Remote reservoir shocks are the serious upgrade for anyone who runs a heavily loaded off-road caravan on corrugated tracks. Radflo — a California-based manufacturer that built its reputation in race-prepped 4WDs — has become one of the more talked-about options for Black Series HQ Series caravans.
What Makes Radflo Different
Monotube design: Oil and nitrogen gas are in a single tube separated by a dividing piston. Larger oil volume than a twin-tube shock means more heat capacity and more consistent damping under sustained use.
Remote reservoir: The separate canister adds additional oil volume. More oil = more heat capacity. On long corrugated tracks where a conventional shock would overheat and fade, the remote reservoir maintains consistent damping.
Radflo's specific advantage: Unlike Fox and King, Radflo shocks are fully rebuildable and revalveable in-house. You can send them back to Radflo for custom tuning or rebuild after hard use.
On-Track Performance
We ran the Radflo-equipped HQ19 over 3,000 km of outback tracks in Australia's Northern Territory — including the Gibb River Road and sections of the Tanami — with the van loaded to roughly 85% of ATM.
Corrugation handling: At 60–80 km/h on corrugated gravel, the van tracked smoothly. When we pushed to 90 km/h, the shocks didn't overheat or fade — damping stayed consistent throughout a 300 km run. Standard twin-tube shocks showed noticeable fade after 150–200 km of sustained corrugations at speed.
On-road behaviour: Remote reservoir shocks with off-road valving feel firmer on smooth highway. That's intentional — the valving is optimised for off-road loading. For serious off-roaders, the firmer highway feel is irrelevant compared to the improvement off-road.
Radflo vs Fox vs King
| Radflo | Fox | King | |
|---|---|---|---|
| Rebuildable | Yes (in-house) | Yes (dealer network) | Yes (dealer network) |
| Custom valving | Yes | Yes | Yes |
| Price per shock | $320–420 | $340–450 | $380–500 |
Fox has the widest dealer network in North America. King is for extreme use — likely overkill for a caravan. Radflo is the value proposition: comparable construction to Fox, slightly lower price, excellent rebuild support directly from the manufacturer.
Verdict
Worth it if you run heavily loaded on sustained corrugated tracks. The heat management makes a real difference, and rebuildability means these shocks will outlast the caravan if maintained.
Who should buy them? Serious off-roaders who run remote tracks at sustained speed with loaded vans. Weekend campers on graded dirt roads don't need remote reservoir shocks — upgraded twin-tubes will serve them fine for a lot less money.
Radflo remote reservoir shocks for Black Series HQ Series at RV Parts Giant.