Sunday, November 15, 2009

Two Successful Experiments, Two Planned Experiments

Ok, so we've been slowing chipping away at sustainability. At first we thought we'd have to save up and buy a Prius or something, then we discovered bikes do the job nicely. Now that the bike thing is somewhat under control we've been moving towards food sustainability. We found a local CSA-it's a local farm where you can purchase a share in the farm's productivity for the year. In addition we began a home garden to supplement the food from the CSA.

The garden turned out surprisingly well. I began researching gardening (because I knew that I would totally *fail* otherwise) and found quite a lot of good info online concerning permaculture. I bought a book called "Gaia's Garden" Toby Hemenway and "The Four Season Harvest" by Eliot Colleman. Gaia's garden laid out a very clear plan for "sheet mulching". I heard mention of sheet mulching a lot on permaculture sites, but hadn't actually been able to find instructions for implementing it without the book. Essentially you loosen but not turn the soil with a fork, then put a layer of nitrogen rich material down. Blood-meal or cut weeds work well. Then you put a weed barrier than composts such as cardboard down. Then pile on 8-12 inches of compostables watching your balance of nitrogen to carbon components to maintain a 50/50 mixture. At this point I added a bacterial-composter which was not in the book, but seemed to work well for me. Then apply 2" of compost and 2" of mulch. Water the whole thing as you are mixing it up to the consistancy of a damp sponge. Then water it regularly. In the warm weather of May and June, I had 8" of nice black soil teeming with soil life in about 5-6 weeks! Amazing! The garden took off and we are still eating ripe tomatoes in November! The best part, I found was that I had no digging, no heavy garden work and almost no weeds.

We moved into our house in May and the plants were ready because I'd started them inside in March but the garden beds weren't ready. Starting in May, we didn't have much time for our sheet-mulch to decompose. So I modified the "recipe" by making the compost/planting layer deeper. I used one big bale of peat-moss and 4 bags of mushroom compost per 3' x 10' bed to make the planting layer about 6" deep. Then by the time the seedlings were growing deeper than 6", the compost underneath would be rotted down. This was a bit of a gamble, as I didn't know if the mushroom compost would be too hot and burn the roots, but it seems the peat moss diluted it enough so as not to hurt the plants. The garden was quite a success. We planted chard, tomatoes, zucchini, onions, basil, broccoli, spaghetti squash, butternut squash and bell peppers. All of the plants yielded well. The tomatoes got in the ground a little late for our area and consequently about 1/4 of them ripened on the bush and the rest I put in boxes in the pantry, layered 1-2 deep. They are just about all ripened now and we have been enjoying fresh tomatoes all fall! I may plant tomato bushes late in the season again just so I can enjoy them next fall.

I mentioned Elliot Coleman's book earlier, the "Four Season Harvest". I got very excited reading this book, thinking that winter gardening could provide fresh veggies for the family in the winter. So I headed over to our local gardening center to pick up some cold-season seeds, only to be informed by the gardener on duty at the time that Coleman's book, written in the Northeast (Maine) would not translate to our climate--at least not without modification for climate. He told me that the challenge here in Colorado for a cold-frame is that we have very low humidity which means that we have very broad swings in temperature. Seriously, for those of you who have never been here, it can be 70 during the day in December and then 20 at night or the next day. The problem this creates for plants is that their leaves don't get adjusted to the cold and then they get killed by the frost. This problem is exacerbated by a cold-frame. As it stores heat when the sun in shinning and it's already hot, so temps can get as hot as 140 very quickly and then the glass and wood doesn't insulate well enough to keep the plants from freezing at night. Well, I bought my seeds (I can't believe they even had all those winter seeds, Botanical Interests rocks!). Then I went home to brain-storm with Anthony. We decided to try insulating with straw-bales for the walls of the cold frame and then providing thermal mass with water. To do a good job of it, we'd really need a lot of water, but for starters, we did about 40 milk jugs filled with water lining the inside of the straw bales. Then to keep the cost of our experiment down, we just threw plastic supported by stakes over the top of the bales of straw. I planted seeds Aug 15 and covered the plants in early October.

It worked! I was totally shocked. The plants inside the "cold frame" not only survived, but thrived. Their leaves grew right up to the top of the cold frame and were pushing on the plastic. The ones outside the cold frame survived, but didn't grow much, (probably too cold). So, since it worked and the plants grew I built a tunnel arching over the top. This should take care of the snow crushing the plants problem I had with a flat top to the cold frame. And here, we have a new experiment. Will the water still be enough thermal mass to keep the plants going? Probably not without adding more jugs, because the mass of air just increased many times without the water mass increasing, so I anticipate I will need to add more water. Another experiment, I just planted some spinach and some kohlrabi. If stuff is growing, I may be able to plant more and have it grow this time of year, who knows! This will be my 3rd attempt to plant spinach. For some reason my spinach seeds have not been germinating. I am not sure of the cause. It could be slugs, squirrels which love to dig in my gardens, maybe I didn't keep the soil moist enough because I planted them next to mature plants which didn't need as much watering last time, maybe the soil is too acidic with all that peat in there. I'm not sure. If these don't germinate, I may try a different pack of seeds-maybe something happened to the seeds. I guess we'll see.

And this leads me to my next experiment, can we produce enough food on our .25 acre lot to mostly or entirely feed our family from our gardens? Maybe... if I garden three-dimensionally and try a forest garden. I'm currently looking into replacing our 100' long hedge row of an ornamental shrub with a hedge of hazelnuts. There are a couple nurseries out there supplying cold-hardy varieties. The extension out here said that hazelnuts aren't that productive here because of "the climate", but I will have to have more specific information than that before I give up on the idea.

Monday, November 2, 2009

Nuvinci Longterm Review

Since we seem to get almost as many questions about the hub as we do the bikes we ride, I figured it was time to do a full fledged follow up instead of my abbreviated comments here and there.

At present we've got roughly 5-6k miles and 1.5 years of use on our Nuvinci hub, all of which has been with a rather full load (rider, 2 kids, assorted kid-related stuff), and all of that with a gearing lower than the mfg. reccomended minimum of 2:1. We have it geared closer to 1.78 : 1.

We've used it in single digit temps (F) and used it to tote 160lbs of kids and gear up over mountain passes a number of times.

This is all to say that the following comments come from pretty extensive and tough usage of the hub.

First let me say unabashedly that my wife and I both LOVE the hub. We would in no way change the decision we made to purchase this hub. In fact at this point even if given the chance to have a Rohloff at the same price as the nuvinci my wife and I both would choose the Nuvinci. It has earned our respect on a number of levels.

This hub is the closest I think you can come to the simplicity of riding a singlespeed while still having a full range of gearing at your fingertips. Its range of roughly 350% is really quite broad. A couple friends of ours who live essentially car free with 3 kids just got one for their Yuba on our recommendation and were initially planning to run it with a triple chainring up front, but after testing it out are now rethinking that plan and going for the low maint. singlespeed driveline as the range has so far proved more than adequate. There are gearing calculators out that to give you more precise numbers, but for some real world perspective, we can with the same gearing cruise along going 24mph without spinning like a track cyclist, and at the same time tote the kids and gear up a steepish mountain climb going 3.5-4mph.

Riding it is experientially really is a lot like riding a singlespeed in that it is so quiet, so smooth, and efficient as well, yet you still retain the ability to shift, but even that is a very different experience since there is no clicking or any other indication of a shifter other than a shift in cadence.

While I'm mentioning efficiency and shifting, I'll elaborate on two aspects of the nuvinci often talked about. I have not stuck this hub on any kind of testing bench and so cannot give hard numbers, but what I can say is that each person that has ridden ours, and Nickie and I as well find it perfectly comparable to riding a derailler based drive train. Here's an example. Shortly after I first built up the big dummy using the nuvinci 1.5 years ago, I commuted to work on it for a couple weeks. I'd been doing that same commute for several years, so was quite familiar with timeframes, and exertion levels. My commute was at the time 12 miles over slightly rolling terrain. The bike I typically rode has about the same body position, with rack and panniers and similar tires. The Big Dummy equipped with nuvinci probably weighed around 10 lbs more. Over the course of those couple weeks, I did not see any perceptable difference in commute times. In fact if anything my commute time was a minute to two faster on the big dummy. I keep my drivetrains in top condition and use the same lube on both. So as for efficiency, whether its because its really that good or because you are always in exactly the gear you want to be. It is certainly efficient enough to not be a detriment in any way.

As for the shifting experience, this is worth expanding on as well. This may sound like an obvious statement, but more than you might imagine, but... the nuvinci does not shift like anything else you've ridden. They say this in the literature, and it is certainly true, this bike will not shift at a standstill IF (thats a big if) you are putting any load on the pedals. The reason for this is obvious if you think about the design of the hub. It uses a traction fluid between the drive spheres and the output discs. When you apply load you are applying load to the traction fluid between the input and output and you are fighting against the hubs' means of transmitting torque. It simply will not budge. Now if you take your foot off the pedal you can spin the shifter through the whole range like its not even hooked up to anything. This understanding becomes important as you think about how it shifts on the go. A common question pertaining to gear hubs is "Can it shift under load". The short answer is definitely yes.

The long answer is this. Since, when you are applying torque to the hub it cannot shift without movement of the spheres you must think of shifting in a different way than you would on a bike with stepped gears. The word "shifting" really is quite appropriate. With a drivetrain that is infinitely variable, you tend to be subtly shifting your gearing much of the time as terrain changes ever so slightly. With this hub you walk it in whatever direction you need it to go as conditions dictate. As you apply steady gentle pressure to the shifter in whatever direction you need it to go, your hub will walk there during the lighter parts of your stroke at a perfectly ample rate to handle all but the most abrupt of changes. This may sound complicated and a large annoyance but in reality its much more intuitive after just a couple rides then any of our stepped drivetrains could ever be. On the occasion that you do hit a very abrupt change in slope and suddenly need to be in a different gearing, you just let off the load for a millisecond and give the shifter a good quick twist and you are immediately in that different gearing then dial in precisely as you begin pedaling.

It only takes so long to explain it because it is such a different experience to other gear hubs or derailleurs. After just a couple rides you'll find it to be more intuitive, quicker and easier to use than a derailleur can ever be.

Lastly let me comment on durability and service. In the time we've had this hub we have not had a single problem with it, NONE. And regarding service I've not had to do anything to it. One beautiful thing about this hub is that it is sealed for life. At first that is scary for someone who likes to be able to fix and service just about anything, but in thinking about how overbuilt the internals are and the fact that you don't have metal on metal transmitting torque through the hub, sealed for life starts to make a lot of sense and really begin to shine. It is as efficient today as it was out of the box, just as smooth and just as wonderful to use. I have replaced the cables since we first set it up, but I would call that general service on a bike, not a function of the hub itself, and I'm really considering using gore ride on cables to minimize that portion.

Are there any drawbacks? Sure, its heavy, but in this case on a cargo bike that is mission critical kid transport, I'll take overbuilt and heavy any day. Also Installation is a little tricky the first time you do it and there are a couple potential gotcha's. It is imperative that you do not kink the shifter cables. Since it is a little bit like a push pull with the dual cable setup a kink will really make shifting suffer and likely result in a cable failure. Also when you clip the excess cable at the pulleys you must clip it short enough that it does not scrape the inside of the shifter box. This will also cause poor draggy shifting. You will also need to keep a close eye on cable stretch for a time using the barrel adjusters to take out any slack so that you're not actually pushing one cable through the housing when shifting.

To sum up, it is a great low maint (no maint?) drivetrain option for the transportational cyclist. It has a very usable range, it is certainly efficient enough to not draw any negative attention to itself. It is a delight to use in its infinite adjustability, and I sincerely hope that they continue to manufacture and refine this hub for future generations.