Wednesday, July 8, 2009

integral rucksack as seat back on 'bent


D: on a diamond-frame bicycle I typically wear a backpack to carry stuff.
I never really got into panniers.
I attach baskets at the bike rear too.

On a recumbent, one cannot wear a backpack.
I suppose a backpack could be layed down flat and bungeed to the pannier mount.
But I'm always afraid of all those straps dangling getting caught in the wheel.

Furthermore, one cannot attach a taller rucksack in this fashion due to length.
One use of a recumbent I had in mind was a road tour.

I also wished that panniers were more able to be carried as a backpack when removed from the bike.
In other words, I think the walker and not the biker element should be central to design.

Well, I was trying to figure out how to attach a rucksack to a recumbent bike.
On my Cruzbike, I'm gonna insert a tube in the seat tube of the mountain bike frame.
I'd like to make it telescoping to adjust height.
I imagine a curved T shape at the top, to simulate shoulders.

Some folks use a pack external metal frame to make their recumbent seat back.
...
Eureka!

Use a largely intact and portable rucksack as the seat back.
Look at the pic.
You'd hafta have a slot to hold the base of the pack.
Or you could make the bottom modular, to slide the bottom tubes onto a mount tube set.
To use as a backpack you'd then attach the part you sawed off.
I imagine some packs use press-fit tubes and would not require modification.

Hmm, I cannot find a good pic of the seat rear.
Anyway, the standard bike seat tube is used to anchor the rear of the Cruzbike seat.
There is an open tube at the top, with an indent to prevent sliding.
A tube with a slot would fit securely.
On a 3 tube (big-small-big) telescoping arrangement, you could keep it retracted when not in use. Or for a small backpack.
Obviously, the old hiking trick of placing heavy objects low is desirable.
The whole thing should be on an angle (already is) for a tall rucksack.
You don't want to increase air resistance or make the bike more top-heavy.

----------
Cruzbike mods.
I've been reading over oval chainrings.
Some old Biopace ones are cheapest.
But the O.symetric ones are potentially usable too.

I have a cheapo-bike frame. It uses 2 not 1 tubes for the seat area.
This elevates the seat a few more inches.
I'll likely get my welder bud to chop one off, then reinforce it.
I'll try to get him to go with motif, to make it look right still.
We added some screw holes for the seat.
Psychologically, I wanted the seat more secure.
I'm sure it would have been fine.
But my Mark1 will have square tube frame for the reason of stability.

We're gonna try a before 'n after with circular and oval chainrings.
I'll try to record a video.

I wrote Cruzbike and suggested they offer the steering handlebars for the Silvio as an option on the conversion kit.
The big chopper ones must be massive, make the bike boom-heavy, and the shipping costs were more than the handlebars were! They really drove up the price.
Also, I would be curious about an under-seat steering retrofit.