasing spring pre-load but never found this necessary.
ETA: Apologies Paul but just noticed your query was from over a year ago when CooperMan gave similar advice. Intrigued to know if you followed it up as may be of use to other ARP4 owners?
