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  • #4271
    admin
    Member

    Hi this is a topic that has been raised before (Dec 2009) but I would like to ask for advice on the softness of trailer suspension.

    I have just launched my Mk 2 after a 3 year renovation (3 years! I had a few other pressing tasks to do as well). The Rapide Trailer part of the Combo has rubber sausages trapped in a square tube with a square axle through the middle. I estimate it is thirty years old and not surprisingly the suspension appears to be seized completely and gives the boat some very nasty jolts over only moderately disfigured road surfaces.

    So I am committed to replacing the suspension units and I am looking for soft ones. This implies that they should be rated for only a little more than the boat+ trolley combination which I estimate to be about 200kg, so a pair of 250kG suspension unit should do the job. There are a few suppliers out there who will sell them, does anyone have a good experience to share in terms of a comfortable ride as a result of fitting one or another of the available units?

    What about a sprung cradle of some sort so that the boat is suspended above the trolley by a gnat’s? Inconvenient for launch (needs deeper water) and for climbing around rigging while still on dry land (to be minimised). Even widening the contact points would perhaps help to reduce the effect of an impact, so maybe provide a platform for the keel to sit on ahead of the roller.

    Now that Kez is useable I intend to trail her all over the place and I do not want to cause damage if I can avoid it (of course…). [attachment=1:3iar2scv]DSCN0574 (WinCE).JPG[/attachment:3iar2scv]

    #9922
    Swiebertje
    Participant

    Most MK2’s are overweight. They often are in the 220+ kg region. But remember this is the weight of the bare hull. You need to add the weight of the rig, sails and equipment and we all carry too much gear šŸ˜„ (Think anchors, engine, petrol, poles, spare ropes and what not). Then add the trolley and some contingency to make sure not to overload the springs. Overloading is far worse than a soggy trailer. An overloaded spring does not work any more and every bump in the road is directly transferred to your pride and joy’s hull. Also note that while cornering a lot of the weight shifts to one hub and spring. I think 500 kg is a better choice for your hubs and springs (250 kg each).

    Cantilevered springs (rubber) / hub combinations are available everywhere for little money. On my trailer they bolt under using 4 bolts each on existing mounting plates, a job easily done yourself in an hour or so. Bring the old hubs along to compare the holes to the new ones to avoid having to drill new holes. I would prefer a caravan or builders-trailer specialist. In my experience suppliers with ‘marine’ in their name are often twice as expensive while the materials are exactly the same.

    #9923
    admin
    Member

    Yes, your point is well made and I shall take the boat + trailer + representative gear down to a weigh-bridge near here before I buy anything.

    The replacement is a bit complicated because I will have to cut the old suspension units off and grind a smooth patch and get new plates (with suitable holes) welded back on, the tube the old suspension units are pressed into was welded to the frame before it was galvanised. Rapide have gone out of business and West Mersea who nominally took over the business do not provide replacements of this model. which dates from the ’70’s

    All eminently solveable (soluble?) but I wanted to draw on the vast experience represented on this forum before I get my angle-grinder out.

    Mike

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