Retro fit bunks to small trailer for 3.6m sib

[rich222]

Hi all,

I have acquired a 3.6m Yam inflatable (not rib) and 10hp ob.

The trailer it cam with doesn't have bunks which may be ok if the boat is empty and there's no outboard on (the boat weight is 70kg), but if I want to tow with the motor on and with kit in the boat, I would be looking at double that, so maybe 150kg.

I think the trailer defo needs bunks!

So can I get away with a pair of single mounting point bunks, or maybe 2 pairs (inner and outer) or should I look at fabricating a forward support so that the bunks are supported fore and aft?

Any advice welcome!

[jeffstevens763@g]

That's easy to do on your trailer Rich
all you would need is a cross bar at the front box section would be best for strength ( the metal store sell that) the small T bunks you have (4 at the back) carry two forward on to the bar leave the other two buy some buffalo board for your bunks between the two just make sure they aren't too long between the supports. When you have done it you might need a keel bunk at the front or run one right through to support the engine.
You will have to block up on the supports to clear the mudguards and get rid of the rollers replace with wood for fixing the bunks also looks like you can extend the axel which might help especially if you can get the Mudgard clear of the boat and have the boat low down which is great for launching you will have to play with it best for you.

[rich222]

Originally Posted by jeffstevens763@g

That's easy to do on your trailer Rich
all you would need is a cross bar at the front box section would be best for strength ( the metal store sell that) the small T bunks you have (4 at the back) carry two forward on to the bar leave the other two buy some buffalo board for your bunks between the two just make sure they aren't too long between the supports. When you have done it you might need a keel bunk at the front or run one right through to support the engine.
You will have to block up on the supports to clear the mudguards and get rid of the rollers replace with wood for fixing the bunks also looks like you can extend the axel which might help especially if you can get the Mudgard clear of the boat and have the boat low down which is great for launching you will have to play with it best for you.

Thanks for the suggestions. The boat is slightly wider than the inside of the mudguards and with the inflated keel on the middle roller, the side tubes sit a few inches above the mudguards.

There are some useful holes already drilled in about the right place for a front cross member.

I read that I want to set the bunks to sit just where the hull/keel meets the tubes.

I might add some short side bunks onto the mudguards to locate the boat - side to side when getting back on the trailer.

I'll look up buffalo boards - never heard of that!

I assume carpet lining is just a case of stapling on some man-made carpet? (no doubt there is a 'marine grade' version for ££££!)

I wasn't sure how much, if any, support is really needed on the keel, if I have decent length bunks.

I plan to add some support for the transome and a much wider bow pad, more suitable for an inflatable.

Box section steel is pretty cheap, so that's no problem.

[jeffstevens763@g]

Personnely I don't like my bunks on the floor joint I prefer mine on the tube bottom if you look on my new trailer thread you will see how I had mine made you will see a keel pad at the rear I have added since then a keel pad at the front to stop bow bounce

[rich222]

Looking a few pics of inflatables on trailers, I also wondered if it is better to have the axle close to the transome.

I think my trailer is adjustable in length and width.

It would be interesting to know what the boat manufacturers actually recommend for a trailer!

[jeffstevens763@g]

If you look at mine you will see how they set it up for balance you need some weight on the tow ball