WHY?

The panniers

I use plastic jerry cans normally used to carry water, of 20 litres capacity. These are cheap, robust and about the right size, too big and you carry too much (available from K mart, disposal stores and ?). Once the plastic top is cut away from the bottom the plastic will distort when loaded unless supported. When cutting off the top leave some support at both ends by cutting high to leave some surfaces that are not vertical (see the mounting diagram for a cut line). I use the mounting to the bike to perform most of this strengthening on the bike side of the pannier. On the other side of the pannier on the Mk 1 I ran a small 6 mm by 4 mm aluminium bar around the top edge the gaive the good support, but retains enough flexibility that if distorted by accident can be forced back by hand if required. I did not use any strengthening on the Mk2 - they did distort. For the Mk3 I am going to use parts of the Mk1, the 12 mm half round indents on the large sides cut out and screw on.
If you require more capacity, I've seen a pair that consisted of two jerry cans bolted together to form one pannier! They used metal reinforcing on the joints to avoid leaks caused by flexing.
I don't require the extra capacity, caring tent, sleeping bag, water, oil, tools and spares outside the panniers. The panniers carry camera, torch, maps, food, cooking and clothing gear. I'm revising what is carried where on 2 points, what can be replaced cheaply at remote locations (mainly food and clothes) and survival items.

The Lid

Most people use a canvas cover held on with press studs. My mark 1 used a canvas top (from some old back packs the I had used as throw over saddle bags) fastened on to the top. These worked well using a zipper closure keeping out most of the dust and water. However these lose the security advantage of hard panniers. By using the original plastic top (mark 2) the security advantage is retained together with a handle, a solid surface (use both together for a seat) and when open a clean surface. However the lid was cut as a straight horizontal line on the can. This reduced the strength of the pannier. The original filling and breather holes were left on the lid.
For Mk3 the original filling and breather holes at the top were filled in using the sealing caps. The plastic is thermoplastic (in this case polyethylene), meaning you can melt it and let it set without harm. The mounting threads of the holes on the can were cut flush. The each hole edge was then smoothed using a hot implement, I used a soldering iron, you need a temperature around 130 Celsius, if you get the plastic too warm it will not set back to the same strength, hotter still and it may burn. The top of the caps were cut off and trimmed to about the same size as the holes, leaving the internal lip on the cap as a handle. The caps were then placed over the holes (upside down using the lip as a handle) and the hot implement used to fuse the edges together. The lids were then cut off and the under side of the sealed holes checked for a good seal. Where required more sealing can be done using the hot implement.
Sealing the lid edges can be done with automotive rubber/plastic trim. This can be obtained from Clarks Rubber in Australia, or an automotive trimer.
The hinge can be plastic (obtained from a boating shop). There are two sizes, long-short and long-long, this refers to the size of each half of the hindge short has 2 mounting holes and long has 3 mounting holes, if possible use the long-long.

Lid Locks

I have not decided on a locking mechanism, but have rejected several due to previous failures or the possibility of rust.
Possibly some bmw pannier locks could do, at least you can match the lock key with the ignition key. Unfortunatly these could be forced due to the angles and forces involved. And they do get obstinate with dust and ware!
An alternative are stainless steel latches offered by blackwoods (same place as the isolation rubbers) that have a security hole used to place paddlocks through to provide security. The forces on these would ensure that they stay closed when stressed. They should not rust, and the operating clearenes should be good for dust and mud.

Mounts

3 point mounting for panniers to be provided as shown in diagram below (mark 3).

The nylon bottom mount is made from a kitchen cutting board (best to buy 2 - keep the kitchen happy). This provides a slipping surface, best to provide a surface on the frame area that is easy to replace. A piece of plastic hose (garden watering hose) split and pushed over the frame may do.
The upper mounts are rubber vibration isolators similar to bmw airhead battery mounts. These remove vibration shock loading into the frame with minimum ware. These mounts should not be subject to too much shear forces, limits on the sideways movements can be provided by brackets with limited clearance. Tension forces should be non existent, other wise the rubber will separate from the metal ends. These vibration isolators are available from Blackwoods in Australia, and are made by Silent block in Melbourne, Victoria. There must be other manufactures around the world. You can choose the isolator you use based on the weight you carry from the table below. I think 30 kgs would suit me, so part No B241 would do. The values given in the table are for one isolator.

The nut used to hold the pannier on are restrained by the lid of the pannier from rotating. Once the lid is removed or hinged out of the way the nuts can be unfastened by hand. If the lid is locked down the pannier should remain on. These nuts may be avalibale at boat shops.
If the mounts are symmetrical then the panniers will mount on either side, could be of use, you never know and there is no disadvantage to making them symmetrical.

Painting

Well these are plastic so something like the plastic bumper bar paint should work. You may also consider 'contact' a stick on plastic that is used to cover books, kitchen shelves ... Personally I have not bothered, on the G/S I'm not too worried by what it looks like.

The Frame

Well I have to leave something out. So I leave this bit to you. Each bike and its rider (and passenger?) have different requirements as to where the pannier should go. Try to mount the panniers low and as far forward as possible. Make the frame able to with stand the full weight of a fall. If it bends or brakes you need to be able to make repairs by the road side with the bikes tool kit. Think about it. A frame that bends rather than brakes may be preferred as you can bend it back by the road side easily. There is a balance, but my balance point is different to yours.
I may put up the frame I make up for the K75GS. But it will only be an example, you will have a different bike.

Water Bottles

I mounted external water bottles using push bike (pedal bike ...) water bottles and carriers. You can buy these from a push bike shop. The metal carrier ones (the pushies call them 'cages') made of 2 or more bits of metal welded together fell apart and are not suitable. The plastic one piece 'cages' are the best, the aluminium 'cages' next best. This was a good way of carrying water as the water was accessible during the ride, easy to fill up, easy to clean. Problems are theft, loss and damage, but they are easy to replace, most small places have them. But not the good 'cages', they are only avalible at good push bike shops.

Possible Problems?

1) the rubber mounts seperating due to tensile and/or shear forces. Shear froces could be limited by a metal peg on the panier mount into a hole stop on the bike. Tensile forces are not easily delt with.
2) The bottom of the Mk 2 panniers show some signs of distortion caused by the 1,600 km of corrigations thet they have been over. I think another layer of plastic that puts the forces out to wards the edge of the panner may solve the problem. The Mk1s shown little sign of this type of potential failure.

Mark 4?

Will there be a mark 4? Possibly, further ideas and modifications will appear here, your contributions are more than welcome.
 
 You can e-mail me at Yahoo.     Back to my home page     Dated 8 October 2001