Pvc bunk for transporting ai upright?

[Nello]

I'm thinking of doing something like this to transport my ai upright on my car and trailer.

Thinking of using 50mm pvc pipe, without the T bar at the rear, so just connected to the roof racks and the bars on the trailer.
For the car, roof rack dimensions are - 80cm rear overhang from rear rack, 90cm between racks and 80cm front overhang.
What are people's thoughts?
Would I use pressure pipe or normal stormwater?

[joffarob]

I would recommend looking at some aluminium pipe rather than pvc pipe.
Pvc pipe will need to be supported closer to the end to stop it sagging. Pressure pipe is thicker so will be better than dwv but an overhang of 800mm will bounce around a bit and not support the yak and
Left attached to the racks without support will bow.

[Wind Waker]

I would use alloy pipe and cut a piece of pvc to snap lock over it with some carpet glued on. That would be sweet. Also have a look but the middle will need to be further apart then the ends or it won't actually cradle it

[shane]

Nello, It doesn't need to be as long as the picture and should be set out based on your hull. Any of the length thats not in direct contact with the hull is unnecessary. Ideally you want to distribute load from the roof racks longitudinally along the scupper hole line of your yak (the strongest line). On the PA this is easy as it has twin hull grooves along the scupper hole line, but I'm not as clear on the under hull layout of an AI, but suspect its similar. Although you may need to just space them wider to support the outer curve of the hull due to the narrower width of the AI. With my PA I place a length of PVC wrapped with pool noodle (about 1m long each) along each groove across the roof racks. This is sufficient to spread the load so its not concentrated in the couple of small spots in contact with the roof racks.

My tubes are removed before the yak and placed after its in place. If you're going to fix them in place you need to consider if it will help or hinder your loading approach in any way. You may consider making them removable but link them by straps that set the correct width and stop them moving apart out from under the hull.

[Nello]

Thanks for the feedback guys, alloy is a good idea but sadly it's a bit too pricey.
Other plans are to use timber to make up a copy of the hobie ai cradles, or just transport upside down on the car.
The trailer has four bars over a span of 3 metres so might do pvc on the trailer as the pvc will be fully supported and not flex.

[laneends]

I use 32mm pressure pvc. It bends to conform to curve of hull. Most of weight is taken at bar location, the rest is just a spreader. Strapping to solid tubes will flatten hull out. Ditto if you have a center support. Depends on how far apart your bars are. I also have a bit of extension with elbow for some extra bracing forward so I can push yak further forward to reduce rear overhang.
Have tubes attached to bars (even if oonly bungeed down,yak is strapped to bars and dont over tighten yak down. I used to leave tubes loose and rely on strapping of yak to hold it still, but that over tightend yak.

Technically you can have distance from back axle to end of yak not greater than 75% of wheelbase. Less overhang the better as it reduces chance of someone cleaning it up driving past when parked at 90 degree.

You also have the amas to store

[shane]

A bit of flex in the PVC isn't too bad as it can fit the shape of the hull. Whatever you use consider the impact of sand against the rails scratching up the yak. For this reason timber covered in marine carpet is another worthy consideration, particularly if you're using it to slide it on.

[Nello]

Thanks for the pics laneends, good seeing what others have done

A bit of flex in the PVC isn't too bad as it can fit the shape of the hull. Whatever you use consider the impact of sand against the rails scratching up the yak. For this reason timber covered in marine carpet is another worthy consideration, particularly if you're using it to slide it on.

I've thought of timber and it would work well, especially if sliding on which is what I'm hoping to do, one of the downsides is it'd rot out over time.
Wonder if it'd be fine to leave the timber flat or try and curve it so the tops a bit circular to fit the groove of the yak.

[laneends]

The other aspect of flex in pvc is that it that curves sideways as well as down, as your chimes are not perfectly straight either.

Timber is going to add even more weight to the roof bars.

I just bungie one tube to bars, the other is strung to that with a bit of cord. Then its easy to remove. The bungie is just to stop tube slipping, yak being strapped to bars not tube. Yak holds tubes in place.

Shanes point about scratches due to sliding is valid, especially if you want to be prissy about a scratched bottom .

[westy]

you can glue carpet to pvc pipe, think Mav has done this on his trailer