28 Jan 2011

Rear carrier

28th Jan 2010.  I had put on the new chain and finished the rack the previous evening. The chain grease I had been spraying was glued all over the frame and components. It took an hour and spray-on engine cleaner to make any impact on the gooey mess. I even cleaned the wheels! Then I was kept awake much of the night with aches and pains.

The carrier has six point support and is simply clipped into place. The entire things weighs only a couple of ounces. The rucksack frame had the two top horns cut off where they supported the original rucksack. Now I have a bar to lift the trike out of the shed. Normally I would lift the trike by grasping the rear wheels.  By raising the rear end and walking backwards the front wheel follows true. If the trike is simply pulled backwards, on all three wheels, then the wheel castors from side to side.

I would have liked another crossbar to protect the gears and chain but I may lace a cord if it proves necessary. The latest sports bag is much larger than before. In the picture above it has been lifted temporarily out of the way to expose the carrier frame. I could never get away with such a wide bag before because there was no proper support. The bag would swing into the spokes on vicious pavement ramps when taken at speed!

A better view of the doubled, pipe clips. I sawed the heads off short machine screws to hold the pipe clips together in pairs by their threaded, brass inserts. The top two clips are for 12mm copper pipes and fit the short taper at the top of the Higgins stays. The rucksack frame uses 15mm clips on the crossbars. The larger main tube at the bottom of the carrier uses 22mm but are slightly oversized. The Higgins seat stays are mostly 15mm diameter below the short taper. The pairs of clips are self aligning to take care of the odd angles.

The cord at the top will probably be replaced by a strap for neatness. It ensures that the carrier does not slip downwards when loaded. One, cloth, bag handle is supported by the carrier. The free handle is supported by a toe strap from the saddle frame. In the past the carrying handles would slowly part from the bag requiring inevitable replacement. My wife now calls me a "bag lady" (amongst other things) because of my constant search for the perfect shopping bag. :-)

I'll take another picture when the bag is full of shopping. It probably has twice the capacity of the last one. The great advantage of the frame is that the bag is held well away from my feet. With some bags my heels would strike the bag on every turn of the pedals. It would be better if the rucksack frame had straight rails, for even more clearance, but beggars can't be choosers. The entire thing cost me only small change. The charity shops have lots of cheap rucksacks so I shall keep an eye out for a new donor frame.

The top corners of the frame don't get in the way until I hang right off the side on fast corners. It isn't a problem but more clearance at the top will obviously help. A straight top tube will provide the necessary clearance for my acrobatics. I used the frame yesterday with only two clips and some cord and it stayed firmly in place for over 20 miles. Today is the real test with the bigger bag and a full compliment of clips.

Well, the carrier was fine and stayed fixed. However the bag hopped into the spokes a few times so it still needs proper restraint. I could shorten the frame some more and lower it out of the way for cornering. I will see how it goes. I may find a tapered or triangular frame on my travels.

I have now applied a hooked bungee cord and the bag is completely safe from leaping into the spokes.

Note: Further experience suggested the forward, sports bag handle be fixed with Ty-wraps to the rucksack frame top tube. This finally stopped all lateral bag movement. This procedure has been carried out with all subsequent bags.

The free bag handle is simply dropped over the nose of the saddle to rest against the seat pin. This helps to support the weight of the loaded bag.

I have also used short lengths of cord to fasten the rucksack frame to the trike stays.  Otherwise the carrier frame tended to unclip from the trike seat stays if the trike was lifted by the carrier.

Click on any image for an enlargement.

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