More on the longtail minivelo idea

I want a longtail, something like the Surly Big Dummy or the Kona Ute, because of its practicality. You can haul a lot of stuff on those bikes, but I'm not sure I'd like to own a bike of that size. I think one way of reducing the length of the bike would be to use 20 inch tires, and make the rear chainstays not too long. Xtracycles extend the wheelbase about 15 inches - and this makes it possible to haul up to six panniers on the extended rear platform.

I'd be happy with a pair of large panniers - so an extra 8 to 10 inches of extended wheelbase should be OK. If an xtracycle bike would have 30+ inches of chainstay length, my plan would be to go 22 to 25 inches - this brings the BB to the center of the wheelbase.

I also want front suspension, and plan to use standard (26") MTB suspension forks with 20" wheels, and use disk brakes.


My initial plan is to use the Be-Bike Haze frame as a template, at least for the front of the bike:


Keep the geometry for the front of the bike intact, build an extended rear with an integrated rack, and find a way to break apart the front triangle for easy transport.

Here's an illustrated guide to what I want to do:

The "ghost" of the be-bike is there so that you can see where the changes were made. The red frame is the front of the bike with be-bike geometry, while the blue rear part shows the extended longtail with the integrated rack.

This shows the bike broken apart. The fork rests on top of the looong seatstays, while the rest of the front triangle falls to one side of the stays. The rear rack can be built wide to accomodate the front triangle. The front wheel is strapped to the side of the rear triangle. Skate wheels are shown attached to the rear rack like a brompton.This shows the bike top side down, so that it can be rolled around.  A soft cover can be made, open at the bottom. Paded with cardboard or newpapers, it should be a large alternative to a suitcase, since the rear rack protects most of the components anyway. 

There are a couple of concerns.  A bashguard should be sufficient to protect the chainwheel during travel.  disk brakes will give good stopping power, but the rotors might get bent during transport. 

The budget is also a concern.  Since there's a definite small budget to the custom frame, I don't think I can go with S&S couplers. I'm thinking the ritchey/dahon system might be easier to replicate, or maybe copy some other coupler that uses bolts instead.

The simplest front rack

 

Image from Dennis Bean Larson

Fixed Gear Gallery had a grocery-getter competition. One of the entries that caught my eye was this bike from Dennis Bean-Larson.  The main detail that struck me was the use of an old front fork as support for a front rack.  The platform is made from wood, and the rear supporting plank of wood is simply connected to the handlebars using a velcro strap.  More details here.

Thinking about longtails.

Project Rwanda's Coffee Bike

With soaring oil prices, cargo bikes are suddenly getting a lot of interest. There have been several on the marken (none of which are readily available in the Philippines), but it's interesting to see the various designs available worldwide.

Above is the Coffee Bike, designed by Tom Ritchie, sold to coffee farmers in Rwanda for under $200. If you live in the US, supposedly you can get one for a tax deductible $1000 donation - proceeds of which go to the NGO Project Rwanda.

It is a good example of the longtail design. One of the first to popularize this type of modified bike is xtracycle with their Free Radical product - a bolt-on extension that converts a normal bicycle into a longtail hauler.
Xtracycle also provides accessories that help in hauling cargo, including racks, bags and decks. They've been around for a couple of years, and have a good following. The only negative comment that's been around is that the cost of the product and accessories, together bring up the price of going into longtails significantly, so that it might actually be better to get a purposely built longtail frame. For DIY types, there are also a lot of instrutions online on how to make your own for a lot less money. Below is a DIY example from fordfasteRR of Velocide.com.
Anyway, DIY or not, the xtracycle design generated a lot of interest in longtails, so that soon bike companies were coming up with a few models:

Surly Big Dummy:




Kona Ute:

Yuba Mundo:


Madsen kg271


8freight


So there you have it. Extend the chainstays, get long chians and brake cables, add on some racks (or a bucket), sell you car.

What I really want to see is a smaller version. With 20" wheels. Just enough for one passenger or a pair of large panniers, instead of space for 3 pairs. Get a minivelo, extend the rear triangle an extra 10 inches, add integrated rack and a couple of footpegs. Oh, and make it separable like the Hunter cargo bike or a Bike Friday. That would make for a really cool travel/commuter/hauler bike.

Hunter Cycles Cargo Bike

 

 Image from Hunter Cycles:   http://huntercycles.blogspot.com/2008/07/zoman-and-zobike.html

This custom break-apart bike from Hunter Cycles appeals to me on so many levels.  20 inch wheels?  Check.  Breaks into a small package for travel?  Check.  Cargo capacity?  Spades.  There area also details that are neat.  Normal components - hubs, brakes, threadless headset, BMX stem and handlebars. Woot!

Back to the 80's: The Mongoose Moosegoose

Mongoose Moosegoose - the bike for moose-sized kids. Longer seat tube, taller headtube. It's the sensible BMX design for cruising around the neighborhood. Alas, didn't get popular with the kids at the time.

Champion Square-back Cruiser

Photo from BMX Museum, bmxmuseum.com

Another dual downtube bike, a rare Champion Square Back Cruiser. This gold and red number is a flashback from the disco era of 1978. The style is coming back though. Fireman's bikes sells a very similar frame, without the dual downtube madness.

Twin downtube bikes exist!

Twin top tube bikes aren't very common anymore, but they certainly exist. A good example are a generation of BMX bikes in the 80's. The twin top tubes gave the bikes added stiffness and allowed the rider to stand on top of the two tubes for tricks.


The other bike that had twin top tubes were Mixtes. The Mixte design began as a bike that could be used both by men and women. The low top tube allowed the ladies to wear skirts and still pedal the bike, but the bike was still stiff and handled well.


Now on to the downtube twins. They are rare, but examples exist. The most popular examples Were designed by Ernesto Colnago, the Bitubo, Titanio, and the Bi-Titan. These were designed to make the frame stiffer.


There were other bikes with twin top tubes, as can be seen in the photo below:



So it can be done. All I need now is a framebuilder crazy enough to try. :)