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-   -   Making your own luggage rack - Any tips? (http://www.horizonsunlimited.com/hubb/equipping-bike-whats-best-gear/making-your-own-luggage-rack-38462)

Alexlebrit 18 Oct 2008 11:32

Making your own luggage rack - Any tips?
 
I've read threads and links before about making your own hard panniers, but nothing on fabricating a rack to hang them off. I'm wondering if anyone has any tips for designing and making one.

I've got the idea that mild steel is best to use as it's easy to weld if it gets broken, and round section tube is better than square. I reckon that bolting things together is better than welding, because it's easier to replace a sheared bolt in the wild than weld up a popped join. I've got access to a pipe bender and a drill press so I'm OK there.

So does anyone have any advice they could give me? Number of hard points on the bike you need to fix to, that kind of thing. Any pictures of existing racks would be great too they seem quite hard to google up.

Big Yellow Tractor 18 Oct 2008 12:19

Hi Alex,

First thing, does anyone already make a rack for your bike or for a similar model ? If they do, buy it and adapt. It will take you serious time to make a rack; if your time is cheap (or like me you enjoy messing about with bits of tube) then crack on.

If your bike is designed to take a pillion, you have a fairly straightforward job; mountings can be found at the pillion pegs and up at the seat. A lot of bikes have a long seat (so a solo rider can move about) but little or no subframe; these will need more thought.

Have a look at where the forces are acting. If you have mountings up at the back of the seat and down near the swing-arm pivot, the weight on your rack is trying to pull the back of the bike off onto the rear wheel, do you need to strengthen the subframe and/or it's mountings to resist this ?

Be careful not to over-engineer, you can use quite light gauge tube if you design it right.

What boxes / bags are you going to fit ? if you already have them, then spend some time hanging them on the bike to check where best to mount them before you start.

Search the net and look at other bikes for ideas. You will see some comercial stuff that is pretty crappy. Also think about where and how you will ride; off road will really punish your luggage.

Regards

BYT

AussieNat 18 Oct 2008 12:34

Yes steel is the way to go in my book.
I dont think there really is too much difference between round and box section though. I chose box because of the thin wall thickness available, the panniers I made are'nt that big so there wasn't a need for over engineering. Just be carefully that the seam is situated away from the stresses.

You can kill 2birds with the support frame with some brainwork. Triagulating the frame makes the whole bike stronger. This is usually done by fitting a diagonal brace from the front foot peg mount up to the strongest mounting point at the back. It depends on your bike though.

From this you can nut out how to mount your boxes.

The mounting system we have on bike has proved to be strong and secure. I can take the boxes off in under 20seconds as there is only one lock (each side) to close and fit the box to the frame.
This way I can unpack quickly as well as get the bike through doorways with minimal fuss.

Take a look at the bike prep section of our blog.
Any Qs, dont hesitate.
N+A

Alexlebrit 18 Oct 2008 13:40

Thanks for that advice it's great, I'd thought about taking it down to the pillion pegs (yes it does have a pillion seat). It's also already got a rear (top box) rack, so logically those mountings should help a lot. My main reasons for round tubing are aesthetics and also because my pipe bender only bends round tubes.

Unfortunately no, no-one makes a rack at the moment for pannier boxes, I've searched everywhere. Found a couple of places that would fabricate one, but they're very expensive and also a very, very long way away.

Caminando 18 Oct 2008 18:44

Some good comment above. Round tube is actually stronger than square, but square is so much easier to work with. Thats what I used. I bought a cheap little electric welding machine (£50) and welded up a frame. I meant to improve/replace it because it was a rough prototype, but I just keep using it. The square tube has a nice light thin wall, but this makes it tricky to weld.

I took the carrier down to the pillion pegs. I have mounted my carrier to 6 points in total.

I got my machine in Weldom-should be one near you. It has maybe increased in price as I got mine some time ago. It's a Nordikka. I think you can get these machines in Bricodepot too.

Flyingdoctor 18 Oct 2008 19:12

Flat bar can be used as well. If the forces acting on it are across the large flat face. A combination of both will give you the best of both worlds Slim and strong. It needs to hold the weight of the bike because it will fall over!

Here's some pics from the minimilist touring thread on ADV. A nice neat job.

http://i210.photobucket.com/albums/b...amish/adv4.jpg

http://i210.photobucket.com/albums/b...amish/adv5.jpg

oldbmw 18 Oct 2008 19:36

A trick I learned when using round tube, pinch the end a bit rather than try fabricating and welding an angled join on a joint. Also every one welds in a compressive support from teh footrests. but why not a tensive support from on high at aboutthe rear of the fuel tank to the rear bottom edge.

Caminado.. oddly I have a Nordika I bought here also...Nice to weld now without getting shocks :)

DLbiten 18 Oct 2008 20:17

I looked in to making racks for my bike but went with premade ones. You will want 3 hard mounting points for each side then a bar to "tie" each of the side together at the back lower end, as there is almost no way to secure this area. As seen in the above pics but the rack in the pics look like SS look good but triky to weld. Do NOT use flat bar stock for the the rack suports, the round frame that the luggage is bolted to can be flat as it dose little suporting. But the rack suports, the parts that hold the rack to the bikes subfram need to vary strong and tuff. They flex with every bump and brake in time or they will brake a weld. If you must use flat bar stock fave a few welded up and have another folded over the bar stock and round rack.

Round tube is the way to go if you can if you see this too hard and need to go square tube (or rectangular) your rack will end up being hever for the same strength. A good weld will last longer then a bolt and it hold up better to the vibrations and hits. Bolting the mess together will be ok in town but on bad roads you may well be replacing bolts every few days the hols for the bolts will enlarge to the point where you will to some how have to find a way fix it. (like cutting it out and welding on a new piece.)

One thing I looked in to was getting square tubing that had a ID (inner dimension) gust bigger the the OD (outer dimension) of the rack. A few little chunks of this will help with any quick fix you may need.

Dont over build the rack I have seen some racks that just do not hold the luggage on the bike. There hever than the luggage (and every thing in it)

Big Yellow Tractor 18 Oct 2008 21:29

Quote:

Originally Posted by DLbiten (Post 211523)
One thing I looked in to was getting square tubing that had a ID (inner dimension) gust bigger the the OD (outer dimension) of the rack. A few little chunks of this will help with any quick fix you may need

I had thought of that. Also, if you have a couple of bits of tube that have been cut open lengthways, they would make a good splint with a couple of hose clips.

I started building a my rack but got a bit stuck on the best lower mounting. Couldn't come up with anything I liked so have walked away. Hopefully when I re-start, I'll have a flash of inspiration.

A good tip when joining tube end to side (T-shape) is to put the tube in a drill press and run a holesaw the same diameter as the tube though it. This gives the perfect fit. The same can be achieved with a small angle grinder and a bit of fiddling. Another way is to crush the last inch of tube in a vice. If you slip a bit of flat up inside so it doesn't crumple, you get a neat fit.

RogerM 18 Oct 2008 22:32

With a tube bender you can get away with having far fewer welds - they are the weak spots. Dont butt weld, if you must have a butt weld of a piece of flat to round, put the round through the flat, weld both sides and grind off. If you use tube then dont weld on the bends. Put a brace behind each bend greater than 45 degrees. Anneal all the bends and welds - having "hard" welds and "soft" tube is where the frame fails. Ideally then harden the whole thing using heat and quenching in old engine oil.

If you are a crap welder like me, then use round bar so that you cant blow through as with tube.

See if you can find some pics of the Krauser carriers for BMWs circa 1980, or the BMW frames from the mid 1980s.

Ironheadziggy76 19 Oct 2008 05:55

Here is a picture of one I built for my DL650, I built it a little heavy due to using Ammo cans. My battery is about to run down, I'll add some more pics later.

http://i179.photobucket.com/albums/w...6/IMG_0183.jpg

Alexlebrit 19 Oct 2008 16:09

Some great tips there thanks, I'm definately going for round tubing myself, like I said I can bend tubing no bother, but welding? That's a different story, I can count my successful welding exploits on one finger. Fortunately I know a man who can.

So far it looks like:
  • Round tubing is stronger than square for the sae weight.
  • Welds are better than bolts.
  • Flat bar can be used for the frame, but not for the frame to bike attachments.
  • Pinching round tubing flat is fine.
  • Attach it to 3 points per side minimum.
  • Add a "crossbar" between them at the back.
So, next step for me, work out what luggage I'm going to use so I can see the fixings, and then I'm going to make a tester out of PVC tubing, to get the fit etc, I often do this, built a bicycle frme out of it once to see how it looked. That should help me line things up, and I can use carboard boxes as "panniers to check clearnace etc and then onto steel.

So, the inevitable question after, what about surface finishes to stop the rust setting in?

tommysmithfromleeds 19 Oct 2008 17:05

hey alex, what heppened to the panniers and racks that come with the derbi terra adventurer? i have been trying to get some for some time to adapt. are they not making them anymore? also if you are planning on welding you can get these which make the job a piece of p*ss

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Alexlebrit 19 Oct 2008 17:24

Well I've got mine, and they're great, but it appears that it was one batch and they've now stopped having them (think they fell out with their suppliers). But I was asking for a friend actually who's just got themselves a Derbi Senda Baja something or other, and of course there's not a rack in site for them.

Big Yellow Tractor 19 Oct 2008 17:40

Quote:

Originally Posted by tommysmithfromleeds (Post 211595)
hey alex, what heppened to the panniers and racks that come with the derbi terra adventurer? i have been trying to get some for some time to adapt. are they not making them anymore? also if you are planning on welding you can get these which make the job a piece of p*ss

Magnet Products | Purchase and commission bespoke magnet products

Don't be afraid to tack on a temporary brace here & there to hold things true. Just make sure your tack is somewhere that's easy to get to with grinder.


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