Homemade recovery track rack (Imitation maxtraxx mounting system)
This project came about as I wanted to store our recovery tracks on the roof in a semi permanent manner. When we have been on trips before, we have strapped them on top of the main roof rack as in the picture below. This was ok with just two, but meant if we wanted surfboards we had to faff about with the tracks in order to get the boards and vice versa. They also weigh a reasonable amount, the 4 Britpart tracks we now have weigh about 15kg combined. Which is a fair weight to be storing so high when we already have a lot of heavy stuff up there. Having the weight lower would be better for weight distribution as well as reducing the leverage and therefore strain on the current rack system.
This was the design brief I came up with:
1. Mount off the factory roof rails. Therefore being able to be stored and removed without needing to touch the surfboards.
2. Be as light and as low as possible.
3. Be capable of holding four tracks.
4. Ideally be possible to lock the tracks down in place.
I thought about this for a long time and explored a few different ideas but this one made it to production as it was simple to make and use, as well as strong. It also used materials I had available or were possible to buy over the internet as I was unable to go to the shops in the current coronavirus outbreak.
Materials:
2 lengths of carbon fibre tubing (broken windsurf masts) Could be substituted for tube or box section made of anything.
4 A4 stainless U bolts
1m of A4 stainless M8 threaded rod
Selection of A4 stainless nuts.
4 M8 bownuts
I bought the stainless parts from a website called 'U bolts R us'.
I have struggled with corrosion on fastenings on the roofrack in the past. I think it is especially bad for me because I'm at the beach a lot, saltwater drips off windsurf kit onto the rack and the nuts tend to rust immediately. A4 stainless is designed for marine use and seemed like an area worth spending money in this case. This website has so many different products and is fantastic, but you need to know exactly what you want. *I'm not associated with them in any way, I just found their product range was perfect for me. *
The Bars
The bars were easy enough to make. I just cut some old sections of broken windsurf mast to the right size with a hacksaw. Then drilled a couple of holes in each end to take the stainless U bolts. This is where the U bolts R us website was great as they have literally every size and shape. I couldn't get the right ones in any big DIY stores near me. The front bar has the pins to locate the tracks and the rear one holds the front of the telescopic poles that support the awning. Any metal tube or box section would substitute in here fine. I just had a pile of carbon tubing available, which incidentally is perfect as it's strong, light and doesn't corrode at all.
The Pins
After a bit of experimentation I arrived at making my own J bolts as the way to locate the pins in the bar. I bent the threaded bar using a desk vice and a big hammer. The key to this seemed to be grinding off the threads on the outer and inner faces of the section that was going to bend. Otherwise the metal cracks between the threads as the stress is not distributed evenly. The bend stops the bar from rotating in the hole when you tighten the bownut that holds the tracks down. It also means you can't just undo the pin from the bottom as a way of stealing the tracks. They are secured from the top with a nylock nut that is wound down to the bar. By happy accident it turns out that an M8 nut fits perfectly in the hole for these tracks.
Locking the Tracks Down
This took a lot of trial and error to sort out.
I toyed with the idea of drilling a hole through the rod to hold a padlock. However it was extremely difficult to get this hole right through the middle. M8 rod is also so thin that even when you do, there's so little metal left that I could easily break them with a set of pliers. My conclusion is therefore that if you want to use this method then use M10 thread as an absolute minimum, ideally M12. At this stage I had already bought all the stuff so I was committed to making it work with M8. The image below shows the test pieces that were sacrificed in this process.
My solution was extremely simple, I bent some sections of standard steel strapping that I had lying around. This stuff is available from any builders merchant for a couple of quid. I just drilled out a couple of the holes to 8mm and cut them to shape with a grinder. They work by fitting snugly around the rod and engaging in the solid edges of the track. This stops them from being able to rotate. A padlock then just goes through the bownut and the bracket and the track is locked down as the bownut can no longer be undone.
I'm sure this design could be modified to fit almost any type of recovery track. Just some changes to the shape so it can't rotate and you're good to go.
I hope you find this interesting. The Coronavirus lock-down has meant I had an awful lot of time with which to plan and experiment with this. Obviously I haven't had a chance to test it on a trip yet but I have high hopes for it in the future. I expect it to work really well.