Bike rack on a trailer.

Benjahmin

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So, I've had the local blacksmith make me a pair of de-mountable 'roof bars' for my 6'x4' camping trailer. The cross bars are 1" square tube. I need to find a pair of cycle racks that will mount onto the bars and will carry my pedelecs (approx 25Kg each). One is a Big Bear step through the other a Carrera crossfire conversion.

This one, with adaptor for square bars, looks good, but is only rated at 20Kg.
http://www.thule.com/en/gb/products/carriers-and-racks/bike-carriers/roof-mounted-bike-carriers/thule-proride-598-_-598001
Can't use a tow bar carrier as I need to tow my trailer full of camping gear.
Can anyone help?
Ben
 

DAJ

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Can't you get the blacksmith to finish the job for you and use some pipe lagging to protect the frame?
 

Benjahmin

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I'd rather use a proprietry rack to make sure the bikes are good and secure. Thule 598 looks good, just not sure if it will fit 25mm square tube. Might have to bite the bullit and see.
I'll post photos when it's all done, in case it helps someone else.
 

VictoryV

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Can't use a tow bar carrier as I need to tow my trailer full of camping gear.
Can anyone help?
Ben[/QUOTE]
You need to consider lateral stability, when bikes are on the car roof they have the whole weight of the car stopping them from "tipping over" when going round corners. Your trailer will be considerably lighter (despite its full load) and narrower, also your towbar attachment allows for rotation about the towing axis, so that if the trailer did topple there would be no resistance to its rotation. If a caravan can be toppled by high winds then your trailer with the bikes acting as "sails" may be vulnerable. Also wind blast off lorries could be a concern too. Could you mount the bikes on the rear of the trailer in the same manner as a towbar carrier?
 

Benjahmin

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Thanks for the suggestion Alan. Unfortunately I can't use that because I have a Vitara with a rear mounted spare wheel. Also one bike is a stepthrough, although I am aware of frame converters. How I wish such a simple solution would work.:(
VictoryV you bring up some apparently valid concerns. I am hoping to use a bike rack that has a frame stabalising arm (as in the Thule), these are meant for roof mount where I would have thought the cornering G force was as high as a trailer. Most of the weight will be low down in the body of the trailer which I hope will ofset the bikes. Turbulence could be a problem but some extra strapping should take care of that. I shall be monitering it closely on the first journeys as the trailer only has rubber ball suspension and no dampers and I wonder if the bikes will get shaken too much.
The trailer is a standard single axle and I think mounting the bikes on the back would add too much weight behind the axle so pulling up on the tow hitch.

The bars and mounting brackets I've had made are constructed from 1" square tube and, all in, weigh about 15Kg. This will mostly be low on the trailer so again lowering the centre of gravity. The rated load weight is 450Kg, I would think that bikes and camping gear comes in at about 300Kg. The track of the trailer is about 4'6", cornering would have to be significant to turn that over. Maybe I'll cut out the handbrake turns though:eek::D

Thanks for the suggestions guys.
 

anotherkiwi

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Most times you see bikes on camping trailers they are strapped laid down on the roof rack to keep the CG and lateral wind drag low as noted by VictoryV.

Ideas:
- folding pedals
- blocks of dense foam at strategic places
- of course the batteries and other removable bits in the car
 
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Benjahmin

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Benjahmin

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Like my paintwork too much to go lying one bike on top of another. However this has got me thinking about brace strapping and how to do it.
 

Benjahmin

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What I needed was to carry my bikes on my camping trailer but still be able to access my camping gear. The racks also needed to be demountable as I use the trailer for logs, materials, trips to the tip etc.
O.K. So I decided to go for a pair of Thule 598's from Roofbox, as they were the only ones specifying 20kg/bike, and had adaptors for square bars.
I got the local blacksmith to make me 4 of these:
DSCF2994.JPG
and 2 of these:DSCF2995.JPG
The lower mounting holes of the brackets are fitted to the trailer chassis, the upper two were drilled through the side and all were fixed with 8mm ss bolts with penny washers on the inside to spread the load. Used nylock nuts for anti vibration security.
DSCF2996.JPG
The pin through the bracket, with R clip, secures the bar leg in place.
DSCF3002.JPG
So I now had me a trailer with a 'roof rack'. There was about 2mm of front/back play in the front bar, but this dissappeared when the Thules were fixed in place. There was no lateral movement as the wooden spacers behind the bracket, make the legs quite tight. Some silicone spray helped getting the legs in and out. I expect the wood will compress/wear after a few uses, if it does I will replace with hardwood. The spacers are there to allow the tarpaulin to fit in place
I had ordered adaptors for square bars, these fit around the bar and easily clip into place. They can be 'handed', so fit either side.
Minus batteries etc. the bikes aren't too bad and the lift isn't very high (even for a short arse like me).
DSCF3000.JPG
When I first put the bikes in place the racks held them well. But I gave the trailer a few heavy sideways pushes with my boot and there was a lot of lateral movement relative to the trailer. So I made a padded wooden brace to fit inbetween the saddle stems. Then, using ratchet straps, I pulled the left bike to the right, and the right bike to the left, so locking them together.
DSCF3001.JPG
Now, when I 'push' the trailer sideways, the bikes move with it but not relative too it, so removing strain from the rack and fixings. The brace is crude but is held in place by the straps pulling the bikes together. I'll be putting some sort of safety cable on it before venturing on the motorway.
Next step is to hitch the rig up to the car and drive it round some dodgy Welsh roads and see how it does. I'll post any mods I have to do.
Hope this helps someone else.
Ben
 
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VictoryV

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Next step is to hitch the rig up to the car and drive it round some dodgy Welsh roads and see how it does. I'll post any mods I have to do.
Hope this helps someone else.
Ben
That looks a really neat rig. You may want to consider directly cargo strapping the bikes to each other, as well as the ones you have from each bike across to the trailer frame, this is becuase the direct strap will be quite short, under good tension and have very little any stretch or flex so the bikes will form a really solid unit and the brace would be unlikely to slip.

Also, can I suggest some form of load in the trailer for your trial, as it would be when used properly, so that there is some counterbalance to the bikes' potential radial moment when going round corners, you don't want the trailer to be lifting a wheel when cornering.
 
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Benjahmin

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My main concern , with an unloaded trailer, would be the amount of bounce from the rubber suspension. Think I've got a few spare paving slabs hanging around ! With the existing load straps the bikes already form a tight unit with no movement. I used woven ratchet straps not bungees.
It certainly beats hanging the two bikes of a 4x4 spare wheel carrier. That was hairy. I had an extra strap around the rack and through the roof bars, to take out all the extra bounce, and give the spare wheel mountings some assistance. Did it once, never again, wouldn't recommend it.
 

Benjahmin

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Took the rig out for a test drive over the Bank holiday weekend. As suspected, the trailer bounced around on our 'well made' local roads. It was alarming at first, but I could see that the bikes were not moving relative to the trailer. They stayed nicely upright and rigid. Cornering wasn't a problem, 40Kg of bike is still only a fraction of overall trailer weight.
The Thule 598's are easy to mount and dismount and putting the bikes on them is a breeze. The ratchet straps holding the wheels perform well and have a sliding rubber cover to protect the rim. The Big Bear front wheel does tend to twist slightly as the wider tyre doesn't sit as deeply into the holder. Once it found it's angle, however, it was stable. The frame stay is friction hinged and stays where you put it as you load the bike. The tightening mechanism works well and again is padded so as not to damage the frame.
I do have to say, though, that without my extra strapping the bikes 'flex' a lot, relative to the rack. If it was on the roof of a car there would be a lot of movement going on. I don't think the bikes would come off, but surely there's going to be some repetitive strain damage?
Anyway, all in all pleased with it and happy to take it on holiday, when the trailer will be weighted down with tent, surf boards etc.
 
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