Building a rack – 2 of 3

Building a rack – Part 1 is here

Some 30 years ago, when it came to making a rack for my first Sahara bike, the design was fairly obvious: a platform (left).

Even though I’d been riding for a few years with fiberglass or PVC/cardboard panniers bolted or hung to side racks, or more commonly just a big top box on the back, when it came to carrying a big load to the desert, a platform was the way to go.

The execution using Dexion shelving was lame, although to be fair that slack-rack did carry the load (radically reduced once on the road, like every first-timer before and since…). And it did finish the trip, probably because there was so much flex, it was unable to summon up the tension to snap. The ‘L’ platform element was bolted onto a Craven rack – the ‘Jesse Luggage’ of its day, with plywood planks screwed on top.

Platform racks have been around for years of course, among other places used on ex-army BSAs from the 50s and 60s, like the one pictured right.

I’ve always like the principle there but these tinny, hinged trays were designed to take a specific, army issue pannier and then swivel up out of the way when not in use. It’s a logical and effective form of support, but this ‘one rack fits one box’ makes them of limited use. To me the benefits of a platform rack – hinged or fixed – is that within limits you can securely load anything on there; box, bag, sickly calf, bulging sack, but to do that the support arms would get in the way.

Same goes for this solid version on the right, spotted at a rally year ago (notice the nifty mini-inner platforms – just spotted those). A great placement for a certain sized box which would need next to nothing to keep it located in the tray, but although I’ve run racks in the Sahara very similar to that in the past (but using soft bags, below left) nowadays you can’t help worrying about that hard front edge on your legs. That never occurred to me until Desert Riders when we had big metal boxes behind us to remind you how they might hurt. It makes you think that that this formerly unremarked-upon anxiety becomes almost like an urban myth, a bit like the lethal risks of sealing spoked rims to run tubeless (don’t start me on that).

I suppose the reason platforms are not used these days is that they’re perceived to get in the way of the legs when not in use, though I must say on my ’82 Sahara trip on which I fell off and paddled in soft sand plenty of times, that never was an issue. Twenty years later on Desert Riders using alloy TT Zega boxes it certainly was when riding tough terrain off piste. When overlanding your gear is on there all the time and so a fixed platform rack is no different from the angular edge of a Zega box, except when it comes to removing baggage and wheeling a bike onto a building for safe keeping. Above left, Sean F made a neat job of limiting any shin-snapping risk with his ‘back bevelled’ fixed platform rack for his soft-bagged DR650. See his website for more images.

That’s a great idea for a rack, but lacking such welding skills or gear, another way of doing it could be to buy a pack frame off ebay for a few quid (left). I thought about that but in the end decided that the time spent in chopping off and plugging the unneeded sections plus adapting it to fit the flat side of a bike would not be worthwhile. As a load carrier it’s more suited to its intended purpose of portaging a radio on a soldier’s back.

Of course when you’re using a rigid container like an alloy box there’s no need to have a  full-width platform as above; an inch-wide lip of steel will support a metal box, as it did on our Desert Riders XRL racks (right) made by Overland Solutions. The quality and finish were superb, but that rack was an overweight solution – a common flaw in rudimentary engineering when slapping metal over metal in search of strength but actually blinding the function adding damaging weight. We did carry very heavy loads at times (left), but two of the XRLs cracked their subframes.

I’d like to make a platform rack like Sean’s, but with a hinged element so as to carry anything that will fit on. The problem with this is that hinging without using the interfering suspended side struts of the ‘BSA’ racks (right) requires some sort of unsupported platform or cantilever. As always, you must imagine how such a rack will react when it slides down the road or endures corrugated tracks. with maximum loads

There are various ways of arranging this cantilever, but the only one I’ve seen so far was on these Chinese 125s (left) pictured in Angola on someone’s blog who’s name I’m sorry to say escapes me. The pivot is inboard of a shallow ‘L’ bar on which it rests when deployed. Providing all elements are chunky enough, the high leverage on the pivot and load on the bar can be met. A wider ‘L’ bar means less load on the pivot but you don’t want the fixed part too wide.

By chance a quick search on Google Images most probably located that ‘Angolan’ rack (right), produced by none other than The Chongqing Meihuan Machine Manufacturing Company. With a closer look you can see the pivot/support works almost as I speculated, lowering on a spring to rest horizontally on the over the pillion footplate. Note the cute sub-racklets at the back, too.

And here is another hinged plat-back made for this lightweight utility bike by Italian custom bike maker, Borile. Like the Angolan rack, when deployed as a platform it’s a bit on the wide side for overlanding duties rather than transporting your goods to market, but the principle is Angolan and on the right path for what I have in mind.

Introducing the Pipe Rack I don’t think one could describe my Suzuki’s chassis (right) as something that Brunel would have tipped his hat to. Thin bits of box section glued together with spit and stamped bits of plate. You get what you pay for and GS500s are not to be mistaken with the GSXR pocket rockets. The GS500 is more of a pocket.

Anything too clever or hefty, like the OS XRL rack above, would merely see the GS’s subframe wilt like the late summer corn. Up to a point a beam could be added from the pillion mounts down towards the footrests to help support the back end (left). I may get round to doing that.

Trying to work out how to make the platform (or get it made), it occurred to me that a metal support tube as strong as any on the machine was staring me in the face: the silencer. By chance I’d had the pipe lowered to make room for my planned DIY panniers (which eventually became a set of Magadans) until a light bulb flickered on for a split second: use the pipe.

All that had to be done was separate the pipe’s heat (not that much on the pre-catalyzed GS5) from the bag’s base and possibly add support at the back. A mention of Giant Loop’s good-but-too-short stainless pipe guard (right; £15 from Adv Spec) gave me the idea to make my own from a bit of 2 by 4 ally channel. On top of that screwed a layer of plywood on which rests the pannier. rkg-exclampThe good thing is that my Mags are throwovers so the full weight need not be taken on the platforms. But there’ll come a time when that needs to be done so I plan to add  a support from the silencer’s snout to the subframe (or the rest of the rack when complete), using a 2 1/2 inch exhaust clamp 9right).

Weighing in at about a kilo and costing £15 for the alloy and a quid for a pair of hose clips, it didn’t take long to drill, screw and hammer the pipe rack into place.

Narrowing it down I want my luggage to be as slim as possible, a far cry from the BMW with Monsoons on a M Mule rack set up I used earlier in the year (right), and many similar set-ups you’ll see around. The GS is a slim bike as it is, so if there’s no need for excessive width, why put up with it?

As mentioned, the silencer was lowered to hang/mount the bags low too, but the side panels (or whatever you’d call them) spoiled the party by bulging out needlessly (left, on the left).

In the end the simplest solution was to just saw the width out of them, so gaining at least 2 inches of slimness each side. The back light cowling wants to be kept, so the excised side section will be replaced by a bit of flat plastic (£5 flower trays off amazon, right). Unfortunately, being a pillock, I mistakenly drew two right-hand panels off my cardboard template, noticed it just in time and redrew a left side one – but then forgot to follow that outline in the thrill of angle grinding the plastic. Well, it’s another fiver. I did the rounds already looking for plastic flotsam on nearby shores.

Now, the pillion peg mounts stick out so they’ve been ground off to maintain the slim profile. The platforms can act as pillion footboards, when needed and the sawn off mounts have been drilled to take the front mounts of the rack

The mini H&B back rack got removed to get to the side panels/cowling (all one part of plastic) and I wondered if it was even worth refitting it. I’d like a wide sheep rack similar to that pictured right. Cycleracks sent me one years ago, but it seems Customs took a dislike to it so it got sent back before I got it. There’s a lot to be said for a good wide platform on the back, whether you use soft, firm or hard luggage. if nothing else it’s a handy thing to grab as you pull you bike out of a Vietnamese paddy field, or with a partial flat board, to use as a table if you’re lacking metal boxes.

Half Pipe Were the GS a twin low-pipe bike like a Bonneville, I’d get away with the same pipe rack arrangement on the other side, but it isn’t so a proper rack has to be devised, probably with a hinged platform based on the Angolan model pictured above. More about that in part 3 of 4 of the thrilling series: ‘Building a rack’.

This entry was posted in AMH News, Project Bikes, Resources, Suzuki GS500R Overlander and tagged , , , , , , , , , . Bookmark the permalink.

One Response to Building a rack – 2 of 3

  1. Pingback: Soft Bag Comparison: Adv Spec Magadan; Enduristan Monsoon, Kriega Overlander - The HUBB

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