Clearance between tube and guide post

ba_fisher · 04 August 2016, 02:21

Hi, I'm trying to install guide posts on the trailer for my 4.3m RIB. How much clearance should I allow? The post is made of PVC and does not rotate.

I've set the clearance to half inch now, but haven't tightened the bolts yet until I hear from you guys, hopefully with a single and correct answer :-)

Poly · 04 August 2016, 11:42

How much error can your trailer accommodate and still align the hull? If you think of it as being a tool to make sure that the hull lines up with the rollers / bunks right that should answer your question. I don't have guides but 1/2" seems very tight. Not sure what/if there is a downside to being too tight, but I don't see any advantage of being 1/2" rather than 1-2" as the trailer can't be that close anyway (or it would be impossible without guides).

jyasaki · 04 August 2016, 14:44

I have mine pretty tight. The rub rail hits the posts, so no harm done from friction.

That said, when you need them the most (loading on a river with current running), they tend to flex enough to be largely useless (though I suppose they keep the boat from getting way too far out of line.) I often end up hitching the bow and using the motor to keep the boat lined up as the trailer is pulled from the water (can't do that recovering solo though.)

jky

jeffstevens763@g · 04 August 2016, 18:38

I've gone for an inch each side with a platic pipe over the steel up right on my docking arms to act as rollers and find I can just bounce the sib over to line up if needed but a god send in a cross wind. I made mine out of key lock hand rail parts and if needed I can undo an Allen key and take the upright off if required ( if it rubs. )

Cheers

ba_fisher · 07 August 2016, 19:31

Thanks for all the input!

I ended up making the posts very close - they are about 1/4 inches away from touching the rub rails. I launched and recovered the boat by "walking" it off and on. There wasn't any issue. After I recovered the boat, it was leveled perfectly.

In the past, the back of the boat would be off by a few inches and I would have to make it level by lifting one of the tubes at the back and push.