The Bettie download20
by Byron on Sep 07, 2006 at 9:52 PM
Bettie is a Bike Hugger project to build a sport-utility bike with a Karate Monkey 29-incher frame, Stokemonkey, and an Xtracycle. Bettie has an enormous carrying capacity, it’s heavy duty – 2 adults or an adult and 2 kids at a time – and is fun (really, really fun). The total Bettie download follows.
We chose the Surly Karate Monkey for it’s big wheels and versatility and a look at the specs will tell you why – the frame is built to be built into something else, your ideal Frankenstein. Bettie with this set up, as Todd describes in his blog post, addresses my biggest concern about putting your foot-down when weighted. Imagine coming up a hill in Seattle, stopping at a light fully loaded, and shifting all the weight with your back to one toe. Much easier to just foot down. Additionally it’s like riding a “working” bike, an industrial cruiser with a very nice motor assist from Stokemonkey.
By running a 29-incher with 26 inch wheels and 2.35 inch tires, we get a lower center of gravity and a cushy ride. Much of that ride has to do with the balloon tires. For the skinny tour crowd, big tires take some getting used to, but do roll and ride very nice.
A sport-utility “balloon” bike
We need to run at least 2.35s (the biggest tire we could find) to keep Bettie low, but not too low and are running the Big Apples from Schwalbe, which offer among other things, “carefree cycling.” See Balloonbikes for more on the benefits of big tires.
Amazing Cargo Capacity
Human Electric Hybrid
Todd of Cleverchimp has been enormously helpful and you can find his comments in our posts. We chose a complete Stokemonkey kit with the big-ass battery. We live in a very hilly part of Seattle and need the juice.
- Nitto Albatross bar – a comfortable cockpit with upright position, wide bars, and lots of room for the controls (tip: these are cruiser bars that accept bar end shifters)
- Magura Gustav M – a legendary downhill disc brake with enough stopping power to fold the fork in half. Remember an adult, 2 kids, in hilly Seattle, so we chose lots of brake.
- DT Swiss FR 6.1D – extremely stiff, “big hit” rims. Made to ride through a war zone or the streets of Seattle.
- Sugino Mighty Crankset – 44/32/22 9-speed compact MTB cranks – right and left chainrings, one for you to drive and the other for the Stokemonkey.
- Shimano 16T freewheel threaded onto the Stokemonkey – the freewheel drives the left chain ring. That’s your motor assist.
- Deore LX derailleurs – “pretty standard really.”
- Bar end shifters – for the flexibility of switching to friction mode, if things go bad with the drivetrain, and because the throttle is taking up space for grip shift or other levers.
- MKS platform pedals with Powergrips – old school and functional. You don’t want cleats, clips, or anything else with Bettie. Just hop on and ride – same goes for the seat.
- Brooks B17 – been riding all over town without bike shorts. Bouncy big tires and springy seat adds to the fun factor.
- Loud bell from REI – announce your motor-assisted smugness when you pass fellow cyclists.
Jedi master mechanic
As I’ve been posting, we’re having a great time with Bettie and most of that is no parking, no sitting in traffic, and no car. I’ve been running errands, going on dates, and Pam has been riding the kids around. Bettie is doing exactly what we wanted and performing well.
There have been some surprises. Bettie makes dogs angry. I guess that’s all the sounds because some dogs have gone into vicious mode when I ride by – Cap’n our Pug likes Bettie, but only after lots of alert barking and a good long sniff. Of course, you can easily out run them with a twist of the throttle.
Motor-assist is just that: an assist. You’re still working and need to learn quickly how to stay on top of the gear. To ride Bettie daily, you’ll need good bike-handling skills, basic fitness, and situational awareness. You’re the motor in the human electric hybrid drive and efficiency is very important. Riding heavy on the throttle is going to burn through the batteries. It’ll be fun, but not good for commuting. With the motor-assist on, Bettie is like a fixed gear and you can’t stop pedaling. It’s easy to get lulled into la-la land, on Bettie, but realize your riding a big bike at fast speeds.
The magic, the secret sauce of Bettie and the genius of Xtracycle and Cleverchimp is that they’ve invented products that allows us to do what we want without a car. As an inventor myself, they get full props and one of the first things I did with Bettie was deliver an order of Clip-n-Seals to the mail drop.
Riding Bettie Downtown
And More Bettie
- Tags: Bettie, Sport-utility bike, Project
- Sport-utility bike photos
- Videos: Staying on top of the gear, Bettie first ride, Riding Bettie downtown
Our next project is to build up a light-duty commuter.